ABSTRACT
Coronavirus disease 2019 (COVID-19) is often accompanied by pneumonia and can be fatal. We report a case of COVID-19-associated myocardial injury mimicking fulminant myocarditis. Endomyocardial biopsy revealed numerous von Willebrand factor-rich microthrombi with small myocardial necrotic areas, complement deposits in small vessels/microthrombi, and macrophage-predominant interstitial infiltration. These findings, distinct from those of typical lymphocytic myocarditis, show diffuse endothelial injury, complement activation, and activated macrophages as characteristic features of COVID-19-associated pathogenesis. Dysregulated serum cytokine profiles predicting severe/critical COVID-19-associated myocardial injury were also determined. This case emphasizes the occurrence of fatal cardiac manifestation with microthrombotic injury in the early stage of COVID-19.