Clinical question: Does dabigatran or rivaroxaban have more bleeding episodes?
Background: Alternatives to warfarin exist for stroke prevention in nonvalvular atrial fibrillation (AF). The RE-LY and ROCKET-AF trials demonstrated noninferiority to warfarin for both dabigatran (a direct thrombin inhibitor) and rivaroxaban (a factor Xa inhibitor), respectively. Although indirect comparisons have been done using data from these trials, direct, head-to-head comparisons are not available.
Study design: New-user cohort study.
Setting: Medicare beneficiaries 65 years or older with AF and a prescription for either dabigatran or rivaroxaban.
Synopsis: Researchers enrolled 52,240 patients on dabigatran and 66,651 patients on rivaroxaban. Exclusions comprised those taking warfarin, residing in a skilled nursing facility, or already hospitalized on the study’s index date, as well as those with a separate indication for anticoagulation. CHADS2 and HAS-BLED scores were calculated. Primary outcomes were thromboembolic stroke, intracranial hemorrhage, major extracranial bleeding events, and acute myocardial infarction. Mean duration of treatment was 108 days, with mean 111 days of follow-up.
Intracranial hemorrhage and extracranial major bleeding events were significantly greater in the rivaroxaban group than the dabigatran group. There was no significant difference in thromboembolic stroke events.
Limitations include short treatment and follow-up times. Additionally, the study is not generalizable to younger populations.
Bottom line: In elderly patients with non-valvular AF, rivaroxaban was associated with more adverse bleeding events than dabigatran, with no difference in stroke prevention.
Citation: Graham DJ, Reichman ME, Wernecke M, et al. Stroke, bleeding, and mortality risks in elderly Medicare beneficiaries treated with dabigatran or rivaroxaban for nonvalvular atrial fibrillation. JAMA Intern Med. 2016;176:1662-71.
Dr. Graves is an assistant professor at the University of Utah School of Medicine and associate program director of quality and patient safety for the University of Utah Internal Medicine residency training program.