Comparison of Direct Oral Anticoagulants versus Warfarin in Patients with Atrial Fibrillation and Bioprosthetic Heart Valves.

Duan, Lewei; Doctor, Jason N; Adams, John L; Romley, John A; Nguyen, Leigh-Anh; An, Jaejin; Lee, Ming-Sum

There are limited data regarding direct oral anticoagulants (DOACs) for stroke prevention in patients with bioprosthetic heart valves (BHVs) and atrial fibrillation (AF). The objectives of this study were to evaluate the ambulatory utilization of DOACs and to compare the effectiveness and safety of DOACs versus warfarin in patients with AF and BHVs. We conducted a retrospective cohort study at a large integrated health care delivery system in California. Patients with BHVs and AF treated with warfarin, dabigatran, rivaroxaban or apixaban between September 12, 2011 and June 18, 2020 were identified. Inverse probability of treatment-weighted comparative effectiveness and safety of DOACs compared with warfarin were determined. Use of DOACs gradually increased since 2011, with a significant upward in trend after a stay-at-home order related to COVID-19. Among 2672 adults with BHVs and AF who met the inclusion criteria, 439 were exposed to a DOAC and 2233 were exposed to warfarin. For the primary effectiveness outcome of ischemic stroke, systemic embolism and transient ischemic attack, no significant association was observed between use of DOACs compared with warfarin (HR 1.19, 95% CI 0.96-1.48, p=0.11). Use of DOACs was associated with lower risk of the primary safety outcome of intracranial hemorrhage, gastrointestinal bleeding, and other bleed (HR 0.69, 95% CI 0.56 to 0.85, p <0.001). Results were consistent across multiple subgroups in the sensitivity analyses. These findings support the use of DOACs for AF in patients with BHVs.