Treatment patterns and real-world effectiveness of warfarin in nonvalvular atrial fibrillation within a managed care system

Abstract

Within usual clinical care for the managed care population examined, warfarin remains underused despite current guidelines recommending its use in nearly all patients with nonvalvular atrial fibrillation. Although utilization of anticoagulation clinics and INR values attained were unknown in this study, the observed risk reductions for ischemic stroke and thromboembolism were lower than those achieved in clinical trials, while no increased risk for hemorrhage was observed. These findings suggest that warfarin is used conservatively, and dosed cautiously, diminishing the full potential benefit of anticoagulant therapy in patients with nonvalvular atrial fibrillation.