An Open-label, 2 x 2 Factorial, Randomized Controlled, Clinical Trial to Evaluate the Safety of Apixaban vs. Vitamin K Antagonist and Aspirin vs. Aspirin Placebo in Patients With Atrial Fibrillation and Acute Coronary Syndrome or Percutaneous Coronary Intervention

The purpose of this study is to determine if Apixaban is safer than a Vitamin K Antagonist given for 6 months in terms of bleeding in patients with an irregular heart beat (atrial fibrillation) and a recent heart attack or a recent procedure to open up a blood vessel in the heart. All patients would also be taking a class of medicines called P2Y12 inhibitors (such as clopidogrel/Plavix) and be treated for up to 6 months. The primary focus will be a comparison of the bleeding risk of Apixaban, with or without aspirin, versus a Vitamin K antagonist, such as warfarin, with or without aspirin.