Cardiac pathology in COVID-19: a single center autopsy experience

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is commonly associated with myocardial injury and heart failure. The pathophysiology behind this phenomenon remains unclear, with many diverse and multifaceted hypotheses. To contribute to this understanding, we describe the underlying cardiac findings in fifty patients who died with coronavirus disease 2019 (COVID-19). METHODS: Included were autopsies performed on patients with a positive SARS-CoV-2 reverse-transcriptase-polymerase-chain reaction test from the index hospitalization. In the case of out-of-hospital death, patients were included if post-mortem testing was positive. Complete autopsies were performed according to a COVID-19 safety protocol, and all patients underwent both macroscopic and microscopic examination. If available, laboratory findings and echocardiograms were reported. RESULTS: The median age of the decedents was 63.5 years. The most common comorbidities included hypertension (90.0%), diabetes (56.0%) and obesity (50.0%). Lymphocytic inflammatory infiltrates in the heart were present in eight (16.0%) patients, with focal myocarditis present in two (4.0%) patients. Acute myocardial ischemia was observed in eight (16.0%) patients. The most common findings were myocardial fibrosis (80.0%), hypertrophy (72.0%), and microthrombi (66.0%). The most common causes of death were COVID-19 pneumonia in 18 (36.0%), COVID-19 pneumonia with bacterial superinfection in 12 (24.0%), and COVID-19 pneumonia with pulmonary embolism in 10 (20.0%) patients. CONCLUSIONS: Cardiovascular comorbidities were prevalent, and pathologic changes associated with hypertensive and atherosclerotic cardiovascular disease were the most common findings. Despite markedly elevated inflammatory markers and cardiac enzymes, few patients exhibited inflammatory infiltrates or necrosis within cardiac myocytes. A unifying pathophysiologic mechanism behind myocardial injury in COVID-19 remains elusive, and additional autopsy studies are needed.