Abstract

Atrial fibrillation affects approximately 5 million patients in the United States. The rate of stroke in adults with atrial fibrillation depending on their risk factors varies between 1-20% annually. Anticoagulation with vitamin K antagonists such as warfarin has been the mainstay therapy but it is cumbersome and requires close follow-up. Since 2010, three new oral anticoagulants have received Food and Drug Administration approval for stroke prevention in atrial fibrillation. This review summarizes data from three landmark trials: RE-LY, ROCKET-AF, and ARISTOTLE. In addition, issues relating to cost, reversal, drug interactions, and perioperative discontinuation are discussed. Compared to Warfarin, Dabigatran 150mg twice daily lowered the primary outcome of stroke/systemic embolism by 34% (number needed to treat/yr 169) and had similar incidence of major bleeding. Rivaroxaban demonstrated non inferiority compared to the warfarin group for the primary outcome of stroke and systemic embolism and major bleeding. Apixaban showed a relative risk reduction for the primary outcome of 21% (number needed to treat 300), and lowered major bleeding down by 31% (number needed to treat /yr 104). Apixaban also showed a mortality benefit compared to warfarin (3.52 vs. 3.94%/year, p 0.047). All 3 oral anticoagulants lowered rates of intracranial hemorrhage. The use of Rivaroxaban and Apixaban has been projected to reduce medical costs when compared to warfarin, and Dabigatran is projected to have similar costs. All the 3 oral anticoagulants have robust randomized controlled trials supporting their comparability to warfarin therapy for stroke prevention in non valvular atrial fibrillation, with Apixaban showing superiority in incidence of strokes, major bleeding and mortality.

Keywords: Anticoagulants, atrial fibrillation, stroke.