5716Age and gender differences in stroke and bleeding risks in atrial fibrillation patients treated with non-vitamin K antagonist oral anticoagulants

Abstract

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) are recommended in preference to warfarin in most patients with atrial fibrillation when oral anticoagulation is indicated. However, little evidence exists to guide the choice among different NOACs. Purpose: To compare the effectiveness (ischemic stroke and systemic embolism) and safety (major bleeding) between NOACs according to age and sex. Methods: Using a large U.S. administrative database, OptumLabs Data Warehouse, we identified 51,691 patients with non-valvular atrial fibrillation who initiated apixaban, dabigatran or rivaroxaban between 10/1/2010-3/31/2016. We used generalized boosted models, based on 15,000 regression trees, to calculate weights between patients receiving different NOACs to achieve optimal balance on 56 baseline demographic characteristics, comorbidities and medication use. We used cox proportional hazards regression to investigate outcomes and plotted Kaplan-Meier curves for cumulative risks according to age and sex. Results: Dabigatran was associated with lower risk of ischemic stroke or systemic embolism than the other two drugs in women aged greater or equal to 75 years. Rivaroxaban was associated with significantly higher risk of major bleeding in comparison to apixaban in all age and gender groups. Conclusion: Age and gender need to be considered when selecting NOACs for patients with atrial fibrillation. In most cases, apixaban was associated with similar effectiveness, and similar or better safety than dabigatran or rivaroxaban. In elderly women, dabigatran was associated with better effectiveness and similar safety compared with apixaban and rivaroxaban. (Figure Presented).