Abstract 19749: Racial Differences in Outcomes With Dabigatran in Elderly Atrial Fibrillation Patients
Introduction: Dabigatran was shown to be superior to warfarin in stroke prevention in patients with non-valvular atrial fibrillation (AF) in the RE-LY clinical trial. However, the majority of patients were white, and it is unclear whether its beneficial results can be extrapolated to black patients.
Hypothesis: To study the outcomes of dabigatran in comparison to warfarin, in white and black patients with AF.
Methods: Patients with newly diagnosed AF from November 2010 to December 2011 were identified using the Medicare Beneficiary Summary Chronic Condition flags. Inclusion criteria was age 66 or older, black or white race, enrolled in Medicare Part D, and received warfarin or dabigatran within 90 days of AF diagnosis. Patients who were on warfarin prior to the AF diagnosis were excluded. The primary outcome of death and secondary outcomes of stroke, gastrointestinal bleeding and intracranial hemorrhage were investigated in analyses that incorporated propensity matching by anticoagulant type within race.
Results: Overall, 69,391 white patients and 3,738 black patients met inclusion criteria. Compared to white patients, black patients had higher CHA2DS2-VASc scores (5.44 vs. 4.68). Dabigatran was used in 14,162 (20%) whites compared to only 424 (11%) blacks. It was associated with lower relative hazard of death (relative to warfarin) for whites [Hazard ratio (HR) = 0.61; p=0.001]. This finding was not significant for blacks [HR=0.44; p=0.12]. Dabigatran use was not associated with the risk of stroke in whites [HR=0.84; p=0.22] or blacks [HR=0.91; p=0.89]. The hazard of gastrointestinal hemorrhage was higher for whites taking dabigatran vs warfarin [HR=1.39; p=.001]. A similar relative hazard was noted for blacks but was not statistically significant [HR=1.44; p=0.41]. The whites on dabigatran had lower risk of intracranial hemorrhage compared to warfarin (HR 0.35, p=.007). No intracranial hemorrhages were noted in the blacks on dabigatran.
Conclusions: In an elderly Medicare population with newly diagnosed AF, compared to warfarin, dabigatran use in blacks was associated with trend towards lower mortality, higher gastrointestinal hemorrhage, and similar rates of stroke. These findings were similar to those seen in white patients.
Author Disclosures: R. Kabra: Other; Modest; I am participating and recruiting patients for multicenter clinical trials sponsored by St Jude medical, Zoll, boehringer Ingelheim, Jannsen pharmaceuticals. M. Vaughan-Sarrazin: None.
- © 2014 by American Heart Association, Inc.