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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">Q6khdZ4BHrthtw4GK75th5f</article-id>
      <article-id pub-id-type="other">00010</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2007001500010</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v1">S0066-782X(07)08900310</article-id>
      <article-id pub-id-type="doi">10.1590/S0066-782X2007001500010</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Ponto de Vista</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Estaria a press&#227;o diast&#243;lica perdendo sua utilidade na cl&#237;nica?</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Luna</surname>
            <given-names>Rafael Leite</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Luna</surname>
            <given-names>Leonardo Castro</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
      </contrib-group>
      <aff id="aff01">
        <addr-line>
          <named-content content-type="city">Rio de Janeiro</named-content>
          <named-content content-type="state">RJ</named-content>
        </addr-line>
        <institution content-type="orgname">Hospital das Cl&#237;nicas de Jacarepagu&#225;</institution>
        <institution content-type="orgdiv1">Instituto de P&#243;s-Gradua&#231;&#227;o M&#233;dica Carlos Chagas </institution>
        <country country="BR">Brasil</country>
      </aff>
      <pub-date date-type="collection" publication-format="electronic">
        <month>09</month>
        <year>2007</year>
      </pub-date>
      <volume>89</volume>
      <issue>3</issue>
      <fpage>e19</fpage>
      <lpage>e21</lpage>
      <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>
      <pub-date publication-format="electronic" date-type="pub">
        <day>25</day>
        <month>09</month>
        <year>2007</year>
      </pub-date>
    </article-meta>
  </front>
  <body>
    <p>
      <bold>PONTO DE VISTA</bold>
    </p>
    <p>Estaria a press&#227;o diast&#243;lica perdendo sua utilidade na cl&#237;nica? </p>
    <p>
      <bold>Rafael Leite Luna; Leonardo Castro Luna</bold>
    </p>
    <p> Instituto de P&#243;s-Gradua&#231;&#227;o M&#233;dica Carlos Chagas - Hospital das Cl&#237;nicas de Jacarepagu&#225; - Rio de Janeiro, RJ - Brasil</p>
    <p>
      <xref ref-type="corresp" rid="end">Correspond&#234;ncia</xref>
    </p>
    <p><bold>Palavras-chave: </bold>Press&#227;o arterial/&#233;tica, hipertens&#227;o, seguimentos.</p>
    <p>A medicina est&#225; sempre em evolu&#231;&#227;o e novos estudos e pesquisas nos mostram, com freq&#252;&#234;ncia, fatos que p&#245;em em d&#250;vida antigos dogmas: &#233; o caso, no momento, da press&#227;o diast&#243;lica. </p>
    <p>Tradicionalmente, a hipertens&#227;o arterial &#233; dividida em duas categorias cl&#237;nicas principais: a hipertens&#227;o sist&#243;lica isolada, mais comum e atributo da idade; e a hipertens&#227;o sist&#243;lica e diast&#243;lica combinadas, menos comum<sup>1</sup>. Ultimamente, uma s&#233;rie de trabalhos p&#244;s em d&#250;vida a utilidade cl&#237;nica da press&#227;o diast&#243;lica, como veremos a seguir.</p>
    <p>Todos n&#243;s, de uma gera&#231;&#227;o anterior, quando l&#237;amos o resultado de um ensaio terap&#234;utico, j&#225; sab&#237;amos que ele estava sempre baseado na cifra diast&#243;lica; o mesmo acontecia quando avali&#225;vamos o resultado de um tratamento anti-hipertensivo.</p>
    <p>Os m&#233;dicos tinham, no &#250;ltimo s&#233;culo, a tend&#234;ncia de estimar a eleva&#231;&#227;o da press&#227;o diast&#243;lica como fator mais importante do que a da cifra sist&#243;lica, isso baseado na cren&#231;a de que ela estava mais bem relacionada &#224; les&#227;o dos org&#227;os-alvo, o que, hoje em dia, n&#227;o est&#225; se confirmando.</p>
    <p>Em 1920, quando a press&#227;o come&#231;ou a ser freq&#252;entemente medida, a diast&#243;lica j&#225; era tida como a mais importante e, embora essa prefer&#234;ncia nunca tivesse sido devidamente justificada, esse tipo de pensamento prevaleceu durante boa parte do s&#233;culo XX.</p>
    <p>Assim foi com cada ensaio ou estudo cl&#237;nico, desde o primeiro, at&#233; ao Systolic Hypertension in the Elderly Program (SHEP), em 1991<sup>2</sup>.</p>
    <p>Segundo Safar, nos ensaios que avaliavam os benef&#237;cios do tratamento anti-hipertensivo, a press&#227;o diast&#243;lica era escolhida como o &#250;nico crit&#233;rio de inclus&#227;o de pacientes; conseq&#252;entemente, se a press&#227;o sist&#243;lica estivesse elevada e a diast&#243;lica normal eles eram exclu&#237;dos dos ensaios e, portanto, n&#227;o analisados<sup>3</sup>. Essa deforma&#231;&#227;o de planejamento introduzia um erro de avalia&#231;&#227;o n&#227;o somente na sele&#231;&#227;o dos pacientes, mas tamb&#233;m no fim do seguimento cl&#237;nico, pois a press&#227;o diast&#243;lica poderia ser normalizada, mas n&#227;o se apreciava a press&#227;o sist&#243;lica.</p>
    <p>Esse fato ficou muito claro no estudo HOT, que avaliava pacientes de meia-idade com hipertens&#227;o sist&#243;lica e diast&#243;lica combinadas; no fim do ensaio, apesar de a press&#227;o diast&#243;lica estar rigorosamente controlada, constatou-se o fraco resultado da medica&#231;&#227;o em termos de risco cardiovascular, e a raz&#227;o foi atribu&#237;da &#224; falta de controle da press&#227;o sist&#243;lica, a qual n&#227;o era, diga-se de passagem, o objetivo do trabalho<sup>4</sup>.</p>
    <p>Na d&#233;cada de 50 do s&#233;culo passado, segundo Kaplan, as companhias de seguro j&#225; chamavam a aten&#231;&#227;o para o fato de que n&#237;veis sist&#243;licos elevados eram um risco &#224; sa&#250;de cardiovascular, mas isso n&#227;o foi levado em considera&#231;&#227;o<sup>1</sup>.</p>
    <p>No ano de 1971, uma publica&#231;&#227;o do estudo de Framingham documentou, pela primeira vez, com toda a sua autoridade, o grande valor preditivo da press&#227;o sist&#243;lica para as doen&#231;as cardiovasculares. Os dados desse estudo, baseados em 30 anos de evolu&#231;&#227;o de uma coorte, relacionou o grau de desenvolvimento da doen&#231;a cardiovascular com a press&#227;o sist&#243;lica, em todas as idades e em ambos os sexos<sup>5</sup>. A bem da verdade, j&#225; havia ind&#237;cios desde os estudos originais de press&#227;o arterial, na primeira metade do s&#233;culo passado, sobre a import&#226;ncia da cifra sist&#243;lica; n&#227;o se sabia bem por que isso n&#227;o era devidamente reconhecido<sup>6</sup>.</p>
    <p>Influenciado pelos trabalhos aqui citados, o Programa Nacional de Educa&#231;&#227;o em Hipertens&#227;o, dos Estados Unidos, recomendou, em 1990, que a press&#227;o sist&#243;lica tivesse um papel mais importante no diagn&#243;stico e tratamento da hipertens&#227;o arterial<sup>7</sup>.</p>
    <p>Sabe-se, hoje em dia, que a hipertens&#227;o sist&#243;lica isolada est&#225; presente em dois ter&#231;os dos pacientes com mais de 60 anos, o grupo et&#225;rio que, atualmente, segundo Staessen e cols., tamb&#233;m inclui a maioria dos hipertensos<sup>8</sup>.</p>
    <p>Um dos problemas existentes na avalia&#231;&#227;o da press&#227;o sist&#243;lica, em pacientes idosos, &#233; a sua queda na disfun&#231;&#227;o ventricular esquerda, dificultando a defini&#231;&#227;o do seu devido n&#237;vel, embora exista, sempre, uma hist&#243;ria bem evidente de que havia uma hipertens&#227;o na hist&#243;ria pregressa do paciente.</p>
    <p>Em 1995, o famoso levantamento epidemiol&#243;gico NHANES III, dos Estados Unidos, mostrou dados fundamentais e de grande import&#226;ncia, demonstrando que as press&#245;es sist&#243;lica e diast&#243;lica se elevam normal e continuamente, durante a vida, at&#233; os 50 anos na maioria dos indiv&#237;duos; ap&#243;s essa idade, a press&#227;o sist&#243;lica continua se elevando, por&#233;m a press&#227;o diast&#243;lica sofre, de modo geral, uma tend&#234;ncia a queda<sup>9</sup>. Asmar e cols. pensam que essas mudan&#231;as s&#227;o devidas ao aumento da rigidez da aorta e das grandes art&#233;rias, e possivelmente t&#234;m raz&#227;o<sup>10</sup>.</p>
    <p>No momento atual, reconhece-se a press&#227;o sist&#243;lica como o melhor preditor de risco cardiovascular ap&#243;s a idade de 50 anos<sup>11</sup>; corroborando esse dado, o grande ensaio Prospective Studies Collaboration mostrou que, entre os 40 e os 90 anos, a press&#227;o sist&#243;lica &#233; mais preditiva do risco de morte na doen&#231;a isqu&#234;mica do cora&#231;&#227;o do que a press&#227;o diast&#243;lica<sup>12</sup>.</p>
    <p>Como acabamos de comentar, no &#250;ltimo quarto do s&#233;culo, v&#225;rios estudos epidemiol&#243;gicos valorizaram a press&#227;o sist&#243;lica como a mais importante em rela&#231;&#227;o ao risco cardiovascular, principalmente nas pessoas idosas. Contudo, s&#243; na d&#233;cada de 1990 foi registrada uma mudan&#231;a na mentalidade m&#233;dica dando-se, desde ent&#227;o, mais &#234;nfase &#224; press&#227;o sist&#243;lica do que &#224; diast&#243;lica, tanto do ponto de vista diagn&#243;stico como do de classifica&#231;&#227;o e manejo da press&#227;o arterial.</p>
    <p>Em pessoas com menos de 45 anos a hipertens&#227;o sist&#243;lica isolada &#233; rara, mas, nessa idade, podem ocorrer press&#245;es diast&#243;licas isoladamente elevadas com sist&#243;licas normais; contudo, elas s&#227;o uma minoria, como vemos na <xref ref-type="table" rid="tab01">tabela 1</xref>.</p>
    <table-wrap id="tab01">
      <graphic xlink:href="1678-4170-abc-89-03-0e19-00010-gt01.jpg"/></table-wrap>
    <p>Uma das raz&#245;es alegadas no s&#233;culo passado, para a import&#226;ncia cl&#237;nica dada &#224; cifra diast&#243;lica, era a de que as art&#233;rias estariam expostas por mais tempo &#224; press&#227;o durante o per&#237;odo diast&#243;lico do que durante o per&#237;odo sist&#243;lico; devemos, contudo, chamar a aten&#231;&#227;o de que durante a di&#225;stole a press&#227;o transmural vai progressivamente decaindo at&#233; o in&#237;cio da s&#237;stole. Outra raz&#227;o alegada no passado, do ponto de vista cl&#237;nico, era a de que a circula&#231;&#227;o coronariana, dando-se no per&#237;odo diast&#243;lico, era mais influenciada pelo n&#237;vel de press&#227;o nesse per&#237;odo; importante, portanto, para determinar a integridade das art&#233;rias coron&#225;rias. Devemos, contudo, lembrar novamente que, durante a di&#225;stole, h&#225; uma queda cont&#237;nua da press&#227;o arterial e &#233; poss&#237;vel que n&#227;o seja a cifra diast&#243;lica o fator importante para explicar a coronariopatia, por&#233;m outros fatores a&#237; envolvidos, tais como a fun&#231;&#227;o endotelial, o n&#237;vel de lip&#237;dios ou a trombofilia, sendo necess&#225;rio que os n&#237;veis tensionais sejam ajustados para que eles possam ser valorizados.</p>
    <p>Sabemos que a press&#227;o sist&#243;lica depende, na sua eleva&#231;&#227;o, do aumento do d&#233;bito sist&#243;lico, da eleva&#231;&#227;o da resist&#234;ncia perif&#233;rica ou da rigidez das grandes art&#233;rias.</p>
    <p>N&#227;o se tem estudado particularmente, do ponto de vista fisiopatol&#243;gico, a press&#227;o diast&#243;lica; sabe-se que ela se eleva com o aumento da resist&#234;ncia perif&#233;rica, mas, diferentemente da sist&#243;lica, ela baixa com a rigidez das grandes art&#233;rias; teoricamente, portanto, a press&#227;o diast&#243;lica pode ser normal porque as influ&#234;ncias exercidas pela resist&#234;ncia perif&#233;rica e pela rigidez a&#243;rtica podem se anular mutuamente, embora devamos chamar a aten&#231;&#227;o de que essas altera&#231;&#245;es arteriais sejam, <italic>per si</italic>, fatores de risco.</p>
    <p>Para nossa surpresa, j&#225; no fim do s&#233;culo passado apareceram trabalhos cient&#237;ficos que puseram em d&#250;vida a id&#233;ia arraigada, estabelecida durante os &#250;ltimos cem anos, de que a press&#227;o diast&#243;lica elevada representava o mesmo risco cardiovascular da hipertens&#227;o sist&#243;lica; esses trabalhos contrariavam o pensamento m&#233;dico predominante, fruto de muitos anos de uma avalia&#231;&#227;o m&#233;dica duvidosa.</p>
    <p>Em 1995, Alderman e seu grupo de Nova York publicaram o primeiro artigo informando que pacientes jovens e de meia-idade (&lt;60 anos), cujo dist&#250;rbio cardiovascular era a eleva&#231;&#227;o da press&#227;o diast&#243;lica, tinham melhor progn&#243;stico do que aqueles com a eleva&#231;&#227;o combinada da sist&#243;lica e da diast&#243;lica com risco mais alto de infarto do mioc&#225;rdio. Al&#233;m disso, quando os pacientes com hipertens&#227;o diast&#243;lica isolada eram estratificados de acordo com o n&#237;vel de press&#227;o sist&#243;lica, isto &#233;, abaixo e acima de 140 mmHg, o infarto do mioc&#225;rdio s&#243; ocorria com a sist&#243;lica acima de 140 mmHg, qualquer que fosse o n&#237;vel da diast&#243;lica (90 a 115 mmHg), e mesmo se os pacientes tivessem os n&#237;veis de colesterol e glicose, o n&#250;mero de cigarros e o sexo ajustados pela an&#225;lise multivariada, a associa&#231;&#227;o com infarto s&#243; se dava quando houvesse hipertens&#227;o sist&#243;lica e diast&#243;lica combinadas e n&#227;o com a hipertens&#227;o diast&#243;lica isolada<sup>13</sup>.</p>
    <p>No ano 2000, um grupo do Jap&#227;o, Hozawa e cols., num trabalho com 1.913 pacientes de 40 ou mais anos, seguidos por mais de oito anos, mostrou que a hipertens&#227;o diast&#243;lica isolada tem baixo risco de mortalidade cardiovascular, semelhante &#224;quele dos indiv&#237;duos com press&#227;o normal, sugerindo que o progn&#243;stico da hipertens&#227;o deveria estar baseado no n&#237;vel sist&#243;lico, e n&#227;o no n&#237;vel diast&#243;lico<sup>14</sup>.</p>
    <p>Em 2001, Benetos e cols.<sup>15</sup> fizeram, em Paris, com 77.023 homens e 48.480 mulheres, um amplo estudo relacionado ao risco que ofereciam as hipertens&#245;es sist&#243;lica e diast&#243;lica. Desse estudo surgiram interessantes conclus&#245;es: 1. em homens e mulheres com press&#227;o sist&#243;lica normal (&lt;140 mmHg), a press&#227;o diast&#243;lica n&#227;o era uma determinante da mortalidade cardiovascular, mesmo depois de ajustada para a idade e n&#237;vel de press&#227;o sist&#243;lica; 2. nos homens com hipertens&#227;o sist&#243;lica isolada foram observadas as mais altas taxas de mortalidade; 3. nas mulheres com hipertens&#227;o sist&#243;lica isolada havia tamb&#233;m uma alta taxa de mortalidade que aumentava se a press&#227;o diast&#243;lica estivesse tamb&#233;m elevada.<sup>15</sup></p>
    <p>Strandberg e cols.<sup>16</sup>, no ano de 2002, estudando uma coorte de 342 pacientes com hipertens&#227;o diast&#243;lica isolada observada por eles durante 32 anos, n&#227;o encontraram nenhum aumento de mortalidade cardiovascular, desde que n&#227;o houvesse a eleva&#231;&#227;o combinada das press&#245;es diast&#243;lica e sist&#243;lica, quando a mortalidade cardiovascular aumentava 2,7 vezes mais, mostrando, de maneira clara, que o risco s&#243; aparecia quando a cifra sist&#243;lica estivesse, tamb&#233;m, elevada<sup>16</sup>.</p>
    <p>Da mesma maneira, Pickering n&#227;o encontrou aumento do risco cardiovascular na eleva&#231;&#227;o isolada da press&#227;o diast&#243;lica, dizendo, de maneira taxativa: "N&#227;o h&#225; no momento, absolutamente, nenhuma indica&#231;&#227;o para o tratamento da hipertens&#227;o diast&#243;lica isolada"<sup>17</sup>. </p>
    <p>Conforme a press&#227;o sist&#243;lica veio crescendo de import&#226;ncia, um grande n&#250;mero de estudos sobre a press&#227;o de pulso e seu valor progn&#243;stico foi aparecendo, principalmente no grupo de Framingham que, agora mesmo, publicou um brilhante trabalho correlacionando a fibrila&#231;&#227;o atrial &#224; press&#227;o de pulso<sup>18</sup>; contudo, em rela&#231;&#227;o a essa press&#227;o, temos seguido as id&#233;ias de Pastor-Barriuso e cols. que, baseados nos dados do NHANES, t&#234;m inferido que: "A complexidade da associa&#231;&#227;o entre a press&#227;o de pulso e a mortalidade tem desencorajado seu uso em rela&#231;&#227;o ao progn&#243;stico ou as decis&#245;es terap&#234;uticas"<sup>19</sup>.</p>
    <p>Raciocinando de modo simplista, e especulando que n&#227;o existiria risco na eleva&#231;&#227;o da press&#227;o diast&#243;lica, concluir&#237;amos que n&#227;o haveria tamb&#233;m dano aos &#243;rg&#227;os-alvo em raz&#227;o somente ao aumento isolado dessa press&#227;o; esse tipo de racioc&#237;nio necessita ser devidamente demonstrado e comprovado, pois a id&#233;ia aceita, tradicionalmente, &#233; a de que a eleva&#231;&#227;o da press&#227;o diast&#243;lica prejudicaria o c&#233;rebro, o cora&#231;&#227;o e o rim, do mesmo modo como o aumento da press&#227;o sist&#243;lica o faz.</p>
    <p>Essa s&#233;rie de trabalhos nos aponta para uma poss&#237;vel futura desclassifica&#231;&#227;o do valor cl&#237;nico da cifra diast&#243;lica, pois, pelos estudos descritos, n&#227;o se encontrou risco de morte nos pacientes com hipertens&#227;o diast&#243;lica isolada seguida, por vezes, durante muitos anos. Somente aqueles pacientes que apresentassem, tamb&#233;m, eleva&#231;&#227;o da cifra sist&#243;lica seriam os que correriam risco.</p>
    <p>Todos esses estudos levaram Beevers, na Inglaterra, a declarar, ultimamente, que alguns cl&#237;nicos e epidemiologistas v&#234;m questionando se ainda vale a pena medir a press&#227;o diast&#243;lica, tal a destacada import&#226;ncia da press&#227;o sist&#243;lica como sinal preditor de risco cardiovascular e a nega&#231;&#227;o rec&#237;proca da press&#227;o diast&#243;lica como risco cardiovascular<sup>20</sup>.</p>
    <p>Mesmo ap&#243;s todas essas evid&#234;ncias, manda a salutar prud&#234;ncia que, ap&#243;s um s&#233;culo acompanhando a press&#227;o arterial de maneira tradicional, devamos, ainda hoje, continuar a dar a devida aten&#231;&#227;o &#224; cifra diast&#243;lica, embora os resultados aqui relatados comecem a levantar d&#250;vidas sobre sua real necessidade. </p>
    <p>Desse modo, sendo a press&#227;o sist&#243;lica comprovadamente importante ap&#243;s os 50 anos e n&#227;o se registrando risco cardiovascular com a hipertens&#227;o diast&#243;lica isolada, pergunta-se: - Qual a necessidade da medida da cifra diast&#243;lica na pr&#225;tica cl&#237;nica di&#225;ria?</p>
    <p>
      <bold>Potencial Conflito de Interesses</bold>
    </p>
    <p>Declaro n&#227;o haver conflitos de interesses pertinentes.</p>
    <p>
      <bold>Fontes de Financiamento</bold>
    </p>
    <p>O presente estudo n&#227;o teve fontes de financiamento externas.</p>
    <p>
      <bold>Vincula&#231;&#227;o Acad&#234;mica</bold>
    </p>
    <p>N&#227;o h&#225; vincula&#231;&#227;o desse estudo a programas de p&#243;s-gradua&#231;&#227;o.</p>
    <p>
      <bold>Refer&#234;ncias</bold>
    </p>
    <p>1. Kaplan NM. Clinical hypertension. 9th ed. Philadelphia: Lippincott; 2006. p. 123.</p>
    <p>2. SHEP Cooperative Research Group. Final results of the systolic hypertension in the elderly. JAMA. 1991; 265: 3255-64.</p>
    <p>3. Safar ME. Therapeutic trials and large arteries in hypertension. Am Heart J. 1988; 115: 702-10.</p>
    <p>4. Hansson C, Zanchetti A, Carruthers SG, Dahlof B, Elmfeldt D, Julius S, et al. for the HOT Study Group. Effects of intensive blood pressure lowering and low dose aspirin in patients with hypertension. Lancet. 1998; 351: 1755-62.</p>
    <p>5. Kannel WB, Gordon T, Schwartz MJ. Systolic versus diastolic blood pressure and risk of coronary heart disease. Am J Cardiol. 1971; 27: 335-46.</p>
    <p>6. Swales JD. Systolic versus diastolic pressure. J Hum Hypertens. 2000; 14: 477-9.</p>
    <p>7. Izzo JL, Levy D, Black HR. Clinical advisor statement: interpretation of systolic blood pressure in older americans. Hypertension. 2000; 35: 1021-4.</p>
    <p>8. Staessen JA, Thyrs L, Fajard R, O'Brien ET, Clement D, de Leeuw PW, et al. Predicting cardiovascular risk using conventional vs ambulatory blood pressure in older patients with systolic hypertension. JAMA. 1999; 282: 539-46.</p>
    <p>9. Burt VL, Whelton P, Roccella EJ, Brown G, Cutler JP, Higgins M, et al. Prevalence of hypertension in the US adult population: results from the Third National Health and Nutrition Examination Survey 1988-91. Hypertension. 1995; 25: 305-13.</p>
    <p>10. Asmar R, Rudnichi A, Blacher J.Pulse pressure and aortic pulse wave are markers of cardiovascular risk in hypertensive populations. Am J Hypertens. 2001; 14: 91-7.</p>
    <p>11. Vardan S, Mookherjee S. Perspective in isolated systolic hypertension in elderly patients. Arch Fam Med. 2000; 9: 319-23.</p>
    <p>12. Lewingston S, Clarke R, Qizilbash N, Peto R, Collins R. Age-specific relevance of usual blood pressure:a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002; 360: 1903-13.</p>
    <p>13. Fang J, Madhaven C, Cohen H, Alderman MH. Isolated diastolic hypertension: a favorable finding among young and middle-aged hypertensive subjects. Hypertension. 1995; 26: 377-82.</p>
    <p>14. Hozawa A, Onkubo T, Nagai K, Kikuio M, Matsubaa M, Tsuji M, et al. Prognosis of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure at home: the Okasoma Study. Arch Intern Med. 2000; 160: 3301-6.</p>
    <p>15. Benetos A, Frederique T, Safar ME, Bean KE, Guize L.Should systolic and diastolic blood pressure be considered for cardiovascular risk evaluation:a study in middle-aged men and women. Hypertension. 2001; 37: 163-8. </p>
    <p>16. Strandberg TG, Salomaa VV, Vanhanen HT. Isolated diastolic hypertension, pulse pressure, and mean arterial pressure as predictors of mortality during a follow-up of 32 years. J Hypertens. 2002; 20: 399-404.</p>
    <p>17. Pickering TG. Isolated diastolic hypertension. J Clin Hypertens. 2003; 5: 411-3.</p>
    <p>18. Mitchell GF, Vasan MS, Keyes MJ, Panse H, Wang TJ, Larsen MG, et al. Pulse pressure and risk of new-onset atrial fibrillation. JAMA. 2007; 297: 709-15.</p>
    <p>19. Pastor-Barriuso R, Banegas RJ, Damian SR, Appel GJ, Guallan E. Systolic blood pressure, diastolic blood pressure and pulse pressure: an evaluation of their joint effect on mortality. Ann Intern Med. 2003; 139: 731-9.</p>
    <p>20. Beevers DG. Epidemiological, pathophysiological and clinical significance of systolic, diastolic and pulse pressure. J Hum Hypertens. 2004; 18: 531-3.</p>
    <p>
      <fn id="end" fn-type="corresp">
        <p>Correspond&#234;ncia:</p>
        <p> Rafael Leite Luna </p>
        <p> Praia do Flamengo, 374/501 - Flamengo </p>
        <p> 22210-030 </p>
        <p> Rio de Janeiro, RJ - Brasil </p>
        <p> E-mail: </p>
        <p>
          <email xlink:href="rluna@cardiol.br">rluna@cardiol.br</email>
        </p>
      </fn>
    </p>
    <p>Artigo recebido em 02/03/07, revisado recebido em 25/03/07; aceito em 09/05/07.</p>
  </body>
  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Point of View</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="en">Is diastolic pressure losing its clinical usefulness?</article-title>
      </title-group>
    </front-stub>
    <body>
      <p>
        <bold>POINT OF VIEW</bold>
      </p>
      <p>Is diastolic pressure losing its clinical usefulness? </p>
      <p>
        <bold>Rafael Leite Luna; Leonardo Castro Luna</bold>
      </p>
      <p>Instituto de P&#243;s-Gradua&#231;&#227;o M&#233;dica Carlos Chagas, Hospital das Cl&#237;nicas de Jacarepagu&#225; - Rio de Janeiro, RJ - Brazil</p>
      <p>
        <xref ref-type="corresp" rid="end-body2">Mailing address</xref>
      </p>
      <p><bold>Key words: </bold>Blood pressure/thic; hypertension; follow-up studies. </p>
      <p>Medical science is constantly evolving, and new studies and research frequently show facts that challenge old dogmas; currently, this is the case with diastolic arterial pressure. </p>
      <p>Traditionally, arterial hypertension is divided into two main clinical categories: isolated systolic hypertension, which is more common and an attribute of age, and combined systolic and diastolic hypertension, which is less common<sup>1</sup>. Lately, a series of studies has questioned the clinical usefulness of diastolic pressure, as we will see below. </p>
      <p>Those of us from a previous generation remember that whenever we read the outcome of a therapeutic trial, we knew that it was always based on diastolic results; the same was true when we evaluated the results of an antihypertensive treatment.</p>
      <p>During the last century, physicians had the tendency to estimate diastolic pressure elevation as being more important than the systolic value, based on the belief that it had a better correlation with target-organ damage; currently this point of view lacks confirmation.</p>
      <p>In 1920, when blood pressure started to be measured frequently, the diastolic component was considered more important, and although this preference has never been duly justified, it prevailed for a good part of the 20<sup>th</sup> century. </p>
      <p>This was the standard for each assay or clinical study, from the first to the last, up to the Systolic Hypertension in the Elderly Program (SHEP), in 1991<sup>2</sup>.</p>
      <p>According to Safar, in assays evaluating the benefits of antihypertensive treatment, diastolic pressure was chosen as the only criterion for inclusion of patients. Consequently, if the systolic pressure was elevated and the diastolic pressure was normal, subjects were excluded from the assessments and were, therefore, not analyzed<sup>3</sup>. This flaw in planning introduced an assessment error not only in patient selection, but also at the end of clinical follow-up, since diastolic pressure could be normalized but the systolic pressure was not appreciated. </p>
      <p>This fact became very clear in the HOT [Hypertension Optimal Treatment] Study that analyzed middle-aged patients with combined systolic and diastolic hypertension. At the end of the study, despite a rigorous control of the diastolic pressure, a poor result in the medication was noted in terms of cardiovascular risk, and the reason was attributed to a lack of systolic pressure control, which incidentally, was not the objective of the trial<sup>4</sup>.</p>
      <p>During the 1950s, according to Kaplan, insurance companies had already begun to pay attention to the fact that elevated systolic levels represented a cardiovascular health risk, but this was not taken into consideration<sup>1</sup>.</p>
      <p>In 1971, a publication of the Framingham Study documented, for the first time and with the full weight of its authority, the great predictive value of systolic pressure for cardiovascular disease. The data from this study, based on the 30-year evolution of a cohort, associated the degree of cardiovascular disease development with systolic pressure for all ages and in both genders<sup>5</sup>.</p>
      <p>In fact, since the original studies of arterial pressure, in the first half of the previous century, there were signs of the importance of the systolic measurement; it was not well understood why its value was not properly recognized<sup>6</sup>.</p>
      <p>On the other hand, influenced by the abovementioned studies, in 1990 the National High Blood Pressure Education Program of the United States recommended that systolic pressure be ascribed a more important role in the diagnosis and treatment of arterial hypertension<sup>7</sup>.</p>
      <p>Today, it is known that isolated systolic hypertension is present in two-thirds of patients aged over 60 years. It is the age group that currently also includes, according to Staessen et al., the majority of hypertensive individuals<sup>8</sup>.</p>
      <p>One of the problems in evaluating systolic pressure in elderly patients is its drop in left ventricular dysfunction, making it difficult to define its true level, although there is always an evident hypertensive antecedent in the patient&#146;s medical history.</p>
      <p>In 1995, the famous epidemiological survey, NHANES III, performed in the USA, showed fundamental and vitally important data demonstrating that systolic and diastolic pressures undergo a normal and continuous increase during life up to 50 years of age in most individuals. From then on, the systolic pressure continues to increase, but the diastolic pressure generally shows a tendency to fall<sup>9</sup>. Asmar et al., consider these changes a result of increased rigidity of the aorta and large arteries, and they are possibly correct<sup>10</sup>.</p>
      <p>Today, systolic pressure is recognized as the best predictor of cardiovascular risk after 50 years of age<sup>11</sup>. Corroborating this fact, the large Prospective Studies Collaboration trial showed that between the ages of 40 and 90 years, systolic pressure is more predictive than diastolic pressure of the risk of death in ischemic heart disease<sup>12</sup>.</p>
      <p>As mentioned above, over the last quarter of century, several epidemiological studies have valued systolic pressure as the most important parameter for cardiovascular risk, primarily in elderly people. Nevertheless, it was only during the 1990s that a change in medical mentality occurred, starting to emphasize systolic pressure over diastolic pressure, both in the diagnosis and in the classification and management of arterial pressure.</p>
      <p>In persons under 45 years of age, isolated systolic hypertension is rare, but at this age, isolated elevated diastolic pressures with normal systolic pressures may appear, although in a minority, as displayed in <xref ref-type="table" rid="tab01-body2">Table 1</xref>.</p>
      <table-wrap id="tab01-body2">
        <graphic xlink:href="1678-4170-abc-89-03-0e19-00010-gt01-en.jpg"/></table-wrap>
      <p>One of the reasons alleged in the past century for the clinical importance given to the diastolic parameter was that during the diastolic period, arteries would be exposed to pressure for a longer time than during the systolic period. However we point out the fact that during diastole, the transmural pressure progressively falls until the beginning of systole. Another reason claimed in the past, from the clinical point of view, was that coronary circulation, during the diastole, was more influenced by the pressure level during this period and was important, therefore, for determining the integrity of the coronary arteries.</p>
      <p>Again, we should bear in mind that during diastole, there is a continuous drop in arterial pressure. It is possible that the diastolic measurement is not the most important factor for explaining coronary artery disease, but that there are other factors involved, such as endothelial function, lipid levels, or thrombophilia, and tension levels need to be adjusted in order for their value to be appreciated.</p>
      <p>We know that a rise in systolic pressure depends on increased systolic output, increased peripheral resistance, or rigidity of the large arteries. </p>
      <p>From a pathophysiological point of view diastolic pressure has not yet been specifically studied. It is known that it increases with the rise in peripheral resistance but unlike the systolic it decreases with the rigidity of large arteries. Theoretically, then, diastolic pressure can be normal, since the effects exerted by peripheral resistance and by aortic rigidity can mutually annul each other, although these changes are, <italic>per se</italic>, risk factors. </p>
      <p>To our surprise, at the end of the last century, scientific studies appeared challenging the deep-rooted idea established over the previous one-hundred years that elevated diastolic pressure represented the same cardiovascular risk as systolic hypertension. These papers contradicted the prevailing medical opinion of the time that resulted from many years of questionable medical assessments.</p>
      <p>In 1995, Alderman and his group, in New York published the first article informing that young and middle-aged (&lt;60 years) patients whose cardiovascular disorder was elevated diastolic pressure, presented a better prognosis than those with elevated systolic and diastolic pressures combined, with a higher risk for myocardial infarction. Additionally, when patients with isolated diastolic hypertension were stratified according to systolic pressure levels, i.e., above and under 140 mmHg, myocardial infarction only happened with systolic pressures above 140 mmHg, regardless of the diastolic level (90 to 115 mmHg). In addition, even if the patients presented levels of cholesterol and glucose, number of cigarettes, and genders adjusted for a multivariate analysis, the association with infarction only appeared in the presence of combined systolic and diastolic hypertension, and not with isolated diastolic hypertension<sup>13</sup>.</p>
      <p>In 2000, a group in Japan headed by Hozawa et al., in a study with 1913 patients 40 years of age or over, who were followed for more than eight years, showed that isolated diastolic hypertension offers a low risk for cardiovascular mortality, similar to that of individuals with normal pressures. This suggests that the prognosis of hypertension should be based on the systolic and not on the diastolic level<sup>14</sup>.</p>
      <p>In 2001, Benetos et al.<sup>15</sup>, in Paris, carried out a large study with 77023 men and 48480 women on the risks offered by systolic and diastolic hypertension. This study produced some interesting conclusions, as follows: 1. In men and women with normal systolic pressure (&lt;140 mmHg), diastolic pressure was not a determinant of cardiovascular mortality, even after being adjusted for age and systolic pressure level; 2. The highest mortality rates were noted in men with isolated systolic hypertension; 3. In women with isolated systolic hypertension, there was also an elevated mortality rate that increased if the diastolic pressure was also high<sup>15</sup>.</p>
      <p>Strandberg et al.<sup>16</sup>, in 2002, studying a cohort of 342 patients with isolated diastolic hypertension observed for 32 years, found no increase in cardiovascular mortality as long as there was no combined elevation of diastolic and systolic pressures. In this case, cardiovascular mortality increased 2.7 fold, clearly showing that the risk only appeared when systolic levels were also elevated<sup>16</sup>.</p>
      <p>Likewise, Pickering found no increased cardiovascular risk in isolated diastolic pressure elevation, and assertively stated: "There is absolutely no indication, at present, for treating isolated diastolic hypertension" <sup>17</sup>.</p>
      <p>As systolic pressure grew in importance, a large number of studies on pulse pressure and its prognostic value began to appear, especially in Framingham&#146;s group, that has just published a brilliant paper correlating atrial fibrillation and pulse pressure<sup>18</sup>. Nevertheless, as to pulse pressures, we have followed the ideas of Pastor-Barriuso et al.<sup>19</sup> who have inferred, based on NHANES data, that: &#168;The complexity of the association between pulse pressure and mortality has discouraged its use in prognosis or therapeutic decisions&#168;<sup>19</sup>.</p>
      <p>Thinking simplistically and speculating that there would be no risk of diastolic pressure elevation, we conclude that there would also be no damage to target-organs simply due to an isolated rise in this pressure. This type of reasoning needs to be duly demonstrated and confirmed, since the traditionally accepted idea is that an increase in diastolic pressure would damage the brain, heart, and kidneys, in the same way as an increased systolic pressure would. </p>
      <p>This series of studies points to a possible future declassification of the clinical value of the diastolic level, since according to the abovementioned papers, no risk of death was found in patients with isolated diastolic hypertension that had been followed, in some cases, for many years. Only those patients who also showed elevated systolic levels were at risk.</p>
      <p>All these studies led Beevers, in England, to recently declare that some clinicians and epidemiologists question if the diastolic pressure measurement is still worth the trouble, considering the outstanding importance of the systolic pressure in predicting cardiovascular risk and the reciprocal negation of diastolic pressure as a cardiovascular risk<sup>20</sup>.</p>
      <p>Even with all this evidence, prudence demands that after a century of monitoring arterial pressure in the traditional way, we should still continue to pay attention to diastolic results, in spite of the fact that the studies mentioned above question whether it is really necessary. </p>
      <p>Therefore, if systolic pressure is provenly important after 50 years, and if there is no recorded cardiovascular risk with isolated diastolic hypertension, we ask: In daily clinical practice, is the measurement of diastolic pressure necessary?</p>
      <p>
        <bold>Potential Conflict of Interest</bold>
      </p>
      <p>No potential conflict of interest relevant to this article was reported.</p>
      <p>
        <bold>Sources of Funding</bold>
      </p>
      <p>There were no external funding sources for this study.</p>
      <p>
        <bold>Study Association</bold>
      </p>
      <p>This study is not associated with any graduation program.</p>
      <p>
        <bold>References</bold>
      </p>
      <p>1. Kaplan NM. Clinical hypertension. 9th ed. Philadelphia: Lippincott; 2006. p. 123.</p>
      <p>2. SHEP Cooperative Research Group. Final results of the systolic hypertension in the elderly. JAMA. 1991; 265: 3255-64.</p>
      <p>3. Safar ME. Therapeutic trials and large arteries in hypertension. Am Heart J. 1988; 115: 702-10.</p>
      <p>4. Hansson C, Zanchetti A, Carruthers SG, Dahlof B, Elmfeldt D, Julius S, et al. for the HOT Study Group. Effects of intensive blood pressure lowering and low dose aspirin in patients with hypertension. Lancet. 1998; 351: 1755-62.</p>
      <p>5. Kannel WB, Gordon T, Schwartz MJ. Systolic versus diastolic blood pressure and risk of coronary heart disease. Am J Cardiol. 1971; 27: 335-46.</p>
      <p>6. Swales JD. Systolic versus diastolic pressure. J Hum Hypertens. 2000; 14: 477-9.</p>
      <p>7. Izzo JL, Levy D, Black HR. Clinical advisor statement: interpretation of systolic blood pressure in older americans. Hypertension. 2000; 35: 1021-4.</p>
      <p>8. Staessen JA, Thyrs L, Fajard R, O'Brien ET, Clement D, de Leeuw PW, et al. Predicting cardiovascular risk using conventional vs ambulatory blood pressure in older patients with systolic hypertension. JAMA. 1999; 282: 539-46.</p>
      <p>9. Burt VL, Whelton P, Roccella EJ, Brown G, Cutler JP, Higgins M, et al. Prevalence of hypertension in the US adult population: results from the Third National Health and Nutrition Examination Survey 1988-91. Hypertension. 1995; 25: 305-13.</p>
      <p>10. Asmar R, Rudnichi A, Blacher J.Pulse pressure and aortic pulse wave are markers of cardiovascular risk in hypertensive populations. Am J Hypertens. 2001; 14: 91-7.</p>
      <p>11. Vardan S, Mookherjee S. Perspective in isolated systolic hypertension in elderly patients. Arch Fam Med. 2000; 9: 319-23.</p>
      <p>12. Lewingston S, Clarke R, Qizilbash N, Peto R, Collins R. Age-specific relevance of usual blood pressure:a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002; 360: 1903-13.</p>
      <p>13. Fang J, Madhaven C, Cohen H, Alderman MH. Isolated diastolic hypertension: a favorable finding among young and middle-aged hypertensive subjects. Hypertension. 1995; 26: 377-82.</p>
      <p>14. Hozawa A, Onkubo T, Nagai K, Kikuio M, Matsubaa M, Tsuji M, et al. Prognosis of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure at home: the Okasoma Study. Arch Intern Med. 2000; 160: 3301-6.</p>
      <p>15. Benetos A, Frederique T, Safar ME, Bean KE, Guize L.Should systolic and diastolic blood pressure be considered for cardiovascular risk evaluation:a study in middle-aged men and women. Hypertension. 2001; 37: 163-8. </p>
      <p>16. Strandberg TG, Salomaa VV, Vanhanen HT. Isolated diastolic hypertension, pulse pressure, and mean arterial pressure as predictors of mortality during a follow-up of 32 years. J Hypertens. 2002; 20: 399-404.</p>
      <p>17. Pickering TG. Isolated diastolic hypertension. J Clin Hypertens. 2003; 5: 411-3.</p>
      <p>18. Mitchell GF, Vasan MS, Keyes MJ, Panse H, Wang TJ, Larsen MG, et al. Pulse pressure and risk of new-onset atrial fibrillation. JAMA. 2007; 297: 709-15.</p>
      <p>19. Pastor-Barriuso R, Banegas RJ, Damian SR, Appel GJ, Guallan E. Systolic blood pressure, diastolic blood pressure and pulse pressure: an evaluation of their joint effect on mortality. Ann Intern Med. 2003; 139: 731-9.</p>
      <p>20. Beevers DG. Epidemiological, pathophysiological and clinical significance of systolic, diastolic and pulse pressure. J Hum Hypertens. 2004; 18: 531-3.</p>
      <p>
        <fn id="end-body2" fn-type="corresp">
          <p>Mailing adress:</p>
          <p> Rafael Leite Luna </p>
          <p> Praia do Flamengo, 374/501 - Flamengo </p>
          <p> 22210-030</p>
          <p> Rio de Janeiro, RJ - Brazil</p>
          <p> E-mail: </p>
          <p>
            <email xlink:href="rluna@cardiol.br">rluna@cardiol.br </email>
          </p>
        </fn>
      </p>
      <p>Manuscript received March 2, 2007; revised manuscript received March 25, 2007; accepted May 9, 2007.</p>
      <p>11. Vardan S, Mookherjee S. Perspective in isolated systolic hypertension in elderly patients. Arch Fam Med. 2000; 9: 319-23.</p>
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  </sub-article>
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