Acute Myocardial Infarction with Microthrombi in Cardiac Small Vessels after COVID-19 Vaccination (ChAdOx1 nCov-19): A Case Report

We present the postmortem findings of an unexpected death due to acute myocardial infarction (AMI) with microthrombi and thrombosis in other vessels after the first dose of coronavirus disease 2019 (COVID-19) vaccination (ChAdOx1 nCov-19). The deceased was a 69-year-old woman who complained of nonspecific symptoms shortly after vaccination and was found dead on the sixth day. Postmortem examination revealed AMI and complications (left ventricular rupture, hemopericardium) with microthrombi in small cardiac vessels, which are similar to the characteristic findings of myocardial injury caused by microthrombi in patients with COVID-19. Nonobstructive thromboembolism in the pulmonary arteries and inferior vena cava, and fibrin microthrombi in some small vessels in the brain were also observed. It is unclear whether these findings are associated with COVID-19 vaccination, and further comprehensive studies are needed.