Oral Antithrombotic Therapy in Atrial Fibrillation Associated With Acute or Chronic Coronary Artery Disease

Randomized controlled trials have demonstrated benefits from antithrombotic therapies for coronary artery disease (primary prevention, stable coronary artery disease, acute coronary syndromes, and percutaneous intervention) and for atrial fibrillation. The regimens with the optimal balance of efficacy and safety with coronary artery disease depend on the particular clinical manifestation, with atrial fibrillation on the risk of stroke, and with both conditions on the competing risk of major bleeding with the chosen antithrombotic therapy. The antithrombotic agents include aspirin, P2Y12 receptor inhibitors (clopidogrel, prasugrel, and ticagrelor) and oral anticoagulants (warfarin and the novel oral anticoagulants, dabigatran, rivaroxaban, and apixaban). Atrial fibrillation and coronary artery disease often occur in the same patient and require decisions as to what individual or combination of antithrombotic therapies are necessary to provide optimal protection against coronary events and stroke, and cause as little bleeding as possible. Practice guidelines now recommend oral anticoagulant therapy for most patients with atrial fibrillation and consideration of "triple therapy" (oral anticoagulant and aspirin and clopidogrel) when there is a concomitant acute coronary syndrome or stent placement, though acknowledging the risks of major bleeding. In the absence of definitive trials of combination therapies, such practice guidelines are based on extrapolations from randomized trials and observational data.