This study is an adaptive, prospective, randomized platform trial designed to compare the effectiveness and safety of antithrombotic therapy with no antithrombotic therapy after hospitalization for 48 hours or longer for COVID-19. For Stage 1 of this study, participants will be randomized to either prophylactic anticoagulation or matching placebo for 30 days, and then followed for an additional 60 days after the completion of treatment (total duration of follow-up, 90 days).~The primary objective is to determine the most effective and safe antithrombotic strategy to prevent the composite outcome of symptomatic deep vein thrombosis, pulmonary embolism, other venous thromboembolism, ischemic stroke, myocardial infarction, other arterial thromboembolism, and all-cause mortality by 30 days following discharge from the hospital.~Biobanking of samples for future biomarker and mechanistic studies will be available for centers able to participate and collect samples from eligible participants. Samples will be collected at the time of enrollment and after the completion of 30 days of therapy
A multicenter, adaptive, randomized platform trial evaluating the efficacy and safety of antithrombotic strategies in patients with COVID-19 following hospital discharge