Reduced dose of rivaroxaban and dabigatran vs. vitamin K antagonists in very elderly patients with atrial fibrillation in a nationwide cohort study

Abstract

Aims: The real-life benefits and risks of the non-vitamin K antagonist oral anticoagulants for stroke prevention in very elderly patients with atrial fibrillation (AF) are still debated. Methods and results: Cohorts of new users of rivaroxaban 15 mg, dabigatran 110 mg, or vitamin K antagonists (VKA) for AF ≥85 years old in 2013 or 2014 were identified in the nationwide French claims database and followed-up for 1 year. Cohorts were compared after 1:1 matching using high-dimensional propensity score. Compared to VKA use and considering 1-year cumulative incidences, risk of stroke, and systemic embolism was not different with rivaroxaban use [hazard ratio 1.14, 95% confidence interval (CI): 0.93-1.40] and lower with dabigatran use (0.77, 95% CI: 0.60-0.99), risk of major bleeding was not different with rivaroxaban use (0.91, 95% CI: 0.74-1.11) and with dabigatran use (0.81, 95% CI: 0.64-1.03), risk of all-cause death was borderline to significance lower with rivaroxaban use (0.91, 95% CI: 0.83-1.00), and lower with dabigatran use (0.87, 95% CI: 0.78-0.97). The risk for a composite of all events above was not different with rivaroxaban use (0.96, 95% CI: 0.88-1.04) and lower with dabigatran use (0.87, 95% CI: 0.79-0.96) as compared with VKA use. The risk for the composite of all events was not different with rivaroxaban use as compared with dabigatran use (1.09, 95% CI: 0.97-1.23). Conclusion: This study shows for the first time in more than 25 000 new real-life anticoagulant users for AF aged ≥85 years a neutral overall benefit-risk of rivaroxaban 15 mg vs. VKA and a favourable overall benefit-risk of dabigatran 110 mg vs. VKA on relevant clinical events. Study registration: European Medicines Agency EUPAS14567 (www.encepp.eu) and Clinicaltrials.gov id NCT02864758.