Comparison of effectiveness and safety of treatment with apixaban vs. other oral anticoagulants among elderly nonvalvular atrial fibrillation patients

Abstract

Objective: To compare the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) of elderly (≥65 years of age) nonvalvular atrial fibrillation (NVAF) patients initiating apixaban vs. rivaroxaban, dabigatran, or warfarin.

Methods: NVAF patients with Medicare Advantage coverage in the US initiating oral anticoagulants (OACs, index event) were identified from the Humana database (1 January 2013–30 September 2015) and grouped into cohorts depending on OAC initiated. Propensity score matching (PSM), 1:1, was conducted among patients treated with apixaban vs. each other OAC, separately. Rates of S/SE and MB were evaluated in the follow-up. Cox regressions were used to compare the risk of S/SE and MB between apixaban and each of the other OACs during the follow-up.

Results: The matched pairs of apixaban vs. rivaroxaban (n = 13,620), apixaban vs. dabigatran (n = 4654), and apixaban vs. warfarin (n = 14,214) were well balanced for key patient characteristics. Adjusted risks for S/SE (hazard ratio [HR] vs. rivaroxaban: 0.72, p = .003; vs. warfarin: 0.65, p < .001) and MB (HR vs. rivaroxaban: 0.49, p < .001; vs. warfarin: 0.53, p < .001) were significantly lower during the follow-up for patients treated with apixaban vs. rivaroxaban and warfarin. Adjusted risks for S/SE (HR: 0.78, p = .27) and MB (HR: 0.82, p = .23) of NVAF patients treated with apixaban vs. dabigatran trended to be lower, but did not reach statistical significance.

Conclusions: In the real-world setting after controlling for differences in patient characteristics, apixaban is associated with significantly lower risk of S/SE and MB than rivaroxaban and warfarin, and a trend towards better outcomes vs. dabigatran among elderly NVAF patients in the US.

Keywords:

• Elderly
• nonvalvular atrial fibrillation
• oral anticoagulants
• apixaban
• rivaroxaban
• dabigatran
• warfarin
• effectiveness
• safety

View correction statement:

Correction to: Steven Deitelzweig et al., Comparison of effectiveness and safety of treatment with apixaban vs. other oral anticoagulants among elderly nonvalvular atrial fibrillation patients

Transparency

Declaration of funding

This work was supported by Pfizer and Bristol-Myers Squibb.

Author contributions: S.D., X.L., K.G., J.T., J.M., T.C., and J.L. were responsible for study design. All authors contributed to data analysis and interpretation. M.L.-S., B.M., and J.L. drafted the manuscript with critical contributions from other authors. All authors approved the final manuscript for publication.

Declaration of financial/other relationships

S.D. has disclosed that he is a consultant for Pfizer and Bristol-Myers Squibb. X.L., J.T. and J.M. have disclosed that they are employees of Pfizer and own stock in the company. K.G. and T.C. have disclosed that they are employees of Bristol-Myers Squibb and own stock in the company. M.L.-S., B.M. and J.L. have disclosed that they are employees of Novosys Health, which has received research funds from Pfizer and Bristol-Myers Squibb in connection with conducting this study and development of this manuscript.

CMRO peer reviewers on this manuscript have received an honorarium from CMRO for their review work, but have no relevant financial or other relationships to disclose.