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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">SvrfpKR6v6HCym7MtdwZdLh</article-id>
      <article-id specific-use="scielo-v2" pub-id-type="publisher-id">S0066-782X2026000200610</article-id>
      <article-id pub-id-type="other">00610</article-id>
      <article-id pub-id-type="doi">10.36660/abc.20250437</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Artigo Original</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Valor Preditivo do &#205;ndice de Inflama&#231;&#227;o Imune Sist&#234;mica para a Recorr&#234;ncia de Pericardite Aguda Idiop&#225;tica</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-0737-6927</contrib-id>
          <name>
            <surname>Unkun</surname>
            <given-names>Tuba</given-names>
          </name>
          <role>Concep&#231;&#227;o e desenho da pesquisa and An&#225;lise estat&#237;stica</role>
          <role>An&#225;lise e interpreta&#231;&#227;o dos dados, Reda&#231;&#227;o do manuscrito e Revis&#227;o cr&#237;tica do manuscrito quanto ao conte&#250;do</role>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-7946-1229</contrib-id>
          <name>
            <surname>Sengor</surname>
            <given-names>Busra Guvendi</given-names>
          </name>
          <role>Obten&#231;&#227;o de dados</role>
          <role>An&#225;lise e interpreta&#231;&#227;o dos dados, Reda&#231;&#227;o do manuscrito e Revis&#227;o cr&#237;tica do manuscrito quanto ao conte&#250;do</role>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
      </contrib-group>
      <aff id="aff1">
        <label>1</label>
        <institution content-type="orgdiv1">Department of cardiology</institution>
        <institution content-type="orgname">Kartal Kosuyolu Education and Research Hospital</institution>
        <addr-line>
          <named-content content-type="city">Istanbul</named-content>
        </addr-line>
        <country country="TR">Turquia</country>
        <institution content-type="original">Department of cardiology, Kartal Kosuyolu Education and Research Hospital, Istanbul &#8211; Turquia</institution>
      </aff>
      <author-notes>
        <corresp id="c01"><label>Correspond&#234;ncia</label>: Tuba Unkun &#8226; Kartal Kosuyolu Research and Education Hospital &#8211; Department of Cardiology Denizer caddesi, Cevizli kavsagi, Istanbul, 34718 &#8211; Turquia. E-mail: <email>tubaunkun@yahoo.com</email> </corresp>
        <fn fn-type="edited-by">
          <label>Editor respons&#225;vel pela revis&#227;o:</label>
          <p>Gl&#225;ucia Maria Moraes de Oliveira</p>
        </fn>
        <fn fn-type="coi-statement">
          <label>Potencial conflito de interesse</label>
          <p> N&#227;o h&#225; conflito com o presente artigo.</p>
        </fn>
      </author-notes>
      <pub-date date-type="pub" publication-format="electronic">
        <day>30</day>
        <month>03</month>
        <year>2026</year>
      </pub-date>
      <pub-date date-type="collection" publication-format="electronic">
        <month>02</month>
        <year>2026</year>
      </pub-date>
      <volume>123</volume>
      <issue>2</issue>
      <elocation-id>e20250437</elocation-id>
      <history>
        <date date-type="received">
          <day>20</day>
          <month>07</month>
          <year>2025</year>
        </date>
        <date date-type="rev-recd">
          <day>10</day>
          <month>10</month>
          <year>2025</year>
        </date>
        <date date-type="accepted">
          <day>05</day>
          <month>11</month>
          <year>2025</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/" xml:lang="pt">
          <license-p>Este &#233; um artigo de acesso aberto distribu&#237;do sob os termos da licen&#231;a de atribui&#231;&#227;o pelo Creative Commons</license-p>
        </license>
      </permissions>
      <abstract>
        <title>Resumo</title>
        <sec>
          <title>Fundamentos</title>
          <p> Identificar pacientes com risco aumentado de recorr&#234;ncia de pericardite aguda continua sendo um desafio. A Prote&#237;na C-Reativa Ultrassens&#237;vel (PCR-us) pode ser utilizada para prever recorr&#234;ncia, mas apresenta algumas limita&#231;&#245;es.</p>
        </sec>
        <sec>
          <title>Objetivos</title>
          <p> Este estudo teve como objetivo avaliar a associa&#231;&#227;o entre um novo biomarcador, o &#205;ndice de Inflama&#231;&#227;o Imune Sist&#234;mica (SII), e a recorr&#234;ncia da pericardite aguda.</p>
        </sec>
        <sec>
          <title>M&#233;todos</title>
          <p> Este estudo de coorte retrospectivo incluiu 110 pacientes diagnosticados com pericardite aguda idiop&#225;tica. O desfecho prim&#225;rio foi investigar a recorr&#234;ncia da pericardite durante o per&#237;odo de acompanhamento de 18 meses. Os pacientes foram divididos em dois grupos, de acordo com o desenvolvimento ou n&#227;o de recorr&#234;ncia. Foram avaliados exame f&#237;sico, eletrocardiograma, ecocardiograma e resultados laboratoriais desses pacientes. Valores de p &lt; 0,05 foram considerados estatisticamente significativos.</p>
        </sec>
        <sec>
          <title>Resultados</title>
          <p> A idade m&#233;dia dos pacientes foi de 42,8 &#177; 15,2 anos, e 42,7% eram do sexo masculino. O grupo com recorr&#234;ncia de pericardite (RP) apresentou contagens de leuc&#243;citos significativamente mais altas (8,7 &#177; 3,2 vs. 12 &#177; 4,7; p = 0,001), contagens de neutr&#243;filos (5,4 &#177; 2,7 vs. 9 &#177; 4,5; p &lt; 0,001), n&#237;veis de PCR-us (29,1 &#177; 40,9 vs. 49,5 &#177; 62,2; p = 0,048) e rela&#231;&#227;o neutr&#243;filo/linf&#243;cito (2,9 &#177; 2,5 vs. 6 &#177; 2,8; p &lt; 0,001). O SII (783,2 &#177; 770,2 vs. 1664,2 &#177; 1086,6; p &lt; 0,001) tamb&#233;m foi significativamente mais elevado nos pacientes com recorr&#234;ncia. Tanto o SII quanto a PCR-us mostraram associa&#231;&#227;o independente com a recorr&#234;ncia (p &lt; 0,001 e p &lt; 0,05, respectivamente).</p>
        </sec>
        <sec>
          <title>Conclus&#227;o</title>
          <p> O SII e a PCR-us foram identificados como preditores independentes de recorr&#234;ncia em pacientes com pericardite aguda durante o acompanhamento de 18 meses. Assim como a PCR-us, o SII pode ser utilizado como um par&#226;metro importante na predi&#231;&#227;o da pericardite recorrente.</p>
        </sec>
      </abstract>
      <abstract abstract-type="graphical">
        <p>
          <fig id="f01">
            <label>Figura Central:</label>
            <caption>
              <title>Valor Preditivo do &#205;ndice de Inflama&#231;&#227;o Imune Sist&#234;mica para a Recorr&#234;ncia de Pericardite Aguda Idiop&#225;tica</title>
              <p>Arq Bras Cardiol. 2026; 123(2):e20250437</p>
            </caption>
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              <graphic xlink:href="https://minio.scielo.br/documentstore/1678-4170/SvrfpKR6v6HCym7MtdwZdLh/eb0593964483ce183336ea1598c5c8c330b0b1a5.png" specific-use="scielo-web"/>
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          </fig>
        </p>
      </abstract>
      <kwd-group xml:lang="pt">
        <title>Palavras-chave:</title>
        <kwd>&#205;ndice de Inflama&#231;&#227;o Imune Sist&#234;mica</kwd>
        <kwd>Pericardite</kwd>
        <kwd>Prote&#237;na C-Reativa</kwd>
      </kwd-group>
      <funding-group>
        <funding-statement><bold>Fontes de financiamento</bold> O presente estudo n&#227;o teve fontes de financiamento externas.</funding-statement>
      </funding-group>
      <counts>
        <fig-count count="6"/>
        <table-count count="6"/>
        <equation-count count="0"/>
        <ref-count count="28"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <sec sec-type="intro">
      <title>Introdu&#231;&#227;o</title>
      <p>Pericardite aguda &#233; a doen&#231;a peric&#225;rdica mais comum observada na pr&#225;tica cl&#237;nica.<sup><xref ref-type="bibr" rid="B1">1</xref>,<xref ref-type="bibr" rid="B2">2</xref></sup> Para o diagn&#243;stico, s&#227;o necess&#225;rios pelo menos dois dos seguintes quatro crit&#233;rios: dor tor&#225;cica, atrito peric&#225;rdico, achados eletrocardiogr&#225;ficas anormais &#8211; como depress&#227;o do segmento PR e eleva&#231;&#227;o difusa do segmento ST &#8211; e derrame peric&#225;rdico novo ou em progress&#227;o. Achados adicionais de suporte incluem marcadores inflamat&#243;rios elevados, como Prote&#237;na C-Reativa Ultrassens&#237;vel (PCRus) e velocidade de hemossedimenta&#231;&#227;o (VHS), bem como a detec&#231;&#227;o de inflama&#231;&#227;o por t&#233;cnicas de imagem, como resson&#226;ncia magn&#233;tica card&#237;aca (RMC) ou tomografia computadorizada.<sup><xref ref-type="bibr" rid="B3">3</xref></sup> As complica&#231;&#245;es da pericardite incluem tamponamento card&#237;aco, pericardite constritiva e, mais comumente, pericardite recorrente.<sup><xref ref-type="bibr" rid="B4">4</xref>,<xref ref-type="bibr" rid="B5">5</xref></sup> A pericardite aguda &#233; uma condi&#231;&#227;o inflamat&#243;ria que afeta o peric&#225;rdio. N&#237;veis elevados de PCR-us t&#234;m sido associados &#224; recorr&#234;ncia da pericardite e a desfechos card&#237;acos adversos.<sup><xref ref-type="bibr" rid="B6">6</xref>,<xref ref-type="bibr" rid="B7">7</xref></sup> A busca por biomarcadores confi&#225;veis, capazes de prever a recorr&#234;ncia na pr&#225;tica cl&#237;nica, ainda est&#225; em andamento.</p>
      <p>Recentemente, o &#205;ndice de Inflama&#231;&#227;o Imune Sist&#234;mica (SII, do ingl&#234;s <italic>Systemic Immune-Inflammation Index</italic>), um indicador simples e abrangente, tem ganhado destaque.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> O SII reflete o estado inflamat&#243;rio e imunol&#243;gico geral ao incorporar tr&#234;s biomarcadores: plaquetas, neutr&#243;filos e linf&#243;citos.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> O &#237;ndice &#233; comumente utilizado para prever a presen&#231;a e o progn&#243;stico de diversas neoplasias.<sup><xref ref-type="bibr" rid="B10">10</xref></sup> Estudos recentes tamb&#233;m demonstraram que o SII est&#225; associado ao progn&#243;stico cl&#237;nico em uma variedade de doen&#231;as cardiovasculares.<sup><xref ref-type="bibr" rid="B1">1</xref><xref ref-type="bibr" rid="B1">1</xref></sup> No entanto, a rela&#231;&#227;o entre o SII e o progn&#243;stico de pacientes com pericardite aguda ainda n&#227;o foi estabelecida. O objetivo deste estudo &#233; investigar a associa&#231;&#227;o entre a recorr&#234;ncia da pericardite ap&#243;s um epis&#243;dio agudo e o &#237;ndice SII.</p>
    </sec>
    <sec sec-type="methods">
      <title>M&#233;todo</title>
      <sec>
        <title>Popula&#231;&#227;o e desenho do estudo</title>
        <p>Este estudo do tipo coorte retrospectivo foi conduzido no <italic>Kartal Ko&#351;uyolu High Specialty Training and Research Hospital</italic>, Istambul, Turquia, entre janeiro de 2021 e mar&#231;o de 2024. O estudo envolveu 331 pacientes diagnosticados com pericardite aguda. Cento e cinquenta pacientes foram exclu&#237;dos devido ao tempo insuficiente de acompanhamento ap&#243;s o diagn&#243;stico. Quinze pacientes com fra&#231;&#227;o de eje&#231;&#227;o (FE) inferior a 53&#8211;54% (&lt;53% para homens e &lt;54% para mulheres)<sup><xref ref-type="bibr" rid="B3">3</xref></sup> ou n&#237;veis positivos de troponina, e 56 pacientes com causas espec&#237;ficas subjacentes (como neoplasias, tuberculose, doen&#231;as autoimunes, pericardite purulenta, les&#227;o p&#243;s-mioc&#225;rdica ou p&#243;s-infarto do mioc&#225;rdio, insufici&#234;ncia renal [Taxa de Filtra&#231;&#227;o Glomerular, TFG &lt;60 mL/min], dist&#250;rbios hep&#225;ticos [atividade s&#233;rica de Aspartato Aminotransferase (AST) duas vezes acima do limite normal e &gt;80 U/L ou Alanina Aminotransferase (ALT) &gt;112 U/L. Ap&#243;s as exclus&#245;es, o grupo de estudo consistiu em 110 pacientes diagnosticados com pericardite aguda (<xref ref-type="fig" rid="f02">Figura 1</xref>). O estudo foi autorizado pelo comit&#234; de &#233;tica local.</p>
        <p>
          <fig id="f02">
            <label>Figura 1</label>
            <caption>
              <title>&#8211; Diagrama de fluxo da popula&#231;&#227;o estudada com pericardite aguda.</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-123-02-e20250437-50437-gf01.tif"/></fig>
        </p>
        <p>Todos os dados cl&#237;nicos e demogr&#225;ficos, incluindo idade, sexo e hist&#243;rico m&#233;dico, foram obtidos do sistema digital de prontu&#225;rios do hospital. Todos os pacientes apresentaram seu primeiro epis&#243;dio de pericardite, e o diagn&#243;stico foi estabelecido com base na presen&#231;a de pelo menos dois dos quatro crit&#233;rios descritos nas diretrizes mais recentes: dor tor&#225;cica peric&#225;rdica, anormalidades eletrocardiogr&#225;ficas (nova eleva&#231;&#227;o difusa do segmento ST ou depress&#227;o do PR), derrame peric&#225;rdico e atrito peric&#225;rdico.<sup><xref ref-type="bibr" rid="B3">3</xref></sup> Os eletrocardiogramas de admiss&#227;o, radiografias de t&#243;rax, ecocardiogramas e resultados de exames laboratoriais foram coletados dos registros hospitalares. Os exames laboratoriais inclu&#237;ram hemograma completo, PCR-us, troponina I de alta sensibilidade, bioqu&#237;mica s&#233;rica, testes de fun&#231;&#227;o tireoidiana e rastreamento para doen&#231;as espec&#237;ficas (como doen&#231;as autoimunes e tuberculose). A Raz&#227;o Neutr&#243;filo-Linf&#243;cito (RNL) foi calculada como a raz&#227;o entre a contagem de neutr&#243;filos e linf&#243;citos em amostras de sangue perif&#233;rico. O SII foi calculado como SII = PLT &#215; RNL.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> As contagens sangu&#237;neas completas foram determinadas utilizando um autoanalisador (Horiba ABX Diagnostics, Fran&#231;a), e os n&#237;veis de Prote&#237;na C-Reativa foram medidos pelo m&#233;todo nefelom&#233;trico (Beckman Coulter).</p>
        <p>As imagens ecocardiogr&#225;ficas foram obtidas do sistema digital de prontu&#225;rios do hospital. O diagn&#243;stico de tamponamento card&#237;aco foi estabelecido com base em uma combina&#231;&#227;o de sintomas cl&#237;nicos (como pulso paradoxal, hipotens&#227;o e taquicardia) juntamente com evid&#234;ncias ecocardiogr&#225;ficas. A pericardiocentese foi realizada em pacientes com derrame peric&#225;rdico grave acompanhado de instabilidade hemodin&#226;mica ou quando os achados cl&#237;nicos sugeriam pericardite bacteriana ou neopl&#225;sica.</p>
        <p>De acordo com as recomenda&#231;&#245;es das diretrizes, Anti-Inflamat&#243;rios N&#227;o Esteroides (AINEs) ou aspirina foram utilizados como op&#231;&#227;o de tratamento de primeira linha na dose m&#225;xima tolerada.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B1">1</xref><xref ref-type="bibr" rid="B2">2</xref></sup> A dose m&#225;xima foi administrada por 1-2 semanas e, caso os n&#237;veis de PCR-us se normalizassem, a dose era reduzida gradualmente ao longo de 3-4 semanas. Em todos os casos, colchicina 0,5 mg duas vezes ao dia foi prescrita por 3 meses, com ajustes baseados na depura&#231;&#227;o de creatinina, peso corporal e idade.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B1">1</xref><xref ref-type="bibr" rid="B3">3</xref></sup> Nenhum paciente recebeu terapia com corticosteroides. A pericardite recorrente foi definida como a presen&#231;a de dor tor&#225;cica recorrente associada a pelo menos um dos seguintes sinais: febre, atrito peric&#225;rdico, anormalidades eletrocardiogr&#225;ficas, evid&#234;ncia de derrame peric&#225;rdico, aumento da contagem de leuc&#243;citos ou eleva&#231;&#227;o de PCR-us.<sup><xref ref-type="bibr" rid="B3">3</xref></sup></p>
        <p>Todos os pacientes inclu&#237;dos no estudo foram acompanhados por aproximadamente 18 meses a partir do diagn&#243;stico. Cerca de 10 dias ap&#243;s a alta, foram acompanhados mensalmente durante os 3 meses seguintes e, posteriormente, a cada 3 meses at&#233; completar 18 meses. As consultas cl&#237;nicas inclu&#237;ram exame f&#237;sico, exames laboratoriais (hemograma completo e PCR), ECG e avalia&#231;&#245;es ecocardiogr&#225;ficas. O desfecho do estudo foi a ocorr&#234;ncia da primeira recorr&#234;ncia de pericardite. Os pacientes foram divididos em dois grupos com base no desenvolvimento ou n&#227;o de pericardite recorrente.</p>
      </sec>
      <sec>
        <title>An&#225;lise estat&#237;stica</title>
        <p>O estudo foi aprovado pelo comit&#234; de &#233;tica local e esteve em conformidade com os princ&#237;pios da Declara&#231;&#227;o de Helsinque. As an&#225;lises estat&#237;sticas foram realizadas utilizando o <italic>Statistical Package for the Social Sciences</italic> (SPSS; Vers&#227;o 26.0, IBM). As vari&#225;veis cont&#237;nuas foram apresentadas como m&#233;dia e desvio padr&#227;o, devido &#224; normalidade dos dados. As vari&#225;veis categ&#243;ricas foram apresentadas em frequ&#234;ncias absolutas e relativas. A suposi&#231;&#227;o de normalidade dos dados foi avaliada pelo teste de Kolmogorov&#8211;Smirnov. A compara&#231;&#227;o entre os grupos foi realizada utilizando o teste <italic>t</italic> de Student para amostras independentes ou o teste do qui-quadrado, conforme apropriado. O modelo <italic>Enter</italic> foi utilizado na regress&#227;o log&#237;stica m&#250;ltipla. Os resultados desses modelos foram interpretados em termos de raz&#245;es de chances ajustadas (<italic>aORs</italic>) com intervalos de confian&#231;a de 95% (IC95%). A an&#225;lise da curva ROC (<italic>Receiver Operating Characteristic</italic>) foi utilizada para determinar o ponto de corte ideal de PCR-us e SII na recorr&#234;ncia da pericardite. Os resultados foram avaliados com intervalo de confian&#231;a de 95%, e valores de p &lt; 0,05 foram considerados estatisticamente significativos.</p>
      </sec>
    </sec>
    <sec sec-type="results">
      <title>Resultados</title>
      <p>Os pacientes foram divididos em dois grupos de acordo com a recorr&#234;ncia. A popula&#231;&#227;o do estudo consistiu em 110 pacientes (47 homens, 42,7%), com idade m&#233;dia de 42,8 &#177; 15,2 anos. As caracter&#237;sticas dos pacientes est&#227;o apresentadas na <xref ref-type="table" rid="t1">Tabela 1</xref>.</p>
      <p>
        <table-wrap id="t1">
          <label>Tabela 1</label>
          <caption>
            <title>&#8211; Caracter&#237;sticas demogr&#225;ficas e cl&#237;nicas dos pacientes</title>
          </caption>
          <table frame="hsides" rules="groups">
            <colgroup width="20%">
              <col/>
              <col/>
              <col/>
              <col/>
              <col/>
            </colgroup>
            <thead>
              <tr>
                <th colspan="2" scope="col">Vari&#225;veis</th>
                <th scope="col" style="font-weight:normal"> Sem recorr&#234;ncia (n=81) </th>
                <th scope="col" style="font-weight:normal"> Com recorr&#234;ncia (n=29) </th>
                <th scope="col">Valor p</th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td colspan="2">Idade (anos)</td>
                <td align="center">42,19 &#177;15,5</td>
                <td align="center">42 &#177;15,2</td>
                <td align="center">0,956<sup>1</sup></td>
              </tr>
              <tr>
                <td rowspan="2">G&#234;nero (n)</td>
                <td>Masculino</td>
                <td align="center">34</td>
                <td align="center">13</td>
                <td align="center" rowspan="2">0,790<sup>2</sup></td>
              </tr>
              <tr>
                <td>Feminino</td>
                <td align="center">47</td>
                <td align="center">16</td>
              </tr>
              <tr>
                <td rowspan="2">ECG (n)</td>
                <td>Sem altera&#231;&#227;o</td>
                <td align="center">21</td>
                <td align="center">9</td>
                <td align="center" rowspan="2">0,596<sup>2</sup></td>
              </tr>
              <tr>
                <td>Com altera&#231;&#227;o</td>
                <td align="center">60</td>
                <td align="center">20</td>
              </tr>
              <tr>
                <td rowspan="3">Efus&#227;o peric&#225;rdica (n)</td>
                <td>Leve</td>
                <td align="center">66 (81,4%)</td>
                <td align="center">15 (51,7%)</td>
                <td rowspan="3">
                  <bold>0,006*</bold>
                </td>
              </tr>
              <tr>
                <td>Moderada</td>
                <td align="center">4 (4,9%)</td>
                <td align="center">5 (17,2%)</td>
              </tr>
              <tr>
                <td>Grave</td>
                <td align="center">11 (13,7%)</td>
                <td align="center">9 (31,1%)</td>
              </tr>
              <tr>
                <td colspan="2">Presen&#231;a de dor tor&#225;cica (n)</td>
                <td align="center">70</td>
                <td align="center">27</td>
                <td align="center">0,105<sup>2</sup></td>
              </tr>
              <tr>
                <td colspan="2">Atrito peric&#225;rdico (n)</td>
                <td align="center">17</td>
                <td align="center">2</td>
                <td align="center">0,065<sup>2</sup></td>
              </tr>
            </tbody>
          </table>
          <table-wrap-foot>
            <fn id="TFN1">
              <p>
                <italic><sup>1</sup>Teste t para amostras independentes; <sup>2</sup>Teste do qui-quadrado, *p&lt;0,05; ECG: eletrocardiograma.</italic>
              </p>
            </fn>
          </table-wrap-foot>
        </table-wrap>
      </p>
      <p>Todos os pacientes receberam o mesmo tratamento (AINEs e colchicina). N&#227;o houve diferen&#231;a entre os grupos em rela&#231;&#227;o &#224; idade, sexo, dor tor&#225;cica e altera&#231;&#245;es eletrocardiogr&#225;ficas. As contagens de leuc&#243;citos e neutr&#243;filos foram mais elevadas no grupo com recorr&#234;ncia (p&lt;0,001; <xref ref-type="table" rid="t2">Tabela 2</xref>). SII, RNL e PCR-us tamb&#233;m foram significativamente mais altos nos pacientes com recorr&#234;ncia (p&lt;0,001; p&lt;0,001; p=0,048). Outros achados est&#227;o apresentados na <xref ref-type="table" rid="t2">Tabela 2</xref>.</p>
      <p>
        <table-wrap id="t2">
          <label>Tabela 2</label>
          <caption>
            <title>&#8211; Compara&#231;&#227;o das vari&#225;veis laboratoriais entre os pacientes com e sem recorr&#234;ncia</title>
          </caption>
          <table frame="hsides" rules="groups">
            <colgroup width="25%">
              <col/>
              <col/>
              <col/>
              <col/>
            </colgroup>
            <thead>
              <tr>
                <th align="left">Vari&#225;veis</th>
                <th style="font-weight:normal"> Sem recorr&#234;ncia (n=81) </th>
                <th style="font-weight:normal"> Com recorr&#234;ncia (n=29) </th>
                <th>Valor p</th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td>PCR-us (mg/L)</td>
                <td align="center">29,1 &#177;40,9</td>
                <td align="center">49,5 &#177;62,2</td>
                <td align="center">0,048</td>
              </tr>
              <tr>
                <td>Leuc&#243;citos (c&#233;lulas/&#181;L)</td>
                <td align="center">8,7 &#177;3,2</td>
                <td align="center">12 &#177;4,7</td>
                <td align="center">0,001*</td>
              </tr>
              <tr>
                <td>Hemoglobina (g/dL)</td>
                <td align="center">13,2 &#177;1,7</td>
                <td align="center">12,8&#177;2</td>
                <td align="center">0,306</td>
              </tr>
              <tr>
                <td>Plaquetas (c&#233;lulas/&#181;L)</td>
                <td align="center">267,4 &#177;86,8</td>
                <td align="center">312,2 &#177;126,3</td>
                <td align="center">0,086</td>
              </tr>
              <tr>
                <td>Neutr&#243;filos (c&#233;lulas/&#181;L)</td>
                <td align="center">5,4&#177; 2,7</td>
                <td align="center">9 &#177; 4,5</td>
                <td align="center">&lt;0,001**</td>
              </tr>
              <tr>
                <td>Linf&#243;citos (c&#233;lulas/&#181;L)</td>
                <td align="center">2,3&#177;1,13</td>
                <td align="center">2,5&#177;3,2</td>
                <td align="center">0,786</td>
              </tr>
              <tr>
                <td>SII</td>
                <td align="center">783,2 &#177; 770,2</td>
                <td align="center">1664,2 &#177;1086,6</td>
                <td align="center">&lt;0,001**</td>
              </tr>
              <tr>
                <td>Rela&#231;&#227;o Neutr&#243;filo/Linf&#243;cito</td>
                <td align="center">2,9 &#177; 2,5</td>
                <td align="center">6 &#177; 2,8</td>
                <td align="center">&lt;0,001**</td>
              </tr>
            </tbody>
          </table>
          <table-wrap-foot>
            <fn id="TFN2">
              <p>
                <italic>PCR: Prote&#237;na C-Reativa; Teste t para amostras independentes, *p&lt;0.05, **p&lt;0.001. SII: &#205;ndice de Inflama&#231;&#227;o Imunol&#243;gica Sist&#234;mica.</italic>
              </p>
            </fn>
          </table-wrap-foot>
        </table-wrap>
      </p>
      <p>Na an&#225;lise de regress&#227;o, as vari&#225;veis de confus&#227;o inclu&#237;ram SII, derrame peric&#225;rdico e PCR-us. O SII esteve associado de forma independente &#224; recorr&#234;ncia [Raz&#227;o de Chances (OR) = 1,4; IC95% (0,96-1,54); p=0,002]. Outras vari&#225;veis est&#227;o apresentadas na <xref ref-type="table" rid="t3">Tabela 3</xref>.</p>
      <p>
        <table-wrap id="t3">
          <label>Tabela 3</label>
          <caption>
            <title>&#8211; An&#225;lise de regress&#227;o log&#237;stica para prever recorr&#234;ncia</title>
          </caption>
          <table frame="hsides" rules="groups">
            <colgroup width="25%">
              <col/>
              <col/>
              <col/>
              <col/>
            </colgroup>
            <thead>
              <tr>
                <th align="left">Vari&#225;veis</th>
                <th>Odds Ratio</th>
                <th>IC95%</th>
                <th>Valor p</th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td>SII</td>
                <td align="center">1,4</td>
                <td align="center">0,96-1,54</td>
                <td align="center">0,002</td>
              </tr>
              <tr>
                <td>Efus&#227;o Peric&#225;rdica</td>
                <td align="center">1,2</td>
                <td align="center">0,78-2,7</td>
                <td align="center">0,23</td>
              </tr>
              <tr>
                <td>PCR-us</td>
                <td align="center">0,9</td>
                <td align="center">0,98-1,009</td>
                <td align="center">0,8</td>
              </tr>
            </tbody>
          </table>
          <table-wrap-foot>
            <fn id="TFN3">
              <p>
                <italic>SII: &#205;ndice de Inflama&#231;&#227;o Imunol&#243;gica Sist&#234;mica; PCR-us: Prote&#237;na C-Reativa Ulltrassens&#237;vel</italic>
              </p>
            </fn>
          </table-wrap-foot>
        </table-wrap>
      </p>
      <p>Na an&#225;lise ROC (<xref ref-type="fig" rid="f03">Figura 2</xref>), o SII foi identificado como o par&#226;metro mais associado &#224; recorr&#234;ncia. O ponto de corte determinado para o SII no diagn&#243;stico de recorr&#234;ncia foi 462,5, com sensibilidade de 82,8% e especificidade de 40%. Os resultados da an&#225;lise ROC est&#227;o mostrados na <xref ref-type="fig" rid="f03">Figura 2</xref> (AUC: 0,751; IC: 0,630&#8211;0,872; p=0,001).</p>
      <p>
        <fig id="f03">
          <label>Figura 2</label>
          <caption>
            <title>&#8211; An&#225;lise da curva ROC (Receiver Operating Characteristic).</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-123-02-e20250437-50437-gf02.tif"/></fig>
      </p>
    </sec>
    <sec sec-type="discussion">
      <title>D&#305;scuss&#227;o</title>
      <p>Nosso estudo demonstrou que o SII &#233; um par&#226;metro simples e de baixo custo para prever a recorr&#234;ncia em pacientes com pericardite aguda. A pericardite aguda &#233; a manifesta&#231;&#227;o mais frequente das doen&#231;as peric&#225;rdicas e est&#225; associada a significativa morbidade. A pericardite recorrente, a complica&#231;&#227;o mais comum ap&#243;s a pericardite aguda, tem impacto substancial na qualidade de vida dos pacientes.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B14">14</xref></sup> Identificar indiv&#237;duos com risco de recorr&#234;ncia continua sendo um grande desafio cl&#237;nico.</p>
      <p>Na pr&#225;tica cl&#237;nica, identificar pacientes com alto risco de recorr&#234;ncia ap&#243;s um primeiro epis&#243;dio de pericardite aguda &#233; fundamental, j&#225; que a pericardite recorrente leva a ataques repetidos e &#224; progress&#227;o para doen&#231;a cr&#244;nica.<sup><xref ref-type="bibr" rid="B15">15</xref></sup> No entanto, atualmente n&#227;o h&#225; marcador espec&#237;fico ou processo diagn&#243;stico para detectar esses pacientes. Indiv&#237;duos com risco aumentado de recorr&#234;ncia podem se beneficiar de acompanhamento mais pr&#243;ximo e tratamento m&#233;dico mais intensivo. Al&#233;m disso, modalidades avan&#231;adas de imagem, como a RMC, podem ser &#250;teis antes da suspens&#227;o da terapia. Com sua capacidade de demonstrar inflama&#231;&#227;o tecidual persistente, a RMC pode auxiliar na determina&#231;&#227;o da dura&#231;&#227;o do tratamento.<sup><xref ref-type="bibr" rid="B3">3</xref></sup></p>
      <p>Pacientes com alto risco de recorr&#234;ncia ap&#243;s um primeiro epis&#243;dio de pericardite aguda n&#227;o foram adequadamente investigados at&#233; o momento. De acordo com estudos anteriores, o uso de colchicina durante o ataque inicial demonstrou ser o fator mais eficaz na redu&#231;&#227;o da recorr&#234;ncia. Por outro lado, o uso de corticosteroides, etiologias espec&#237;ficas da pericardite aguda, tratamento inadequado e a presen&#231;a de derrame peric&#225;rdico foram todos associados a maiores taxas de recorr&#234;ncia.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B5">5</xref>,<xref ref-type="bibr" rid="B16">16</xref>-<xref ref-type="bibr" rid="B20">20</xref></sup></p>
      <p>Marcadores inflamat&#243;rios s&#227;o utilizados para prever a recorr&#234;ncia na pericardite aguda. A PCR-us pode ser usada tanto para o diagn&#243;stico quanto para avaliar a resposta ao tratamento.<sup><xref ref-type="bibr" rid="B6">6</xref>,<xref ref-type="bibr" rid="B21">21</xref></sup> Imazio et al.<sup><xref ref-type="bibr" rid="B7">7</xref></sup> demonstraram que a eleva&#231;&#227;o persistente da PCR-us pode prever a recorr&#234;ncia da pericardite. Estudos indicaram que o NLR, outro marcador inflamat&#243;rio, &#233; mais eficaz que a PCR-us na predi&#231;&#227;o da recorr&#234;ncia da pericardite.<sup><xref ref-type="bibr" rid="B2">2</xref><xref ref-type="bibr" rid="B2">2</xref></sup> Um estudo recente mostrou que o D-d&#237;mero &#233; um biomarcador potencial para avalia&#231;&#227;o progn&#243;stica na pericardite aguda e complicada.<sup><xref ref-type="bibr" rid="B2">2</xref><xref ref-type="bibr" rid="B3">3</xref></sup> Em outro estudo, o Infla Score &#8212; desenvolvido pela combina&#231;&#227;o de diversos marcadores inflamat&#243;rios &#8212; mostrou-se eficaz na predi&#231;&#227;o da recorr&#234;ncia da pericardite.<sup><xref ref-type="bibr" rid="B24">24</xref></sup> O SII tem se mostrado, em estudos, um marcador inflamat&#243;rio mais potente do que NLR ou plaqueta isoladamente, com melhor valor progn&#243;stico.<sup><xref ref-type="bibr" rid="B25">25</xref></sup> Neste estudo, verificamos que o SII esteve mais significativamente associado &#224; probabilidade de recorr&#234;ncia da pericardite do que NLR, plaqueta e PCR-us isoladamente, sugerindo que o SII pode servir como um preditor mais confi&#225;vel do estado inflamat&#243;rio dos pacientes, resultando em maior confiabilidade na predi&#231;&#227;o da recorr&#234;ncia da pericardite.</p>
      <p>Hipotetizamos que o uso do SII &#8211; um &#237;ndice simples, mais abrangente e menos vari&#225;vel, que incorpora simultaneamente m&#250;ltiplos biomarcadores inflamat&#243;rios &#8211; pode servir como par&#226;metro complementar &#224; PCR, rotineiramente utilizado no acompanhamento, e tamb&#233;m fornecer valor progn&#243;stico significativo na detec&#231;&#227;o de inflama&#231;&#227;o ativa subjacente na pericardite aguda e recorrente. Composto por neutr&#243;filos, linf&#243;citos e plaquetas, o SII foi recentemente desenvolvido como biomarcador abrangente de inflama&#231;&#227;o sist&#234;mica.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Originalmente, o SII foi identificado como um fator progn&#243;stico poderoso em pacientes com carcinoma hepatocelular.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> Atualmente, o SII &#233; amplamente empregado como marcador preditivo e progn&#243;stico em diversas doen&#231;as, incluindo c&#226;ncer, doen&#231;as cardiovasculares e renais.<sup><xref ref-type="bibr" rid="B26">26</xref>-<xref ref-type="bibr" rid="B28">28</xref></sup></p>
      <p>O SII ganhou popularidade nos &#250;ltimos anos devido ao seu papel como marcador inflamat&#243;rio, semelhante &#224; PCR-us. Trata-se de um par&#226;metro simples, adequado para uso rotineiro, e sua variabilidade &#233; menor do que a da PCR-us. Em nosso estudo, o SII foi identificado como um preditor independente de pericardite recorrente, sugerindo que pode servir como um par&#226;metro valioso na pr&#225;tica cl&#237;nica. Quando utilizado em conjunto com a PCR-us, em vez de como substituto, o SII pode melhorar a predi&#231;&#227;o de pacientes em risco de recorr&#234;ncia da pericardite.</p>
      <p>Em nosso conheciento, n&#227;o foram conduzidas pesquisas em indiv&#237;duos com pericardite aguda para explorar a associa&#231;&#227;o entre o SII e o progn&#243;stico. Em nosso estudo, o SII superou a PCR-us na predi&#231;&#227;o da recorr&#234;ncia da pericardite.</p>
      <p>Este estudo apresenta v&#225;rias limita&#231;&#245;es. Em primeiro lugar, o tamanho relativamente pequeno da amostra, composta por 110 pacientes, pode limitar a generaliza&#231;&#227;o dos achados para cen&#225;rios cl&#237;nicos mais amplos e popula&#231;&#245;es mais diversas. Al&#233;m disso, o desenho retrospectivo do estudo implicou que certas vari&#225;veis &#8211; como ades&#227;o ao tratamento, dura&#231;&#227;o dos sintomas e consist&#234;ncia do acompanhamento &#8211; n&#227;o pudessem ser totalmente padronizadas ou controladas. A aus&#234;ncia de medi&#231;&#245;es seriadas dos par&#226;metros laboratoriais tamb&#233;m representa uma limita&#231;&#227;o significativa.</p>
      <p>Adicionalmente, apenas pacientes com pericardite isolada foram inclu&#237;dos. A miopericardite e a perimiocardite, que envolvem inflama&#231;&#227;o concomitante do peric&#225;rdio e mioc&#225;rdio, podem apresentar sintomas cl&#237;nicos e achados iniciais semelhantes, aumentando o risco de classifica&#231;&#227;o incorreta na aus&#234;ncia de exames de imagem avan&#231;ados. Contudo, como t&#233;cnicas avan&#231;adas de imagem (por exemplo, a RMC) n&#227;o est&#227;o rotineiramente dispon&#237;veis em todos os cen&#225;rios cl&#237;nicos, esses pacientes foram exclu&#237;dos. Embora essa abordagem tenha permitido a sele&#231;&#227;o de uma popula&#231;&#227;o de estudo mais homog&#234;nea e de menor risco, ela limita a generaliza&#231;&#227;o dos resultados para todo o espectro das doen&#231;as peric&#225;rdicas. Al&#233;m disso, de um total de 331 pacientes, apenas 110 que atenderam aos crit&#233;rios de inclus&#227;o predefinidos e que possu&#237;am dados cl&#237;nicos e de acompanhamento suficientes foram inclu&#237;dos na an&#225;lise. Como dados cl&#237;nicos, laboratoriais ou de tratamento detalhados n&#227;o foram coletados de forma sistem&#225;tica para os 221 pacientes exclu&#237;dos, n&#227;o foi poss&#237;vel realizar uma an&#225;lise separada desse grupo. Isso pode ter introduzido um vi&#233;s de sele&#231;&#227;o e reduzido a validade externa do estudo.</p>
      <p>Por fim, embora todos os pacientes tenham recebido prescri&#231;&#227;o de AINEs e colchicina na alta, em conformidade com as diretrizes da <italic>European Society of Cardiology</italic>, a ades&#227;o ao tratamento ap&#243;s a alta n&#227;o p&#244;de ser monitorada de forma sistem&#225;tica devido ao car&#225;ter retrospectivo do estudo. M&#233;todos comumente empregados em ensaios cl&#237;nicos randomizados, como acompanhamento telef&#244;nico, entrevistas presenciais ou contagem de comprimidos, n&#227;o foram aplicados. Consequentemente, a uniformidade do tratamento e a avalia&#231;&#227;o da efic&#225;cia terap&#234;utica representam limita&#231;&#245;es adicionais.</p>
      <p>O SII foi identificado como um preditor independente para recorr&#234;ncia de pericardite em pacientes com pericardite aguda durante o acompanhamento. Nosso estudo indica que o SII pode ser utilizado para classifica&#231;&#227;o de risco, em conjunto com a PCR-us, na predi&#231;&#227;o da recorr&#234;ncia da pericardite (<xref ref-type="fig" rid="f01">Figura Central</xref>).</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <title>Refer&#234;ncias</title>
      <ref id="B1">
        <label>1</label>
        <mixed-citation>1. Spodick DH. Acute Pericarditis: Current Concepts and Practice. JAMA. 2003;289(9):1150-3. doi: 10.1001/jama.289.9.1150.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Spodick</surname>
              <given-names>DH</given-names>
            </name>
          </person-group>
          <article-title>Acute Pericarditis: Current Concepts and Practice</article-title>
          <source>JAMA</source>
          <year>2003</year>
          <volume>289</volume>
          <issue>9</issue>
          <fpage>1150</fpage>
          <lpage>1153</lpage>
          <pub-id pub-id-type="doi">10.1001/jama.289.9.1150</pub-id>
        </element-citation>
      </ref>
      <ref id="B2">
        <label>2</label>
        <mixed-citation>2. Imazio M, Cecchi E, Demichelis B, Chinaglia A, Ierna S, Demarie D, et al. Myopericarditis versus Viral or Idiopathic Acute Pericarditis. Heart. 2008;94(4):498-501. doi: 10.1136/hrt.2006.104067.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Cecchi</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Demichelis</surname>
              <given-names>B</given-names>
            </name>
            <name>
              <surname>Chinaglia</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Ierna</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Demarie</surname>
              <given-names>D</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Myopericarditis versus Viral or Idiopathic Acute Pericarditis</article-title>
          <source>Heart</source>
          <year>2008</year>
          <volume>94</volume>
          <issue>4</issue>
          <fpage>498</fpage>
          <lpage>501</lpage>
          <pub-id pub-id-type="doi">10.1136/hrt.2006.104067</pub-id>
        </element-citation>
      </ref>
      <ref id="B3">
        <label>3</label>
        <mixed-citation>3. Adler Y, Charron P, Imazio M, Badano L, Bar&#243;n-Esquivias G, Bogaert J, et al. 2015 ESC Guidelines for the Diagnosis and Management of Pericardial Diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC) Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2015;36(42):2921-64. doi: 10.1093/eurheartj/ehv318.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Adler</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Charron</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Badano</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Bar&#243;n-Esquivias</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Bogaert</surname>
              <given-names>J</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>2015 ESC Guidelines for the Diagnosis and Management of Pericardial Diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC) Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS)</article-title>
          <source>Eur Heart J</source>
          <year>2015</year>
          <volume>36</volume>
          <issue>42</issue>
          <fpage>2921</fpage>
          <lpage>2964</lpage>
          <pub-id pub-id-type="doi">10.1093/eurheartj/ehv318</pub-id>
        </element-citation>
      </ref>
      <ref id="B4">
        <label>4</label>
        <mixed-citation>4. Imazio M, Spodick DH, Brucato A, Trinchero R, Adler Y. Controversial Issues in the Management of Pericardial Diseases. Circulation. 2010;121(7):916-28. doi: 10.1161/CIRCULATIONAHA.108.844753.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Spodick</surname>
              <given-names>DH</given-names>
            </name>
            <name>
              <surname>Brucato</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Trinchero</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Adler</surname>
              <given-names>Y</given-names>
            </name>
          </person-group>
          <article-title>Controversial Issues in the Management of Pericardial Diseases</article-title>
          <source>Circulation</source>
          <year>2010</year>
          <volume>121</volume>
          <issue>7</issue>
          <fpage>916</fpage>
          <lpage>928</lpage>
          <pub-id pub-id-type="doi">10.1161/CIRCULATIONAHA.108.844753</pub-id>
        </element-citation>
      </ref>
      <ref id="B5">
        <label>5</label>
        <mixed-citation>5. Lazaros G, Tousoulis D. Interleukin-1 Inhibition with Anakinra: A Valuable Ally to Reverse Constrictive Pericarditis? Heart. 2020;106(20):1540-2. doi: 10.1136/heartjnl-2020-317187.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lazaros</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Tousoulis</surname>
              <given-names>D</given-names>
            </name>
          </person-group>
          <article-title>Interleukin-1 Inhibition with Anakinra: A Valuable Ally to Reverse Constrictive Pericarditis?</article-title>
          <source>Heart</source>
          <year>2020</year>
          <volume>106</volume>
          <issue>20</issue>
          <fpage>1540</fpage>
          <lpage>1542</lpage>
          <pub-id pub-id-type="doi">10.1136/heartjnl-2020-317187</pub-id>
        </element-citation>
      </ref>
      <ref id="B6">
        <label>6</label>
        <mixed-citation>6. Mager A, Hammer Y, Ofek H, Kedmi I, Iakobishvili Z, Kornowski R. Prognostic and Diagnostic Significance of Serum High-Sensitivity C-Reactive Protein Level in Patients with Acute Idiopathic Pericarditis. Isr Med Assoc J. 2019;21(11):747-751.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Mager</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Hammer</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Ofek</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Kedmi</surname>
              <given-names>I</given-names>
            </name>
            <name>
              <surname>Iakobishvili</surname>
              <given-names>Z</given-names>
            </name>
            <name>
              <surname>Kornowski</surname>
              <given-names>R</given-names>
            </name>
          </person-group>
          <article-title>Prognostic and Diagnostic Significance of Serum High-Sensitivity C-Reactive Protein Level in Patients with Acute Idiopathic Pericarditis</article-title>
          <source>Isr Med Assoc J</source>
          <year>2019</year>
          <volume>21</volume>
          <issue>11</issue>
          <fpage>747</fpage>
          <lpage>751</lpage>
        </element-citation>
      </ref>
      <ref id="B7">
        <label>7</label>
        <mixed-citation>7. Imazio M, Brucato A, Maestroni S, Cumetti D, Dominelli A, Natale G, et al. Prevalence of C-Reactive Protein Elevation and Time Course of Normalization in Acute Pericarditis: Implications for the Diagnosis, Therapy, and Prognosis of Pericarditis. Circulation. 2011;123(10):1092-7. doi: 10.1161/CIRCULATIONAHA.110.986372.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Brucato</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Maestroni</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Cumetti</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Dominelli</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Natale</surname>
              <given-names>G</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Prevalence of C-Reactive Protein Elevation and Time Course of Normalization in Acute Pericarditis: Implications for the Diagnosis, Therapy, and Prognosis of Pericarditis</article-title>
          <source>Circulation</source>
          <year>2011</year>
          <volume>123</volume>
          <issue>10</issue>
          <fpage>1092</fpage>
          <lpage>1097</lpage>
          <pub-id pub-id-type="doi">10.1161/CIRCULATIONAHA.110.986372</pub-id>
        </element-citation>
      </ref>
      <ref id="B8">
        <label>8</label>
        <mixed-citation>8. Hu B, Yang XR, Xu Y, Sun YF, Sun C, Guo W, et al. Systemic Immune-Inflammation Index Predicts Prognosis of Patients after Curative Resection for Hepatocellular Carcinoma. Clin Cancer Res. 2014;20(23):6212-22. doi: 10.1158/1078-0432.CCR-14-0442.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Hu</surname>
              <given-names>B</given-names>
            </name>
            <name>
              <surname>Yang</surname>
              <given-names>XR</given-names>
            </name>
            <name>
              <surname>Xu</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Sun</surname>
              <given-names>YF</given-names>
            </name>
            <name>
              <surname>Sun</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Guo</surname>
              <given-names>W</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Systemic Immune-Inflammation Index Predicts Prognosis of Patients after Curative Resection for Hepatocellular Carcinoma</article-title>
          <source>Clin Cancer Res</source>
          <year>2014</year>
          <volume>20</volume>
          <issue>23</issue>
          <fpage>6212</fpage>
          <lpage>6222</lpage>
          <pub-id pub-id-type="doi">10.1158/1078-0432.CCR-14-0442</pub-id>
        </element-citation>
      </ref>
      <ref id="B9">
        <label>9</label>
        <mixed-citation>9. Aziz MH, Sideras K, Aziz NA, Mauff K, Haen R, Roos D, et al. The Systemic-Immune-Inflammation Index Independently Predicts Survival and Recurrence in Resectable Pancreatic Cancer and its Prognostic Value Depends on Bilirubin Levels: A Retrospective Multicenter Cohort Study. Ann Surg. 2019;270(1):139-46. doi: 10.1097/SLA.0000000000002660.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Aziz</surname>
              <given-names>MH</given-names>
            </name>
            <name>
              <surname>Sideras</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Aziz</surname>
              <given-names>NA</given-names>
            </name>
            <name>
              <surname>Mauff</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Haen</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Roos</surname>
              <given-names>D</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>The Systemic-Immune-Inflammation Index Independently Predicts Survival and Recurrence in Resectable Pancreatic Cancer and its Prognostic Value Depends on Bilirubin Levels: A Retrospective Multicenter Cohort Study</article-title>
          <source>Ann Surg</source>
          <year>2019</year>
          <volume>270</volume>
          <issue>1</issue>
          <fpage>139</fpage>
          <lpage>146</lpage>
          <pub-id pub-id-type="doi">10.1097/SLA.0000000000002660</pub-id>
        </element-citation>
      </ref>
      <ref id="B10">
        <label>10</label>
        <mixed-citation>10. Yang R, Chang Q, Meng X, Gao N, Wang W. Prognostic Value of Systemic Immune-Inflammation Index in Cancer: A Meta-Analysis. J Cancer. 2018;9(18):3295-302. doi: 10.7150/jca.25691.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Yang</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Chang</surname>
              <given-names>Q</given-names>
            </name>
            <name>
              <surname>Meng</surname>
              <given-names>X</given-names>
            </name>
            <name>
              <surname>Gao</surname>
              <given-names>N</given-names>
            </name>
            <name>
              <surname>Wang</surname>
              <given-names>W</given-names>
            </name>
          </person-group>
          <article-title>Prognostic Value of Systemic Immune-Inflammation Index in Cancer: A Meta-Analysis</article-title>
          <source>J Cancer</source>
          <year>2018</year>
          <volume>9</volume>
          <issue>18</issue>
          <fpage>3295</fpage>
          <lpage>3302</lpage>
          <pub-id pub-id-type="doi">10.7150/jca.25691</pub-id>
        </element-citation>
      </ref>
      <ref id="B11">
        <label>11</label>
        <mixed-citation>11. Yang YL, Wu CH, Hsu PF, Chen SC, Huang SS, Chan WL, et al. Systemic Immune-Inflammation Index (SII) Predicted Clinical Outcome in Patients with Coronary Artery Disease. Eur J Clin Invest. 2020;50(5):e13230. doi: 10.1111/eci.13230.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Yang</surname>
              <given-names>YL</given-names>
            </name>
            <name>
              <surname>Wu</surname>
              <given-names>CH</given-names>
            </name>
            <name>
              <surname>Hsu</surname>
              <given-names>PF</given-names>
            </name>
            <name>
              <surname>Chen</surname>
              <given-names>SC</given-names>
            </name>
            <name>
              <surname>Huang</surname>
              <given-names>SS</given-names>
            </name>
            <name>
              <surname>Chan</surname>
              <given-names>WL</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Systemic Immune-Inflammation Index (SII) Predicted Clinical Outcome in Patients with Coronary Artery Disease</article-title>
          <source>Eur J Clin Invest</source>
          <year>2020</year>
          <volume>50</volume>
          <issue>5</issue>
          <elocation-id>e13230</elocation-id>
          <pub-id pub-id-type="doi">10.1111/eci.13230</pub-id>
        </element-citation>
      </ref>
      <ref id="B12">
        <label>12</label>
        <mixed-citation>12. Lazaros G, Imazio M, Brucato A, Tousoulis D. Untying the Gordian Knot of Pericardial Diseases: A Pragmatic Approach. Hellenic J Cardiol. 2016;57(5):315-22. doi: 10.1016/j.hjc.2016.11.024.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lazaros</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Brucato</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Tousoulis</surname>
              <given-names>D</given-names>
            </name>
          </person-group>
          <article-title>Untying the Gordian Knot of Pericardial Diseases: A Pragmatic Approach</article-title>
          <source>Hellenic J Cardiol</source>
          <year>2016</year>
          <volume>57</volume>
          <issue>5</issue>
          <fpage>315</fpage>
          <lpage>322</lpage>
          <pub-id pub-id-type="doi">10.1016/j.hjc.2016.11.024</pub-id>
        </element-citation>
      </ref>
      <ref id="B13">
        <label>13</label>
        <mixed-citation>13. Imazio M, Brucato A, Trinchero R, Spodick D, Adler Y. Colchicine for Pericarditis: Hype or Hope? Eur Heart J. 2009;30(5):532-9. doi: 10.1093/eurheartj/ehn608.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Brucato</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Trinchero</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Spodick</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Adler</surname>
              <given-names>Y</given-names>
            </name>
          </person-group>
          <article-title>Colchicine for Pericarditis: Hype or Hope?</article-title>
          <source>Eur Heart J</source>
          <year>2009</year>
          <volume>30</volume>
          <issue>5</issue>
          <fpage>532</fpage>
          <lpage>539</lpage>
          <pub-id pub-id-type="doi">10.1093/eurheartj/ehn608</pub-id>
        </element-citation>
      </ref>
      <ref id="B14">
        <label>14</label>
        <mixed-citation>14. Imazio M, Gaita F. Diagnosis and Treatment of Pericarditis. Heart. 2015;101(14):1159-68. doi: 10.1136/heartjnl-2014-306362.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Gaita</surname>
              <given-names>F</given-names>
            </name>
          </person-group>
          <article-title>Diagnosis and Treatment of Pericarditis</article-title>
          <source>Heart</source>
          <year>2015</year>
          <volume>101</volume>
          <issue>14</issue>
          <fpage>1159</fpage>
          <lpage>1168</lpage>
          <pub-id pub-id-type="doi">10.1136/heartjnl-2014-306362</pub-id>
        </element-citation>
      </ref>
      <ref id="B15">
        <label>15</label>
        <mixed-citation>15. Cremer PC, Kumar A, Kontzias A, Tan CD, Rodriguez ER, Imazio M, et al. Complicated Pericarditis: Understanding Risk Factors and Pathophysiology to Inform Imaging and Treatment. J Am Coll Cardiol. 2016;68(21):2311-28. doi: 10.1016/j.jacc.2016.07.785.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Cremer</surname>
              <given-names>PC</given-names>
            </name>
            <name>
              <surname>Kumar</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Kontzias</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Tan</surname>
              <given-names>CD</given-names>
            </name>
            <name>
              <surname>Rodriguez</surname>
              <given-names>ER</given-names>
            </name>
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Complicated Pericarditis: Understanding Risk Factors and Pathophysiology to Inform Imaging and Treatment</article-title>
          <source>J Am Coll Cardiol</source>
          <year>2016</year>
          <volume>68</volume>
          <issue>21</issue>
          <fpage>2311</fpage>
          <lpage>2328</lpage>
          <pub-id pub-id-type="doi">10.1016/j.jacc.2016.07.785</pub-id>
        </element-citation>
      </ref>
      <ref id="B16">
        <label>16</label>
        <mixed-citation>16. Lazaros G, Antonopoulos AS, Lazarou E, Vlachopoulos C, Vogiatzi G, Vassilopoulos D, et al. Age- and Sex-Based Differences in Patients with Acute Pericarditis. Eur J Clin Invest. 2021;51(3):e13392. doi: 10.1111/eci.13392.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lazaros</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Antonopoulos</surname>
              <given-names>AS</given-names>
            </name>
            <name>
              <surname>Lazarou</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Vlachopoulos</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Vogiatzi</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Vassilopoulos</surname>
              <given-names>D</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Age- and Sex-Based Differences in Patients with Acute Pericarditis</article-title>
          <source>Eur J Clin Invest</source>
          <year>2021</year>
          <volume>51</volume>
          <issue>3</issue>
          <elocation-id>e13392</elocation-id>
          <pub-id pub-id-type="doi">10.1111/eci.13392</pub-id>
        </element-citation>
      </ref>
      <ref id="B17">
        <label>17</label>
        <mixed-citation>17. Lazaros G, Antonopoulos AS, Vlachopoulos C, Oikonomou E, Karavidas A, Chrysochoou C, et al. Predictors of Switching from Nonsteroidal Anti-Inflammatory Drugs to Corticosteroids in Patients with Acute Pericarditis and Impact on Clinical Outcome. Hellenic J Cardiol. 2019;60(6):357-63. doi: 10.1016/j.hjc.2018.04.001.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lazaros</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Antonopoulos</surname>
              <given-names>AS</given-names>
            </name>
            <name>
              <surname>Vlachopoulos</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Oikonomou</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Karavidas</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Chrysochoou</surname>
              <given-names>C</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Predictors of Switching from Nonsteroidal Anti-Inflammatory Drugs to Corticosteroids in Patients with Acute Pericarditis and Impact on Clinical Outcome</article-title>
          <source>Hellenic J Cardiol</source>
          <year>2019</year>
          <volume>60</volume>
          <issue>6</issue>
          <fpage>357</fpage>
          <lpage>363</lpage>
          <pub-id pub-id-type="doi">10.1016/j.hjc.2018.04.001</pub-id>
        </element-citation>
      </ref>
      <ref id="B18">
        <label>18</label>
        <mixed-citation>18. Chiabrando JG, Bonaventura A, Vecchi&#233; A, Wohlford GF, Mauro AG, Jordan JH, et al. Management of Acute and Recurrent Pericarditis: JACC State-of-the-Art Review. J Am Coll Cardiol. 2020;75(1):76-92. doi: 10.1016/j.jacc.2019.11.021.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Chiabrando</surname>
              <given-names>JG</given-names>
            </name>
            <name>
              <surname>Bonaventura</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Vecchi&#233;</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Wohlford</surname>
              <given-names>GF</given-names>
            </name>
            <name>
              <surname>Mauro</surname>
              <given-names>AG</given-names>
            </name>
            <name>
              <surname>Jordan</surname>
              <given-names>JH</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Management of Acute and Recurrent Pericarditis: JACC State-of-the-Art Review</article-title>
          <source>J Am Coll Cardiol</source>
          <year>2020</year>
          <volume>75</volume>
          <issue>1</issue>
          <fpage>76</fpage>
          <lpage>92</lpage>
          <pub-id pub-id-type="doi">10.1016/j.jacc.2019.11.021</pub-id>
        </element-citation>
      </ref>
      <ref id="B19">
        <label>19</label>
        <mixed-citation>19. Alraies MC, AlJaroudi W, Yarmohammadi H, Yingchoncharoen T, Schuster A, Senapati A, et al. Usefulness of Cardiac Magnetic Resonance-Guided Management in Patients with Recurrent Pericarditis. Am J Cardiol. 2015;115(4):542-7. doi: 10.1016/j.amjcard.2014.11.041.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Alraies</surname>
              <given-names>MC</given-names>
            </name>
            <name>
              <surname>AlJaroudi</surname>
              <given-names>W</given-names>
            </name>
            <name>
              <surname>Yarmohammadi</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Yingchoncharoen</surname>
              <given-names>T</given-names>
            </name>
            <name>
              <surname>Schuster</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Senapati</surname>
              <given-names>A</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Usefulness of Cardiac Magnetic Resonance-Guided Management in Patients with Recurrent Pericarditis</article-title>
          <source>Am J Cardiol</source>
          <year>2015</year>
          <volume>115</volume>
          <issue>4</issue>
          <fpage>542</fpage>
          <lpage>547</lpage>
          <pub-id pub-id-type="doi">10.1016/j.amjcard.2014.11.041</pub-id>
        </element-citation>
      </ref>
      <ref id="B20">
        <label>20</label>
        <mixed-citation>20. Imazio M, Cecchi E, Demichelis B, Ierna S, Demarie D, Ghisio A, et al. Indicators of Poor Prognosis of Acute Pericarditis. Circulation. 2007;115(21):2739-44. doi: 10.1161/CIRCULATIONAHA.106.662114.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Cecchi</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Demichelis</surname>
              <given-names>B</given-names>
            </name>
            <name>
              <surname>Ierna</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Demarie</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Ghisio</surname>
              <given-names>A</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Indicators of Poor Prognosis of Acute Pericarditis</article-title>
          <source>Circulation</source>
          <year>2007</year>
          <volume>115</volume>
          <issue>21</issue>
          <fpage>2739</fpage>
          <lpage>2744</lpage>
          <pub-id pub-id-type="doi">10.1161/CIRCULATIONAHA.106.662114</pub-id>
        </element-citation>
      </ref>
      <ref id="B21">
        <label>21</label>
        <mixed-citation>21. Imazio M, Brucato A, Trinchero R, Spodick D, Adler Y. Individualized Therapy for Pericarditis. Expert Rev Cardiovasc Ther. 2009;7(8):965-75. doi: 10.1586/erc.09.82.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Imazio</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Brucato</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Trinchero</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Spodick</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Adler</surname>
              <given-names>Y</given-names>
            </name>
          </person-group>
          <article-title>Individualized Therapy for Pericarditis</article-title>
          <source>Expert Rev Cardiovasc Ther</source>
          <year>2009</year>
          <volume>7</volume>
          <issue>8</issue>
          <fpage>965</fpage>
          <lpage>975</lpage>
          <pub-id pub-id-type="doi">10.1586/erc.09.82</pub-id>
        </element-citation>
      </ref>
      <ref id="B22">
        <label>22</label>
        <mixed-citation>22. Yilmaz F, Yilmaz FK, Karag&#246;z A, Yildirim A, Gunes HM, Akbas RB, et al. Usefulness of Neutrophil-To-Lymphocyte Ratio for Predicting Acute Pericarditis Outcomes. Acta Cardiol. 2022;77(5):422-30. doi: 10.1080/00015385.2021.1951998.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Yilmaz</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Yilmaz</surname>
              <given-names>FK</given-names>
            </name>
            <name>
              <surname>Karag&#246;z</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Yildirim</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Gunes</surname>
              <given-names>HM</given-names>
            </name>
            <name>
              <surname>Akbas</surname>
              <given-names>RB</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Usefulness of Neutrophil-To-Lymphocyte Ratio for Predicting Acute Pericarditis Outcomes</article-title>
          <source>Acta Cardiol</source>
          <year>2022</year>
          <volume>77</volume>
          <issue>5</issue>
          <fpage>422</fpage>
          <lpage>430</lpage>
          <pub-id pub-id-type="doi">10.1080/00015385.2021.1951998</pub-id>
        </element-citation>
      </ref>
      <ref id="B23">
        <label>23</label>
        <mixed-citation>23. Lazaros G, Lazarou E, Vlachopoulos C, Tsioufis C. Exploring the Potential of D-Dimer as a Diagnostic and Prognostic Biomarker for Acute Pericarditis. Biomark Med. 2025;19(1):1-3. doi: 10.1080/17520363.2024.2448021.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lazaros</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Lazarou</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Vlachopoulos</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Tsioufis</surname>
              <given-names>C</given-names>
            </name>
          </person-group>
          <article-title>Exploring the Potential of D-Dimer as a Diagnostic and Prognostic Biomarker for Acute Pericarditis</article-title>
          <source>Biomark Med</source>
          <year>2025</year>
          <volume>19</volume>
          <issue>1</issue>
          <fpage>1</fpage>
          <lpage>3</lpage>
          <pub-id pub-id-type="doi">10.1080/17520363.2024.2448021</pub-id>
        </element-citation>
      </ref>
      <ref id="B24">
        <label>24</label>
        <mixed-citation>24. Andreis A, Solano A, Balducci M, Picollo C, Ghigliotti M, Giordano M, et al. INFLA-Score: A New Diagnostic Paradigm to Identify Pericarditis. Hellenic J Cardiol. 2025;84:43-50. doi: 10.1016/j.hjc.2024.03.010.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Andreis</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Solano</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Balducci</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Picollo</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Ghigliotti</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Giordano</surname>
              <given-names>M</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>INFLA-Score: A New Diagnostic Paradigm to Identify Pericarditis</article-title>
          <source>Hellenic J Cardiol</source>
          <year>2025</year>
          <volume>84</volume>
          <fpage>43</fpage>
          <lpage>50</lpage>
          <pub-id pub-id-type="doi">10.1016/j.hjc.2024.03.010</pub-id>
        </element-citation>
      </ref>
      <ref id="B25">
        <label>25</label>
        <mixed-citation>25. Geng Y, Shao Y, Zhu D, Zheng X, Zhou Q, Zhou W, et al. Systemic Immune-Inflammation Index Predicts Prognosis of Patients with Esophageal Squamous Cell Carcinoma: A Propensity Score-matched Analysis. Sci Rep. 2016;6:39482. doi: 10.1038/srep39482.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Geng</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Shao</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Zhu</surname>
              <given-names>D</given-names>
            </name>
            <name>
              <surname>Zheng</surname>
              <given-names>X</given-names>
            </name>
            <name>
              <surname>Zhou</surname>
              <given-names>Q</given-names>
            </name>
            <name>
              <surname>Zhou</surname>
              <given-names>W</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Systemic Immune-Inflammation Index Predicts Prognosis of Patients with Esophageal Squamous Cell Carcinoma: A Propensity Score-matched Analysis</article-title>
          <source>Sci Rep</source>
          <year>2016</year>
          <volume>6</volume>
          <size units="pages">39482</size>
          <pub-id pub-id-type="doi">10.1038/srep39482</pub-id>
        </element-citation>
      </ref>
      <ref id="B26">
        <label>26</label>
        <mixed-citation>26. Chen JH, Zhai ET, Yuan YJ, Wu KM, Xu JB, Peng JJ, et al. Systemic Immune-Inflammation Index for Predicting Prognosis of Colorectal Cancer. World J Gastroenterol. 2017;23(34):6261-72. doi: 10.3748/wjg.v23.i34.6261.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Chen</surname>
              <given-names>JH</given-names>
            </name>
            <name>
              <surname>Zhai</surname>
              <given-names>ET</given-names>
            </name>
            <name>
              <surname>Yuan</surname>
              <given-names>YJ</given-names>
            </name>
            <name>
              <surname>Wu</surname>
              <given-names>KM</given-names>
            </name>
            <name>
              <surname>Xu</surname>
              <given-names>JB</given-names>
            </name>
            <name>
              <surname>Peng</surname>
              <given-names>JJ</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Systemic Immune-Inflammation Index for Predicting Prognosis of Colorectal Cancer</article-title>
          <source>World J Gastroenterol</source>
          <year>2017</year>
          <volume>23</volume>
          <issue>34</issue>
          <fpage>6261</fpage>
          <lpage>6272</lpage>
          <pub-id pub-id-type="doi">10.3748/wjg.v23.i34.6261</pub-id>
        </element-citation>
      </ref>
      <ref id="B27">
        <label>27</label>
        <mixed-citation>27. Chovanec M, Cierna Z, Miskovska V, Machalekova K, Kalavska K, Rejlekova K, et al. Systemic Immune-Inflammation Index in Germ-Cell Tumours. Br J Cancer. 2018;118(6):831-8. doi: 10.1038/bjc.2017.460.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Chovanec</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Cierna</surname>
              <given-names>Z</given-names>
            </name>
            <name>
              <surname>Miskovska</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>Machalekova</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Kalavska</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Rejlekova</surname>
              <given-names>K</given-names>
            </name>
            <etal>et al</etal>
          </person-group>
          <article-title>Systemic Immune-Inflammation Index in Germ-Cell Tumours</article-title>
          <source>Br J Cancer</source>
          <year>2018</year>
          <volume>118</volume>
          <issue>6</issue>
          <fpage>831</fpage>
          <lpage>838</lpage>
          <pub-id pub-id-type="doi">10.1038/bjc.2017.460</pub-id>
        </element-citation>
      </ref>
      <ref id="B28">
        <label>28</label>
        <mixed-citation>28. Erdogan M, Erd&#246;l MA, &#214;zt&#252;rk S, Durmaz T. Systemic Immune-Inflammation Index is a Novel Marker to Predict Functionally Significant Coronary Artery Stenosis. Biomark Med. 2020;14(16):1553-61. doi: 10.2217/bmm-2020-0274.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Erdogan</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Erd&#246;l</surname>
              <given-names>MA</given-names>
            </name>
            <name>
              <surname>&#214;zt&#252;rk</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Durmaz</surname>
              <given-names>T</given-names>
            </name>
          </person-group>
          <article-title>Systemic Immune-Inflammation Index is a Novel Marker to Predict Functionally Significant Coronary Artery Stenosis</article-title>
          <source>Biomark Med</source>
          <year>2020</year>
          <volume>14</volume>
          <issue>16</issue>
          <fpage>1553</fpage>
          <lpage>1561</lpage>
          <pub-id pub-id-type="doi">10.2217/bmm-2020-0274</pub-id>
        </element-citation>
      </ref>
    </ref-list>
    <fn-group>
      <fn fn-type="other">
        <label>Vincula&#231;&#227;o acad&#234;mica</label>
        <p> N&#227;o h&#225; vincula&#231;&#227;o deste estudo a programas de p&#243;s-gradua&#231;&#227;o.</p>
      </fn>
      <fn fn-type="other">
        <label>Aprova&#231;&#227;o &#233;tica e consentimento informado</label>
        <p> Este estudo foi aprovado pelo Comit&#234; de &#201;tica do Kartal Kosuyolu Education and Research Hospital sob o n&#250;mero de protocolo 2024/16/1200. Todos os procedimentos envolvidos nesse estudo est&#227;o de acordo com a Declara&#231;&#227;o de Helsinki de 1975, atualizada em 2013. O consentimento informado foi obtido de todos os participantes inclu&#237;dos no estudo.</p>
      </fn>
      <fn fn-type="other">
        <label>Uso de Intelig&#234;ncia Artificial</label>
        <p> Durante a prepara&#231;&#227;o deste trabalho, o(s) autor(es) usaram ChatGPT e Gemini para verifica&#231;&#227;o gramatical. Ap&#243;s o uso desta ferramenta/servi&#231;o, o(s) autor(es) revisaram e editaram o conte&#250;do conforme necess&#225;rio e assumem total responsabilidade pelo conte&#250;do do artigo publicado.</p>
      </fn>
      <fn fn-type="data-availability" specific-use="data-available-upon-request">
        <label>Disponibilidade de Dados</label>
        <p> Todo o conjunto de dados que d&#225; suporte aos resultados deste estudo est&#225; dispon&#237;vel mediante solicita&#231;&#227;o ao autor correspondente.</p>
      </fn>
      <fn fn-type="financial-disclosure">
        <label>Fontes de financiamento</label>
        <p> O presente estudo n&#227;o teve fontes de financiamento externas.</p>
      </fn>
    </fn-group>
  </back>
  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-id pub-id-type="doi">10.36660/abc.20250437i</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Original Article</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Predictive Value of the Systemic Immune-inflammation Index for Recurrence of Idiopathic Acute Pericarditis</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-0737-6927</contrib-id>
          <name>
            <surname>Unkun</surname>
            <given-names>Tuba</given-names>
          </name>
          <role>Conception and design of the research and Statistical analysis</role>
          <role>Analysis and interpretation of the data, Writing of the manuscript and Critical revision of the manuscript for content</role>
          <xref ref-type="aff" rid="aff1001">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-7946-1229</contrib-id>
          <name>
            <surname>Sengor</surname>
            <given-names>Busra Guvendi</given-names>
          </name>
          <role>Analysis and interpretation of the data, Writing of the manuscript and Critical revision of the manuscript for content</role>
          <xref ref-type="aff" rid="aff1001">
            <sup>1</sup>
          </xref>
        </contrib>
      </contrib-group>
      <aff id="aff1001">
        <label>1</label>
        <country country="TR">T&#252;rkiye</country>
        <institution content-type="original">Department of cardiology, Kartal Kosuyolu Education and Research Hospital, Istanbul &#8211; T&#252;rkiye</institution>
      </aff>
      <author-notes>
        <corresp id="c01001"><label>Mailing Address:</label> Tuba Unkun &#8226; Kartal Kosuyolu Research and Education Hospital &#8211; Department of Cardiology Denizer caddesi, Cevizli kavsagi, Istanbul, 34718 &#8211; T&#252;rkiye. E-mail: tubaunkun@yahoo.com </corresp>
        <fn fn-type="coi-statement">
          <label>Potential conflict of interest</label>
          <p> No potential conflict of interest relevant to this article was reported.</p>
        </fn>
        <fn fn-type="edited-by">
          <label>Editor responsible for the review:</label>
          <p> Gl&#225;ucia Maria Moraes de Oliveira</p>
        </fn>
      </author-notes>
      <abstract>
        <title>Abstract</title>
        <sec>
          <title>Background</title>
          <p> Identifying patients at increased risk of recurrence of acute pericarditis remains challenging. High-sensitivity C-reactive protein (hs-CRP) can be used to predict recurrence, but it has certain limitations.</p>
        </sec>
        <sec>
          <title>Objectives</title>
          <p> This study aimed to evaluate the association between a novel biomarker, the Systemic Immune-Inflammation Index (SII), and the recurrence of acute pericarditis.</p>
        </sec>
        <sec>
          <title>Methods</title>
          <p> This retrospective cohort study included 110 patients diagnosed with acute idiopathic pericarditis, the primary endpoint of the study was to investigate Recurrent Pericarditis (RP) during the 18 month follow-up period. Patients were divided into two groups based on whether or not they developed recurrent pericarditis. Physical examination, electrocardiography, echocardiography, and laboratory test results of these patients were evaluated. P &lt; 0.05 was considered statistically significant.</p>
        </sec>
        <sec>
          <title>Results</title>
          <p> The mean age of the patients was 42.8 &#177; 15.2 years, and 42.7% were male. The group with RP had significantly higher leukocyte counts (8.7 &#177; 3.2 vs. 12 &#177; 4.7; p = 0.001), neutrophil counts (5.4 &#177; 2.7 vs. 9 &#177; 4.5; p &lt; 0.001), hs-CRP levels (29.1 &#177; 40.9 vs. 49.5 &#177; 62.2; p = 0.048), and neutrophil-to-lymphocyte ratio (2.9 &#177; 2.5 vs. 6 &#177; 2.8; p &lt; 0.001). SII (783.2 &#177; 770.2 vs. 1664.2 &#177; 1086.6; p &lt; 0.001) was also significantly higher in patients with recurrence. Both SII and hs-CRP were independently associated with recurrence (p &lt; 0.001 and p &lt; 0.05, respectively).</p>
        </sec>
        <sec>
          <title>Conclusion</title>
          <p> SII and hs-CRP were found to be independent predictors for recurrence in acute pericarditis patients during the 18 month follow-up. Similar to hs-CRP, SII may also be used as an important parameter in predicting recurrent pericarditis.</p>
        </sec>
      </abstract>
      <abstract abstract-type="graphical">
        <p>
          <fig id="f01001">
            <label>Central Illustration:</label>
            <caption>
              <title>Predictive Value of the Systemic Immune-inflammation Index for Recurrence of Idiopathic Acute Pericarditis</title>
              <p>Arq Bras Cardiol. 2026; 123(2):e20250437</p>
            </caption>
            <graphic xlink:href="1678-4170-abc-123-02-e20250437-50437-gf01-en.tif"/></fig>
        </p>
      </abstract>
      <kwd-group xml:lang="en">
        <title>Keywords:</title>
        <kwd>Systemic Immune-inflammation Index</kwd>
        <kwd>Pericarditis</kwd>
        <kwd>C-reactive Protein</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <sec sec-type="intro">
        <title>Introduct&#305;on</title>
        <p>Acute pericarditis is the most common pericardial disease seen in clinical practice.<sup><xref ref-type="bibr" rid="B1">1</xref>,<xref ref-type="bibr" rid="B2">2</xref></sup> At least two of the following four criteria are required for a diagnosis: chest pain, pericardial friction rub, abnormal electrocardiographic findings (PR depression and widespread ST elevation), and new or worsening pericardial effusion. Additional supportive findings include elevated inflammatory markers, such as High Sensitive C-Reactive Protein (hs-CRP) and Erythrocyte Sedimentation Rate (ESR), as well as inflammation detection using imaging techniques such as Cardiac Magnetic Resonance (CMR) or Computed Tomography (CT).<sup><xref ref-type="bibr" rid="B3">3</xref></sup> Complications of pericarditis include cardiac tamponade, constrictive pericarditis, and most commonly, recurrent pericarditis.<sup><xref ref-type="bibr" rid="B4">4</xref>,<xref ref-type="bibr" rid="B5">5</xref></sup> Acute pericarditis is an inflammatory condition that affects the pericardium. established. Elevated hs-CRP levels have been associated with pericarditis recurrence and adverse cardiac outcomes.<sup><xref ref-type="bibr" rid="B6">6</xref>,<xref ref-type="bibr" rid="B7">7</xref></sup> The search for reliable biomarkers capable of predicting recurrence in clinical practice is still ongoing.</p>
        <p>Recently, the Systemic Immune-inflammation Index (SII), a simple yet comprehensive indicator, has gained attention.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> SII reflects the overall inflammatory and immunological state by incorporating three biomarkers: platelets, neutrophils, and lymphocytes.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> The SII index is commonly used for predicting the presence and prognosis of many malignancies.<sup><xref ref-type="bibr" rid="B10">10</xref></sup> Recent studies have also showed that SII is linked to clinical prognosis in a variety of cardiovascular illnesses.<sup><xref ref-type="bibr" rid="B11">11</xref></sup> However, the relationship between SII and the prognosis of acute pericarditis patients has not yet been demonstrated. The purpose of this study is to investigate the relationship between recurrent pericarditis following acute pericarditis and the SII index.</p>
      </sec>
      <sec sec-type="methods">
        <title>Method</title>
        <sec>
          <title>Study population and design</title>
          <p>This retrospective cohort study was conducted at Kartal Ko&#351;uyolu High Specialty Training and Research Hospital, Istambul, Turkey, from January 2021 to March 2024. The study involved 331 patients diagnosed with acute pericarditis. 150 patients were excluded from the study due to insufficient follow-up time after diagnosis. 15 patients with an ejection fraction (EF) less than 53-54 % (&lt; 53% for men and &lt; 54% for women)<sup><xref ref-type="bibr" rid="B3">3</xref></sup> or positive troponin levels, and 56 patients with specific underlying causes (such as malignancies, tuberculosis, autoimmune diseases, purulent pericarditis, post-myocardial damage or after myocardial infarction, renal failure (Glomerular Filtration Rate, GFR &lt;60 mL/min), hepatic disorders &#8211; two-fold higher serum Aspartate Aminotransferase (AST) and &gt;80 U/L or Alanine Aminotransferase (ALT) &gt;112 U/L activity than normal limits. After exclusions study group consist of 110 patients diagnosed with acute pericarditis (<xref ref-type="fig" rid="f02001">Figure 1</xref>). The study was authorized by the local ethics committee.</p>
          <p>
            <fig id="f02001">
              <label>Figure 1</label>
              <caption>
                <title>&#8211; Flow diagram of the studied population with acute pericarditis.</title>
              </caption>
              <graphic xlink:href="1678-4170-abc-123-02-e20250437-50437-gf02-en.tif"/></fig>
          </p>
          <p>All clinical and demographic data, including age, sex, and medical history, were obtained from the hospital&#8217;s digital health record system. All patients experienced their first episode of pericarditis, and the diagnosis was established based on the presence of at least two of the four criteria outlined in the latest guidelines: pericardial chest pain, electrocardiographic abnormalities (new widespread ST elevation or PR depression), pericardial effusion, and pericardial friction rub.<sup><xref ref-type="bibr" rid="B3">3</xref></sup> Admission electrocardiograms, chest X-rays, echocardiograms, and blood test results were retrieved from the hospital records. Blood tests included complete blood count, hs-CRP, high-sensitivity troponin I, serum biochemistry, thyroid function tests, and screening for specific diseases (such as autoimmune disorders and tuberculosis). The Neutrophil-to-Lymphocyte Ratio (NLR) was calculated as the ratio of neutrophil count to lymphocyte count in peripheral blood samples. The SII was calculated as SII = Platelet count (PLT) &#215; NLR.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Complete blood counts were determined using an autoanalyzer (Horiba ABX Diagnostics, France), and C-reactive protein levels were measured using the nephelometric method (Beckman Coulter).</p>
          <p>Echocardiographic images were retrieved from the hospital&#8217;s digital health record system. Cardiac tamponade was diagnosed based on a combination of clinical symptoms (such as pulsus paradoxus, hypotension, and tachycardia) together with echocardiographic evidence. Pericardiocentesis was performed in patients with severe pericardial effusion accompanied by hemodynamic instability or when clinical findings suggested bacterial or neoplastic pericarditis.</p>
          <p>According to guideline recommendations, Nonsteroidal Anti-inflammatory Drugs (NSAIDs) or aspirin were used as the first-line treatment at the maximum tolerated dose.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B12">12</xref></sup> The maximum dose was administered for 1&#8211;2 weeks, and if hs-CRP levels normalized, the dose was tapered over 3&#8211;4 weeks. In all cases, colchicine 0.5 mg twice daily was prescribed for 3 months, with adjustments based on creatinine clearance, body weight, and age.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B1">1</xref><xref ref-type="bibr" rid="B3">3</xref></sup> No patients received corticosteroid therapy. Recurrent pericarditis was defined as the presence of recurrent chest pain in addition to at least one of the following: fever, pericardial friction rub, ECG abnormalities, evidence of pericardial effusion, increased leukocyte count, or elevated hs-CRP.<sup><xref ref-type="bibr" rid="B3">3</xref></sup></p>
          <p>All patients included in the study were followed approximately 18 months from the time of diagnosis. Approximately 10 days after discharge, they were followed monthly for the next 3 months, and thereafter every 3 months up to 18 months. Clinical visits included physical examinations, blood test were including complete blood count and CRP, ECG, and echocardiographic evaluations. The study endpoint was the occurrence of the first recurrence of pericarditis. Patients were divided into two groups based on whether or not they developed recurrent pericarditis.</p>
        </sec>
        <sec>
          <title>Statistical analysis</title>
          <p>The study was approved by the Local Ethics and Clinical Investigation Committee and had conformed to the principles embodied in the Declaration of Helsinki. Statistical analyses were performed by using Statistical Package for the Social Sciences (SPSS; Version 26.0, IBM). Continuous variables were presented as mean and standard deviation due to the normality of the data. Categorical variables were presented by absolute and relative frequencies. Assumption of normality of data were evaluated by Kolmogorov&#8211;Smirnov test. The comparison between groups was made using the Student&#8217;s t-test for independent samples or chi-Square, as appropriate. Enter model was used in multiple logistic regression. Results of these models were interpreted in terms of adjusted odds ratios (aORs) with associated 95% confidence intervals (95% CIs). Receiver operating characteristic curve (ROC curve) analysis was used to find the optimal cut-off for hs-CRP and SII in recurrence of pericarditis Results were evaluated with a confidence interval of 95%, and p &lt; 0.05 was considered statistically significant.</p>
        </sec>
      </sec>
      <sec sec-type="results">
        <title>Results</title>
        <p>Patients were devided in two groups according to recurrence the study population consisted of 110 patients (47 males, 42.7%) and mean age of the patients was 42.8&#177;15.2years. The characteristics of the patients are presented in <xref ref-type="table" rid="t1001">Table 1</xref>.</p>
        <p>
          <table-wrap id="t1001">
            <label>Table 1</label>
            <caption>
              <title>&#8211; Demographic and clinical characteristics of the patients</title>
            </caption>
            <table frame="hsides" rules="groups">
              <colgroup width="20%">
                <col/>
                <col/>
                <col/>
                <col/>
                <col/>
              </colgroup>
              <thead>
                <tr>
                  <th align="left" colspan="2" scope="col">Variables</th>
                  <th scope="col">No recurrence (n=81)</th>
                  <th scope="col">Recurrence (n=29)</th>
                  <th scope="col">p values</th>
                </tr>
              </thead>
              <tbody>
                <tr>
                  <td colspan="2">Age (years)</td>
                  <td align="center">42.19 &#177;15.5</td>
                  <td align="center">42 &#177;15.2</td>
                  <td align="center">0.956<sup>1</sup></td>
                </tr>
                <tr>
                  <td rowspan="2">Gender (n)</td>
                  <td>Man</td>
                  <td align="center">34</td>
                  <td align="center">13</td>
                  <td align="center" rowspan="2">0.790<sup>2</sup></td>
                </tr>
                <tr>
                  <td>Woman</td>
                  <td align="center">47</td>
                  <td align="center">16</td>
                </tr>
                <tr>
                  <td rowspan="2">ECG (n)</td>
                  <td>No change</td>
                  <td align="center">21</td>
                  <td align="center">9</td>
                  <td align="center" rowspan="2">0.596<sup>2</sup></td>
                </tr>
                <tr>
                  <td>Change</td>
                  <td align="center">60</td>
                  <td align="center">20</td>
                </tr>
                <tr>
                  <td rowspan="3">Pericardial effusion (n)</td>
                  <td>Mild</td>
                  <td align="center">66 (81.4%)</td>
                  <td align="center">15 (51.7%)</td>
                  <td align="center" rowspan="3">
                    <bold>0.006*</bold>
                  </td>
                </tr>
                <tr>
                  <td>Moderate</td>
                  <td align="center">4 (4.9%)</td>
                  <td align="center">5 (17.2%)</td>
                </tr>
                <tr>
                  <td>Severe</td>
                  <td align="center">11 (13.7%)</td>
                  <td align="center">9 (31.1%)</td>
                </tr>
                <tr>
                  <td colspan="2">Presence of chest pain (n)</td>
                  <td align="center">70</td>
                  <td align="center">27</td>
                  <td align="center">0.105<sup>2</sup></td>
                </tr>
                <tr>
                  <td colspan="2">Pericardial friction rub (n)</td>
                  <td align="center">17</td>
                  <td align="center">2</td>
                  <td align="center">0.065<sup>2</sup></td>
                </tr>
              </tbody>
            </table>
            <table-wrap-foot>
              <fn id="TFN1001">
                <p>
                  <italic><sup>1</sup>Independent samples T test, <sup>2</sup>Chi square test, *p&lt;0.05; ECG: electrocardiogram.</italic>
                </p>
              </fn>
            </table-wrap-foot>
          </table-wrap>
        </p>
        <p>All patients received the same treatment (NSAIDs and colchicine). There was no difference in age, gender, chest pain, and ECG changes between the groups. The leukocytes and neutrophyl counts were higher in the recurrence group (p&lt;0.001 <xref ref-type="table" rid="t2001">Table 2</xref>). SII, NLR and hs-CRP were also found to be significantly higher in patients with recurrence (p:&lt;0.001, p:&lt;0.001, p:0.048). Other findings are presented in <xref ref-type="table" rid="t2001">Table 2</xref>.</p>
        <p>
          <table-wrap id="t2001">
            <label>Table 2</label>
            <caption>
              <title>&#8211; Comparisons of laboratuary variables between the patients with and without recurrence</title>
            </caption>
            <table frame="hsides" rules="groups">
              <colgroup width="25%">
                <col/>
                <col/>
                <col/>
                <col/>
              </colgroup>
              <thead>
                <tr>
                  <th align="left">Variables</th>
                  <th>No recurrence (n=81)</th>
                  <th>Recurrence (n=29)</th>
                  <th>p values</th>
                </tr>
              </thead>
              <tbody>
                <tr>
                  <td>Hs-CRP (mg/L)</td>
                  <td align="center">29.1 &#177;40.9</td>
                  <td align="center">49.5 &#177;62.2</td>
                  <td align="center">0.048</td>
                </tr>
                <tr>
                  <td>Leukocyte (cells/&#181;L)</td>
                  <td align="center">8.7 &#177;3.2</td>
                  <td align="center">12 &#177;4.7</td>
                  <td align="center">0.001*</td>
                </tr>
                <tr>
                  <td>Hemoglobin (g/dl)</td>
                  <td align="center">13.2 &#177;1.7</td>
                  <td align="center">12.8&#177;2</td>
                  <td align="center">0.306</td>
                </tr>
                <tr>
                  <td>Platelet (cells/&#181;L)</td>
                  <td align="center">267.4 &#177;86.8</td>
                  <td align="center">312.2 &#177;126.3</td>
                  <td align="center">0.086</td>
                </tr>
                <tr>
                  <td>Neutrophil (cells/&#181;L)</td>
                  <td align="center">5.4&#177; 2.7</td>
                  <td align="center">9 &#177; 4.5</td>
                  <td align="center">&lt;0.001**</td>
                </tr>
                <tr>
                  <td>Lymphocyte (cells/&#181;L)</td>
                  <td align="center">2.3&#177;1.13</td>
                  <td align="center">2.5&#177;3.2</td>
                  <td align="center">0.786</td>
                </tr>
                <tr>
                  <td>SII</td>
                  <td align="center">783.2 &#177; 770.2</td>
                  <td align="center">1664.2 &#177;1086.6</td>
                  <td align="center">&lt;0.001**</td>
                </tr>
                <tr>
                  <td>Neutrophil Lymphocyte ratio</td>
                  <td align="center">2.9 &#177; 2.5</td>
                  <td align="center">6 &#177; 2.8</td>
                  <td align="center">&lt;0.001**</td>
                </tr>
              </tbody>
            </table>
            <table-wrap-foot>
              <fn id="TFN2001">
                <p>
                  <italic>Independent samples T test, *p&lt;0.05, **p&lt;0.001; SII: Systemic Immune-Inflammation Index.</italic>
                </p>
              </fn>
            </table-wrap-foot>
          </table-wrap>
        </p>
        <p>In regression analysis the co-founding variables included SII, pericardial effusion, hs-CRP. SII was independently associated with recurrence. (Odds Ratio (OR) = 1.4 with %95 CI [0.96-1.54] p:0.002). Other variables are presented in <xref ref-type="table" rid="t3001">Table 3</xref>.</p>
        <p>
          <table-wrap id="t3001">
            <label>Table 3</label>
            <caption>
              <title>&#8211; Logistic regression analysis to predict recurrence</title>
            </caption>
            <table frame="hsides" rules="groups">
              <colgroup width="25%">
                <col/>
                <col/>
                <col/>
                <col/>
              </colgroup>
              <thead>
                <tr>
                  <th align="left">Variables</th>
                  <th>Odds Ratio</th>
                  <th>95% CI</th>
                  <th>p values</th>
                </tr>
              </thead>
              <tbody>
                <tr>
                  <td>SII</td>
                  <td align="center">1.4</td>
                  <td align="center">0.96-1.54</td>
                  <td align="center">0.002</td>
                </tr>
                <tr>
                  <td>Pericardial effusion</td>
                  <td align="center">1.2</td>
                  <td align="center">0.78-2.7</td>
                  <td align="center">0.23</td>
                </tr>
                <tr>
                  <td>Hs-CRP</td>
                  <td align="center">0.9</td>
                  <td align="center">0.98-1.009</td>
                  <td align="center">0.8</td>
                </tr>
              </tbody>
            </table>
            <table-wrap-foot>
              <fn id="TFN3001">
                <p>
                  <italic>SII: Systemic Immune-Inflammation Index.</italic>
                </p>
              </fn>
            </table-wrap-foot>
          </table-wrap>
        </p>
        <p>In ROC analysis (<xref ref-type="fig" rid="f03001">Figure 2</xref>), SII was found the most associated parameter with recurrence. The cut-off point determined for SII in the diagnosis of recurrence is 462.5 with 82.8% sensivity and 40% specifity . The ROC analysis results are shown in <xref ref-type="fig" rid="f03001">Figure 2</xref> . (AUC:0.751, CI:0.630-0.872, p:0.001).</p>
        <p>
          <fig id="f03001">
            <label>Figure 2</label>
            <caption>
              <title>&#8211; Receiver operating characteristic (ROC) analysis.</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-123-02-e20250437-50437-gf03-en.tif"/></fig>
        </p>
      </sec>
      <sec sec-type="discussion">
        <title>Discussion</title>
        <p>Our study demonstrated that SII is simply calculated and cheap parameter for predicting recurrence in acute pericarditis patients. Acute pericarditis is the most frequent presentation of pericardial disorders and causes significant morbidity. Recurrent pericarditis, the most common complication following acute pericarditis, significantly impacts the patient&#8217;s quality of life.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B14">14</xref></sup> Identifying patients prone to recurrence is challenging.</p>
        <p>In clinical practice, identifying patients with a high risk of recurrence among those diagnosed with a first episode of acute pericarditis is crucial, as recurrent pericarditis leads to repeated attacks and chronic disease progression.<sup><xref ref-type="bibr" rid="B15">15</xref></sup> However there is not specific marker or diagnostic process for detecting this patients . Patients with a high risk of recurrence may benefit from close monitoring and intense medical treatment. Also they could additionally benefit from expert imaging modalities (such as CMR) prior to discontinuing medication. CMR, with its ability to show ongoing inflammation in the tissue, will be beneficial for determining the treatment duration.<sup><xref ref-type="bibr" rid="B3">3</xref></sup></p>
        <p>Patients at high risk of recurrence after a first episode of acute pericarditis have not been adequately investigated to date. According to previous studies, colchicine use during the initial attack has been shown to be the most effective factor in reducing recurrence. Conversely, the use of corticosteroids, specific etiologies of acute pericarditis, inadequate treatment, and the presence of pericardial effusion have all been associated with higher recurrence rates.<sup><xref ref-type="bibr" rid="B3">3</xref>,<xref ref-type="bibr" rid="B5">5</xref>,<xref ref-type="bibr" rid="B16">16</xref>-<xref ref-type="bibr" rid="B20">20</xref></sup></p>
        <p>Inflammatory markers are used to predict the recurrence in acute pericarditis. Hs-CRP can be used to diagnose as well as assess therapy response.<sup><xref ref-type="bibr" rid="B6">6</xref>,<xref ref-type="bibr" rid="B21">21</xref></sup> Imazio et al.<sup><xref ref-type="bibr" rid="B7">7</xref></sup> found that sustained hs-CRP rise could predict pericarditis recurrence. Studies have indicated that NLR, an inflammatory marker, is more effective than hs-CRP in predicting pericarditis recurrence.<sup><xref ref-type="bibr" rid="B22">22</xref></sup> A recent study has shown that D-dimer is a potential biomarker for prognostic assessment in acute and complicated pericarditis.<sup><xref ref-type="bibr" rid="B23">23</xref></sup> In another study, the Infla Score &#8211; developed by combining various inflammatory markers &#8211; was found to be effective in predicting pericarditis recurrence.<sup><xref ref-type="bibr" rid="B24">24</xref></sup> SII has been found in studies to be more potent inflammatory marker than NLR or PLT alone, with a better prognostic value.<sup><xref ref-type="bibr" rid="B25">25</xref></sup> In this study, we found that SII was more significantly linked with the likelihood of recurrent pericarditis than NLR, PLT, and hs-CRP alone, suggesting that SII may serve as a more reliable predictor of the patients&#8217; inflammatory status, resulting in higher predictive reliability for recurrent pericarditis.</p>
        <p>We hypothesized that the use of the SII &#8211; a simple, more comprehensive, and less variable index that simultaneously incorporates multiple inflammatory biomarkers &#8211; may serve as a supportive parameter to CRP, which is routinely used in follow-up, and may also provide significant prognostic value in detecting underlying active inflammation in acute and recurrent pericarditis. Comprising neutrophils, lymphocytes, and platelets, SII has recently been developed as a comprehensive biomarker of systemic inflammation.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> SII was originally found to be a powerful prognostic factor for patients with hepatocellular carcinoma.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> SII is now widely employed as a predictive and prognostic marker in a variety of disorders, including cancer, cardiovascular disease, and kidney disease.<sup><xref ref-type="bibr" rid="B26">26</xref>-<xref ref-type="bibr" rid="B28">28</xref></sup></p>
        <p>SII has gained popularity in recent years due to its role as an inflammatory marker, similar to hs-CRP. It is a simple parameter suitable for routine use, and its variability is lower than that of hs-CRP. In our study, SII was identified as an independent predictor of recurrent pericarditis, suggesting that it may serve as a valuable parameter in clinical practice. When used in conjunction with hs-CRP, rather than as a substitute, SII could improve the prediction of patients at risk for recurrent pericarditis.</p>
        <p>To the best of our knowledge, no research has been conducted in acute pericarditis individuals to explore the association between SII and prognosis. In our study, SII exceeded hs-CRP in predicting pericarditis recurrence.</p>
        <p>This study has several limitations. First, the relatively small sample size of 110 patients may limit the generalizability of the findings to broader clinical settings and more diverse patient populations. In addition, the retrospective design of the study meant that certain variables &#8211; such as treatment adherence, symptom duration, and consistency of follow-up &#8211; could not be fully standardized or controlled. The absence of serial measurements of laboratory parameters also represents a significant limitation.</p>
        <p>Furthermore, only patients with isolated pericarditis were included. Myopericarditis and perimyocarditis, which involve concurrent pericardial and myocardial inflammation, may present with similar clinical symptoms and initial findings, increasing the risk of misclassification in the absence of advanced imaging. However, because advanced imaging techniques (e.g., cardiac MRI) are not routinely available in all clinical settings, these patients were excluded. While this approach allowed for the selection of a lower-risk and more homogeneous study population, it limits the generalizability of the findings to the broader spectrum of pericardial disease. In addition, out of a total of 331 patients, only 110 who met the predefined inclusion criteria and had sufficient clinical data and follow-up information were included in the analysis. Since detailed clinical, laboratory, or treatment data were not systematically collected for the 221 excluded patients, a separate analysis of this group could not be performed. This may have introduced a potential selection bias and reduced the external validity of the study.</p>
        <p>Finally, although all patients were prescribed NSAIDs and colchicine at discharge in accordance with European Society of Cardiology guidelines, post-discharge adherence to treatment could not be systematically monitored due to the retrospective nature of the study. Methods commonly employed in randomized controlled trials, such as telephone follow-ups, face-to-face interviews, or pill counts, were not applied. Consequently, treatment uniformity and the assessment of therapeutic efficacy represent additional limitations.</p>
        <p>SII was found to be an independent predictor for pericarditis recurrence in patients with acute pericarditis during the follow-up. Our study indicates that SII could be used for risk classification in addition to hs-CRP for prediction of recurrence pericarditis (<xref ref-type="fig" rid="f01001">Central Illustration</xref>).</p>
      </sec>
    </body>
    <back>
      <fn-group>
        <fn fn-type="other">
          <label>Study association</label>
          <p> This study is not associated with any thesis or dissertation work.</p>
        </fn>
        <fn fn-type="other">
          <label>Ethics approval and consent to participate</label>
          <p> This study was approved by the Ethics Committee of the Kartal Kosuyolu Education and Research Hospital under the protocol number 2024/16/1200. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study.</p>
        </fn>
        <fn fn-type="other">
          <label>Use of Artificial Intelligence</label>
          <p> During the preparation of this work, the author(s) used ChatGPT and Gemini for grammar check. After using this tool/service, the author(s) reviewed and edited the content as needed and take full responsibility for the content of the published article.</p>
        </fn>
        <fn fn-type="data-availability" specific-use="data-available-upon-request">
          <label>Data Availability Statement</label>
          <p> All datasets supporting the results of this study are available upon request from the corresponding author.</p>
        </fn>
        <fn fn-type="financial-disclosure">
          <label>Sources of funding</label>
          <p> There were no external funding sources for this study.</p>
        </fn>
      </fn-group>
    </back>
  </sub-article>
</article>
