IMPORTANCE: Assessment of the causative association between the COVID-19 and cause of death has been hampered by limited availability of systematically performed autopsies . We aimed to present autopsy-confirmed causes of death in patients who died with COVID-19 and to assess the association between thrombosis and diffuse alveolar damage consistent with COVID-19 (DAD).
METHODS: Consecutive forensic (n=60) and clinical (n=42) autopsies with positive postmortem SARS-CoV2 PCR in lungs (age 73±14 years , 50% men) were included . Cause of death analysis was based on a review of medical records and histology reports . Thrombotic phenomena in lungs were defined as pulmonary thromboembolism (PE), thrombosis in pulmonary artery branches or microangiopathy in capillary vessels .
RESULTS: COVID-19 caused or contributed to death in 71% of clinical and 83% of forensic autopsies, in whom significant DAD was observed . Of the patients with COVID-19 as the primary cause of death, only 19% had no thrombotic phenomena in the lungs, as opposed to 38% among those with COVID-19 as a contributing cause of death and 54% among patients whose death was not related to COVID-19 (p=0.002). PE was observed in 5 patients . Two patients fulfilled the criteria for lymphocyte myocarditis .
CONCLUSIONS: Vast majority of all PCR-positive fatalities, including out-of-hospital deaths, during SARS-CoV2 pandemic were related to DAD caused by COVID-19 . Pulmonary artery thrombosis and microangiopathy in pulmonary tissue were common and associated with the presence of DAD, while venous PE was rarely observed . Histology-confirmed lymphocyte myocarditis was a rare finding.