Influence of Epidemiologic and Clinical Trends on Risk Stratification and Net Clinical Benefit of Long-term Oral Anticoagulation for Nonvalvular Atrial Fibrillation

Abstract

The prevalence of atrial fibrillation without rheumatic valvular disease, nonvalvular atrial fibrillation (NVAF), increases with age and independently predicts future stroke and systemic embolism. Randomized controlled trials of long-term oral anticoagulation for NVAF since the 1980s report a 67% risk reduction in stroke and systemic embolism. Data from these trials are used in risk calculators to predict stroke and bleeding; clinicians use these calculators to determine individualized net clinical benefit of oral anticoagulation. Over the past three decades, NVAF stroke rates have declined independent of oral anticoagulation. Newer asymptomatic (subclinical) NVAF populations are being identified, and clinical practice has changed with increasingly older patients (with higher fall and bleeding risk) receiving oral anticoagulation. These trends suggest contemporary patients with NVAF may derive a lower net benefit from oral anticoagulation compared with those in the original randomized controlled trial. Methods that evaluate for and continuously monitor net clinical benefit of oral anticoagulation for contemporary NVAF are necessary.