In patients with atrial fibrillation, standard anticoagulation with a vitamin K antagonist plus dual antiplatelet therapy with a P2Y12 inhibitor and aspirin is the standard of care after percutaneous coronary intervention (PCI). While this therapy reduces the risk of thrombosis and stroke, it increases the risk of bleeding. It is unclear whether the antiplatelet effect of aspirin and clopidogrel may worsen atrial fibrillation (AF).