Background: There is a paucity of real-world studies examining stroke/systemic embolism (S/SE) and major bleeding (MB) risks among non-valvular atrial fibrillation (NVAF) patients who switched from warfarin to a direct oral anticoagulant.
Methods: A retrospective study was conducted using four United States commercial claims databases from January 1, 2012 to March 31, 2019. The study population included NVAF patients initially treated with warfarin and switched to an apixaban, dabigatran, or rivaroxaban within 90 days after their warfarin prescription ended. Patients were matched 1:1 between direct oral anticoagulants in each database using propensity scores and then pooled for the final analysis. Cox proportional hazard models were used to calculate the risk of S/SE and MB.
Results: The final population consisted of 2,611 apixaban-dabigatran, 12,165 apixaban-rivaroxaban, and 2,672 dabigatran-rivaroxaban pairs. Apixaban (vs dabigatran) was associated with a lower risk of S/SE (hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.39-0.96) and MB (HR: 0.67; 95% CI: 0.50-0.91). Apixaban (vs rivaroxaban) was associated with a similar risk of S/SE (HR: 0.88; 95% CI: 0.73-1.07) and lower risk of MB (HR: 0.60; 95% CI: 0.52-0.68). There were no significant differences in risk of S/SE and MB between dabigatran and rivaroxaban.
Conclusion: These results provide important insight into how risk of S/SE and MB for NVAF patients varies when switching from warfarin.