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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">TVpx9BWfw3Sv8NZs347d8Cg</article-id>
      <article-id specific-use="scielo-v2" pub-id-type="publisher-id">S0066-782X2021001301045</article-id>
      <article-id pub-id-type="publisher-id">abc.20201210</article-id>
      <article-id pub-id-type="doi">10.36660/abc.20201210</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Carta Cient&#237;fica</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Trombose de Aorta e Art&#233;ria Renal como Manifesta&#231;&#227;o Cl&#237;nica Inicial da COVID-19 em um Receptor de Transplante Card&#237;aco</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-0207-3986</contrib-id>
          <name>
            <surname>Belfort</surname>
            <given-names>Deborah de S&#225; Pereira</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-2533-5638</contrib-id>
          <name>
            <surname>Marcondes-Braga</surname>
            <given-names>Fabiana G.</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
          <xref ref-type="corresp" rid="c1"/>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-0894-1131</contrib-id>
          <name>
            <surname>Mangini</surname>
            <given-names>Sandrigo</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-5960-2952</contrib-id>
          <name>
            <surname>Cafezeiro</surname>
            <given-names>Caio Rebou&#231;as Fonseca</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Furlan</surname>
            <given-names>Di&#243;genes Amauri Gon&#231;alves</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Bacal</surname>
            <given-names>Fernando</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
        </contrib>
        <aff id="aff1">
          <label>1</label>
          <institution content-type="orgname">Universidade de S&#227;o Paulo</institution>
          <institution content-type="orgdiv1">Faculdade de Medicina</institution>
          <institution content-type="orgdiv2">Hospital das Cl&#237;nicas</institution>
          <addr-line>
            <named-content content-type="city">S&#227;o Paulo</named-content>
            <named-content content-type="state">SP</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Instituto do Cora&#231;&#227;o (InCor), Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo, S&#227;o Paulo, SP - Brasil</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c1"><bold>Correspond&#234;ncia: Fabiana G. Marcondes-Braga &#8226;</bold> Universidade de S&#227;o Paulo Faculdade de Medicina Hospital das Cl&#237;nicas Instituto do Cora&#231;&#227;o - Avenida Dr. En&#233;as Carvalho de Aguiar, 44. CEP <postal-code>05410-020</postal-code>, S&#227;o Paulo, SP - Brasil. E-mail: <email>fgmarcondes@yahoo.com.br</email>, <email>fgmarcondes@gmail.com</email></corresp>
        <fn fn-type="con">
          <p>
            <bold>Contribui&#231;&#227;o dos autores</bold>
          </p>
          <p>Concep&#231;&#227;o e desenho da pesquisa: Belfort DSP, Marcondes-Braga FG, Mangini S, Cafezeiro CRF, Furlan DAG, Bacal F; Obten&#231;&#227;o de dados: Belfort DSP, Cafezeiro CRF, Furlan DAG; Reda&#231;&#227;o do manuscrito: Belfort DSP, Marcondes-Braga FG, Cafezeiro CRF, Furlan DAG; Revis&#227;o cr&#237;tica do manuscrito quanto ao conte&#250;do intelectual importante: Belfort DSP, Marcondes-Braga FG, Mangini S, Bacal F.</p>
        </fn>
        <fn fn-type="conflict">
          <p>
            <bold>Potencial conflito de interesse</bold>
          </p>
          <p>N&#227;o h&#225; conflito com o presente artigo</p>
        </fn>
      </author-notes>
      <pub-date publication-format="electronic" date-type="pub">
        <day>22</day>
        <month>11</month>
        <year>2021</year>
      </pub-date>
      <pub-date publication-format="electronic" date-type="collection">
        <month>11</month>
        <year>2021</year>
      </pub-date>
      <volume>117</volume>
      <issue>5</issue>
      <fpage>1045</fpage>
      <lpage>1047</lpage>
      <history>
        <date date-type="received">
          <day>12</day>
          <month>11</month>
          <year>2020</year>
        </date>
        <date date-type="rev-recd">
          <day>27</day>
          <month>01</month>
          <year>2021</year>
        </date>
        <date date-type="accepted">
          <day>24</day>
          <month>03</month>
          <year>2021</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xml:lang="en" xlink:href="https://creativecommons.org/licenses/by/4.0/">
          <license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution License</license-p>
        </license>
      </permissions>
      <kwd-group xml:lang="pt">
        <title>Palavras-chave</title>
        <kwd>COVID-19</kwd>
        <kwd>Tromboembolia</kwd>
        <kwd>Transplante de Cora&#231;&#227;o</kwd>
      </kwd-group>
      <counts>
        <fig-count count="8"/>
        <table-count count="0"/>
        <equation-count count="0"/>
        <ref-count count="13"/>
        <page-count count="3"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <sec sec-type="intro">
      <title>Introdu&#231;&#227;o</title>
      <p>A nova infec&#231;&#227;o pelo coronav&#237;rus surgiu em Wuhan, na China, no final do ano de 2019, e &#233; hoje uma pandemia.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> A rela&#231;&#227;o da COVID-19 com eventos tromb&#243;ticos j&#225; est&#225; bem estabelecida, mesmo em pacientes em anticoagula&#231;&#227;o profil&#225;tica. Embora eventos tromboemb&#243;licos arteriais e venosos tenham sido descritos, principalmente acidente vascular cerebral e infarto agudo do mioc&#225;rdio (IAM),<sup><xref ref-type="bibr" rid="B2">2</xref>,<xref ref-type="bibr" rid="B3">3</xref></sup> existem poucos relatos de trombose arterial em locais incomuns.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> Quase todos os relatos s&#227;o de eventos tromb&#243;ticos ocorridos em pacientes internados em unidade de terapia intensiva (UTI), e a incid&#234;ncia de tromboembolismo em casos moderados de COVID-19 ainda n&#227;o est&#225; clara.</p>
      <p>N&#243;s apresentamos um caso de um receptor de transplante card&#237;aco, do sexo masculino, admitido no departamento de emerg&#234;ncia apresentando trombose da art&#233;ria renal direita e da aorta tor&#225;cica descendente associada com COVID-19.</p>
      <sec sec-type="cases">
        <title>Apresenta&#231;&#227;o do caso</title>
        <p>Paciente de 28 anos de idade, do sexo masculino, receptor de transplante card&#237;aco desde 2018, com hist&#243;ria de cardiomiopatia dilatada familiar, foi admitido no departamento de emerg&#234;ncia com dor aguda no flanco direito por tr&#234;s dias, associada a febre, calafrios, n&#225;usea e v&#244;mitos. O paciente negou sintomas respirat&#243;rios, mialgia, cefaleia, ou outros sintomas que poderiam sugerir infec&#231;&#227;o viral. Al&#233;m de diabetes mellitus e dislipidemia, o paciente n&#227;o apresentava nenhuma outra comorbidade. O paciente estava em uso regular de tacrolimo, micofenolato e prednisona.</p>
        <p>O exame f&#237;sico revelou press&#227;o arterial de 150/100 mmHg, frequ&#234;ncia card&#237;aca de 100 bpm, taxa respirat&#243;ria de 20 ciclos por minuto, e satura&#231;&#227;o de oxig&#234;nio sangu&#237;neo de 96% em ar ambiente. N&#227;o foram detectados ru&#237;dos respirat&#243;rios na avalia&#231;&#227;o pulmonar, e o exame abdominal revelou sensibilidade no &#226;ngulo costovertebral. Os exames de sangue mostraram n&#237;veis de prote&#237;na C reativa de 317mg/dL, lactato desidrogenase de 1827U/L, D-d&#237;mero de 4126ng/mL, ferritina de 651ng/mL, leuc&#243;citos de 16100/mm<sup>3</sup> e nenhuma outra altera&#231;&#227;o.</p>
        <p>Tomografia computorizada (TC) abdominal e de t&#243;rax revelou trombose luminal perif&#233;rica esparsa na aorta tor&#225;cica descendente (<xref ref-type="fig" rid="f1">Figura 1</xref>). Um dos trombos se estendeu at&#233; o &#243;stio da art&#233;ria renal direita, causando oclus&#227;o parcial do segmento proximal da art&#233;ria (<xref ref-type="fig" rid="f2">Figuras 2</xref> e <xref ref-type="fig" rid="f3">3</xref>). O rim direito apresentou &#225;reas hipodensas compat&#237;veis com infarto renal (<xref ref-type="fig" rid="f3">Figura 3</xref>). Nenhuma outra art&#233;ria foi afetada. Al&#233;m desses achados, opacidade em vidro fosco foi detectada em 25% do par&#234;nquima pulmonar (<xref ref-type="fig" rid="f4">Figura 4</xref>) e, por essa raz&#227;o, suspeitou-se de COVID-19. O m&#233;todo de rea&#231;&#227;o em cadeia da polimerase fluorescente em tempo real (teste nasofar&#237;ngeo) revelou resultado positivo para SARS-Cov-2. Testes de coagulopatia foram realizados antes de se iniciar a anticoagula&#231;&#227;o. N&#237;veis de prote&#237;na C, prote&#237;na S, a antitrombina III foram normais, o teste de muta&#231;&#227;o da protrombina foi negativo, os testes de detec&#231;&#227;o de anticorpos anticardiolipina (aCL) (IgG e IgM) foram negativos, e o teste de detec&#231;&#227;o de anticoagulante l&#250;pico foi positivo.</p>
        <fig id="f1">
          <label>Figura 1</label>
          <caption>
            <title>Tomografia computorizada abdominal revelando trombose luminal perif&#233;rica esparsa na aorta tor&#225;cica descendente (seta).</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf01.tif"/></fig>
        <fig id="f2">
          <label>Figura 2</label>
          <caption>
            <title>Reconstru&#231;&#227;o tridimensional da aorta abdominal mostrando suboclus&#227;o do segmento proximal da art&#233;ria renal direita.</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf02.tif"/></fig>
        <fig id="f3">
          <label>Figura 3</label>
          <caption>
            <title>Tomografia computorizada abdominal mostrando um dos trombos se estendendo at&#233; o &#243;stio da art&#233;ria renal direita, causando oclus&#227;o parcial do segmento proximal da art&#233;ria (seta). Rim direito com &#225;reas hipodensas compat&#237;veis com infarto renal.</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf03.tif"/></fig>
        <fig id="f4">
          <label>Figura 4</label>
          <caption>
            <title>Tomografia computadorizada de t&#243;rax apresentando opacidade em vidro fosco em 25% do par&#234;nquima pulmonar.</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf04.tif"/></fig>
        <p>Foram prescritos hidrata&#231;&#227;o, antibi&#243;ticos (ceftriaxona e azitromicina), e anticoagula&#231;&#227;o com enoxaparina. Tacrolimo e micofenolato foram interrompidos, e a prednisona substitu&#237;da por hidrocortisona 150 mg/dia na admiss&#227;o. O paciente apresentou melhora e ficou assintom&#225;tico. Marcadores inflamat&#243;rios diminu&#237;ram nos dias seguintes. A imunossupress&#227;o foi reiniciada ap&#243;s cinco dias de admiss&#227;o, e prescrita varfarina. O paciente recebeu alta no 15&#186; de interna&#231;&#227;o ap&#243;s ajuste da dose de varfarina.</p>
      </sec>
    </sec>
    <sec sec-type="discussion">
      <title>Discuss&#227;o</title>
      <p>Desde o surto da COVID-19, uma variedade de apresenta&#231;&#227;o cl&#237;nica tem sido descrita. A maioria dos pacientes apresentam sintomas leves, mas at&#233; 14% dos pacientes infectados desenvolvem pneumonia intersticial, e 5% necessitam de ventila&#231;&#227;o mec&#226;nica.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> Eventos tromboemb&#243;licos em pacientes cr&#237;ticos foram associados com COVID-19 em v&#225;rios estudos.<sup><xref ref-type="bibr" rid="B2">2</xref>-<xref ref-type="bibr" rid="B4">4</xref></sup></p>
      <p>Os mecanismos de dist&#250;rbios tromb&#243;ticos e das coagulopatias n&#227;o foram totalmente esclarecidos. A COVID-19 est&#225; associada a um estado pr&#243;-inflamat&#243;rio, e a tempestade de citocinas descrita na COVID-19 contribui para trombose por meio da ativa&#231;&#227;o de mon&#243;citos, neutr&#243;filos e endot&#233;lio.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> Essas c&#233;lulas ativam plaquetas e aumentam os n&#237;veis de fator de von Willebrand e fator VIII, que contribuem para a gera&#231;&#227;o de trombina e forma&#231;&#227;o de co&#225;gulo de fibrina. A trombina, por outro lado, amplifica as vias pr&#243;-inflamat&#243;rias.<sup><xref ref-type="bibr" rid="B5">5</xref></sup> O v&#237;rus pode ainda causar endotelite pelo receptor de enzima conversora da angiotensina 2, levando a microangiopatia tromb&#243;tica.<sup><xref ref-type="bibr" rid="B6">6</xref></sup></p>
      <p>Apesar de a doen&#231;a grave provocar um estado de hipercoagulabilidade, eventos tromboemb&#243;licos podem ocorrer em ambientes ambulatoriais, o que refor&#231;a que a doen&#231;a cr&#237;tica n&#227;o &#233; o &#250;nico fator envolvido. Overstad et al. relataram tromboembolismo venoso (TEV) em quatro pacientes em isolamento domiciliar,<sup><xref ref-type="bibr" rid="B7">7</xref></sup> e um estudo na It&#225;lia mostrou que 50% dos eventos tromboemb&#243;licos foram diagnosticados nas primeiras 24 horas de interna&#231;&#227;o.<sup><xref ref-type="bibr" rid="B8">8</xref></sup></p>
      <p>Eventos tromboemb&#243;licos arteriais, apesar de menos comuns que TEV, ocorrem em at&#233; 10,5% dos pacientes hospitalizados.<sup><xref ref-type="bibr" rid="B2">2</xref></sup> Acidente vascular cerebral foi descrito em 1,6% a 3,8% dos pacientes com COVID-19,<sup><xref ref-type="bibr" rid="B2">2</xref>,<xref ref-type="bibr" rid="B4">4</xref></sup> enquanto a incid&#234;ncia de infarto agudo do mioc&#225;rdio variar de 1,1%4 na It&#225;lia a 8,9% em diferentes centros de Nova Iorque.<sup><xref ref-type="bibr" rid="B2">2</xref></sup> Locais incomuns de ocorr&#234;ncia de trombose tamb&#233;m s&#227;o descritos. Acroisquemia e isquemia nos membros foram descritos em um caso associado com m&#250;ltiplos infartos cerebrais.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Isquemia intestinal foi detectada em uma mulher com insufici&#234;ncia respirat&#243;ria aguda trombose da veia porta direita e trombose da veia mesent&#233;rica superior na admiss&#227;o.<sup><xref ref-type="bibr" rid="B10">10</xref></sup> Dois casos de infarto renal foram relatados por Post et al.,<sup><xref ref-type="bibr" rid="B11">11</xref></sup> um deles em um receptor de transplante renal, e ambos internados na UTI.</p>
      <p>H&#225; poucos relados de casos de COVID-19 envolvendo receptores de transplante card&#237;aco. Uma s&#233;rie de casos em Nova Iorque relatou mortalidade de 25%, mas nenhum caso de evento tromboemb&#243;lico foi descrito.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> N&#243;s descrevemos aqui o primeiro caso de trombose arterial em um paciente submetido a transplante card&#237;aco.</p>
      <p>Devido &#224; apresenta&#231;&#227;o at&#237;pica, buscamos por uma trombofilia subjacente, e encontramos resultado positivo no teste de detec&#231;&#227;o de anticoagulante l&#250;pico. Foi relatada associa&#231;&#227;o da COVID-19 com resultado positivo para anticorpos antifosfolip&#237;dios (AA). Zhang et al.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> descreveram tr&#234;s casos de trombose associada com AA, representada por aCL e anti-&#946;2-glicoprote&#237;na I (a&#946;2GPI), mas n&#227;o foi detectado anticoagulante l&#250;pico em nenhum dos pacientes.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Por outro lado, Harzallah et al.<sup><xref ref-type="bibr" rid="B12">12</xref></sup> relataram positividade para o anticoagulante l&#250;pico em 45% dos 56 pacientes, e teste positivo para aCL ou a&#946;2GP somente em 10% dos pacientes, a maioria associado com aCL.<sup><xref ref-type="bibr" rid="B12">12</xref></sup> Contudo, sabe-se que infec&#231;&#245;es agudas s&#227;o sabidamente associadas com AA positivos.<sup><xref ref-type="bibr" rid="B13">13</xref></sup> Por isso, a import&#226;ncia da positividade para AA na COVID-19 precisa ainda ser determinada.</p>
    </sec>
    <sec sec-type="conclusions">
      <title>Conclus&#227;o</title>
      <p>Este relato de caso ilustra a heterogeneidade da apresenta&#231;&#227;o cl&#237;nica da COVID-19, e refor&#231;a a exist&#234;ncia de um estado pr&#243;-tromb&#243;tico, mesmo em ambiente ambulatorial. Ainda, este estudo contribui com informa&#231;&#245;es sobre a presen&#231;a de AA na COVID-19, apesar que sua import&#226;ncia na fisiopatologia dos eventos tromboemb&#243;licos ainda n&#227;o ter sido definida nesse cen&#225;rio. A implica&#231;&#227;o desses achados nos pacientes transplantados &#233; ainda menos clara, e este relato de caso destaca a necessidade de mais pesquisas.</p>
    </sec>
  </body>
  <back>
    <fn-group>
      <fn fn-type="supported-by" id="fn1">
        <p>
          <bold>Fontes de financiamento</bold>
        </p>
        <p>O presente estudo n&#227;o teve fontes de financiamento externas.</p>
      </fn>
      <fn fn-type="other" id="fn2">
        <p>
          <bold>Vincula&#231;&#227;o acad&#234;mica</bold>
        </p>
        <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-group>
    <ref-list>
      <title>Refer&#234;ncias</title>
      <ref id="B1">
        <label>1</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Wu</surname>
              <given-names>Z</given-names>
            </name>
            <name>
              <surname>McGoogan</surname>
              <given-names>JM</given-names>
            </name>
          </person-group>
          <article-title>Characteristics of and Important Lessons from the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention</article-title>
          <source>JAMA</source>
          <year>2020</year>
          <volume>323</volume>
          <issue>13</issue>
          <fpage>1239</fpage>
          <lpage>1242</lpage>
          <pub-id pub-id-type="doi">10.1001/jama.2020.2648</pub-id>
        </element-citation>
        <mixed-citation>1 Wu Z, McGoogan JM. Characteristics of and Important Lessons from the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention. JAMA. 2020;323(13):1239-42. doi: 10.1001/jama.2020.2648.</mixed-citation>
      </ref>
      <ref id="B2">
        <label>2</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Bilaloglu</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Aphinyanaphongs</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Jones</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Iturrate</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Hochman</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Berger</surname>
              <given-names>JS</given-names>
            </name>
          </person-group>
          <article-title>Thrombosis in Hospitalized Patients with COVID-19 in a New York City Health System</article-title>
          <source>JAMA</source>
          <year>2020</year>
          <volume>324</volume>
          <issue>8</issue>
          <fpage>799</fpage>
          <lpage>801</lpage>
          <pub-id pub-id-type="doi">10.1001/jama.2020.13372</pub-id>
        </element-citation>
        <mixed-citation>2 Bilaloglu S, Aphinyanaphongs Y, Jones S, Iturrate E, Hochman J, Berger JS. Thrombosis in Hospitalized Patients with COVID-19 in a New York City Health System. JAMA. 2020;324(8):799-801. doi: 10.1001/jama.2020.13372.</mixed-citation>
      </ref>
      <ref id="B3">
        <label>3</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lodigiani</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Iapichino</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>Carenzo</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Cecconi</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Ferrazzi</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Sebastian</surname>
              <given-names>T</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Venous and Arterial Thromboembolic Complications in COVID-19 Patients Admitted to an Academic Hospital in Milan, Italy</article-title>
          <source>Thromb Res</source>
          <year>2020</year>
          <volume>191</volume>
          <fpage>9</fpage>
          <lpage>14</lpage>
          <pub-id pub-id-type="doi">10.1016/j.thromres.2020.04.024</pub-id>
        </element-citation>
        <mixed-citation>3 Lodigiani C, Iapichino G, Carenzo L, Cecconi M, Ferrazzi P, Sebastian T, et al. Venous and Arterial Thromboembolic Complications in COVID-19 Patients Admitted to an Academic Hospital in Milan, Italy. Thromb Res. 2020;191:9-14. doi: 10.1016/j.thromres.2020.04.024.</mixed-citation>
      </ref>
      <ref id="B4">
        <label>4</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Abou-Ismail</surname>
              <given-names>MY</given-names>
            </name>
            <name>
              <surname>Diamond</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Kapoor</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Arafah</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Nayak</surname>
              <given-names>L</given-names>
            </name>
          </person-group>
          <article-title>The Hypercoagulable State in COVID-19: Incidence, Pathophysiology, and Management</article-title>
          <source>Thromb Res</source>
          <year>2020</year>
          <volume>194</volume>
          <fpage>101</fpage>
          <lpage>115</lpage>
          <pub-id pub-id-type="doi">10.1016/j.thromres.2020.06.029</pub-id>
        </element-citation>
        <mixed-citation>4 Abou-Ismail MY, Diamond A, Kapoor S, Arafah Y, Nayak L. The Hypercoagulable State in COVID-19: Incidence, Pathophysiology, and Management. Thromb Res. 2020;194:101-15. doi: 10.1016/j.thromres.2020.06.029.</mixed-citation>
      </ref>
      <ref id="B5">
        <label>5</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Foley</surname>
              <given-names>JH</given-names>
            </name>
            <name>
              <surname>Conway</surname>
              <given-names>EM</given-names>
            </name>
          </person-group>
          <article-title>Cross Talk Pathways between Coagulation and Inflammation</article-title>
          <source>Circ Res</source>
          <year>2016</year>
          <volume>118</volume>
          <issue>9</issue>
          <fpage>1392</fpage>
          <lpage>1408</lpage>
          <pub-id pub-id-type="doi">10.1161/CIRCRESAHA.116.306853</pub-id>
        </element-citation>
        <mixed-citation>5 Foley JH, Conway EM. Cross Talk Pathways between Coagulation and Inflammation. Circ Res. 2016;118(9):1392-408. doi: 10.1161/CIRCRESAHA.116.306853.</mixed-citation>
      </ref>
      <ref id="B6">
        <label>6</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Nascimento</surname>
              <given-names>JHP</given-names>
            </name>
            <name>
              <surname>Gomes</surname>
              <given-names>BFO</given-names>
            </name>
            <name>
              <surname>Carmo</surname>
              <given-names>PRD</given-names>
              <suffix>Jr</suffix>
            </name>
            <name>
              <surname>Petriz</surname>
              <given-names>JLF</given-names>
            </name>
            <name>
              <surname>Rizk</surname>
              <given-names>SI</given-names>
            </name>
            <name>
              <surname>Costa</surname>
              <given-names>IBSDS</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>COVID-19 and Hypercoagulable State: A New Therapeutic Perspective</article-title>
          <source>Arq Bras Cardiol</source>
          <year>2020</year>
          <volume>114</volume>
          <issue>5</issue>
          <fpage>829</fpage>
          <lpage>833</lpage>
          <pub-id pub-id-type="doi">10.36660/abc.20200308</pub-id>
        </element-citation>
        <mixed-citation>6 Nascimento JHP, Gomes BFO, Carmo PRD Jr, Petriz JLF, Rizk SI, Costa IBSDS, et al. COVID-19 and Hypercoagulable State: A New Therapeutic Perspective. Arq Bras Cardiol. 2020;114(5):829-33. doi: 10.36660/abc.20200308.</mixed-citation>
      </ref>
      <ref id="B7">
        <label>7</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Overstad</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Tjonnfjord</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Garabet</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Fronas</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Bergan</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Aballi</surname>
              <given-names>S</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Venous Thromboembolism and Coronavirus Disease 2019 in an Ambulatory Care Setting - A report of 4 Cases</article-title>
          <source>Thromb Res</source>
          <year>2020</year>
          <volume>194</volume>
          <fpage>116</fpage>
          <lpage>118</lpage>
          <pub-id pub-id-type="doi">10.1016/j.thromres.2020.06.032</pub-id>
        </element-citation>
        <mixed-citation>7 Overstad S, Tjonnfjord E, Garabet L, Fronas S, Bergan J, Aballi S, et al. Venous Thromboembolism and Coronavirus Disease 2019 in an Ambulatory Care Setting - A report of 4 Cases. Thromb Res. 2020;194:116-8. doi: 10.1016/j.thromres.2020.06.032.</mixed-citation>
      </ref>
      <ref id="B8">
        <label>8</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Latif</surname>
              <given-names>F</given-names>
            </name>
            <name>
              <surname>Farr</surname>
              <given-names>MA</given-names>
            </name>
            <name>
              <surname>Clerkin</surname>
              <given-names>KJ</given-names>
            </name>
            <name>
              <surname>Habal</surname>
              <given-names>MV</given-names>
            </name>
            <name>
              <surname>Takeda</surname>
              <given-names>K</given-names>
            </name>
            <name>
              <surname>Naka</surname>
              <given-names>Y</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Characteristics and Outcomes of Recipients of Heart Transplant with Coronavirus Disease 2019</article-title>
          <source>JAMA Cardiol</source>
          <year>2020</year>
          <volume>5</volume>
          <issue>10</issue>
          <fpage>1165</fpage>
          <lpage>1169</lpage>
          <pub-id pub-id-type="doi">10.1001/jamacardio.2020.2159</pub-id>
        </element-citation>
        <mixed-citation>8 Latif F, Farr MA, Clerkin KJ, Habal MV, Takeda K, Naka Y, et al. Characteristics and Outcomes of Recipients of Heart Transplant with Coronavirus Disease 2019. JAMA Cardiol. 2020;5(10):1165-9. doi: 10.1001/jamacardio.2020.2159.</mixed-citation>
      </ref>
      <ref id="B9">
        <label>9</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Zhang</surname>
              <given-names>Y</given-names>
            </name>
            <name>
              <surname>Xiao</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Zhang</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Xia</surname>
              <given-names>P</given-names>
            </name>
            <name>
              <surname>Cao</surname>
              <given-names>W</given-names>
            </name>
            <name>
              <surname>Jiang</surname>
              <given-names>W</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Coagulopathy and Antiphospholipid Antibodies in Patients with Covid-19</article-title>
          <source>N Engl J Med</source>
          <year>2020</year>
          <volume>382</volume>
          <issue>17</issue>
          <fpage>38</fpage>
          <lpage>38</lpage>
          <pub-id pub-id-type="doi">10.1056/NEJMc2007575</pub-id>
        </element-citation>
        <mixed-citation>9 Zhang Y, Xiao M, Zhang S, Xia P, Cao W, Jiang W, et al. Coagulopathy and Antiphospholipid Antibodies in Patients with Covid-19. N Engl J Med. 2020;382(17):38. doi: 10.1056/NEJMc2007575.</mixed-citation>
      </ref>
      <ref id="B10">
        <label>10</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Barry</surname>
              <given-names>O</given-names>
            </name>
            <name>
              <surname>Mekki</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Diffre</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Seror</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>El Hajjam</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Carlier</surname>
              <given-names>RY</given-names>
            </name>
          </person-group>
          <article-title>Arterial and Venous Abdominal Thrombosis in a 79-year-old Woman with COVID-19 Pneumonia</article-title>
          <source>Radiol Case Rep</source>
          <year>2020</year>
          <volume>15</volume>
          <issue>7</issue>
          <fpage>1054</fpage>
          <lpage>1057</lpage>
          <pub-id pub-id-type="doi">10.1016/j.radcr.2020.04.055</pub-id>
        </element-citation>
        <mixed-citation>10 Barry O, Mekki A, Diffre C, Seror M, El Hajjam M, Carlier RY. Arterial and Venous Abdominal Thrombosis in a 79-year-old Woman with COVID-19 Pneumonia. Radiol Case Rep. 2020;15(7):1054-7. doi: 10.1016/j.radcr.2020.04.055.</mixed-citation>
      </ref>
      <ref id="B11">
        <label>11</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Post</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>den Deurwaarder</surname>
              <given-names>ESG</given-names>
            </name>
            <name>
              <surname>Bakker</surname>
              <given-names>SJL</given-names>
            </name>
            <name>
              <surname>Haas</surname>
              <given-names>RJ</given-names>
            </name>
            <name>
              <surname>van Meurs</surname>
              <given-names>M</given-names>
            </name>
            <name>
              <surname>Gansevoort</surname>
              <given-names>RT</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Kidney Infarction in Patients with COVID-19</article-title>
          <source>Am J Kidney Dis</source>
          <year>2020</year>
          <volume>76</volume>
          <issue>3</issue>
          <fpage>431</fpage>
          <lpage>435</lpage>
          <pub-id pub-id-type="doi">10.1053/j.ajkd.2020.05.004</pub-id>
        </element-citation>
        <mixed-citation>11 Post A, den Deurwaarder ESG, Bakker SJL, Haas RJ, van Meurs M, Gansevoort RT, et al. Kidney Infarction in Patients with COVID-19. Am J Kidney Dis. 2020;76(3):431-5. doi: 10.1053/j.ajkd.2020.05.004.</mixed-citation>
      </ref>
      <ref id="B12">
        <label>12</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Harzallah</surname>
              <given-names>I</given-names>
            </name>
            <name>
              <surname>Debliquis</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Dr&#233;nou</surname>
              <given-names>B</given-names>
            </name>
          </person-group>
          <article-title>Lupus Anticoagulant is Frequent in Patients with Covid-19</article-title>
          <source>J Thromb Haemost</source>
          <year>2020</year>
          <volume>18</volume>
          <issue>8</issue>
          <fpage>2064</fpage>
          <lpage>2065</lpage>
          <pub-id pub-id-type="doi">10.1111/jth.14867</pub-id>
        </element-citation>
        <mixed-citation>12 Harzallah I, Debliquis A, Dr&#233;nou B. Lupus Anticoagulant is Frequent in Patients with Covid-19. J Thromb Haemost. 2020;18(8):2064-5. doi: 10.1111/jth.14867.</mixed-citation>
      </ref>
      <ref id="B13">
        <label>13</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Devreese</surname>
              <given-names>KMJ</given-names>
            </name>
            <name>
              <surname>Ortel</surname>
              <given-names>TL</given-names>
            </name>
            <name>
              <surname>Pengo</surname>
              <given-names>V</given-names>
            </name>
            <name>
              <surname>Laat</surname>
              <given-names>B</given-names>
            </name>
          </person-group>
          <article-title>Laboratory Criteria for Antiphospholipid Syndrome: Communication from the SSC of the ISTH</article-title>
          <source>J Thromb Haemost</source>
          <year>2018</year>
          <volume>16</volume>
          <issue>4</issue>
          <fpage>809</fpage>
          <lpage>813</lpage>
          <pub-id pub-id-type="doi">10.1111/jth.13976</pub-id>
        </element-citation>
        <mixed-citation>13 Devreese KMJ, Ortel TL, Pengo V, Laat B. Laboratory Criteria for Antiphospholipid Syndrome: Communication from the SSC of the ISTH. J Thromb Haemost. 2018;16(4):809-13. doi: 10.1111/jth.13976.</mixed-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="S01" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Research Letter</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Aortic and Renal Artery Thrombosis as the First Clinical Manifestation of COVID-19 in a Heart Transplant Recipient</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-0207-3986</contrib-id>
          <name>
            <surname>Belfort</surname>
            <given-names>Deborah de S&#225; Pereira</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-2533-5638</contrib-id>
          <name>
            <surname>Marcondes-Braga</surname>
            <given-names>Fabiana G.</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>1</sup>
          </xref>
          <xref ref-type="corresp" rid="c2"/>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0003-0894-1131</contrib-id>
          <name>
            <surname>Mangini</surname>
            <given-names>Sandrigo</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-5960-2952</contrib-id>
          <name>
            <surname>Cafezeiro</surname>
            <given-names>Caio Rebou&#231;as Fonseca</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Furlan</surname>
            <given-names>Di&#243;genes Amauri Gon&#231;alves</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>1</sup>
          </xref>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Bacal</surname>
            <given-names>Fernando</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>1</sup>
          </xref>
        </contrib>
        <aff id="aff2">
          <label>1</label>
          <addr-line>
            <named-content content-type="city">S&#227;o Paulo</named-content>
            <named-content content-type="state">SP</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Instituto do Cora&#231;&#227;o (InCor), Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo, S&#227;o Paulo, SP - Brazil</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c2"><bold>Mailing Address: Fabiana G. Marcondes-Braga &#8226;</bold> Universidade de S&#227;o Paulo Faculdade de Medicina Hospital das Cl&#237;nicas Instituto do Cora&#231;&#227;o - Avenida Dr. En&#233;as Carvalho de Aguiar, 44. Postal Code <postal-code>05410-020</postal-code>, S&#227;o Paulo, SP - Brazil. E-mail: <email>fgmarcondes@yahoo.com.br</email>, <email>fgmarcondes@gmail.com</email></corresp>
        <fn fn-type="con">
          <p>
            <bold>Author Contributions</bold>
          </p>
          <p>Conception and design of the research: Belfort DSP, Marcondes-Braga FG, Mangini S, Cafezeiro CRF, Furlan DAG, Bacal F; Acquisition of data: Belfort DSP, Cafezeiro CRF, Furlan DAG; Writing of the manuscript: Belfort DSP, Marcondes-Braga FG, Cafezeiro CRF, Furlan DAG; Critical revision of the manuscript for intellectual content: Belfort DSP, Marcondes-Braga FG, Mangini S, Bacal F.</p>
        </fn>
        <fn fn-type="conflict">
          <p>
            <bold>Potential Conflict of Interest</bold>
          </p>
          <p>No potential conflict of interest relevant to this article was reported.</p>
        </fn>
      </author-notes>
      <kwd-group xml:lang="en">
        <title>Keywords</title>
        <kwd>COVID-19</kwd>
        <kwd>Thromboembolism</kwd>
        <kwd>Heart Transplantation</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <sec sec-type="intro">
        <title>Introduction</title>
        <p>The novel coronavirus infection emerged in Wuhan, China, in the end of 2019 and is now a pandemic.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> The relation between COVID-19 and thrombotic events is well established, even for patients under prophylactic anticoagulation. Although venous and arterial thromboembolic events have been described, usually stroke and acute myocardial infarction (AMI),<sup><xref ref-type="bibr" rid="B2">2</xref>,<xref ref-type="bibr" rid="B3">3</xref></sup> there are few reports of arterial thrombosis in unusual sites.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> Almost all reports of thrombotic events are of intensive care unit (ICU) patients, and the incidence of thromboembolism in mild cases of COVID-19 is still not clear.</p>
        <p>We report a case of a male heart transplant recipient admitted to emergency department with thrombosis of right renal artery and thoracic descending aorta associated with COVID-19.</p>
        <sec>
          <title>Case presentation</title>
          <p>A 28-year-old male heart transplant recipient since 2018, with previous familial dilated cardiomyopathy was admitted to the emergency department with acute right flank pain for three days associated with fever, chills, nausea, and vomiting. He denied respiratory symptoms, myalgia, headache or other symptoms which could suggest viral infection. Apart from diabetes mellitus and dyslipidemia, he had had no other comorbidity. The patient was on regular use of tacrolimus, mycophenolate and prednisone.</p>
          <p>Physical exam revealed blood pressure of 150/100 mmHg, heart rate of 100 beats per minute, respiratory rate of 20 cycles per minute and blood oxygen saturation of 96% in ambient air. No rales were detected in lung evaluation and abdominal exam showed right costovertebral angle tenderness. Blood tests showed C-reactive protein of 317mg/dL, lactate dehydrogenase of 1,827U/L, D-dimer of 4,126ng/mL, ferritin of 651ng/mL, leukocytosis of 16,100/mm<sup>3</sup> and no other alterations.</p>
          <p>An abdominal and thoracic computed tomography scan (CT scan) was performed and, surprisingly, revealed sparse luminal peripheral thrombi in the descending thoracic aorta (<xref ref-type="fig" rid="f5">Figure 1</xref>). One of the thrombi extended to the right renal artery ostium and caused partial occlusion of its proximal segment (<xref ref-type="fig" rid="f6">Figures 2</xref> and <xref ref-type="fig" rid="f7">3</xref>). Right kidney presented multiple hypodense areas compatible with renal infarcts (<xref ref-type="fig" rid="f7">Figure 3</xref>). No other artery was affected. Besides those findings, ground-glass opacities were found in 25% of pulmonary parenchyma (<xref ref-type="fig" rid="f8">Figure 4</xref>), and for this reason COVID-19 was suspected. Nasopharynx real-time fluorescence polymerase chain reaction result for SARS-CoV-2 was positive. Coagulopathy tests were performed before starting anticoagulation. Protein C, protein S, antithrombin III levels were normal, prothrombin mutation test was negative, anticardiolipin (acL) antibody (IgG and IgM) tests were negative, but lupus anticoagulant (LAC) test was positive.</p>
          <fig id="f5">
            <label>Figure 1</label>
            <caption>
              <title>Abdominal computed tomography scan revealing sparse luminal peripheral thrombi in the descending thoracic aorta (arrow).</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf01-en.tif"/></fig>
          <fig id="f6">
            <label>Figure 2</label>
            <caption>
              <title>Tridimensional reconstruction of abdominal aorta showing partial occlusion of the proximal segment of right renal artery.</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf02-en.tif"/></fig>
          <fig id="f7">
            <label>Figure 3</label>
            <caption>
              <title>Abdominal computed tomography scan showing one of the thrombi extending to right renal artery ostium and causing partial occlusion of the proximal segment of this artery (arrow). Right kidney presents hypodense areas compatible with renal infarcts.</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf03-en.tif"/></fig>
          <fig id="f8">
            <label>Figure 4</label>
            <caption>
              <title>Thoracic computed tomography scan revealing ground-glass opacities in 25% of pulmonary parenchyma.</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-117-05-1045-01210-gf04-en.tif"/></fig>
          <p>Hydration, antibiotics (ceftriaxone and azithromycin) and anticoagulation with enoxaparin were prescribed. Tacrolimus and mycophenolate were discontinued and prednisone was switched to hydrocortisone 150mg/day at admission. The patient improved and became asymptomatic. Inflammatory markers went down the following days. Immunosuppression was restarted after five days of admission and warfarin was prescribed. The patient was discharged on the 15<sup>th</sup> hospitalization day after adjustment of warfarin dose.</p>
        </sec>
      </sec>
      <sec sec-type="discussion">
        <title>Discussion</title>
        <p>Since the outbreak of COVID-19, a wide range of clinical presentations have been described. Most patients have mild symptoms, but up to 14% of infected patients develop interstitial pneumonia and 5% require mechanical ventilation.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> Thromboembolic events in critically ill patients have been associated with COVID-19 in several studies.<sup><xref ref-type="bibr" rid="B2">2</xref>-<xref ref-type="bibr" rid="B4">4</xref></sup></p>
        <p>The mechanisms of the prothrombotic state and coagulopathy are not totally clear. COVID-19 is associated with a marked proinflammatory state, and the cytokine storm described in COVID-19 contributes to thrombosis by activating monocytes, neutrophils, and endothelium.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> These cells activate platelets and increase levels of von Willebrand factor and factor VIII, all contributing to thrombin generation and fibrin clot formation. Thrombin, on the other hand, amplifies pro-inflammatory pathways.<sup><xref ref-type="bibr" rid="B5">5</xref></sup> The virus may also cause endotheliitis through the angiotensin-converting enzyme 2 receptor, leading to thrombotic microangiopathy.<sup><xref ref-type="bibr" rid="B6">6</xref></sup></p>
        <p>Although severe illness itself is known to provoke a hypercoagulable state, thromboembolic events may happen in outpatient settings, highlighting that critical illness is not the only factor involved. Overstad et al. reported venous thromboembolism (VTE) in four patients in isolation at home,<sup><xref ref-type="bibr" rid="B7">7</xref></sup> and a study in Italy showed that 50% of the reported thromboembolic events were diagnosed within 24h of hospital admission.<sup><xref ref-type="bibr" rid="B8">8</xref></sup></p>
        <p>Arterial thromboembolic events, although less common than VTE, occur in up to 10.5% of hospitalized patients.<sup><xref ref-type="bibr" rid="B2">2</xref></sup> Stroke was described in 1.6% and 3.8% of patients with COVID-19,<sup><xref ref-type="bibr" rid="B2">2</xref>,<xref ref-type="bibr" rid="B4">4</xref></sup> while the incidence of acute myocardial infarction (AMI) varies from 1.1%<sup><xref ref-type="bibr" rid="B4">4</xref></sup> in Italy to 8.9% in different centers of New York City.<sup><xref ref-type="bibr" rid="B2">2</xref></sup> Unusual sites of arterial thrombosis are also reported. Limb or acral ischemia was described in a case associated with multiple brain infarcts.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Bowel ischemia was detected in a woman presenting acute respiratory failure and right portal vein and upper mesenteric thrombosis on admission.<sup><xref ref-type="bibr" rid="B10">10</xref></sup> Two cases of renal infarction were reported by Post et al.,<sup><xref ref-type="bibr" rid="B11">11</xref></sup> one of them in a kidney transplant recipient, and both patients were in ICU.</p>
        <p>There are few reports of COVID-19 cases among heart transplant recipients. A series of case in New York reported mortality of 25%, but no cases of arterial thromboembolic events have been described.<sup><xref ref-type="bibr" rid="B8">8</xref></sup> We report here, the first case of arterial thrombosis in a heart transplant patient.</p>
        <p>Because of the atypical presentation, we searched for an underlying thrombophilia, and we found a positive LAC. It has been reported association of COVID-19 with positivity of antiphospholipid antibodies (AA). Zhang et al.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> described three cases of thrombosis associated with AA represented by aCL and anti-&#946;2-glycoprotein I (a&#946;2GPI), but no LAC was detected in any of the patients.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> On the other hand, Harzallah et al.<sup><xref ref-type="bibr" rid="B12">12</xref></sup> reported positivity of LAC in 45% of 56 patients, and only 10% positive for aCL or a&#946;2GPI, most of them associated with LAC.<sup><xref ref-type="bibr" rid="B12">12</xref></sup> However, acute infections are known to be sometimes associated with transient AA.<sup><xref ref-type="bibr" rid="B13">13</xref></sup> For those reasons, the relevance of AA positivity in COVID-19 is yet to be determined.</p>
      </sec>
      <sec sec-type="conclusions">
        <title>Conclusions</title>
        <p>This case report illustrates the heterogeneity of clinical presentation of COVID-19 and reinforces the existence of a prothrombotic state, even in the outpatient setting. Moreover, it adds information to the recent reports regarding the presence of AA in COVID-19, although their importance in the pathophysiology of thromboembolic events in this setting is still not defined. The implication of these findings in transplant patients is even less clear, and this case report highlights the need for further research.</p>
      </sec>
    </body>
    <back>
      <fn-group>
        <fn fn-type="supported-by" id="fn3">
          <p>
            <bold>Sources of Funding</bold>
          </p>
          <p>There were no external funding sources for this study.</p>
        </fn>
        <fn fn-type="other" id="fn4">
          <p>
            <bold>Study Association</bold>
          </p>
          <p>This study is not associated with any thesis or dissertation work.</p>
        </fn>
      </fn-group>
    </back>
  </sub-article>
</article>
