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  <front>
    <journal-meta>
      <journal-id journal-id-type="nlm-ta">Arq Bras Cardiol</journal-id>
      <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>
    </journal-meta>
    <article-meta>
      <article-id specific-use="scielo-v3" pub-id-type="publisher-id">wqXGrvt8CmgQB5HkdvkbzVK</article-id>
      <article-id specific-use="scielo-v2" pub-id-type="publisher-id">S0066-782X2021001300942</article-id>
      <article-id pub-id-type="publisher-id">abc.20210808</article-id>
      <article-id pub-id-type="doi">10.36660/abc.20210808</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Minieditorial</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Import&#226;ncia Diagn&#243;stica e Progn&#243;stica da Capacidade Funcional nas Diversas Formas Evolutivas da Doen&#231;a De Chagas</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="editor">
          <name>
            <surname>Barbosa-Ferreira</surname>
            <given-names>Jo&#227;o Marcos</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
          <xref ref-type="aff" rid="aff2">
            <sup>2</sup>
          </xref>
        </contrib>
        <contrib contrib-type="editor">
          <name>
            <surname>Mady</surname>
            <given-names>Charles</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="editor">
          <contrib-id contrib-id-type="orcid">0000-0002-9323-8805</contrib-id>
          <name>
            <surname>Fernandes</surname>
            <given-names>F&#225;bio</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
          <xref ref-type="corresp" rid="c1"/>
        </contrib>
        <aff id="aff1">
          <label>1</label>
          <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 do Hospital das Cl&#237;nicas</institution>
          <addr-line>
            <named-content content-type="city">S&#227;o Paulo</named-content>
            <named-content content-type="state">SP</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo, S&#227;o Paulo, SP &#8211; Brasil</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution content-type="orgname">Universidade do Estado do Amazonas</institution>
          <addr-line>
            <named-content content-type="city">Manaus</named-content>
            <named-content content-type="state">AM</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Universidade do Estado do Amazonas, Manaus, AM &#8211; Brasil</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c1"><bold>Correspond&#234;ncia: F&#225;bio Fernandes</bold> &#8226; Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo - Av. Dr. En&#233;as C. Aguiar, 44. CEP <postal-code>05403-000</postal-code>, S&#227;o Paulo, SP - Brasil. E-mail: <email>fabio.fernandes@incor.usp.br</email></corresp>
      </author-notes>
      <pub-date publication-format="electronic" date-type="pub">
        <day>22</day>
        <month>11</month>
        <year>2021</year>
      </pub-date>
      <pub-date publication-format="electronic" date-type="collection">
        <month>11</month>
        <year>2021</year>
      </pub-date>
      <volume>117</volume>
      <issue>5</issue>
      <fpage>942</fpage>
      <lpage>943</lpage>
      <permissions>
        <license license-type="open-access" xml:lang="en" xlink:href="https://creativecommons.org/licenses/by/4.0/">
          <license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution License</license-p>
        </license>
      </permissions>
      <kwd-group xml:lang="pt">
        <title>Palavras-chave</title>
        <kwd>Doen&#231;a de Chagas</kwd>
        <kwd>Exerc&#237;cio</kwd>
        <kwd>Cardiopatia Chagasica</kwd>
        <kwd>Teste de Esfor&#231;o/m&#233;todos</kwd>
        <kwd>Insufici&#234;ncia Card&#237;aca/complica&#231;&#245;es</kwd>
        <kwd>Tromboembolia</kwd>
        <kwd>Trypanosoma Cruzi</kwd>
      </kwd-group>
      <counts>
        <fig-count count="0"/>
        <table-count count="0"/>
        <equation-count count="0"/>
        <ref-count count="10"/>
        <page-count count="2"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <p>O estudo publicado por Silva et al.,<sup><xref ref-type="bibr" rid="B1">1</xref></sup> nesta edi&#231;&#227;o nos traz uma reflex&#227;o importante sobre a evolu&#231;&#227;o das diversas formas da doen&#231;a de Chagas (DC), ao demonstrar que os pacientes com a forma indeterminada (FI) possuem capacidade funcional, medida atrav&#233;s do consumo de oxig&#234;nio de pico (VO<sub>2</sub>pico), semelhante a indiv&#237;duos saud&#225;veis sem DC. Por outro lado, pacientes com cardiopatia chag&#225;sica sem disfun&#231;&#227;o ventricular apresentaram capacidade funcional semelhante aos pacientes com disfun&#231;&#227;o ventricular.<sup><xref ref-type="bibr" rid="B1">1</xref></sup></p>
    <p>A FI da DC vem sendo estudada sob diversos aspectos h&#225; v&#225;rios anos. Alguns estudos em pacientes assintom&#225;ticos e que se incluem na defini&#231;&#227;o da FI por n&#227;o apresentarem altera&#231;&#245;es eletrocardiogr&#225;ficas e na radiografia de t&#243;rax, demonstraram altera&#231;&#245;es incipientes em exames complementares que podem sugerir a possibiliade de evolu&#231;&#227;o para as formas mais graves de DC ao longo dos anos. Avalia&#231;&#245;es feitas atrav&#233;s da ecocardiografia apresentaram altera&#231;&#245;es em vari&#225;veis como Doppler tecidual e estudo da deformidade mioc&#225;rdica atrav&#233;s do <italic>strain</italic> bidimensional.<sup><xref ref-type="bibr" rid="B2">2</xref>,<xref ref-type="bibr" rid="B3">3</xref></sup> J&#225; houve demonstra&#231;&#227;o tamb&#233;m de altera&#231;&#245;es do sistema nervoso aut&#244;nomo, principalmente no ramo parassimp&#225;tico, que podem ser potenciais vias de piora no est&#225;gio cl&#237;nico da doen&#231;a no decorrer dos anos.<sup><xref ref-type="bibr" rid="B4">4</xref>,<xref ref-type="bibr" rid="B5">5</xref></sup> Estudos feitos com resson&#226;ncia magn&#233;tica demonstraram presen&#231;a de fibrose mioc&#225;rdica em 12% de pacientes com a FI da doen&#231;a.<sup><xref ref-type="bibr" rid="B6">6</xref></sup> No entanto, apesar dessas pequenas altera&#231;&#245;es, a evolu&#231;&#227;o a longo prazo desses pacientes tem se mostrado favor&#225;vel e semelhante &#224; de indiv&#237;duos saud&#225;veis sem DC. Ianni et al.,<sup><xref ref-type="bibr" rid="B7">7</xref></sup> estudaram pacientes com a FI com base nos achados do eletrocardiograma (ECG) por 8 anos e conclu&#237;ram que a FI da DC representa uma condi&#231;&#227;o benigna com progn&#243;stico favor&#225;vel em longo prazo.<sup><xref ref-type="bibr" rid="B7">7</xref></sup> No entanto, em um pequeno grupo de pacientes pode haver evolu&#231;&#227;o para cardiopatia chag&#225;sica cr&#244;nica (CCC) ou doen&#231;a do aparelho digestivo em cerca de 10 a 20 anos ap&#243;s a infec&#231;&#227;o aguda. Sabino et al.,<sup><xref ref-type="bibr" rid="B8">8</xref></sup> em um estudo de coorte retrospectivo de 10 anos, sugeriram uma taxa de progress&#227;o para cardiomiopatia de 1,85% ao ano em pacientes com a FI da doen&#231;a.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> Portanto, s&#227;o necess&#225;rios estudos que identifiquem marcadores que possam predizer a possibilidade desta evolu&#231;&#227;o e a avalia&#231;&#227;o da capacidade funcional destes pacientes &#233; importante neste aspecto.</p>
    <p>A presen&#231;a de altera&#231;&#245;es eletrocardiogr&#225;ficas sugestivas de comprometimento card&#237;aco, caracter&#237;sticas da DC, em um indiv&#237;duo sintom&#225;tico ou assintom&#225;tico, caracteriza a forma card&#237;aca cr&#244;nica da DC. Este grupo de pacientes pode se apresentar apenas com o ECG alterado, por&#233;m sem sintomas ou presen&#231;a de disfun&#231;&#227;o ventricular ou apresentar-se com sintomas de insufici&#234;ncia card&#237;aca e disfun&#231;&#227;o sist&#243;lica ventricular esquerda de grau at&#233; importante. Estudos com resson&#226;ncia magn&#233;tica demonstraram presen&#231;a de at&#233; 94% de fibrose mioc&#225;rdica em pacientes com ECG alterado, mesmo sem disfun&#231;&#227;o ventricular.<sup><xref ref-type="bibr" rid="B6">6</xref></sup> Estes achados sugerem que este grupo de pacientes, deve ter um acompanhamento cl&#237;nico rigoroso e a avalia&#231;&#227;o da capacidade funcional tamb&#233;m se enquadra neste espectro.</p>
    <p>Por outro lado, pacientes com CCC e grave disfun&#231;&#227;o ventricular representam um grupo de pacientes que t&#234;m um progn&#243;stico pior do que outras etiologias de miocardiopatias. Mady et al.,<sup><xref ref-type="bibr" rid="B9">9</xref></sup> demonstraram que a capacidade funcional, assim como a fra&#231;&#227;o de eje&#231;&#227;o, &#233; um importante preditor de sobrevida neste grupo de pacientes.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Al&#233;m disto, o treinamento f&#237;sico e a reabilita&#231;&#227;o card&#237;aca s&#227;o importantes componentes de melhora cl&#237;nica destes pacientes e o VO<sub>2</sub>pico &#233; tamb&#233;m importante nesta monitoriza&#231;&#227;o.<sup><xref ref-type="bibr" rid="B10">10</xref></sup></p>
    <p>Todos estes aspectos sugerem que o estudo da DC necessita abordar cada vez mais temas que busquem preditores de sua evolu&#231;&#227;o t&#227;o vari&#225;vel de indiv&#237;duo para indiv&#237;duo e o estudo da capacidade funcional &#233; importante neste contexto.</p>
  </body>
  <back>
    <fn-group>
      <fn fn-type="other" id="fn1">
        <p>Minieditorial referente ao artigo: Determinantes da Capacidade Funcional em Pacientes com Doen&#231;a de Chagas</p>
      </fn>
    </fn-group>
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            <name>
              <surname>Cardoso</surname>
              <given-names>RH</given-names>
            </name>
            <name>
              <surname>Barretto</surname>
              <given-names>AC</given-names>
            </name>
            <name>
              <surname>da Luz</surname>
              <given-names>PL</given-names>
            </name>
            <name>
              <surname>Belloti</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Pileggi</surname>
              <given-names>F</given-names>
            </name>
          </person-group>
          <article-title>Survival and predictors of survival in patients with congestive heart failure due to Chagas&#8217; cardiomyopathy</article-title>
          <source>Circulation</source>
          <year>1994</year>
          <volume>90</volume>
          <issue>6</issue>
          <fpage>3098</fpage>
          <lpage>3102</lpage>
        </element-citation>
        <mixed-citation>9 Mady C, Cardoso RH, Barretto AC, da Luz PL, Belloti G, Pileggi F. Survival and predictors of survival in patients with congestive heart failure due to Chagas&#8217; cardiomyopathy. Circulation.1994;90(6):3098-102.</mixed-citation>
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      <ref id="B10">
        <label>10</label>
        <element-citation publication-type="journal">
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            <name>
              <surname>Improta-Caria</surname>
              <given-names>AC</given-names>
            </name>
            <name>
              <surname>Aras</surname>
              <given-names>R</given-names>
              <suffix>Junior</suffix>
            </name>
          </person-group>
          <article-title>Treinamento com Exerc&#237;cio F&#237;sico e Doen&#231;a de Chagas: Fun&#231;&#227;o Potencial dos MicroRNAs</article-title>
          <source>Arq Bras Cardiol</source>
          <volume>117</volume>
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        <mixed-citation>10 Improta-Caria AC, Aras-Junior R. Treinamento com Exerc&#237;cio F&#237;sico e Doen&#231;a de Chagas: Fun&#231;&#227;o Potencial dos MicroRNAs. Arq Bras Cardiol; 117(1):132-41.</mixed-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="S01" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Short Editorial</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Diagnostic and Prognostic Importance of Functional Capacity in the Different Evolutionary Forms of Chagas Disease</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="editor">
          <name>
            <surname>Barbosa-Ferreira</surname>
            <given-names>Jo&#227;o Marcos</given-names>
          </name>
          <xref ref-type="aff" rid="aff3">
            <sup>1</sup>
          </xref>
          <xref ref-type="aff" rid="aff4">
            <sup>2</sup>
          </xref>
        </contrib>
        <contrib contrib-type="editor">
          <name>
            <surname>Mady</surname>
            <given-names>Charles</given-names>
          </name>
          <xref ref-type="aff" rid="aff3">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="editor">
          <contrib-id contrib-id-type="orcid">0000-0002-9323-8805</contrib-id>
          <name>
            <surname>Fernandes</surname>
            <given-names>F&#225;bio</given-names>
          </name>
          <xref ref-type="aff" rid="aff3">
            <sup>1</sup>
          </xref>
          <xref ref-type="corresp" rid="c2"/>
        </contrib>
        <aff id="aff3">
          <label>1</label>
          <addr-line>
            <named-content content-type="city">S&#227;o Paulo</named-content>
            <named-content content-type="state">SP</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo, S&#227;o Paulo, SP &#8211; Brazil</institution>
        </aff>
        <aff id="aff4">
          <label>2</label>
          <addr-line>
            <named-content content-type="city">Manaus</named-content>
            <named-content content-type="state">AM</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Universidade do Estado do Amazonas, Manaus, AM &#8211; Brazil</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c2"><bold>Mailing Addess: F&#225;bio Fernandes</bold> &#8226; Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo - Av. Dr. En&#233;as C. Aguiar, 44. Postal Code <postal-code>05403-000</postal-code>, S&#227;o Paulo, SP - Brazil. E-mail: <email>fabio.fernandes@incor.usp.br</email></corresp>
      </author-notes>
      <kwd-group xml:lang="en">
        <title>Keywords</title>
        <kwd>Chagas Disease</kwd>
        <kwd>Exercise</kwd>
        <kwd>Chagas cardiomyopathy</kwd>
        <kwd>Exercise Test/methods</kwd>
        <kwd>Heart Failure/complications</kwd>
        <kwd>Thromboembolismi</kwd>
        <kwd>Trypanosoma Cruzi</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>The manuscript published by Silva et al.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> in this issue brings us an important reflection on the evolution of the different forms of Chagas disease (CD), by demonstrating that patients with the indeterminate form (IF) have similar functional capacity, measured through peak oxygen uptake (VO<sub>2</sub>peak), to healthy individuals without CD. On the other hand, patients with Chagas&#8217; heart disease without ventricular dysfunction had similar functional capacity to patients with ventricular dysfunction.<sup><xref ref-type="bibr" rid="B1">1</xref></sup></p>
      <p>The IF of CD has been studied under different aspects for several years. Some studies in asymptomatic patients that are included in the definition of IF for not presenting electrocardiographic and chest X-ray alterations, demonstrated incipient alterations in complementary exams that may suggest the possibility of evolution to the more severe forms of CD over the years. Evaluations made through echocardiography showed alterations in variables such as tissue Doppler and study of myocardial deformity through two-dimensional strain.<sup><xref ref-type="bibr" rid="B2">2</xref>,<xref ref-type="bibr" rid="B3">3</xref></sup> There has also been demonstration of changes in the Autonomic Nervous System, especially in the parasympathetic branch, which can be potential pathways for worsening in the stage disease over the years.<sup><xref ref-type="bibr" rid="B4">4</xref>,<xref ref-type="bibr" rid="B5">5</xref></sup> Studies performed with magnetic resonance have demonstrated the presence of myocardial fibrosis in 12% of patients with IF of the disease.<sup><xref ref-type="bibr" rid="B6">6</xref></sup> However, despite these small changes, the long-term evolution of these patients has been shown favorable and similar to that of healthy individuals without CD. Ianni et al.<sup><xref ref-type="bibr" rid="B7">7</xref></sup> studied patients with the IF based on ECG findings for 8 years and concluded that the IF of CD represents a benign condition with a favorable long-term prognosis.<sup><xref ref-type="bibr" rid="B7">7</xref></sup> However, in a small group of patients, there may be evolution for chronic Chagas cardiopathy (CCC) or digestive tract disease in about 10 to 20 years after acute infection. Sabino et al.,<sup><xref ref-type="bibr" rid="B8">8</xref></sup> in a 10-year retrospective cohort study, suggested a rate of progression to cardiomyopathy of 1.85% per year in patients with FI of the disease.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> Therefore, studies that identify markers that can predict the possibility of this evolution are needed and the evaluation of the functional capacity of these patients is important in this aspect.</p>
      <p>The presence of electrocardiographic alterations suggestive of cardiac involvement, characteristic of CD, in a symptomatic or asymptomatic individual, characterizes the chronic cardiac form of CD. This group of patients may present only with an altered electrocardiogram (ECG), but without symptoms or presence of ventricular dysfunction, or present with symptoms of heart failure and significant grade of left ventricular systolic dysfunction. Studies with magnetic resonance have shown the presence of up to 94% of myocardial fibrosis in patients with altered ECG, even without ventricular dysfunction.<sup><xref ref-type="bibr" rid="B6">6</xref></sup> These findings suggest that this group of patients should have a rigorous clinical follow-up and the assessment of functional capacity is also important into this spectrum.</p>
      <p>On the other hand, patients with CCC and severe ventricular dysfunction represent a group of patients who have a worse prognosis than other cardiomyopathy etiologies. Mady et al.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> demonstrated that functional capacity, as well as ejection fraction, is an important predictor of survival in this group of patients.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> In addition, physical training and cardiac rehabilitation are important components of clinical improvement in these patients and VO<sub>2</sub>peak is also important in this monitoring.<sup><xref ref-type="bibr" rid="B10">10</xref></sup></p>
      <p>All these aspects suggest that the study of CD needs to increasingly address themes that seek predictors of its evolution, which varies from individual to individual, and the study of functional capacity is important in this context.</p>
    </body>
    <back>
      <fn-group>
        <fn fn-type="other" id="fn2">
          <p>Short Editorial related to the aticle: Determinants of Functional Capacity in Patients with Chagas Disease</p>
        </fn>
      </fn-group>
    </back>
  </sub-article>
</article>
