Abstract

This paper collates the pathological findings from initial published autopsy reports on 23 patients with coronavirus disease 2019 (COVID-19) from 5 centers in the United States of America, including 3 cases from Houston, Texas. Findings confirm that COVID-19 is a systemic disease with major involvement of the lungs and heart. Acute COVID-19 pneumonia has features of a distinctive acute interstitial pneumonia with a diffuse alveolar damage component, coupled with microvascular involvement with intra- and extravascular fibrin deposition and intravascular trapping of neutrophils, and, frequently, with formation of microthombi in arterioles. Major pulmonary thromboemboli with pulmonary infarcts and/or hemorrhage occurred in 5 of the 23 patients. Two of the Houston cases had interstitial pneumonia with diffuse alveolar damage pattern. One of the Houston cases had multiple bilateral segmental pulmonary thromboemboli with infarcts and hemorrhages coupled with, in nonhemorrhagic areas, a distinctive interstitial lymphocytic pneumonitis with intra-alveolar fibrin deposits and no hyaline membranes, possibly representing a transition form to acute fibrinous and organizing pneumonia. Multifocal acute injury of cardiac myocytes was frequently observed. Lymphocytic myocarditis was reported in 1 case. In addition to major pulmonary pathology, the 3 Houston cases had evidence of lymphocytic pericarditis, multifocal acute injury of cardiomyocytes without inflammatory cellular infiltrates, depletion of splenic white pulp, focal hepatocellular degeneration and rare glomerular capillary thrombosis. Each had evidence of chronic cardiac disease: hypertensive left ventricular hypertrophy (420 g heart), dilated cardiomyopathy (1070 g heart), and hypertrophic cardiomyopathy (670 g heart). All 3 subjects were obese (BMIs of 33.8, 51.65, and 35.2 Kg/m2). Overall, the autopsy findings support the concept that the pathogenesis of severe COVID-19 disease involves direct viral-induced injury of multiple organs, including heart and lungs, coupled with the consequences of a procoagulant state with coagulopathy.