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  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">abc</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia - SBC</publisher-name>
        <publisher-loc>S&#227;o Paulo, SP, Brazil</publisher-loc>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">Tc4Pt7xp5bgmF5xhFWgs6Vm</article-id>
      <article-id pub-id-type="other">00017</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2010001400017</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v1">S0066-782X(10)09500417</article-id>
      <article-id pub-id-type="doi">10.1590/S0066-782X2010005000108</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Artigos Originais</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>&#201; necess&#225;rio suspender o betabloqueador na insufici&#234;ncia card&#237;aca descompensada com baixo d&#233;bito?</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Lima</surname>
            <given-names>Marcelo Villa&#231;a</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Cardoso</surname>
            <given-names>Juliano Novaes</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Ochiai</surname>
            <given-names>Marcelo Eidi</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Grativvol</surname>
            <given-names>Katiuska Massucatti</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Grativvol</surname>
            <given-names>Petherson Susano</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Brancalh&#227;o</surname>
            <given-names>Euler C. O.</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Munhoz</surname>
            <given-names>Robinson Tadeu</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Morgado</surname>
            <given-names>Paulo Cesar</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Scipioni</surname>
            <given-names>Airton R.</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Barretto</surname>
            <given-names>Antonio Carlos Pereira</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
      </contrib-group>
      <aff id="aff01">
        <addr-line>
          <named-content content-type="city">S&#227;o Paulo</named-content>
          <named-content content-type="state">S&#227;o Paulo</named-content>
        </addr-line>
        <institution content-type="orgname">Universidade de S&#227;o Paulo</institution>
        <institution content-type="orgdiv1">Faculdade de Medicina </institution>
        <institution content-type="orgdiv2">Instituto do Cora&#231;&#227;o</institution>
        <country country="BR">Brazil</country>
      </aff>
      <pub-date date-type="collection" publication-format="electronic">
        <month>10</month>
        <year>2010</year>
      </pub-date>
      <volume>95</volume>
      <issue>4</issue>
      <fpage>530</fpage>
      <lpage>535</lpage>
      <history>
        <date date-type="accepted">
          <day>26</day>
          <month>04</month>
          <year>2010</year>
        </date>
        <date date-type="rev-recd">
          <day>05</day>
          <month>04</month>
          <year>2010</year>
        </date>
        <date date-type="received">
          <day>15</day>
          <month>12</month>
          <year>2009</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by-nc/4.0/" xml:lang="en">
          <license-p>This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</license-p>
        </license>
      </permissions>
      <abstract>
        <p>FUNDAMENTO: H&#225; evid&#234;ncias de que a suspens&#227;o do betabloqueador (BB) na descompensa&#231;&#227;o card&#237;aca pode aumentar mortalidade. A dobutamina (dobuta) &#233; o inotr&#243;pico mais utilizado na descompensa&#231;&#227;o, no entanto, BB e dobuta atuam no mesmo receptor com a&#231;&#245;es antag&#244;nicas, e o uso concomitante dos dois f&#225;rmacos poderia dificultar a compensa&#231;&#227;o. OBJETIVO: Avaliar se a manuten&#231;&#227;o do BB associado &#224; dobuta dificulta a compensa&#231;&#227;o card&#237;aca. M&#201;TODOS: Estudados 44 pacientes com FEVE &lt; 45% e necessidade de inotr&#243;pico. Divididos em tr&#234;s grupos de acordo com o uso de BB. Grupo A (n=8): os que n&#227;o usavam BB na admiss&#227;o; Grupo B (n=25): os que usavam BB, por&#233;m foi suspenso para iniciar a dobuta; Grupo C (n=11): os que usaram BB concomitante &#224; dobuta. Para compara&#231;&#227;o dos grupos, foram utilizados os testes t de Student, exato de Fisher e qui-quadrado. Considerado significante p &lt; 0,05. RESULTADOS: FEVE m&#233;dia de 23,8 &#177; 6,6%. O tempo m&#233;dio do uso de dobuta foi semelhante nos tr&#234;s grupos (p=0,35), e o uso concomitante da dobuta com o BB n&#227;o aumentou o tempo de interna&#231;&#227;o (com BB 20,36 &#177; 11,04 dias vs sem BB 28,37 &#177; 12,76 dias, p=NS). Na alta, a dose do BB foi superior nos pacientes em que a medica&#231;&#227;o n&#227;o foi suspensa (35,8 &#177; 16,8 mg/dia vs 23,0 &#177; 16,7 mg/dia, p=0,004). CONCLUS&#195;O: A manuten&#231;&#227;o do BB associado &#224; dobuta n&#227;o aumentou o tempo de interna&#231;&#227;o e n&#227;o foi acompanhada de pior evolu&#231;&#227;o. Os pacientes que n&#227;o suspenderam o BB tiveram alta com doses mais elevadas do medicamento.</p>
      </abstract>
      <kwd-group xml:lang="pt" kwd-group-type="author-generated">
        <kwd>Insufici&#234;ncia card&#237;aca</kwd>
        <kwd>descompensa&#231;&#227;o card&#237;aca</kwd>
        <kwd>dobutamina</kwd>
        <kwd>baixo d&#233;bito card&#237;aco</kwd>
      </kwd-group>
      <pub-date publication-format="electronic" date-type="pub">
        <day>13</day>
        <month>08</month>
        <year>2010</year>
      </pub-date>
    </article-meta>
  </front>
  <body>
    <p>ARTIGO ORIGINAL </p>
    <p> INSUFICI&#202;NCIA CARD&#205;ACA </p>
    <p>
      <bold>&#201; necess&#225;rio suspender o betabloqueador na insufici&#234;ncia card&#237;aca descompensada com baixo d&#233;bito?</bold>
    </p>
    <p>
      <bold>Marcelo Villa&#231;a Lima; Juliano Novaes Cardoso; Marcelo Eidi Ochiai; Katiuska Massucatti Grativvol; Petherson Susano Grativvol; Euler C. O. Brancalh&#227;o; Robinson Tadeu Munhoz; Paulo Cesar Morgado; Airton R. Scipioni; Antonio Carlos Pereira Barretto</bold>
    </p>
    <p> Instituto do Cora&#231;&#227;o da Faculdade de Medicina da USP - InCor HC FMUSP, S&#227;o Paulo, SP - Brasil</p>
    <p>
      <xref ref-type="corresp" rid="nt">Correspond&#234;ncia</xref>
    </p>
    <p>
      <bold>RESUMO</bold>
    </p>
    <p><bold>FUNDAMENTO:</bold> H&#225; evid&#234;ncias de que a suspens&#227;o do betabloqueador (BB) na descompensa&#231;&#227;o card&#237;aca pode aumentar mortalidade. A dobutamina (dobuta) &#233; o inotr&#243;pico mais utilizado na descompensa&#231;&#227;o, no entanto, BB e dobuta atuam no mesmo receptor com a&#231;&#245;es antag&#244;nicas, e o uso concomitante dos dois f&#225;rmacos poderia dificultar a compensa&#231;&#227;o. </p>
    <p><bold>OBJETIVO:</bold> Avaliar se a manuten&#231;&#227;o do BB associado &#224; dobuta dificulta a compensa&#231;&#227;o card&#237;aca. </p>
    <p><bold>M&#201;TODOS: </bold>Estudados 44 pacientes com FEVE &lt; 45% e necessidade de inotr&#243;pico. Divididos em tr&#234;s grupos de acordo com o uso de BB. Grupo A (n=8): os que n&#227;o usavam BB na admiss&#227;o; Grupo B (n=25): os que usavam BB, por&#233;m foi suspenso para iniciar a dobuta; Grupo C (n=11): os que usaram BB concomitante &#224; dobuta. Para compara&#231;&#227;o dos grupos, foram utilizados os testes <italic>t</italic> de <italic>Student</italic>, exato de Fisher e qui-quadrado. Considerado significante p &lt; 0,05. </p>
    <p><bold>RESULTADOS:</bold> FEVE m&#233;dia de 23,8 &#177; 6,6%. O tempo m&#233;dio do uso de dobuta foi semelhante nos tr&#234;s grupos (p=0,35), e o uso concomitante da dobuta com o BB n&#227;o aumentou o tempo de interna&#231;&#227;o (com BB 20,36 &#177; 11,04 dias <italic>vs</italic> sem BB 28,37 &#177; 12,76 dias, p=NS). Na alta, a dose do BB foi superior nos pacientes em que a medica&#231;&#227;o n&#227;o foi suspensa (35,8 &#177; 16,8 mg/dia <italic>vs</italic> 23,0 &#177; 16,7 mg/dia, p=0,004). </p>
    <p><bold>CONCLUS&#195;O:</bold> A manuten&#231;&#227;o do BB associado &#224; dobuta n&#227;o aumentou o tempo de interna&#231;&#227;o e n&#227;o foi acompanhada de pior evolu&#231;&#227;o. Os pacientes que n&#227;o suspenderam o BB tiveram alta com doses mais elevadas do medicamento.</p>
    <p><bold>Palavras-chave: </bold>Insufici&#234;ncia card&#237;aca; descompensa&#231;&#227;o card&#237;aca; dobutamina/administra&#231;&#227;o &amp; dosagem; baixo d&#233;bito card&#237;aco.</p>
    <p>
      <bold>Introdu&#231;&#227;o</bold>
    </p>
    <p>A insufici&#234;ncia card&#237;aca &#233; doen&#231;a prevalente, e os portadores apresentam redu&#231;&#227;o na qualidade de vida e convivem com elevado risco de vida<sup>1</sup>. Estudos epidemiol&#243;gicos mostraram que os pacientes com IC s&#227;o hospitalizados com muita frequ&#234;ncia e que a mortalidade &#233; maior do que muitos tipos de c&#226;ncer<sup>1</sup>.</p>
    <p>O tratamento moderno com os bloqueadores neuro-hormonais vem modificando essa m&#243;rbida hist&#243;ria natural, reduzindo os sintomas, melhorando a qualidade de vida e reduzindo a elevada morbimortalidade<sup>2-4</sup>. Entre os bloqueadores neuro-hormonais, os betabloqueadores t&#234;m um papel importante, modificando mais intensamente a morbimortalidade relacionada &#224; doen&#231;a.</p>
    <p>Desde a documenta&#231;&#227;o de sua efic&#225;cia, a prescri&#231;&#227;o dos BB na IC vem crescendo. No in&#237;cio, era pouco prescrito pelo receio do efeito inotr&#243;pico negativo, mas cresceu com a divulga&#231;&#227;o dos sucessivos ensaios cl&#237;nicos que comprovavam a efic&#225;cia e a seguran&#231;a<sup>2-4</sup>. No InCor, foi poss&#237;vel documentar esse aumento. Em 1999, 9,5% dos pacientes do ambulat&#243;rio recebiam prescri&#231;&#227;o do betabloqueador contra 77,2% no ano de 2004<sup>5</sup>.</p>
    <p>Apesar de corretamente tratados, um percentual vari&#225;vel de pacientes com IC descompensa. Constaram-se um crescimento de pacientes tratados com betabloqueadores e, em consequ&#234;ncia, um aumento de pacientes que descompensam na vig&#234;ncia do tratamento. Em face do conceito de que os BB t&#234;m efeito inotr&#243;pico negativo, esses s&#227;o suspensos na descompensa&#231;&#227;o card&#237;aca pela maioria dos m&#233;dicos. No entanto, an&#225;lise retrospectiva de ensaios cl&#237;nicos e de registros de casos com IC vem documentando que a evolu&#231;&#227;o dos pacientes em que o BB foi suspenso &#233; acompanhada de maior mortalidade do que a observada naqueles em que o BB &#233; mantido<sup>6-8</sup>.</p>
    <p>A essa pol&#234;mica sobre manter ou suspender o BB na descompensa&#231;&#227;o card&#237;aca, soma-se a d&#250;vida de como trat&#225;-la, especialmente nos pacientes que apresentam quadro de baixo d&#233;bito card&#237;aco na descompensa&#231;&#227;o<sup>9,10</sup>. A dobutamina, quando necess&#225;ria, &#233; a medica&#231;&#227;o mais empregada para suporte inotr&#243;pico. Considerando que a dobutamina &#233; um inotr&#243;pico beta estimulante e que os betabloqueadores bloqueiam os receptores beta adren&#233;rgicos, a prescri&#231;&#227;o dos dois concomitantemente poder&#225; resultar em redu&#231;&#227;o do efeito inotr&#243;pico da dobutamina, bem como dificultar e prolongar o tempo necess&#225;rio de tratamento para se obter a compensa&#231;&#227;o card&#237;aca<sup>11</sup>.</p>
    <p>Em nosso hospital, temos visto um n&#250;mero crescente de pacientes em uso concomitante do betabloqueador e da dobutamina. Assim, procuramos analisar prospectivamente se a evolu&#231;&#227;o dos pacientes em uso concomitante das duas drogas seria diferente daqueles que descompensaram sem betabloqueador ou daqueles em que o betabloqueador foi suspenso para que fosse prescrito o suporte inotr&#243;pico com a dobutamina.</p>
    <p>
      <bold>M&#233;todos</bold>
    </p>
    <p>Analisamos prospectivamente, por meio de estudo de coorte, 44 pacientes em classe funcional IV, hospitalizados para compensa&#231;&#227;o de insufici&#234;ncia card&#237;aca no per&#237;odo de fevereiro a dezembro de 2005. Foram selecionados pacientes maiores de 18 anos, com fra&#231;&#227;o de eje&#231;&#227;o do ventr&#237;culo esquerdo inferior a 45% e em uso de dobutamina. Foram exclu&#237;dos do estudo, pacientes portadores de marcapasso card&#237;aco.</p>
    <p>Todos os pacientes foram avaliados clinicamente e submetidos &#224; avalia&#231;&#227;o laboratorial que inclu&#237;a hemograma, dosagem de ureia, creatinina, s&#243;dio e pot&#225;ssio.</p>
    <p>Para a caracteriza&#231;&#227;o dos pacientes quanto ao grau de comprometimento card&#237;aco, considerou-se o ecocardiograma realizado antes da hospitaliza&#231;&#227;o, se esse exame tivesse sido realizado nos seis meses que antecederam a interna&#231;&#227;o. Na aus&#234;ncia, o ecocardiograma foi realizado na interna&#231;&#227;o.</p>
    <p>Desses pacientes com IC descompensada, oito (18,18%) n&#227;o estavam em uso de betabloqueador, e 36 (81,81%) estavam. Quando foi prescrita a dobutamina, o betabloqueador foi suspenso em 25 (69,44%) pacientes e mantido em 11 (30,55%) casos. Para fim de an&#225;lise, os pacientes foram divididos em tr&#234;s grupos de acordo com o uso do betabloqueador: Grupo A (n=8) - os que n&#227;o usavam BB na admiss&#227;o; Grupo B (n=25) - os que usavam BB, por&#233;m foi suspenso para iniciar a dobutamina; Grupo C (n=11) - os que usaram BB concomitante &#224; dobutamina.</p>
    <p>Os pacientes foram acompanhados durante a interna&#231;&#227;o, analisando-se os dias necess&#225;rios para compensa&#231;&#227;o, o tempo que foi necess&#225;rio manter a dobutamina e a dose de carvedilol com a qual o paciente teve alta.</p>
    <p>Compararam-se os tr&#234;s grupos quanto &#224;s caracter&#237;sticas cl&#237;nicas, quanto ao tempo de uso do inotr&#243;pico e ao tempo de interna&#231;&#227;o. </p>
    <p>As vari&#225;veis cont&#237;nuas foram apresentadas por meio de m&#233;dia &#177; desvio padr&#227;o, e as vari&#225;veis categ&#243;ricas, por meio de percentuais. Empregou-se o teste t para a compara&#231;&#227;o dos grupos. Os valores de p apresentados s&#227;o bicaudais, e foi adotado um n&#237;vel de signific&#226;ncia &lt; 0,05.</p>
    <p>
      <bold>Resultados</bold>
    </p>
    <p>Na <xref ref-type="table" rid="tab01">Tabela 1</xref>, apresentamos as principais caracter&#237;sticas dos pacientes estudados.</p>
    <table-wrap id="tab01">
      <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt01.jpg"/></table-wrap>
    <p>A maioria dos pacientes era do sexo masculino, com importante redu&#231;&#227;o da fra&#231;&#227;o de eje&#231;&#227;o, grande dilata&#231;&#227;o do VE e n&#237;veis de ureia e creatinina discretamente elevados. O tempo de interna&#231;&#227;o foi prolongado, e os pacientes tiveram alta com doses mais elevadas de carvedilol do que a da admiss&#227;o. Oitenta e um por cento dos pacientes com IC descompensada estavam em uso de BB.</p>
    <p>Na <xref ref-type="table" rid="tab02">Tabela 2</xref>, apresentamos as caracter&#237;sticas dos pacientes de acordo com os grupos. N&#227;o houve diferen&#231;a entre eles quanto a idade, fra&#231;&#227;o de eje&#231;&#227;o, n&#237;veis de hemoglobina, s&#243;dio e pot&#225;ssio. Os pacientes do grupo que internaram sem betabloqueador (Grupo A) apresentavam n&#237;veis de ureia e creatinina menores do que os que descompensaram e estavam em uso de betabloqueador (Grupos B e C). Os pacientes do Grupo C em que o betabloqueador foi mantido durante o tratamento para a compensa&#231;&#227;o card&#237;aca apresentavam maior dilata&#231;&#227;o ventricular.</p>
    <table-wrap id="tab02">
      <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt02.jpg"/></table-wrap>
    <p>O tempo de interna&#231;&#227;o foi semelhante nos tr&#234;s grupos, mas os pacientes que n&#227;o estavam em uso de betabloqueador na interna&#231;&#227;o (Grupo A) necessitaram de inotr&#243;pico por tempo mais prolongado do que os pacientes que estavam em uso de betabloqueador na chegada ao pronto-socorro (<xref ref-type="table" rid="tab02">Tabelas 2</xref> e <xref ref-type="table" rid="tab03">3</xref>).</p>
    <table-wrap id="tab03">
      <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt03.jpg"/></table-wrap>
    <p>A dose de carvedilol na alta no Grupo C foi maior do que a do grupo em que o carvedilol foi suspenso para a introdu&#231;&#227;o do inotr&#243;pico e daquele que n&#227;o o estava tomando no momento da interna&#231;&#227;o.</p>
    <p>
      <bold>Discuss&#227;o</bold>
    </p>
    <p>A hist&#243;ria natural da insufici&#234;ncia card&#237;aca, doen&#231;a com caracter&#237;sticas de malignidade, vem sendo modificada com o tratamento moderno<sup>2,12</sup>. Os betabloqueadores, por meio da revers&#227;o da remodela&#231;&#227;o card&#237;aca, melhoram a qualidade de vida, s&#227;o importantes na redu&#231;&#227;o da mortalidade e v&#234;m sendo identificados como o principal medicamento para o controle da IC<sup>2-4</sup>.</p>
    <p>Se n&#227;o h&#225; d&#250;vidas sobre o valor do betabloqueador no tratamento da IC cr&#244;nica, o mesmo n&#227;o ocorre quando o paciente descompensa<sup>9,10</sup>. Com o crescente n&#250;mero de pacientes em uso dos betabloqueadores, cresce tamb&#233;m o n&#250;mero de casos que apresentam descompensa&#231;&#227;o card&#237;aca na vig&#234;ncia do tratamento otimizado e em uso dos betabloqueadores. Nessa situa&#231;&#227;o, deve-se suspender o betabloqueador, ou ele pode ser mantido? Em nossa institui&#231;&#227;o, com base no resultado de estudos que sugeriam que a suspens&#227;o do betabloqueador ou mesmo a redu&#231;&#227;o poderiam ser acompanhadas de aumento da mortalidade, passou-se a n&#227;o se suspender rotineiramente o medicamento em todos os quadros de descompensa&#231;&#227;o card&#237;aca. Neste estudo, apresentamos os resultados da an&#225;lise dos pacientes hospitalizados para compensa&#231;&#227;o card&#237;aca em 2005 que tiveram ou n&#227;o o betabloqueador suspenso durante a compensa&#231;&#227;o card&#237;aca.</p>
    <p>S&#227;o internados em nossa institui&#231;&#227;o pacientes com IC que n&#227;o compensaram ou n&#227;o melhoraram com o tratamento administrado no pronto-socorro do Instituto do Cora&#231;&#227;o, havendo, dessa forma, uma sele&#231;&#227;o de pacientes mais graves<sup>12</sup>. Essa casu&#237;stica foi constitu&#237;da por pacientes em classe funcional IV, sinais de congest&#227;o pulmonar e sist&#234;mica e com sinais de baixo d&#233;bito card&#237;aco. No pronto-socorro, todos tiveram prescri&#231;&#227;o de dobutamina em face da presen&#231;a do baixo d&#233;bito e foram hospitalizados para completar a compensa&#231;&#227;o card&#237;aca. Dos 44 pacientes com IC descompensada, oito (18,18%) n&#227;o estavam em uso de betabloqueador, e 36 (81,81%) estavam. Quando a dobutamina foi prescrita, o betabloqueador foi suspenso em 25 (69,44%) e mantido em 11 (30,55%) pacientes.</p>
    <p>Procuramos, neste estudo, verificar se a evolu&#231;&#227;o durante a hospitaliza&#231;&#227;o era diferente conforme a manuten&#231;&#227;o ou n&#227;o do betabloqueador e se a associa&#231;&#227;o da dobutamina com o betabloqueador poderia interferir nessa evolu&#231;&#227;o.</p>
    <p>O primeiro ponto que merece destaque &#233; a constata&#231;&#227;o de que a maioria dos pacientes que descompensaram e procuraram o pronto-socorro estava em uso de betabloqueador (81,8%). Esse n&#250;mero est&#225; de acordo com o levantamento realizado em nossa institui&#231;&#227;o, que revelou que mais de 70% dos pacientes com IC do ambulat&#243;rio recebiam prescri&#231;&#227;o do BB<sup>5</sup>.</p>
    <p>A popula&#231;&#227;o estudada em nosso hospital &#233; muito grave e, de modo geral, necessita de v&#225;rios dias de interna&#231;&#227;o para compensar (m&#233;dia de 23 dias). Esse tempo de interna&#231;&#227;o &#233; maior do que o descrito em outros estudos<sup>13-15</sup>. &#201; descrito que, em geral, os pacientes ficam hospitalizados de quatro a cinco dias para compensar, quando o quadro de IC n&#227;o &#233; grave, e em torno de nove dias para os mais graves<sup>13-15</sup>. No Rio de Janeiro, para pacientes atendidos no pronto-socorro de uma institui&#231;&#227;o privada, o tempo de interna&#231;&#227;o foi de 9,5 dias, e em Porto Alegre, em um Hospital Escola como o nosso, foi de 11 dias, ambos, tempos menores do que o nosso<sup>14,15</sup>. A maior gravidade de nossos casos pode explicar, em parte, esse longo tempo de perman&#234;ncia no hospital.</p>
    <p>N&#227;o temos dados que estratifiquem a gravidade da IC nos hospitais brasileiros. Em trabalho anterior, comparamos o perfil de nossos pacientes com os do descrito no Registro ADHERE americano<sup>12,16</sup>. Dividindo nossos casos segundo a estratifica&#231;&#227;o do estudo ADHERE e comparando as duas coortes, observa-se que nossa popula&#231;&#227;o &#233;, em geral, mais grave do que aquela que participou do Registro ADHERE, pois 74,9% dos pacientes em nosso hospital internam com press&#227;o arterial sist&#243;lica inferior a 115 mmHg, enquanto no Registro ADHERE apenas 18,5% eram hipotensos<sup>12,16</sup>. Desta forma, a nossa maior gravidade &#233; uma das explica&#231;&#245;es para o tempo mais prolongado de interna&#231;&#227;o e necessidade de inotr&#243;pico.</p>
    <p>Na an&#225;lise do tempo de interna&#231;&#227;o, observa-se que os pacientes que n&#227;o usavam betabloqueador ao descompensar ficaram mais tempo hospitalizados (28,37&#177;12,76 dias) e receberam dobutamina por tempo mais prolongado (15,37&#177;4,45 dias) do que os outros dois grupos. O tempo m&#233;dio de interna&#231;&#227;o foi 24% maior nos pacientes do Grupo A do que nos pacientes que estavam sendo tratados com betabloqueador, que foi suspenso posteriormente, e 39% maior do que para o grupo em que o betabloqueador foi mantido. Quanto ao tempo de inotr&#243;pico, nos pacientes que descompensaram e n&#227;o estavam em uso de BB, foi 82% superior do que no Grupo B e quase o dobro do que no Grupo C (94%). As diferen&#231;as n&#227;o atingiram signific&#226;ncia estat&#237;stica, mas a diferen&#231;a num&#233;rica absoluta foi grande. &#201; interessante assinalar que o grupo que n&#227;o estava recebendo o betabloqueador ao chegar ao pronto-socorro apresentava n&#237;veis de ureia e creatinina mais baixos do que o grupo que estava em uso do BB. O n&#227;o uso do BB n&#227;o parece ter ocorrido em raz&#227;o destes pacientes terem quadros de IC mais acentuada ou mais grave.</p>
    <p>Nossos resultados mostraram que estar em uso de betabloqueador ao descompensar n&#227;o indica que a compensa&#231;&#227;o ser&#225; mais dif&#237;cil. Os pacientes tratados com betabloqueadores necessitaram de menos tempo de inotr&#243;pico para a compensa&#231;&#227;o e ficaram, ao todo, menos tempo internados que os sem betabloqueador (20,36&#177;11,04 dias e 22,80&#177;10,31 dias <italic>vs</italic> 28,37&#177;12,76 dias). Esse achado permite inferir que estar em uso de betabloqueador ao descompensar n&#227;o identifica um grupo mais grave ou um grupo em que ser&#225; mais trabalhosa a compensa&#231;&#227;o card&#237;aca. N&#227;o houve diferen&#231;a na prescri&#231;&#227;o de diur&#233;ticos ou vasodilatadores para a compensa&#231;&#227;o nos tr&#234;s grupos.</p>
    <p>Quando se comparam os grupos em que o betabloqueador foi suspenso ao se iniciar a infus&#227;o de dobutamina com o grupo em que o betabloqueador foi mantido durante a infus&#227;o, n&#227;o houve diferen&#231;a expressiva entre eles. Quanto ao tempo de uso do inotr&#243;pico, bem como ao tempo de interna&#231;&#227;o total, embora os n&#250;meros absolutos tenham sido menores no grupo em que o betabloqueador foi mantido, n&#227;o houve signific&#226;ncia estat&#237;stica (<xref ref-type="table" rid="tab02">Tabelas 2</xref> e <xref ref-type="table" rid="tab03">3</xref>). Esse achado permite supor que a n&#227;o suspens&#227;o do betabloqueador n&#227;o influiu negativamente na evolu&#231;&#227;o dos casos.</p>
    <p>Sem d&#250;vida, contribui para o tempo prolongado de interna&#231;&#227;o a conduta de introduzir e otimizar a dose do betabloqueador durante a hospitaliza&#231;&#227;o. Quando analisamos os tr&#234;s grupos, podemos observar que os pacientes permaneceram hospitalizados por cerca de 13 dias ap&#243;s a suspens&#227;o do inotr&#243;pico. Se retirarmos esses 13 dias do tempo total de interna&#231;&#227;o, poder&#237;amos verificar que o tempo restante n&#227;o difere dos descritos nos hospitais brasileiros<sup>12,14,15</sup>.</p>
    <p>Entretanto, com essa conduta, foi poss&#237;vel dar alta para os pacientes com dose eficaz de carvedilol. A dose m&#233;dia da alta foi 26,84 &#177; 17,14 mg/dia, ou seja, em m&#233;dia, 12,5 mg, duas vezes ao dia. Quando comparamos os tr&#234;s grupos, pudemos constatar que a dose do Grupo C, no qual o betabloqueador n&#227;o foi suspenso durante o uso da dobutamina e da compensa&#231;&#227;o card&#237;aca, foi significativamente maior do que a dos outros dois grupos, dos que internaram sem prescri&#231;&#227;o do betabloqueador e daqueles em que a medica&#231;&#227;o foi suspensa. A dose do grupo C foi 34% maior do que a do grupo que n&#227;o estava tomando betabloqueador no pronto-socorro e 55% maior do que no grupo em que o carvedilol foi suspenso ao se introduzir a dobutamina (35,79 &#177; 17,25 mg/dia <italic>vs</italic> 26,56 &#177; 18,83 mg/dia e 23,00 &#177; 16,08 mg/dia).</p>
    <p>Na literatura, crescem os artigos que documentam que a n&#227;o suspens&#227;o dos betabloqueadores na descompensa&#231;&#227;o card&#237;aca &#233; acompanhada de melhor evolu&#231;&#227;o. O primeiro deles foi o artigo de Metra e cols.<sup>6</sup>, que, com base nos dados do estudo COMET, constataram uma redu&#231;&#227;o de mortalidade de 59% para os pacientes que tiveram a dose mantida em rela&#231;&#227;o aos cuja dose foi reduzida ou suspensa<sup>6</sup>. &#201; interessante observar que no estudo COMET, 8% tiveram o betabloqueador suspenso, e 22%, uma redu&#231;&#227;o da dose, sendo a dose mantida em 70% dos casos. Sem d&#250;vida, deve-se considerar a forma de apresenta&#231;&#227;o da descompensa&#231;&#227;o. Nesses casos, a quase totalidade n&#227;o apresentou quadro de baixo d&#233;bito como os nossos, mas o importante &#233; que somente 30% dos casos tiveram a dose reduzida ou suspensa, achado que indica ser poss&#237;vel manter o BB na descompensa&#231;&#227;o card&#237;aca e que a maioria evoluiu bem sem a suspens&#227;o. Nesse estudo, o tempo de interna&#231;&#227;o dos pacientes que tiveram o betabloqueador suspenso foi de 27 &#177; 53 dias. Naqueles em que a dose do betabloqueador foi reduzida, 11 &#177; 9 dias, e, nos que tiveram a dose do betabloqueador mantida durante a descompensa&#231;&#227;o, 9 &#177; 8 dias.</p>
    <p>Orso e cols.<sup>7</sup> no Registro Italiano documentaram que o n&#227;o uso de betabloqueador ou a suspens&#227;o na interna&#231;&#227;o do paciente foram associados ao aumento da mortalidade, confirmada pela an&#225;lise multivariada<sup>7</sup>. Identificaram que os pacientes que internaram sem betabloqueador e n&#227;o o receberam na hospitaliza&#231;&#227;o apresentaram um risco de vida de 3,28 vezes maior do que o grupo que estava em uso do BB e este foi mantido. Observaram tamb&#233;m que para aqueles em uso do BB e que o suspenderam na interna&#231;&#227;o, ocorreu um aumento de 4,20 vezes no risco de vida<sup>7</sup>.</p>
    <p>Fonarow e cols.<sup>8</sup>, no Programa OPTIMIZE-HF, identificaram que 56,9% dos pacientes estavam em uso de betabloqueador ao descompensar e que o suspenderam em somente 3,3% dos casos<sup>8</sup>. Na alta, 26,6% passaram a receber o medicamento. Constataram que manter o betabloqueador esteve associado &#224; redu&#231;&#227;o do risco de morte de 40% em rela&#231;&#227;o aos sem betabloqueador. Em contraste, a suspens&#227;o do betabloqueador foi associada com o aumento do risco de vida de 2,3 vezes em rela&#231;&#227;o aos que continuaram com a medica&#231;&#227;o.</p>
    <p>Jondeau e cols.<sup>17</sup> recentemente publicaram o estudo B-CONVINCED, muito parecido com o nosso, por&#233;m com pacientes menos graves. Analisaram, prospectivamente, 147 pacientes que internaram com insufici&#234;ncia card&#237;aca descompensada, fra&#231;&#227;o de eje&#231;&#227;o menor 40%, previamente em uso de betabloqueador<sup>17</sup>. Os pacientes foram divididos em dois grupos, conforme a manuten&#231;&#227;o da dose do BB na interna&#231;&#227;o ou n&#227;o. Ap&#243;s tr&#234;s dias de evolu&#231;&#227;o, n&#227;o houve diferen&#231;a entre os grupos quanto &#224; compensa&#231;&#227;o da insufici&#234;ncia card&#237;aca. Mais importante, n&#227;o houve diferen&#231;a nos n&#237;veis de BNP, re-hospitaliza&#231;&#227;o e mortalidade em tr&#234;s meses. Conforme nosso estudo, os pacientes do B-CONVINCED que mantiveram o BB durante a descompensa&#231;&#227;o estavam em uso de doses superiores da medica&#231;&#227;o tr&#234;s meses ap&#243;s a alta hospitalar (90% <italic>vs</italic> 76%)<sup>17</sup>.</p>
    <p>Esses resultados d&#227;o substrato para que n&#227;o se suspenda rotineiramente o BB quando o paciente descompensa. &#201; importante ressaltar que, nesses estudos, a maioria dos pacientes n&#227;o apresentava sinais de baixo d&#233;bito e provavelmente n&#227;o recebeu inotr&#243;picos para a compensa&#231;&#227;o. Ainda, houve melhora na sobrevida a m&#233;dio e longo prazos e n&#227;o durante a interna&#231;&#227;o. Por&#233;m, o paciente que recebe alta hospitalar em uso de dose mais alta de betabloqueador tamb&#233;m se beneficiar&#225; a m&#233;dio e longo prazos.</p>
    <p>Nossos dados ampliam essa indica&#231;&#227;o, mostrando que, para os pacientes descompensados com sinais de baixo d&#233;bito que necessitam de tratamento com inotr&#243;picos, tamb&#233;m &#233; poss&#237;vel manter o BB, mas essa conduta n&#227;o foi acompanhada de maior dificuldade na compensa&#231;&#227;o dos pacientes. Ali&#225;s, os dados sugerem que os pacientes responderam bem &#224; conduta, necessitando de menor tempo de inotr&#243;pico e de interna&#231;&#227;o para compensa&#231;&#227;o.</p>
    <p>N&#227;o suspender o BB facilita a otimiza&#231;&#227;o do tratamento no momento da alta. Considerando que muitos m&#233;dicos continuam com receio de prescrev&#234;-lo e, quando o fazem, recorrem a doses baixas, especialmente em pacientes que descompensaram e necessitaram de suporte inotr&#243;pico para compensa&#231;&#227;o, dar alta com o tratamento otimizado &#233; fundamental para que o paciente possa ter o benef&#237;cio desse tipo de tratamento. </p>
    <p>Na literatura, h&#225; v&#225;rios trabalhos que mostram que iniciar o BB durante a interna&#231;&#227;o aumenta a taxa da prescri&#231;&#227;o, aumento esse acompanhado de melhor evolu&#231;&#227;o<sup>18-20</sup>. Entre esses, temos o estudo IMPACT, que comprovou que a conduta de iniciar o BB na interna&#231;&#227;o foi associada &#224; redu&#231;&#227;o de mortalidade<sup>19</sup>.</p>
    <p>Na mesma linha de pesquisa, Fowler e cols.<sup>20</sup> identificaram que ainda &#233; grande o n&#250;mero de pacientes que n&#227;o est&#225; recebendo BB em dose correta, comprovando que 55% est&#227;o sendo tratados com dose inferior a 25 mg, duas vezes ao dia, e 9% tiveram a medica&#231;&#227;o descontinuada<sup>20</sup>. Constataram que cerca de 30% dos pacientes n&#227;o receberam prescri&#231;&#227;o de BB no seguimento, e a n&#227;o prescri&#231;&#227;o teve como a principal causa o n&#227;o in&#237;cio ap&#243;s a hospitaliza&#231;&#227;o<sup>20</sup>.</p>
    <p>Esses dados chamam a aten&#231;&#227;o para a import&#226;ncia de se iniciar o tratamento com BB durante a hospitaliza&#231;&#227;o. Em nosso servi&#231;o, ampliamos essa conduta mantendo o paciente internado por mais alguns dias e procurando dar alta com o tratamento otimizado, uma vez que se observa redu&#231;&#227;o na taxa de re-hospitaliza&#231;&#227;o e da mortalidade e que essa redu&#231;&#227;o &#233; tanto maior quanto maior a dose do BB prescrito. Com essa conduta, pudemos otimizar o tratamento de todos, e a maioria teve alta com dose superior a 12,5 mg de carvedilol, duas vezes ao dia (26,84 &#177; 17,24 mg/dia).</p>
    <p>Com a n&#227;o suspens&#227;o do BB na interna&#231;&#227;o, os pacientes atingiram com a otimiza&#231;&#227;o doses mais elevadas do BB (35,79 &#177; 17,25 mg/dia).</p>
    <p>Em conclus&#227;o, &#233; poss&#237;vel manter o BB durante a descompensa&#231;&#227;o card&#237;aca, mesmo em pacientes com sinais de baixo d&#233;bito que necessitaram de suporte inotr&#243;pico. Essa conduta n&#227;o foi acompanhada de pior evolu&#231;&#227;o. Pudemos observar que foi poss&#237;vel utilizar dobutamina e BB associados e que a evolu&#231;&#227;o desses pacientes foi semelhante ao daqueles em que o BB foi suspenso. Ao n&#227;o suspender o BB, os pacientes puderam ter alta com doses otimizadas da medica&#231;&#227;o.</p>
    <p>Essa conduta pode ter impacto na sobrevida, uma vez que o tratamento otimizado &#233; acompanhado de melhor evolu&#231;&#227;o. Sem d&#250;vida, s&#227;o necess&#225;rios estudos com casu&#237;stica maior e em que os pacientes sejam seguidos para poder comprovar esta hip&#243;tese.</p>
    <p>
      <bold>Limita&#231;&#245;es do estudo</bold>
    </p>
    <p>Trata-se de um estudo n&#227;o randomizado e observacional. Embora a diferen&#231;a entre os grupos seja evidente, n&#227;o atingiu signific&#226;ncia provavelmente pelo tamanho da amostra. Estudos randomizados s&#227;o necess&#225;rios para esclarecer o problema.</p>
    <p>
      <fn id="nt" fn-type="corresp">
        <p><inline-graphic xlink:href="https://minio.scielo.br/documentstore/1678-4170/Tc4Pt7xp5bgmF5xhFWgs6Vm/939a7c0d79456b0ab8f24daba5de3100dd40e8ad.pdf"/> Correspond&#234;ncia: </p>
        <p> Marcelo Villa&#231;a Lima </p>
        <p> Rua Ribeiro de Barros, 55/51, Vila Anglo Brasileira, 05027-020, S&#227;o Paulo, SP - Brasil </p>
        <p> E-mail: </p>
        <p>
          <email xlink:href="villacalima@cardiol.br">villacalima@cardiol.br</email>
        </p>
      </fn>
    </p>
    <p> Artigo recebido em 15/12/09; revisado recebido em 05/04/10; aceito em 26/04/10.</p>
  </body>
  <back>
    <ref-list>
      <ref id="B1">
        <mixed-citation>1. McMurray JJV, Stewart S. The burden of heart failure. Eur Heart J. 2002; 4 (Suppl D): 50-8.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>The burden of heart failure</article-title>
          <source>Eur Heart J.</source>
          <date>
            <year>2002</year>
          </date>
          <fpage>50</fpage>
          <lpage>8</lpage>
          <volume>4</volume>
          <person-group person-group-type="author">
            <name>
              <surname>McMurray</surname>
              <given-names>JJV</given-names>
            </name>
            <name>
              <surname>Stewart</surname>
              <given-names>S.</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B2">
        <mixed-citation>2. Sociedade Brasileira de Cardiologia. III Diretriz de insufici&#234;ncia card&#237;aca cr&#244;nica. Arq Bras Cardiol. 2009; 93 (supl 1): 1-71.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>III Diretriz de insufici&#234;ncia card&#237;aca cr&#244;nica</article-title>
          <source>Arq Bras Cardiol</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>1</fpage>
          <lpage>71</lpage>
          <volume>93</volume>
        </element-citation>
      </ref>
      <ref id="B3">
        <mixed-citation>3. Swedberg K, Cleland J, Dargie H, Drexler H, Follath F, Komajda M, et al. Guidelines for the diagnosis and treatment of chronic heart failure: executive summary (update 2005), task force for the diagnosis and treatment of chronic heart failure of the European Society of Cardiology. Eur Heart J. 2005; 26 (11): 1115-40.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Guidelines for the diagnosis and treatment of chronic heart failure: executive summary (update 2005), task force for the diagnosis and treatment of chronic heart failure of the European Society of Cardiology</article-title>
          <source>Eur Heart J</source>
          <date>
            <year>2005</year>
          </date>
          <fpage>1115</fpage>
          <lpage>40</lpage>
          <issue>11</issue>
          <volume>26</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Swedberg</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Cleland</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Dargie</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Drexler</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Follath</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Komajda</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B4">
        <mixed-citation>4. Jessup M, Abraham WT, Casey DE, Feldman AM, Francis GS, Ganiats TG, et al. 2009 focused update: ACCF/AHA Guidelines for the Diagnosis and Management of Heart Failure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation. Circulation. 2009; 119 (14): 1977-2016.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>2009 focused update: ACCF/AHA Guidelines for the Diagnosis and Management of Heart Failure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation</article-title>
          <source>Circulation</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>1977</fpage>
          <lpage>2016</lpage>
          <issue>14</issue>
          <volume>119</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Jessup</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Abraham</surname>
              <given-names>WT</given-names>
            </name>
            <name>
              <surname>Casey</surname>
              <given-names>DE</given-names>
            </name>
            <name>
              <surname>Feldman</surname>
              <given-names>AM</given-names>
            </name>
            <name>
              <surname>Francis</surname>
              <given-names>GS</given-names>
            </name>
            <name>
              <surname>Ganiats</surname>
              <given-names>TG</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B5">
        <mixed-citation>5. Pereira-Barretto AC. Tratamento da insufici&#234;ncia card&#237;aca cr&#244;nica. In: Nobre F, Serrano Jr CV (editores). Tratado de cardiologia SOCESP. S&#227;o Paulo: Editora Manole Ltda; 2009. p. 1065-74.</mixed-citation>
        <element-citation publication-type="book">
          <source>Tratado de cardiologia SOCESP</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>1065</fpage>
          <lpage>74</lpage>
          <person-group person-group-type="author">
            <name>
              <surname>Pereira-Barretto</surname>
              <given-names>AC.</given-names>
            </name>
            <name>
              <surname>Nobre</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Serrano Jr</surname>
              <given-names>CV</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B6">
        <mixed-citation>6. Metra M, Torp-Pedersen C, Cleland JGF, Di Lenarda A, Kornajota M, Remme WJ, et al. Should beta-blocker therapy be reduced or withdrawn after an episode of decompensated heart failure? Results from COMET. Eur J Heart Fail. 2007; 9 (9): 901-9.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Should beta-blocker therapy be reduced or withdrawn after an episode of decompensated heart failure: Results from COMET</article-title>
          <source>Eur J Heart Fail</source>
          <date>
            <year>2007</year>
          </date>
          <fpage>901</fpage>
          <lpage>9</lpage>
          <issue>9</issue>
          <volume>9</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Metra</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Torp-Pedersen</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Cleland</surname>
              <given-names>JGF</given-names>
            </name>
            <name>
              <surname>Di Lenarda</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Kornajota</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Remme</surname>
              <given-names>WJ</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B7">
        <mixed-citation>7. Orso F, Baldasseroni S, Fabbri G, Gonzini L, Lucci D, D'Ambrosi C, et al. Role of beta-blockers in patients admitted for worsening heart failure in a real world setting: data from the Italian Survey on Acute Heart Failure. Eur J Heart Fail. 2009; 11 (1): 77-84.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Role of beta-blockers in patients admitted for worsening heart failure in a real world setting: data from the Italian Survey on Acute Heart Failure</article-title>
          <source>Eur J Heart Fail</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>77</fpage>
          <lpage>84</lpage>
          <issue>1</issue>
          <volume>11</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Orso</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Baldasseroni</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Fabbri</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Gonzini</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Lucci</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>D'Ambrosi</surname>
              <given-names>C</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B8">
        <mixed-citation>8. Fonarow GC, Abraham WT, Albert NM, Stough WG, Gheorghiode M, Grrnberg BH, et al. Influence of beta-blocker continuation or withdrawal on outcomes in patients hospitalized with heart failure: findings from the OPTIMIZE-HF program. J Am Coll Cardiol. 2008; 52 (3): 190-9.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Influence of beta-blocker continuation or withdrawal on outcomes in patients hospitalized with heart failure: findings from the OPTIMIZE-HF program</article-title>
          <source>J Am Coll Cardiol</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>190</fpage>
          <lpage>9</lpage>
          <issue>3</issue>
          <volume>52</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Fonarow</surname>
              <given-names>GC</given-names>
            </name>
            <name>
              <surname>Abraham</surname>
              <given-names>WT</given-names>
            </name>
            <name>
              <surname>Albert</surname>
              <given-names>NM</given-names>
            </name>
            <name>
              <surname>Stough</surname>
              <given-names>WG</given-names>
            </name>
            <name>
              <surname>Gheorghiode</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Grrnberg</surname>
              <given-names>BH</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B9">
        <mixed-citation>9. Sociedade Brasileira de Cardiologia/ Montera MM, Almeida DR, Tinoco EM, Rocha RM, Moura LAZ, R&#233;a-Neto A, et al. II Diretriz brasileira de insufici&#234;ncia card&#237;aca aguda. Arq Bras Cardiol. 2009; 93 (3 supl 3): 1-65.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>II Diretriz brasileira de insufici&#234;ncia card&#237;aca aguda</article-title>
          <source>Arq Bras Cardiol</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>1</fpage>
          <lpage>65</lpage>
          <issue>3</issue>
          <volume>93</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Montera</surname>
              <given-names>MM</given-names>
            </name>
            <name>
              <surname>Almeida</surname>
              <given-names>DR</given-names>
            </name>
            <name>
              <surname>Tinoco</surname>
              <given-names>EM</given-names>
            </name>
            <name>
              <surname>Rocha</surname>
              <given-names>RM</given-names>
            </name>
            <name>
              <surname>Moura</surname>
              <given-names>LAZ</given-names>
            </name>
            <name>
              <surname>R&#233;a-Neto</surname>
              <given-names>A</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B10">
        <mixed-citation>10. Dickstein K, Cohen-Solal A, Filippatos G, McMurray JJ, Ponikowski P, Poole-Wilson PA, et al. ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2008. Task Force for the diagnosis and treatment of acute and chronic heart failure 2008 of the European Society of Cardiology. Developed in collaboration with the Heart Failure association of the ESC (HFA) and endorsed by the European Society of Intensive Care Medicine. Eur J Heart Fail. 2008; 10 (10): 933-89.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2008: Task Force for the diagnosis and treatment of acute and chronic heart failure 2008 of the European Society of Cardiology. Developed in collaboration with the Heart Failure association of the ESC (HFA) and endorsed by the European Society of Intensive Care Medicine</article-title>
          <source>Eur J Heart Fail</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>933</fpage>
          <lpage>89</lpage>
          <issue>10</issue>
          <volume>10</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Dickstein</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Cohen-Solal</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Filippatos</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>McMurray</surname>
              <given-names>JJ</given-names>
            </name>
            <name>
              <surname>Ponikowski</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Poole-Wilson</surname>
              <given-names>PA</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B11">
        <mixed-citation>11. Gheorghiade M, Zannad F, Sopko G, Klein L, Pi&#241;a IL, Konstam MA, et al. Acute heart failure syndromes: current state and framework for future research. Circulation. 2005; 112 (25): 3958-68.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Acute heart failure syndromes: current state and framework for future research</article-title>
          <source>Circulation</source>
          <date>
            <year>2005</year>
          </date>
          <fpage>3958</fpage>
          <lpage>68</lpage>
          <issue>25</issue>
          <volume>112</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Gheorghiade</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Zannad</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Sopko</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Klein</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Pi&#241;a</surname>
              <given-names>IL</given-names>
            </name>
            <name>
              <surname>Konstam</surname>
              <given-names>MA</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B12">
        <mixed-citation>12. Barretto AC, Del Carlo CH, Cardoso JN, Morgado PC, Munhoz RT, Eid MO, et al. Re-hospitaliza&#231;&#245;es e morte por insufici&#234;ncia card&#237;aca. &#205;ndices ainda alarmantes. Arq Bras Cardiol. 2008; 91 (5): 335-41.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Re-hospitaliza&#231;&#245;es e morte por insufici&#234;ncia card&#237;aca: &#205;ndices ainda alarmantes</article-title>
          <source>Arq Bras Cardiol</source>
          <date>
            <year>2008</year>
          </date>
          <fpage>335</fpage>
          <lpage>41</lpage>
          <issue>5</issue>
          <volume>91</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Barretto</surname>
              <given-names>AC</given-names>
            </name>
            <name>
              <surname>Del Carlo</surname>
              <given-names>CH</given-names>
            </name>
            <name>
              <surname>Cardoso</surname>
              <given-names>JN</given-names>
            </name>
            <name>
              <surname>Morgado</surname>
              <given-names>PC</given-names>
            </name>
            <name>
              <surname>Munhoz</surname>
              <given-names>RT</given-names>
            </name>
            <name>
              <surname>Eid</surname>
              <given-names>MO</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B13">
        <mixed-citation>13. Blackledge HM, Tomlinson J, Squire IB. Prognosis for patients newly admitted to hospital with heart failure: survival trends in 12220 index admissions in Leicestershire 1993-2001. Heart. 2003; 89 (6): 615-20.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Prognosis for patients newly admitted to hospital with heart failure: survival trends in 12220 index admissions in Leicestershire 1993-2001</article-title>
          <source>Heart</source>
          <date>
            <year>2003</year>
          </date>
          <fpage>615</fpage>
          <lpage>20</lpage>
          <issue>6</issue>
          <volume>89</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Blackledge</surname>
              <given-names>HM</given-names>
            </name>
            <name>
              <surname>Tomlinson</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Squire</surname>
              <given-names>IB</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B14">
        <mixed-citation>14. VillaCorta H, Mesquita ET, Cardoso R, Bonates T, Maia ER, Silva ACM, et al. Preditores de sobrevida obtidos na unidade de emerg&#234;ncia em pacientes atendidos por insufici&#234;ncia card&#237;aca descompensada. Rev Port Cardiol. 2003; 22: 495-507.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Preditores de sobrevida obtidos na unidade de emerg&#234;ncia em pacientes atendidos por insufici&#234;ncia card&#237;aca descompensada</article-title>
          <source>Rev Port Cardiol</source>
          <date>
            <year>2003</year>
          </date>
          <fpage>495</fpage>
          <lpage>507</lpage>
          <volume>22</volume>
          <person-group person-group-type="author">
            <name>
              <surname>VillaCorta</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Mesquita</surname>
              <given-names>ET</given-names>
            </name>
            <name>
              <surname>Cardoso</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Bonates</surname>
              <given-names>T</given-names>
            </name>
            <name>
              <surname>Maia</surname>
              <given-names>ER</given-names>
            </name>
            <name>
              <surname>Silva</surname>
              <given-names>ACM</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B15">
        <mixed-citation>15. Rohde LE, Clausell N, Ribeiro JP, Goldraich L, Netto R, Dec GW, et al. Heath outcomes in decompensated congestive heart failure: a comparison of tertiary hospitals in Brazil and United States. Int J Cardiol. 2005; 102 (1): 71-7.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Heath outcomes in decompensated congestive heart failure: a comparison of tertiary hospitals in Brazil and United States</article-title>
          <source>Int J Cardiol</source>
          <date>
            <year>2005</year>
          </date>
          <fpage>71</fpage>
          <lpage>7</lpage>
          <issue>1</issue>
          <volume>102</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Rohde</surname>
              <given-names>LE</given-names>
            </name>
            <name>
              <surname>Clausell</surname>
              <given-names>N</given-names>
            </name>
            <name>
              <surname>Ribeiro</surname>
              <given-names>JP</given-names>
            </name>
            <name>
              <surname>Goldraich</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Netto</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Dec</surname>
              <given-names>GW</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B16">
        <mixed-citation>16. Fonarow GC, Adams KJ, Abraham WT, Yancy CW, Boscardin WJ (for the ADHERE Scientific advisory committee, study group and investigators). Risk stratification for in-hospital mortality in acutely decompensated heart failure: classification and regression tree analysis. JAMA. 2005; 293 (5): 572-80.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Risk stratification for in-hospital mortality in acutely decompensated heart failure: classification and regression tree analysis</article-title>
          <source>JAMA</source>
          <date>
            <year>2005</year>
          </date>
          <fpage>572</fpage>
          <lpage>80</lpage>
          <issue>5</issue>
          <volume>293</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Fonarow</surname>
              <given-names>GC</given-names>
            </name>
            <name>
              <surname>Adams</surname>
              <given-names>KJ</given-names>
            </name>
            <name>
              <surname>Abraham</surname>
              <given-names>WT</given-names>
            </name>
            <name>
              <surname>Yancy</surname>
              <given-names>CW</given-names>
            </name>
            <name>
              <surname>Boscardin</surname>
              <given-names>WJ</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B17">
        <mixed-citation>17. Jondeau G, Neuder Y, Eicher JC, Jourdain P, Fauveau E, Galinier M, et al. B-CONVINCED: beta-blocker continuation vs. interruption in patients with congestive heart failure hospitalized for a decompensation episode. Eur Heart J. 2009; 30 (18): 2186-92.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>B-CONVINCED: beta-blocker continuation vs. interruption in patients with congestive heart failure hospitalized for a decompensation episode</article-title>
          <source>Eur Heart J</source>
          <date>
            <year>2009</year>
          </date>
          <fpage>2186</fpage>
          <lpage>92</lpage>
          <issue>18</issue>
          <volume>30</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Jondeau</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Neuder</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Eicher</surname>
              <given-names>JC</given-names>
            </name>
            <name>
              <surname>Jourdain</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Fauveau</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Galinier</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B18">
        <mixed-citation>18. Patel P, White DL, Deswal A. Translation of clinical Trial results into practice: temporal patterns of beta-blocker utilization for heart failure at hospital discharge and during ambulatory follow-up. Am Heart J. 2007; 153: 515-22.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Translation of clinical Trial results into practice: temporal patterns of beta-blocker utilization for heart failure at hospital discharge and during ambulatory follow-up</article-title>
          <source>Am Heart J</source>
          <date>
            <year>2007</year>
          </date>
          <fpage>515</fpage>
          <lpage>22</lpage>
          <volume>153</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Patel</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>White</surname>
              <given-names>DL</given-names>
            </name>
            <name>
              <surname>Deswal</surname>
              <given-names>A</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B19">
        <mixed-citation>19. Gattis WA, O'Connor CM, Gallup DS, Hasselblad V, Gheorghiade M. Predischarge initiation of carvedilol in patients hospitalized for decompensated heart failure: results of the IMPACT-HF trial. J Am Coll Cardiol. 2004; 43 (9): 1534-41.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Predischarge initiation of carvedilol in patients hospitalized for decompensated heart failure: results of the IMPACT-HF trial</article-title>
          <source>J Am Coll Cardiol</source>
          <date>
            <year>2004</year>
          </date>
          <fpage>1534</fpage>
          <lpage>41</lpage>
          <issue>9</issue>
          <volume>43</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Gattis</surname>
              <given-names>WA</given-names>
            </name>
            <name>
              <surname>O'Connor</surname>
              <given-names>CM</given-names>
            </name>
            <name>
              <surname>Gallup</surname>
              <given-names>DS</given-names>
            </name>
            <name>
              <surname>Hasselblad</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>Gheorghiade</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B20">
        <mixed-citation>20. Fowler MB, Lottes SR, Nelson JJ, Lukas MA, Gilbert EM, Greenberg B, et al. Beta-blocker dosing in community based treatment of heart failure. Am Heart J. 2007; 153 (6): 1029-36.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Beta-blocker dosing in community based treatment of heart failure</article-title>
          <source>Am Heart J</source>
          <date>
            <year>2007</year>
          </date>
          <fpage>1029</fpage>
          <lpage>36</lpage>
          <issue>6</issue>
          <volume>153</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Fowler</surname>
              <given-names>MB</given-names>
            </name>
            <name>
              <surname>Lottes</surname>
              <given-names>SR</given-names>
            </name>
            <name>
              <surname>Nelson</surname>
              <given-names>JJ</given-names>
            </name>
            <name>
              <surname>Lukas</surname>
              <given-names>MA</given-names>
            </name>
            <name>
              <surname>Gilbert</surname>
              <given-names>EM</given-names>
            </name>
            <name>
              <surname>Greenberg</surname>
              <given-names>B</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Original Articles</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="en">Is it necessary to suspend betablockers in decompensated heart failure with low output?</article-title>
      </title-group>
      <abstract xml:lang="en">
        <p>BACKGROUND: There is evidence that the suspension of betablockers (BB) in decompensated heart failure may increase mortality. Dobutamine (dobuta) is the most commonly used inotrope in decompensation, however, BB and dobuta act with the same receptor with antagonist actions, and concurrent use of both drugs could hinder compensation. OBJECTIVE: To evaluate whether the maintenance of BB associated with dobuta difficults cardiac compensation. METHODS: We studied 44 patients with LVEF &lt; 45% and the need for inotropics. Divided into three groups according to the use of BB. Group A (n=8): those who were not using BB at baseline; Group B (n=25): those who used BB, but was suspended to start dobuta; Group C (n = 11): those who used BB concomitant to dobuta. To compare groups, we used the Student t, Fisher exact and chi-square tests. Considered significant if p &lt; 0.05. RESULTS: Mean LVEF 23.8 &#177; 6.6%. The average use of dobuta use was similar in all groups (p = 0.35), and concomitant use of dobutamine with BB did not increase the length of stay (BB 20.36 &#177; 11.04 days vs without BB 28.37 &#177; 12.76 days, p = NS). In the high dose, BB was higher in patients whose medication was not suspended (35.8 &#177; 16.8 mg/day vs 23.0 &#177; 16.7 mg/day, p = 0.004). CONCLUSION: Maintaining BB associated with dobutamine did not increase the length of hospitalization and was not associated with the worst outcome. Patients who did not suspend BB were discharged with higher doses of the drug.</p>
      </abstract>
      <kwd-group xml:lang="en">
        <kwd>Heart failure</kwd>
        <kwd>decompensated heart failure</kwd>
        <kwd>dobutamine</kwd>
        <kwd>low cardiac output</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <bold>ORIGINAL ARTICLE</bold>
      </p>
      <p>
        <fn id="tx-body2">
          <label>
            <bold>Is it necessary to suspend betablockers in decompensated heart failure with low output?</bold>
          </label>
          <p>
            <bold>Marcelo Villa&#231;a Lima; Juliano Novaes Cardoso; Marcelo Eidi Ochiai; Katiuska Massucatti Grativvol; Petherson Susano Grativvol; Euler C. O. Brancalh&#227;o; Robinson Tadeu Munhoz; Paulo Cesar Morgado; Airton R. Scipioni; Antonio Carlos Pereira Barretto</bold>
          </p>
        </fn>
      </p>
      <p> Instituto do Cora&#231;&#227;o da Faculdade de Medicina da USP - InCor HC FMUSP, S&#227;o Paulo, SP - Brazil</p>
      <p>Mailing address</p>
      <p>
        <bold>ABSTRACT</bold>
      </p>
      <p><bold>BACKGROUND: </bold>There is evidence that the suspension of betablockers (BB) in decompensated heart failure may increase mortality. Dobutamine (dobuta) is the most commonly used inotrope in decompensation, however, BB and dobuta act with the same receptor with antagonist actions, and concurrent use of both drugs could hinder compensation.</p>
      <p><bold>OBJECTIVE:</bold> To evaluate whether the maintenance of BB associated with dobuta difficults cardiac compensation.</p>
      <p><bold>METHODS:</bold> We studied 44 patients with LVEF &lt;45% and the need for inotropics. Divided into three groups according to the use of BB. Group A (n=8): those who were not using BB at baseline; Group B (n=25): those who used BB, but was suspended to start dobuta; Group C (n = 11): those who used BB concomitant to dobuta. To compare groups, we used the Student t, Fisher exact and chi-square tests. Considered significant if p &lt; 0.05.</p>
      <p><bold>RESULTS:</bold> Mean LVEF 23.8 &#177; 6.6%. The average use of dobuta use was similar in all groups (p = 0.35), and concomitant use of dobutamine with BB did not increase the length of stay (BB 20.36 &#177; 11.04 days <italic>vs</italic> without BB 28.37 &#177; 12.76 days, p = NS). In the high dose, BB was higher in patients whose medication was not suspended (35.8 &#177; 16.8 mg/day <italic>vs</italic> 23.0 &#177; 16.7 mg/day, p = 0.004).</p>
      <p><bold>CONCLUSION:</bold> Maintaining BB associated with dobutamine did not increase the length of hospitalization and was not associated with the worst outcome. Patients who did not suspend BB were discharged with higher doses of the drug.</p>
      <p><bold>Key words: </bold>Heart failure; decompensated heart failure; dobutamine/administration &amp; dosage; low cardiac output.</p>
      <p>
        <bold>Introduction</bold>
      </p>
      <p>Heart failure is a prevalent disease, and patients have decreased quality of life and live with high risk of life<sup>1</sup>. Epidemiological studies have shown that patients with HF are hospitalized very frequently and that mortality is higher than many cancer types<sup>1</sup>. </p>
      <p>The modern treatment with neurohormonal blockers is modifying the natural morbid history, reducing symptoms, improving quality of life and reducing the high morbimortality<sup>2-4</sup>. Among neurohormonal blockers, betablockers have an important role by modifying more intensely morbimortality related to disease. </p>
      <p>Since the documentation of its efficacy, the prescription of BB in HF has been growing. At first it was just prescribed for fear of negative inotropic effect, but grew with the release of successive clinical trials proving its efficacy and safety<sup>2-4</sup>. At InCor, it was possible to document such an increase. In 1999, 9.5% of outpatient received prescription of betablockers against 77.2% in the year 2004<sup>5</sup>. </p>
      <p>Although properly treated, the variable percentage of patients with HF decompensates. It was found an increase of patients treated with betablockers and, consequently, an increase of patients who decompensate during treatment. In view of the concept that BB has negative inotropic effect, these are suspended in cardiac decompensation by most doctors. However, retrospective analysis of clinical trials and registries of patients with HF have been documenting the evolution of patients in whom BB was suspended is accompanied by higher mortality than the one observed when BB is kept<sup>6-8</sup>. </p>
      <p>The controversy over maintaining or suspending BB in cardiac decompensation, adds to the doubt of how to treat it, especially in patients with low cardiac output table in decompensation<sup>9,10</sup>. Dobutamine, when necessary, is the most used medication for inotropic support. Whereas dobutamine is an inotropic beta stimulant and that betablockers block the beta adrenergic receptors, the prescription of the two concurrently may result in reduced inotropic effect of dobutamine, as well as difficult and prolong the time required to obtain treatment for cardiac compensation<sup>11</sup>.</p>
      <p>In our hospital, we have seen an increasing number of patients using concomitant betablocker and dobutamine. Thus, we analyzed prospectively if the evolution of patients using concomitantly the two drugs would be different from those without betablocker decompensation or those in which the betablocker was suspended for prescribing inotropic support with dobutamine. </p>
      <p>
        <bold>Methods</bold>
      </p>
      <p>We analyzed prospectively, by means of a cohort study, 44 patients in functional class IV, hospitalized for compensation of heart failure in the period from February to December 2005. We selected patients older than 18 years, with a left ventricle ejection fraction below 45% and use of dobutamine. The study excluded patients with cardiac pacemakers. All patients were evaluated clinically and underwent laboratory tests that included complete blood test, urea, creatinine, sodium and potassium content. To characterize the patients as per the degree of cardiac impairment, it was considered the echocardiogram performed prior to hospitalization, if the examination had been conducted within the previous six months before admission. It not, the echocardiogram was performed at admission. These patients with decompensated HF, eight (18.18%) were not taking betablockers, and 36 (81.81%) were. When dobutamine was prescribed, the betablocker was discontinued in 25 (69.44%) patients and maintained in 11 (30.55%) cases. To analyze the data, patients were divided into three groups according to the use of betablockers: Group A (n = 8) - who were not using BB at baseline, Group B (n = 25) - who used BB, but was suspended to start dobutamine, Group C (n = 11) - who used the BB concomitant with dobutamine. </p>
      <p>Patients were followed up during hospitalization, analyzing the days needed for compensation, the time it was necessary to keep the dose of carvedilol and dobutamine in which the patient was discharged. The three groups were compared regarding clinical features, as to the time of use of inotropic and length of hospitalization.</p>
      <p>Continuous variables were presented by mean &#177; standard deviation and categorical variables as percentages. The t test was used for comparison among the groups. The presented P values are two-tailed, and a significance level of &lt; 0.05 was adopted.</p>
      <p>
        <bold>Results</bold>
      </p>
      <p><xref ref-type="table" rid="tab01-body2">Table 1</xref> shows the main characteristics of the studied patients. Most patients were male, with a significant reduction in ejection fraction, large LV dilation and levels of urea and creatinine slightly elevated. The hospitalization was prolonged, and patients were discharged with higher doses of carvedilol than in the admission. Eighty-one percent of patients with decompensated HF were using BB. </p>
      <table-wrap id="tab01-body2">
        <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt01-en.jpg"/></table-wrap>
      <p><xref ref-type="table" rid="tab02-body2">Table 2</xref> shows the characteristics of patients according to the groups. There was no difference between them in age, ejection fraction, hemoglobin, sodium and potassium levels. The patients of the group hospitalized without betablocker (Group A) had levels of urea and creatinine lower than those that decompensated and were taking betablockers (Groups B and C). Patients in Group C where the betablocker was maintained during treatment for cardiac failure had greater ventricular enlargement. </p>
      <table-wrap id="tab02-body2">
        <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt02-en.jpg"/></table-wrap>
      <p>The hospitalization was similar in all three groups, but patients who were not taking betablockers on admission (Group A) needed inotropic for longer periods than patients who were taking betablockers on arrival to the Emergency Room (<xref ref-type="table" rid="tab02-body2">Tables 2</xref> and <xref ref-type="table" rid="tab03-body2">3</xref>). The dose of carvedilol at discharge in Group C was higher than that of the group in which carvedilol was suspended for the introduction of inotropic and than that group that was taking it at the time of admission. </p>
      <table-wrap id="tab03-body2">
        <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt03-en.jpg"/></table-wrap>
      <p>
        <bold>Discussion</bold>
      </p>
      <p>The natural history of heart failure, a disease with features of malignancy, has been modified with modern treatment<sup>2,12</sup>. Betablockers, through the reversal of cardiac remodeling, improve the quality of life, are important in reducing mortality and have been identified as the main drug for controlling HF<sup>2-4</sup>.</p>
      <p>If there is doubt about the value of betablockers in the treatment of chronic HF, the same does not occur when the patient decompensates<sup>9,10</sup>. With the increasing number of patients using betablockers, the number of cases with cardiac decompensation also increases in the presence of optimized treatment and using beta blockers. In this situation, should betablocker be discontinued, or can it be maintained? In our institution, based on the result of studies suggesting that betablocker discontinuation or even reduction could be accompanied by increased mortality, the non suspension of the drug routinely started in all cardiac decompensation conditions. Here we present the results of the analysis of patients hospitalized for cardiac compensation in 2005 who had or not betablocker suspension during cardiac compensation. </p>
      <p>Patients with HF who did not compensate or not improved with treatment administered in the Emergency Room of <italic>Instituto do Cora&#231;&#227;o</italic> were hospitalized in our institution, with the selection of the most severe patients<sup>12</sup>. This sample was consisted of patients in functional class IV signs of pulmonary and systemic congestion and signs of low cardiac output. In the Emergency Room, everyone had a prescription of dobutamine in the face of the presence of low output and were hospitalized to complete the cardiac compensation rate. From the 44 patients with decompensated heart failure, eight (18.18%) were not taking betablockers, and 36 (81.81%) were. When dobutamine was prescribed, the betablocker was discontinued in 25 (69.44%) and maintained in 11 (30.55%) patients. </p>
      <p>We sought, in this study, to determine whether the clinical evolution during hospitalization was different whether or not keeping the betablocker and whether or not the combination of dobutamine with betablockers might interfere in this evolution. </p>
      <p>The first point that deserves mention is the fact that most patients with decompensation and went to the Emergency Room was in use of betablockers (81.8%). That number matches the survey conducted at our institution, which revealed that over 70% of patients with HF to receive outpatient prescription of BB<sup>5</sup>.</p>
      <p>The population studied in our hospital is very serious and generally requires several days of hospitalization to compensate (average of 23 days). The hospitalization time is longer than that reported in other studies<sup>13-15</sup>. It is described that, in general, patients are hospitalized for four to five days to compensate, when the HF condition is not severe, and around nine days for the most severe ones<sup>13-15</sup>. In Rio de Janeiro, for patients treated at the Emergency Room of a private institution, length of hospital stay was 9.5 days, and in Porto Alegre in a school hospital like ours, it was of 11 days, both times smaller than ours<sup>14,15</sup>. The highest severity of our cases may explain, in part, that long hospitalization time. We have no data to stratify the severity of HF in Brazilian hospitals.</p>
      <p>In a previous study, we compared the profile of our patients with those described in American ADHERE registry<sup>12,16</sup>. Dividing our cases according to the stratification of ADHERE study and comparing the two cohorts, we observe that our population is generally more severe than that which participated in ADHERE registry, because 74.9% of patients hospitalized in our hospital with systolic pressure below 115 mmHg, while in ADHERE registry only 18.5% were hypertensives<sup>12,16</sup>. Thus, our greatest severity is one of the explanation for longer periods of hospitalization and need for inotropic. </p>
      <p>In the analysis of hospitalization time, it was observed that patients who were not using betablockers to decompensate were hospitalized longer (28.37 &#177; 12.76 days) and received dobutamine for a longer time (15.37 &#177; 4.45 days) than the other two groups. The average length of hospitalization was 24% higher in patients in Group A than in patients who were being treated with betablockers, which was subsequently suspended, and 39% higher than for the group in which the betablocker was maintained. Concerning the time of inotropic, and decompensation in patients who were not in use of BB was 82% higher than in Group B and almost the double than in Group C (94%). The differences did not reach statistical significance, but the absolute numerical difference was great. It is interesting to note that the group was not receiving betablocker on arrival at the Emergency Room had urea and creatinine levels lower than the group that was in use of BB. Not using the BB does not seem to have occurred because these patients had more severe or worst HF conditions. </p>
      <p>Our results showed that the use of the betablockers to decompensate do not indicate that compensation will be more difficult. Patients treated with betablockers needed less time of inotropic for the compensation and were, overall, less time in hospital than those without betablocker (20.36 &#177; 11.04 days and 22.80 &#177; 10.31 days vs 28.37 &#177; 12.76 days). This finding can be inferred that using betablockers to decompensate does not identify a more severe group or a group in which the cardiac compensation will be more difficult. There was no difference in the prescription of diuretics or vasodilators for compensation in the three groups. </p>
      <p>When comparing the groups in which the betablocker was discontinued when starting the infusion of dobutamine with the group in which the betablocker was maintained throughout the infusion, there was no significant difference between them. As for time of use of inotropic, and the total length of hospital stay, although the absolute numbers have been lower in the group where the betablocker was maintained, there was no statistical significance (<xref ref-type="table" rid="tab02-body2">Tables 2</xref> and <xref ref-type="table" rid="tab03-body2">3</xref>). This finding suggests that the non-suspension of betablockers did not influence negatively the outcome of cases. </p>
      <p>Undoubtedly it contributes to prolonged hospitalization, the conduct of introducing and optimizing the dose of betablocker during hospitalization. When analyzing the three groups, we observed that the patients remained hospitalized for about 13 days after discontinuation of inotropic. If we reduce those 13 days from the total hospitalization time, we can verify that the remaining time does not differ from those described in the Brazilian hospitals<sup>12,14,15</sup>. </p>
      <p>However, with this conduct, it was possible to discharge patients with effective dose of carvedilol. The mean dose of the high one was 26.84 &#177; 17.14 mg/day, i.e,. on average, 12.5 mg twice a day. Comparing the three groups, we found that the dose of Group C, where the betablocker was not suspended during the use of dobutamine and cardiac compensation was significantly higher than the other two groups, those who were hospitalized without prescription of betablocker and those in which the drug was discontinued. The dose of group C was 34% higher than the group who were not taking betablockers in the Emergency Room and 55% higher than in the carvedilol group that was suspended by the introduction of dobutamine (35.79 &#177; 17.25 mg/day <italic>vs</italic> 26.56 &#177; 18.83 mg/day and 23.00 &#177; 16.08 mg/day).</p>
      <p>In the literature, there are more and more articles documenting that the non suspension of betablockers in cardiac decompensation is accompanied by improved outcome. The first one was the article by Metra et al<sup>6</sup> which, based on data from the COMET study, found a mortality reduction of 59% for patients who had dose maintained in respect of those whose dose was reduced or suspended<sup>6</sup>. Interestingly, in the COMET study, 8% had discontinued betablocker, and 22%, a reduction of the dose and the dose maintained at 70% of cases. Without doubt, the form of presentation of decompensation may be considered. In such cases, almost the totality did not present low output condition such as ours, but the important thing is that only 30% of patients had their dosage reduced or discontinued, a finding that indicates that it is possible to keep the BB in cardiac decompensation and that most of them had a good evolution without suspension. In this study, the hospital stays of patients who had discontinued betablockers was of 27 &#177; 53 days. Those in which the betablocker dose was reduced, 11 &#177; 9 days, and, where they had kept the betablocker dose during decompensation, 9 &#177; 8 days. </p>
      <p>Orso et al<sup>7</sup> In the Italian registry documented that the non-use of betablockers or suspension in patient hospitalization were associated with increased mortality, confirmed by multivaried analysis<sup>7</sup>. It was identified that patients who were hospitalized without betablockers and did not receive during hospitalization had a risk of life 3.28 times higher than the group that was using BB and this was maintained. They also observed that for those using BB and suspended in the hospital, an increase of 4.20 times the risk of life occurred<sup>7</sup>.</p>
      <p>Fonarow et al<sup>8</sup> in OPTIMIZE-HF program, found that 56.9% of patients were using betablockers at decompensation and that suspended it in only 3.3% of cases<sup>8</sup>. At discharge, 26.6% began receiving the drug. They found that maintaining the betablocker was associated with reduced risk of death of 40% compared to those without betablocker. In contrast, the suspension of betablockers was associated with increased risk of death of 2.3 times than those who continued with the medication. </p>
      <p>Jondeau et al<sup>17</sup> recently published the study B-CONVINCED, much like ours, but with less severe patients. It prospectively analyzed 147 patients who were hospitalized with decompensated heart failure, an ejection fraction inferior to 40%, previously using betablockers<sup>17</sup>. Patients were divided into two groups according to the maintenance dose of BB on admission or not. After three days of evolution, there was no difference between the groups regarding the compensation of heart failure. More importantly, there was no difference in BNP levels, re-hospitalization and mortality in three months. According to our study, patients in the B-CONVINCED that maintained BB during decompensation were using higher doses of medication three months after discharge (90% <italic>vs</italic> 76%)<sup>17</sup>. </p>
      <p>These results provide the substrate for not routinely suspending BB when the patient decompensates. It is important to emphasize that in these studies, most patients showed no signs of low output and probably did not receive inotropic agents for compensation. Still, there was improvement in survival in the medium- and long-term and not during hospitalization. However, patients who are discharged from hospital using a higher dose of betablockers will also benefit in the medium- and long-term. </p>
      <p>Our data extend this indication, showing that for patients with decompensated low output signals that require treatment with inotropic agents, it is also possible to keep the BB, but this conduct was not accompanied by greater difficulty in compensating patients. Moreover, the data suggest that patients responded well to conduct, requiring shorter hospitalization and inotropic time for compensation. </p>
      <p>Not suspending BB facilitates optimization of treatment at discharge. Whereas many physicians are still afraid to prescribe it, and when they do, they use low doses, especially in patients with decompensation and required inotropic support for compensation, to discharge with optimal treatment is essential so that the patient may benefit from such treatment. </p>
      <p>In the literature, there are several studies that show that starting the BB during hospitalization increases the rate of prescription, being this increase accompanied by better evolution<sup>18-20</sup>. Among these, we have the IMPACT study, which proved that the action of starting BB on admission was associated with a reduction of mortality<sup>19</sup>. </p>
      <p>Following this line of research, Fowler et al<sup>20</sup> identified that there is a huge number of patients not receiving BB in the correct dose, confirming that 55% are being treated with a dose lower than 25 mg twice a day, and 9% had their medication discontinued<sup>20</sup>. They found that about 30% of patients received no prescription of BB in the follow-up, and the non prescription had as main cause the non starting after hospitalization<sup>20</sup>. </p>
      <p>These data point to the importance of starting treatment with BB during hospitalization. In our department, we extended this procedure by keeping the patient hospitalized for a few more days and seeking to discharge with optimal treatment, as it is observed a decrease in the rate of re-hospitalization and mortality and that this reduction is as great as the prescribed BB dose is high. With this procedure, we could optimize treatment for all, and most had a high dose of more than 12.5 mg of carvedilol twice a day (26.84 &#177; 17.24 mg/day). </p>
      <p>With no suspension of BB on admission, the patients achieved with the optimization higher doses of BB (35.79 &#177; 17.25 mg/day). </p>
      <p>In conclusion, it is possible to keep the BB during cardiac decompensation, even in patients with signs of low cardiac output requiring inotropic support. This conduct was not accompanied by the worst outcome. We could observe that dobutamine and BB associated can be used and that the evolution of these patients was similar to those in which the BB was suspended. By not suspending the BB, patients might be discharged with optimal doses of medication. </p>
      <p>This approach may have an impact on survival, since the optimal treatment is accompanied by improved outcome. Undoubtedly, studies are needed with larger sample and in which patients are followed in order to confirm this hypothesis.</p>
      <p>
        <bold>Study limitations</bold>
      </p>
      <p>This is a non randomized, observational study. Although the difference between the groups is evident, it did not reach statistical significance probably due to sample size. Randomized studies are needed to clarify the issue.</p>
      <p>
        <bold>References</bold>
      </p>
    </body>
  </sub-article>
  <sub-article article-type="translation" id="TRes" xml:lang="es">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Art&#237;culos Originales</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="es">&#191;Es necesario suspender el betabloqueante en la insuficiencia card&#237;aca descompensada con bajo d&#233;bito?</article-title>
      </title-group>
      <abstract xml:lang="es">
        <p>FUNDAMENTO: Hay evidencias de que la suspensi&#243;n del betabloqueante (BB) en la descompensaci&#243;n card&#237;aca puede aumentar la mortalidad. La dobutamina (dobuta) es el inotr&#243;pico m&#225;s utilizado en la descompensaci&#243;n, mientras tanto, BB y dobuta act&#250;an en el mismo receptor con acciones antag&#243;nicas, y el uso concomitante de los dos f&#225;rmacos podr&#237;a dificultar la compensaci&#243;n. OBJETIVO: Evaluar si la manutenci&#243;n del BB asociado a la dobuta dificulta la compensaci&#243;n card&#237;aca. M&#201;TODOS: Estudiados 44 pacientes con FEVI &lt; 45% y necesidad de inotr&#243;pico. Divididos en tres grupos de acuerdo con el uso de BB. Grupo A (n=8): los que no usaban BB en la admisi&#243;n; Grupo B (n=25): los que usaban BB, sin embargo fue suspendido para iniciar la dobuta; Grupo C (n=11): los que usaron BB concomitantemente a la dobuta. Para comparaci&#243;n de los grupos, fueron utilizados los test t de Student, exacto de Fisher y qui-cuadrado. Considerado significante P &lt; 0,05. RESULTADOS: FEVI media de 23,8&#177;6,6%. El tiempo medio de uso de dobuta fue semejante en los tres grupos (p=0,35), y el uso concomitante de la dobuta con el BB no aument&#243; el tiempo de internaci&#243;n (con BB 20,36 &#177; 11,04 d&#237;as vs sin BB 28,37 &#177; 12,76 d&#237;as, p=NS). En el alta, la dosis del BB fue superior en los pacientes en que la medicaci&#243;n no fue suspendida (35,8 &#177; 16,8 mg/d&#237;a vs 23,0 &#177; 16,7 mg/d&#237;a, p=0,004). CONCLUSI&#211;N: La manutenci&#243;n del BB asociado a la dobuta no aument&#243; el tiempo de internaci&#243;n y no fue acompa&#241;ada de peor evoluci&#243;n. Los pacientes que no suspendieron el BB tuvieron alta con dosis m&#225;s elevadas del medicamento.</p>
      </abstract>
      <kwd-group xml:lang="es">
        <kwd>Insuficiencia card&#237;aca</kwd>
        <kwd>descompensaci&#243;n card&#237;aca</kwd>
        <kwd>dobutamina</kwd>
        <kwd>bajo d&#233;bito card&#237;aco</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <bold>ART&#205;CULO ORIGINAL</bold>
      </p>
      <p>
        <fn id="top-body3">
          <label>
            <bold>&#191;Es necesario suspender el betabloqueante en la insuficiencia card&#237;aca descompensada con bajo d&#233;bito?</bold>
          </label>
          <p>
            <bold>Marcelo Villa&#231;a Lima; Juliano Novaes Cardoso; Marcelo Eidi Ochiai; Katiuska Massucatti Grativvol; Petherson Susano Grativvol; Euler C. O. Brancalh&#227;o; Robinson Tadeu Munhoz; Paulo Cesar Morgado; Airton R. Scipioni; Antonio Carlos Pereira Barretto</bold>
          </p>
        </fn>
      </p>
      <p>Instituto do Cora&#231;&#227;o da Faculdade de Medicina da USP - InCor HC FMUSP, S&#227;o Paulo, SP - Brasil</p>
      <p>Correspondencia</p>
      <p>
        <bold>RESUMEN</bold>
      </p>
      <p><bold>FUNDAMENTO:</bold> Hay evidencias de que la suspensi&#243;n del betabloqueante (BB) en la descompensaci&#243;n card&#237;aca puede aumentar la mortalidad. La dobutamina (dobuta) es el inotr&#243;pico m&#225;s utilizado en la descompensaci&#243;n, mientras tanto, BB y dobuta act&#250;an en el mismo receptor con acciones antag&#243;nicas, y el uso concomitante de los dos f&#225;rmacos podr&#237;a dificultar la compensaci&#243;n.</p>
      <p><bold>OBJETIVO:</bold> Evaluar si la manutenci&#243;n del BB asociado a la dobuta dificulta la compensaci&#243;n card&#237;aca.</p>
      <p><bold>M&#201;TODOS:</bold> Estudiados 44 pacientes con FEVI &lt; 45% y necesidad de inotr&#243;pico. Divididos en tres grupos de acuerdo con el uso de BB. Grupo A (n=8): los que no usaban BB en la admisi&#243;n; Grupo B (n=25): los que usaban BB, sin embargo fue suspendido para iniciar la dobuta; Grupo C (n=11): los que usaron BB concomitantemente a la dobuta. Para comparaci&#243;n de los grupos, fueron utilizados los test <italic>t</italic> de <italic>Student</italic>, exacto de Fisher y qui-cuadrado. Considerado significante P &lt; 0,05.</p>
      <p><bold>RESULTADOS:</bold> FEVI media de 23,8&#177;6,6%. El tiempo medio de uso de dobuta fue semejante en los tres grupos (p=0,35), y el uso concomitante de la dobuta con el BB no aument&#243; el tiempo de internaci&#243;n (con BB 20,36 &#177; 11,04 d&#237;as <italic>vs</italic> sin BB 28,37 &#177; 12,76 d&#237;as, p=NS). En el alta, la dosis del BB fue superior en los pacientes en que la medicaci&#243;n no fue suspendida (35,8 &#177; 16,8 mg/d&#237;a <italic>vs</italic> 23,0 &#177; 16,7 mg/d&#237;a, p=0,004).</p>
      <p><bold>CONCLUSI&#211;N:</bold> La manutenci&#243;n del BB asociado a la dobuta no aument&#243; el tiempo de internaci&#243;n y no fue acompa&#241;ada de peor evoluci&#243;n. Los pacientes que no suspendieron el BB tuvieron alta con dosis m&#225;s elevadas del medicamento.</p>
      <p><bold>Palabras clave:</bold> Insuficiencia card&#237;aca; descompensaci&#243;n card&#237;aca; dobutamina/administraci&#243;n &amp; dosaje; bajo d&#233;bito card&#237;aco.</p>
      <p>
        <bold>Introducci&#243;n</bold>
      </p>
      <p>La insuficiencia card&#237;aca es enfermedad prevalente, y los portadores presentan reducci&#243;n en la calidad de vida y conviven con elevado riesgo de vida<sup>1</sup>. Estudios epidemiol&#243;gicos mostraron que los pacientes con IC son hospitalizados con mucha frecuencia y que la mortalidad es mayor que muchos tipos de c&#225;ncer<sup>1</sup>.</p>
      <p>El tratamiento moderno con los bloqueadores neurohormonales viene modificando esa m&#243;rbida historia natural, reduciendo los s&#237;ntomas, mejorando la calidad de vida y reduciendo la elevada morbimortalidad<sup>2-4</sup>. Entre los bloqueadores neurohormonales, los betabloqueantes tienen un papel importante, modificando m&#225;s intensamente la morbimortalidad relacionada a la enfermedad.</p>
      <p>Desde la documentaci&#243;n de su eficacia, la prescripci&#243;n de los BB en la IC viene creciendo. En el comienzo, era poco prescripto por el recelo del efecto inotr&#243;pico negativo, pero creci&#243; con la divulgaci&#243;n de los sucesivos ensayos cl&#237;nicos que comprobaban su eficacia y seguridad<sup>2-4</sup>. En el InCor, fue posible documentar ese aumento. En 1999, 9,5% de los pacientes del ambulatorio recib&#237;an prescripci&#243;n del betabloqueante contra 77,2% en el a&#241;o 2004<sup>5</sup>.</p>
      <p>A pesar de ser correctamente tratados, el porcentaje variable de pacientes con IC descompensa. Se constata un crecimiento de pacientes tratados con betabloqueantes y, en consecuencia, un aumento de pacientes que se descompensan en la vigencia del tratamiento. Frente al concepto de que los BB tienen efecto inotr&#243;pico negativo, estos son suspendidos en la descompensaci&#243;n card&#237;aca por la mayor&#237;a de los m&#233;dicos. Mientras tanto, an&#225;lisis retrospectivo de ensayos cl&#237;nicos y de registros de casos con IC viene documentando que la evoluci&#243;n de los pacientes en que el BB fue suspendido es acompa&#241;ada de mayor mortalidad que la observada en aquellos en que el BB es mantenido<sup>6-8</sup>.</p>
      <p>A esa pol&#233;mica sobre mantener o suspender el BB en la descompensaci&#243;n card&#237;aca, se suma la duda de como tratarla, especialmente en los pacientes que presentan cuadro de bajo d&#233;bito card&#237;aco en la descompensaci&#243;n<sup>9,10</sup>. La dobutamina, cuando es necesaria, es la medicaci&#243;n m&#225;s empleada para soporte inotr&#243;pico. Considerando que la dobutamina es un inotr&#243;pico beta estimulante y que los betabloqueantes bloquean los receptores beta adren&#233;rgicos, la prescripci&#243;n de los dos concomitantemente podr&#225; resultar en reducci&#243;n del efecto inotr&#243;pico de la dobutamina, as&#237; como dificultar y prolongar el tiempo necesario de tratamiento para obtener la compensaci&#243;n card&#237;aca<sup>11</sup>.</p>
      <p>En nuestro hospital, hemos visto un n&#250;mero creciente de pacientes en uso concomitante del betabloqueante y de la dobutamina. As&#237;, procuramos analizar prospectivamente si la evoluci&#243;n de los pacientes en uso concomitante de las dos drogas ser&#237;a diferente de aquellos que se descompensaron sin betabloqueante o de aquellos en que el betabloqueante fue suspendido para que fuese prescripto el soporte inotr&#243;pico con la dobutamina.</p>
      <p>
        <bold>M&#233;todos</bold>
      </p>
      <p>Analizamos prospectivamente, por medio de estudio de cohorte, 44 pacientes en clase funcional IV, hospitalizados para compensaci&#243;n de insuficiencia card&#237;aca en el per&#237;odo de febrero a diciembre de 2005. Fueron seleccionados pacientes mayores de 18 a&#241;os, con fracci&#243;n de eyecci&#243;n del ventr&#237;culo izquierdo inferior a 45% y en uso de dobutamina. Fueron excluidos del estudio, pacientes portadores de marcapasos card&#237;aco.</p>
      <p>Todos los pacientes fueron evaluados cl&#237;nicamente y sometidos a evaluaci&#243;n de laboratorio que inclu&#237;a hemograma, dosaje de urea, creatinina, sodio y potasio.</p>
      <p>Para la caracterizaci&#243;n de los pacientes en cuanto al grado de compromiso card&#237;aco, se consider&#243; el ecocardiograma realizado antes de la hospitalizaci&#243;n, si ese examen hubiese sido realizado en los seis meses que antecedieron a la internaci&#243;n. En su ausencia, el ecocardiograma fue realizado en la internaci&#243;n.</p>
      <p>De esos pacientes con IC descompensada, ocho (18,18%) no estaban en uso de betabloqueante, y 36 (81,81%) estaban. Cuando fue prescripta la dobutamina, el betabloqueante fue suspendido en 25 (69,44%) pacientes y mantenido en 11 (30,55%) casos. Para fines de an&#225;lisis, los pacientes fueron divididos en tres grupos de acuerdo con el uso del betabloqueante: Grupo A (n=8) - los que no usaban BB en la admisi&#243;n; Grupo B (n=25) - los que usaban BB, sin embargo fue suspendido para iniciar la dobutamina; Grupo C (n=11) - los que usaron BB concomitante a la dobutamina.</p>
      <p>Los pacientes fueron controlados durante la internaci&#243;n, analiz&#225;ndose los d&#237;as necesarios para compensaci&#243;n, el tiempo que fue necesario mantener la dobutamina y la dosis de carvedilol con la cual el paciente tuvo alta.</p>
      <p>Se compararon los tres grupos en cuanto a las caracter&#237;sticas cl&#237;nicas, en cuanto al tiempo de uso del inotr&#243;pico y al tiempo de internaci&#243;n.</p>
      <p>Las variables continuas fueron presentadas por medio de media &#177; desv&#237;o est&#225;ndar, y las variables categ&#243;ricas, por medio de porcentajes. Se emple&#243; el test t para la comparaci&#243;n de los grupos. Los valores de P presentados son bicaudales, y fue adoptado un nivel de significancia &lt; 0,05.</p>
      <p>
        <bold>Resultados</bold>
      </p>
      <p>En la <xref ref-type="table" rid="t1-body3">Tabla 1</xref>, presentamos las principales caracter&#237;sticas de los pacientes estudiados.</p>
      <table-wrap id="t1-body3">
        <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt01-es.jpg"/></table-wrap>
      <p>La mayor&#237;a de los pacientes era del sexo masculino, con importante reducci&#243;n de la fracci&#243;n de eyecci&#243;n, gran dilataci&#243;n del VI y niveles de urea y creatinina discretamente elevados. El tiempo de internaci&#243;n fue prolongado, y los pacientes tuvieron alta con dosis m&#225;s elevadas de carvedilol que la de la admisi&#243;n. Ochenta y uno por ciento de los pacientes con IC descompensada estaban en uso de BB.</p>
      <p>En la <xref ref-type="table" rid="t2-body3">Tabla 2</xref>, presentamos las caracter&#237;sticas de los pacientes de acuerdo con los grupos. No hubo diferencia entre ellos en cuanto a la edad, fracci&#243;n de eyecci&#243;n, niveles de hemoglobina, sodio y potasio. Los pacientes del grupo que se internaron sin betabloqueante (Grupo A) presentaban niveles de urea y creatinina menores que los que se descompensaron y estaban en uso de betabloqueante (Grupos B y C). Los pacientes del Grupo C en que el betabloqueante fue mantenido durante el tratamiento para la compensaci&#243;n card&#237;aca presentaban mayor dilataci&#243;n ventricular.</p>
      <table-wrap id="t2-body3">
        <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt02-es.jpg"/></table-wrap>
      <p>EL tiempo de internaci&#243;n fue semejante en los tres grupos, pero los pacientes que no estaban en uso de betabloqueante en la internaci&#243;n (Grupo A) necesitaron inotr&#243;pico por tiempo m&#225;s prolongado que los pacientes que estaban en uso de betabloqueante en la llegada al Servicio de Emergencia (<xref ref-type="table" rid="t2-body3">Tablas 2</xref> y <xref ref-type="table" rid="t3-body3">3</xref>).</p>
      <table-wrap id="t3-body3">
        <graphic xlink:href="1678-4170-abc-95-04-0530-00108-gt03-es.jpg"/></table-wrap>
      <p>La dosis de carvedilol en el alta en el Grupo C fue mayor que la del grupo en que el carvedilol fue suspendido para la introducci&#243;n del inotr&#243;pico y de aquel que no lo estaba tomando en el momento de la internaci&#243;n.</p>
      <p>
        <bold>Discusi&#243;n</bold>
      </p>
      <p>La historia natural de la insuficiencia card&#237;aca, enfermedad con caracter&#237;sticas de malignidad, viene siendo modificada con el tratamiento moderno<sup>2,12</sup>. Los betabloqueantes, por medio de la reversi&#243;n de la remodelaci&#243;n card&#237;aca, mejoran la calidad de vida, son importantes en la reducci&#243;n de la mortalidad y vienen siendo identificados como el principal medicamento para el control de la IC<sup>2-4</sup>.</p>
      <p>Si no hay dudas sobre el valor del betabloqueante en el tratamiento de la IC cr&#243;nica, lo mismo no ocurre cuando el paciente se descompensa<sup>9,10</sup>. Con el creciente n&#250;mero de pacientes en uso de los betabloqueantes, crece tambi&#233;n el n&#250;mero de casos que presentan descompensaci&#243;n card&#237;aca en la vigencia del tratamiento optimizado y en uso de los betabloqueantes. En esa situaci&#243;n, &#191;Se debe suspender el betabloqueante, o puede ser mantenido? En nuestra instituci&#243;n, con base en el resultado de estudios que suger&#237;an que la suspensi&#243;n del betabloqueante o aun la reducci&#243;n podr&#237;an ser acompa&#241;adas de aumento de la mortalidad, se comenz&#243; a no suspender rutinariamente el medicamento en todos los cuadros de descompensaci&#243;n card&#237;aca. En este estudio, presentamos los resultados del an&#225;lisis de los pacientes hospitalizados para compensaci&#243;n card&#237;aca en 2005 que tuvieron o no el betabloqueante suspendido durante la compensaci&#243;n card&#237;aca.</p>
      <p>Son internados en nuestra instituci&#243;n pacientes con IC que no se compensaron o no mejoraron con el tratamiento administrado en el Servicio de Emergencia del <italic>Instituto do Cora&#231;&#227;o</italic>, habiendo, de esa forma, una selecci&#243;n de pacientes m&#225;s graves<sup>12</sup>. Esa casu&#237;stica fue constituida por pacientes en clase funcional IV, se&#241;ales de congesti&#243;n pulmonar y sist&#233;mica y con se&#241;ales de bajo d&#233;bito card&#237;aco. En el Servicio de Emergencia, todos tuvieron prescripci&#243;n de dobutamina frente a la presencia del bajo d&#233;bito y fueron hospitalizados para completar la compensaci&#243;n card&#237;aca. De los 44 pacientes con IC descompensada, ocho (18,18%) no estaban en uso de betabloqueante, y 36 (81,81%) estaban. Cuando la dobutamina fue prescripta, el betabloqueante fue suspendido en 25 (69,44%) y mantenido en 11 (30,55%) pacientes.</p>
      <p>Procuramos, en este estudio, verificar si la evoluci&#243;n durante la hospitalizaci&#243;n era diferente seg&#250;n la manutenci&#243;n o no del betabloqueante y si la asociaci&#243;n de la dobutamina con el betabloqueante podr&#237;a interferir en esa evoluci&#243;n.</p>
      <p>El primer punto que merece destacarse es la constataci&#243;n de que la mayor&#237;a de los pacientes que se descompensaron y procuraron el Servicio de Emergencia estaba en uso de betabloqueante (81,8%). Ese n&#250;mero est&#225; de acuerdo con el levantamiento realizado en nuestra instituci&#243;n, que revel&#243; que m&#225;s de 70% de los pacientes con IC del ambulatorio recib&#237;an prescripci&#243;n del BB<sup>5</sup>.</p>
      <p>La poblaci&#243;n estudiada en nuestro hospital es muy grave y, de modo general, necesita varios d&#237;as de internaci&#243;n para compensarse (media de 23 d&#237;as). Ese tiempo de internaci&#243;n es mayor que el descripto en otros estudios<sup>13-15</sup>. Es descripto que, en general, los pacientes permanecen hospitalizados de cuatro a cinco d&#237;as para compensarse, cuando el cuadro de IC no es grave, y alrededor de nueve d&#237;as para los m&#225;s graves<sup>13-15</sup>. En Rio de Janeiro, para pacientes atendidos en el Servicio de Emergencia de una instituci&#243;n privada, el tiempo de internaci&#243;n fue de 9,5 d&#237;as, y en Porto Alegre, en un Hospital Escuela como el nuestro, fue de 11 d&#237;as, ambos, tiempos menores que el nuestro<sup>14,15</sup>. La mayor gravedad de nuestros casos puede explicar, en parte, ese largo tiempo de permanencia en el hospital.</p>
      <p>No tenemos datos que estratifiquen la gravedad de la IC en los hospitales brasile&#241;os. En trabajo anterior, comparamos el perfil de nuestros pacientes con los del descripto en el Registro ADHERE americano<sup>12,16</sup>. Dividiendo nuestros casos seg&#250;n la estratificaci&#243;n del estudio ADHERE y comparando las dos cohortes, se observa que nuestra poblaci&#243;n es, en general, m&#225;s grave que aquella que particip&#243; del Registro ADHERE, pues 74,9% de los pacientes en nuestro hospital se internan con presi&#243;n arterial sist&#243;lica inferior a 115 mmHg, en cuanto en el Registro ADHERE apenas 18,5% eran hipotensos<sup>12,16</sup>. De esta forma, nuestra mayor gravedad es una de las explicaciones para el tiempo m&#225;s prolongado de internaci&#243;n y necesidad de inotr&#243;pico.</p>
      <p>En el an&#225;lisis del tiempo de internaci&#243;n, se observa que los pacientes que no usaban betabloqueante al descompensarse permanecieron m&#225;s tiempo hospitalizados (28,37 &#177; 12,76 d&#237;as) y recibieron dobutamina por tiempo m&#225;s prolongado (15,37 &#177; 4,45 d&#237;as) que los otros dos grupos. El tiempo medio de internaci&#243;n fue 24% mayor en los pacientes del Grupo A que en los pacientes que estaban siendo tratados con betabloqueante, que fue suspendido posteriormente, y 39% mayor que para el grupo en que el betabloqueante fue mantenido. En cuanto al tiempo de inotr&#243;pico, en los pacientes que se descompensaron y no estaban en uso de BB, fue 82% superior que en el Grupo B y casi el doble l que en el Grupo C (94%). Las diferencias no alcanzaron significancia estad&#237;stica, pero la diferencia num&#233;rica absoluta fue grande. Es interesante se&#241;alar que el grupo que no estaba recibiendo el betabloqueante al llegar al Servicio de Emergencia presentaba niveles de urea y creatinina m&#225;s bajos que el grupo que estaba en uso del BB. El no uso del BB no parece haber ocurrido en raz&#243;n de que estos pacientes ten&#237;an cuadros de IC m&#225;s acentuada o m&#225;s grave.</p>
      <p>Nuestros resultados mostraron que estar en uso de betabloqueante al descompensarse no indica que la compensaci&#243;n ser&#225; m&#225;s dif&#237;cil. Los pacientes tratados con betabloqueantes necesitaron menos tiempo de inotr&#243;pico para la compensaci&#243;n y permanecieron, en total, menos tiempo internados que los sin betabloqueante (20,36 &#177; 11,04 d&#237;as y 22,80 &#177; 10,31 d&#237;as <italic>vs</italic> 28,37 &#177; 12,76 d&#237;as). Ese hallazgo permite inferir que estar en uso de betabloqueante al descompensarse no identifica un grupo m&#225;s grave o un grupo en que ser&#225; m&#225;s trabajosa la compensaci&#243;n card&#237;aca. No hubo diferencia en la prescripci&#243;n de diur&#233;ticos o vasodilatadores para la compensaci&#243;n en los tres grupos.</p>
      <p>Cuando se comparan los grupos en que el betabloqueante fue suspendido al iniciarse la infusi&#243;n de dobutamina con el grupo en que el betabloqueante fue mantenido durante la infusi&#243;n, no hubo diferencia significativa entre ellos. En cuanto al tiempo de uso del inotr&#243;pico, as&#237; como al tiempo de internaci&#243;n total, aunque los n&#250;meros absolutos hayan sido menores en el grupo en que el betabloqueante fue mantenido, no hubo significancia estad&#237;stica (<xref ref-type="table" rid="t2-body3">Tablas 2</xref> y <xref ref-type="table" rid="t3-body3">3</xref>). Ese hallazgo permite suponer que la no suspensi&#243;n del betabloqueante no influencia negativamente en la evoluci&#243;n de los casos.</p>
      <p>Sin duda, contribuye al tiempo prolongado de internaci&#243;n la conducta de introducir y optimizar la dosis del betabloqueante durante la hospitalizaci&#243;n. Cuando analizamos los tres grupos, podemos observar que los pacientes permanecieron hospitalizados por cerca de 13 d&#237;as despu&#233;s de la suspensi&#243;n del inotr&#243;pico. Si retiramos esos 13 d&#237;as del tiempo total de internaci&#243;n, podr&#237;amos verificar que el tiempo restante no difiere de los descriptos en los hospitales brasile&#241;os<sup>12,14,15</sup>.</p>
      <p>Mientras tanto, con esa conducta, fue posible darle el alta a los pacientes con dosis eficaz de carvedilol. La dosis media del alta fue 26,84 &#177; 17,14 mg/d&#237;a, o sea, en media, 12,5 mg, dos veces al d&#237;a. Cuando comparamos los tres grupos, pudimos constatar que la dosis del Grupo C, en el cual el betabloqueante no fue suspendido durante el uso de la dobutamina y de la compensaci&#243;n card&#237;aca, fue significativamente mayor que la de los otros dos grupos, de los que se internaron sin prescripci&#243;n del betabloqueante y de aquellos en que la medicaci&#243;n fue suspendida. La dosis del grupo C fue 34% mayor que la del grupo que no estaba tomando betabloqueante en el Servicio de Emergencia y 55% mayor que en el grupo en que el carvedilol fue suspendido al introducirse la dobutamina (35,79 &#177; 17,25 mg/d&#237;a <italic>vs</italic> 26,56 &#177; 18,83 mg/d&#237;a y 23,00 &#177; 16,08 mg/d&#237;a).</p>
      <p>En la literatura, crecen los art&#237;culos que documentan que la no suspensi&#243;n de los betabloqueantes en la descompensaci&#243;n card&#237;aca es acompa&#241;ada de mejor evoluci&#243;n. El primero de ellos fue el art&#237;culo de Metra et al<sup>6</sup>, que, con base en los datos del estudio COMET, constataron una reducci&#243;n de mortalidad de 59% para los pacientes que tuvieron la dosis mantenida en relaci&#243;n a los cuales su dosis fue reducida o suspendida<sup>6</sup>. Es interesante observar que en el estudio COMET, 8% tuvieron el betabloqueante suspendido, y 22%, una reducci&#243;n de la dosis, siendo la dosis mantenida en 70% de los casos. Sin duda, se debe considerar la forma de presentaci&#243;n de la descompensaci&#243;n. En esos casos, la casi totalidad no present&#243; cuadro de bajo d&#233;bito como los nuestros, pero lo importante es que solamente 30% de los casos tuvieron la dosis reducida o suspendida, hallazgo que indica que es posible mantener el BB en la descompensaci&#243;n card&#237;aca y que la mayor&#237;a evolucion&#243; bien sin la suspensi&#243;n. En ese estudio, el tiempo de internaci&#243;n de los pacientes que tuvieron el betabloqueante suspendido fue de 27 &#177; 53 d&#237;as. En aquellos en que la dosis del betabloqueante fue reducida, 11 &#177; 9 d&#237;as, y, en los que tuvieron la dosis del betabloqueante mantenida durante la descompensaci&#243;n, 9 &#177; 8 d&#237;as.</p>
      <p>Orso et al<sup>7</sup> en el Registro Italiano documentaron que el no uso de betabloqueante o la suspensi&#243;n en la internaci&#243;n del paciente fueron asociados al aumento de la mortalidad, confirmada por el an&#225;lisis multivariado<sup>7</sup>. Identificaron que los pacientes que se internaron sin betabloqueante y no lo recibieron en la hospitalizaci&#243;n presentaron un riesgo de vida de 3,28 veces mayor que el grupo que estaba en uso del BB y &#233;ste fue mantenido. Observaron tambi&#233;n que para aquellos en uso del BB y que lo suspendieron en la internaci&#243;n, ocurri&#243; un aumento de 4,20 veces en el riesgo de vida<sup>7</sup>.</p>
      <p>Fonarow et al<sup>8</sup>, en el Programa OPTIMIZE-HF, identificaron que 56,9% de los pacientes estaban en uso de betabloqueante al descompensarse y que lo suspendieron en solamente 3,3% de los casos<sup>8</sup>. En el alta, 26,6% comenzaron a recibir el medicamento. Constataron que mantener el betabloqueante estuvo asociado a la reducci&#243;n del riesgo de muerte de 40% en relaci&#243;n a los sin betabloqueante. En contraste, la suspensi&#243;n del betabloqueante fue asociada con el aumento del riesgo de vida de 2,3 veces en relaci&#243;n a los que continuaron con la medicaci&#243;n.</p>
      <p>Jondeau et al<sup>17</sup> recientemente publicaron el estudio B-CONVINCED, muy parecido al nuestro, sin embargo con pacientes menos graves. Analizaron, prospectivamente, 147 pacientes que se internaron con insuficiencia card&#237;aca descompensada, fracci&#243;n de eyecci&#243;n menor de 40%, previamente en uso de betabloqueante<sup>17</sup>. Los pacientes fueron divididos en dos grupos, seg&#250;n la manutenci&#243;n de la dosis del BB en la internaci&#243;n o no. Despu&#233;s de tres d&#237;as de evoluci&#243;n, no hubo diferencia entre los grupos en cuanto a la compensaci&#243;n de la insuficiencia card&#237;aca. M&#225;s importante, no hubo diferencia en los niveles de BNP, rehospitalizaci&#243;n y mortalidad en tres meses. Seg&#250;n nuestro estudio, los pacientes del B-CONVINCED que mantuvieron el BB durante la descompensaci&#243;n estaban en uso de dosis superiores de la medicaci&#243;n tres meses despu&#233;s del alta hospitalaria (90% <italic>vs</italic> 76%)<sup>17</sup>.</p>
      <p>Esos resultados dan sustrato para que no se suspenda rutinariamente el BB cuando el paciente se descompensa. Es importante resaltar que, en esos estudios, la mayor&#237;a de los pacientes no presentaba se&#241;ales de bajo d&#233;bito y probablemente no recibi&#243; inotr&#243;picos para la compensaci&#243;n. Aun, hubo mejora en la sobrevida a medio y largo plazos y no durante la internaci&#243;n. Sin embargo, el paciente que recebe alta hospitalaria en uso de dosis m&#225;s alta de betabloqueante tambi&#233;n se beneficiar&#225; a medio y largo plazos.</p>
      <p>Nuestros datos ampl&#237;an esa indicaci&#243;n, mostrando que, para los pacientes descompensados con se&#241;ales de bajo d&#233;bito que necesitan tratamiento con inotr&#243;picos, tambi&#233;n es posible mantener el BB, pero esa conducta no fue acompa&#241;ada de mayor dificultad en la compensaci&#243;n de los pacientes. En realidad, los datos sugieren que los pacientes respondieron bien a la conducta, necesitando menor tiempo de inotr&#243;pico y de internaci&#243;n para compensaci&#243;n.</p>
      <p>No suspender el BB facilita la optimizaci&#243;n del tratamiento en el momento del alta. Considerando que muchos m&#233;dicos contin&#250;an con recelo de prescribirlo y, cuando lo hacen, recurren a dosis bajas, especialmente en pacientes que se descompensaron y necesitaron de soporte inotr&#243;pico para compensaci&#243;n, dar alta con el tratamiento optimizado es fundamental para que el paciente pueda tener el beneficio de ese tipo de tratamiento.</p>
      <p>En la literatura, hay varios trabajos que muestran que iniciar el BB durante la internaci&#243;n aumenta la tasa de la prescripci&#243;n, aumento ese acompa&#241;ado de mejor evoluci&#243;n<sup>18-20</sup>. Entre esos, tenemos el estudio IMPACT, que comprob&#243; que la conducta de iniciar el BB en la internaci&#243;n fue asociada a la reducci&#243;n de mortalidad<sup>19</sup>.</p>
      <p>En la misma l&#237;nea de investigaci&#243;n, Fowler et al<sup>20</sup> identificaron que aun es grande el n&#250;mero de pacientes que no est&#225; recibiendo BB en dosis correcta, comprobando que 55% est&#225;n siendo tratados con dosis inferior a 25 mg, dos veces al d&#237;a, y 9% tuvieron la medicaci&#243;n discontinuada<sup>20</sup>. Constataron que cerca de 30% de los pacientes no recibieron prescripci&#243;n de BB en el control, y la no prescripci&#243;n tuvo como principal causa el no comienzo despu&#233;s de la hospitalizaci&#243;n<sup>20</sup>.</p>
      <p>Esos datos llaman la atenci&#243;n hacia la importancia de iniciar el tratamiento con BB durante la hospitalizaci&#243;n. En nuestro servicio, ampliamos esa conducta manteniendo el paciente internado por algunos d&#237;as m&#225;s y procurando darle el alta con el tratamiento optimizado, una vez que se observa reducci&#243;n en la tasa de rehospitalizaci&#243;n y de la mortalidad y que esa reducci&#243;n es tanto mayor cuanto mayor la dosis del BB prescripto. Con esa conducta, pudimos optimizar el tratamiento de todos, y la mayor&#237;a tuvo alta con dosis superior a 12,5 mg de carvedilol, dos veces al d&#237;a (26,84 &#177; 17,24 mg/d&#237;a).</p>
      <p>Con la no suspensi&#243;n del BB en la internaci&#243;n, los pacientes alcanzaron con la optimizaci&#243;n dosis m&#225;s elevadas del BB (35,79 &#177; 17,25 mg/d&#237;a).</p>
      <p>En conclusi&#243;n, es posible mantener el BB durante la descompensaci&#243;n card&#237;aca, aun en pacientes con se&#241;ales de bajo d&#233;bito que necesitaron soporte inotr&#243;pico. Esa conducta no fue acompa&#241;ada de peor evoluci&#243;n. Pudimos observar que fue posible utilizar dobutamina y BB asociados y que la evoluci&#243;n de esos pacientes fue semejante a la de aquellos en que el BB fue suspendido. Al no suspender el BB, los pacientes pudieron tener el alta con dosis optimizadas de la medicaci&#243;n.</p>
      <p>Esa conducta puede tener impacto en la sobrevida, una vez que el tratamiento optimizado es acompa&#241;ado de mejor evoluci&#243;n. Sin duda, son necesarios estudios con casu&#237;stica mayor y en que los pacientes sean controlados para poder comprobar esta hip&#243;tesis.</p>
      <p>
        <bold>Limitaciones del estudio</bold>
      </p>
      <p>Se trata de un estudio no randomizado y observacional. Aunque la diferencia entre los grupos sea evidente, no alcanz&#243; significancia probablemente por el tama&#241;o de la muestra. Estudios randomizados son necesarios para aclarar el problema.</p>
      <p>
        <bold>Potencial Conflicto de Intereses</bold>
      </p>
      <p>Declaro no haber conflicto de intereses pertinentes.</p>
      <p>
        <bold>Fuentes de Financiamiento</bold>
      </p>
      <p>El presente estudio no tuvo fuentes de financiamiento externas.</p>
      <p>
        <bold>Vinculaci&#243;n Acad&#233;mica</bold>
      </p>
      <p>No hay vinculaci&#243;n de este estudio a programas de post-grado.</p>
      <p>
        <bold>Referencias</bold>
      </p>
    </body>
  </sub-article>
</article>
