Warfarin use and the risk of mortality, stroke, and bleeding in hemodialysis patients with atrial fibrillation

Abstract

Background: The optimal management of stroke prophylaxis in hemodialysis patients with atrial fibrillation is controversial.

Objective: The purpose of this study was to determine the risk of mortality, stroke, and bleeding associated with the use of warfarin in hemodialysis patients with atrial fibrillation.

Methods: This was a retrospective, population-based study of hemodialysis patients with atrial fibrillation between January 1, 2006, and September 30, 2015. Association of warfarin use with mortality, stroke, and bleeding was determined by propensity score-matched, Cox proportional hazard models.

Results: Among the 4286 patients with atrial fibrillation on hemodialysis, 989 (23%) were prescribed warfarin. Propensity score matching was used to identify 888 matched pairs with similar baseline characteristics. Warfarin use was associated with lower risk of all-cause death (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.69-0.84) and lower risk of ischemic stroke (HR 0.68, 95% CI 0.52-0.91). Warfarin use was not associated with a higher risk of hemorrhagic stroke (HR 1.2, 95% CI 0.6-2.2) or gastrointestinal bleeding (HR 0.97, 95% CI 0.77-1.2). The treatment effect was largest in the group with the best international normalized ratio control as measured by time in therapeutic range. Subgroup analyses showed warfarin use was associated with survival benefit in most subgroups. The 2 subgroups that did not benefit were patients with a history of hemorrhagic stroke and patients with concurrent aspirin use.

Conclusion: Warfarin use is associated with lower all-cause mortality and ischemic stroke, without significantly increasing the risk of bleeding in hemodialysis patients with atrial fibrillation.

Keywords: Anticoagulation; Atrial fibrillation; Bleeding; Stroke; Warfarin.