Aims: We used the US Department of Defense Military Health System database to compare the safety and effectiveness of direct oral anticoagulants (DOACs) in patients with non-valvular atrial fibrillation (NVAF) initiating dabigatran vs. rivaroxaban or apixaban.
Methods and results: Two cohorts of adults with NVAF, newly initiated on standard-dose DOAC, were identified based on clinical approval dates: July 2011-June 2016 for dabigatran (150 mg b.i.d.) or rivaroxaban (20 mg QD) and January 2013-June 2016 for dabigatran (150 mg b.i.d.) or apixaban (5 mg b.i.d.). Propensity score matching (1:1) identified two well-balanced cohorts (dabigatran vs. rivaroxaban n = 12 763 per treatment group; dabigatran vs. apixaban n = 4802 per treatment group). In both cohorts, baseline characteristics and follow-up duration were similar between treatment groups. Patients newly initiating dabigatran had significantly lower risk of major bleeding vs. rivaroxaban [2.08% vs. 2.53%; hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.70-0.97; P = 0.018], while stroke risk was similar (0.60% vs. 0.78%; HR 0.77, 95% CI 0.57-1.04; P = 0.084). The dabigatran vs. apixaban cohort analysis found no differences in risk of major bleeding (1.60% vs. 1.21%; HR 1.37, 95% CI 0.97-1.94; P = 0.070) or stroke (0.44% vs. 0.35%; HR 1.26, 95% CI 0.66-2.39; P = 0.489).
Conclusion: Among NVAF patients newly initiated on standard-dose DOAC therapy in this study, dabigatran was associated with significantly lower major bleeding risk vs. rivaroxaban, and no significant difference in stroke risk. For dabigatran vs. apixaban, the reduced sample size limited the ability to draw definitive conclusions.
Keywords: Apixaban; Dabigatran; Propensity score matching; Rivaroxaban; US Department of Defense Military Health System.
© The Author(s) 2018. Published by Oxford University Press on behalf of the European Society of Cardiology.