Anticoagulation for New-Onset Post-Operative Atrial Fibrillation After CABG

This is a prospective, multicenter, open-label, randomized trial comparing OAC with no OAC (1:1 ratio) in patients who develop new-onset POAF after CABG. The primary effectiveness endpoint is the composite of death, ischemic stroke, transient ischemic attack (TIA), myocardial infarction (MI), systemic arterial thromboembolism or venous thromboembolism (VTE) at 90 days after randomization. The primary safety endpoint is BARC (Bleeding Academic Research Consortium) grade 3 or 5 bleeding at 90 days after randomization. The overall intent is to evaluate the trade-off in prevention of thromboembolic events versus an increase in bleeding. Patients will be randomly assigned to the following treatment strategies: * OAC-based strategy (experimental arm): OAC with vitamin K antagonist (VKA) with international normalized ratio (INR) target 2-3 or any approved direct oral anticoagulant (apixaban, rivaroxaban, edoxaban or dabigatran) in addition to background antiplatelet therapy with aspirin 75-325mg once-daily or a P2Y12-inhibitor (clopidogrel or ticagrelor) * Antiplatelet-only strategy (control arm): single antiplatelet therapy with aspirin 75-325mg once-daily or a P2Y12-inhibitor (clopidogrel or ticagrelor) The protocol-specified duration of anticoagulation is 90 days. Patients, who are randomized to the control arm and develop recurrent AF after 30 days, may be crossed-over to an OAC. Accrual is expected to take 60 months. Study follow-up visits will be performed at 90 days and phone follow-up at days 30, 60, and 180 days. Data for patients enrolled in the registry will be ascertained from the local clinical site via a review of medical records. The baseline risk profile of registry patients (i.e., patients eligible but unwilling to be randomized) will be analyzed and compared to that of patients randomized in the trial. The usage of anticoagulant and antiplatelet therapies in the registry population overall and baseline CHA2DS2-VASC ischemic stroke risk score will also be determined. Up to 500 patients will also be offered the option to participate in a digital health substudy which includes a wearable heart rhythm monitor device for 30 days post discharge.