Warfarin May Not Reduce Stroke in Dialysis Patients with AF

Mark S. Link, MD

In an observational analysis, warfarin was not protective — and significantly increased bleeding — in this group.

Dialysis patients with atrial fibrillation (AF) have an elevated risk for stroke. Randomized, controlled trials (RCTs) have shown that anticoagulation reduces stroke risk in patients with AF, but no such evidence exists in those undergoing dialysis. Because dialysis patients were excluded from RCTs of novel anticoagulants, warfarin is the only anticoagulant available to them.

To examine the effects of warfarin in AF patients on dialysis, researchers conducted a population-based, retrospective study in a cohort of 205,836 patients hospitalized with AF in Canada. Of 1626 patients who were on dialysis, 46% were prescribed warfarin within 30 days after hospital discharge; compared with nonrecipients, these warfarin recipients were more likely to have congestive heart failure (CHF), diabetes, or both (and thus a higher CHADS2 score) and less likely to have prior bleeding. However, warfarin use in dialysis patients was not associated with reduced stroke risk (hazard ratio, 1.14; 95% confidence interval, 0.781.67) and was associated with increased bleeding risk (HR, 1.44, 95% CI, 1.13–1.85) after adjustment for age, sex, hypertension, diabetes, CHF, history of stroke or transient ischemic attack, prior bleeding, and use of aspirin, clopidogrel, or nonsteroidal anti-inflammatory drugs.

Citation(s):

Shah M et al. Warfarin use and the risk for stroke and bleeding in patients with atrial fibrillation undergoing dialysis. Circulation 2014 Mar 18; 129:1196.

Granger CB and Chertow GM.A pint of sweat will save a gallon of blood: A call for randomized trials of anticoagulation in end-stage renal disease. Circulation 2014 Mar 18; 129:1190.