COVID-19 Outpatient Thrombosis Prevention Trial (ACTIV-4B)

An adaptive randomized double-blind placebo-controlled platform trial to compare the effectiveness of anticoagulation with antiplatelet agents and with placebo to prevent thrombotic events in patients diagnosed with COVID-19 who are not admitted to hospital as COVID-19 related symptoms are currently stable.]]> Inclusion criteria: Age between 40 and 80 years inclusive Documentation of PCR or antigen test positive symptomatic COVID-19 infection in the past 14 days Ability to be contacted by telephone or other electronic methods of communication Negative pregnancy test for WOCBP Exclusion criteria: Indication for therapeutic anticoagulation (mechanical heart valve, AF, APS) Indication for single or dual antiplatelet therapy Lactating Primary brain tumor or acute leukemia Bleeding risk Hospitalization in the past 2 months for: Bleeding due to ulcer or GI tract disease Major surgery, stroke, or intracranial hemorrhage Platelet count < 100,000 per microliter can be obtained after randomization Calculated creatine clearance < 30 ml/min can be obtained after randomization Ever hospitalized after diagnosis of COVID-19 Concomitant need for strong inducers/inhibitors of p-gp and CYP3A4 SARS-CoV-2 PCR or antigen test more than 14 days prior Unable to give written informed consent ]]>