Selecting antithrombotic therapy for patients with atrial fibrillation.

Antithrombotic therapy reduces the risk of systemic embolism in patients with atrial fibrillation, but one approach does not suit all patients. The decision whether to start this therapy—and which agent to use—must take into account the patient’s risk of thromboembolism as well as bleeding. Antithrombotic therapy encompasses anti-platelet drugs such as aspirin and clopidogrel and anticoagulants such as warfarin and the target-specific oral anticoagulants (TSOACs). Oral anticoagulation is more effective than antiplatelet therapy and is preferred in all but those at lowest risk, in whom either antiplatelet therapy or no therapy is deemed adequate. Patients with valvular atrial fibrillation, specifically those who have rheumatic mitral stenosis or a prosthetic heart valve, are at significantly higher risk of systemic embolization. Their overall risk-benefit profile is nearly always in favor of anticoagulation. But the same is not necessarily true for patients with nonvalvular atrial fibrillation. The following discussion sets forth our rationale for clinical decision-making, based on recommendations in the 2014 guidelines from the American Heart Association, American College of Cardiology, and Heart Rhythm Society.1 The second half of this review outlines the oral anticoagulants currently available.