Abstract 216: Impact of Warfarin Use in Patients with End Stage Renal Disease and Atrial Fibrillation

Abstract

Background: Although warfarin is a standard therapyfor atrial fibrillation (AF) patients to prevent stroke, and AF is a frequent comorbidity of patients with end stage renal disease (ESRD), warfarin administration to ESRD patients is viewed with caution because these patients are already at high risk for systemic hemorrhages. Results of studies on the efficacy and safety of warfarin use in patients with ESRD and AF have been inconsistent. Objective: To qualitatively and quantitatively evaluate the risk-benefit profile of warfarin for patients with ESRD. Methods: Pubmed and EMBASE from 1966 to May 2014 were searched to identify relevant studies. Inclusion criteria were cohort studies, patients with ESRD and AF at baseline, assess stroke and/or death as an endpoint during the follow-up period, and reported quantitative estimates of the multivariate adjusted relative risk (RR) and 95% confidence interval (CI) for future stroke and/or death associated with warfarin use. We combined log RR and standard errors using the inverse variance approach. Results: We identified 8 cohort studies with 11773 patients with ESRD and AF. Among 8 studies, 7 reported an estimate of stroke and 4 reported an estimate of death. Pooling the results showed that warfarin use was associated with a neutral effect on stroke (RR 0.91, 95% CI 0.59 to 1.41, P=0.66, Figure) and death (RR 0.68, 95% CI 0.42 to 1.10, P=0.12). There were substantial heterogeneities among these studies. Warfarin use was associated with fewer ischemic stroke events (5 studies, RR 0.57, 95% CI 0.34 to 0.95, P=0.03) and not associated with increased risk of major bleeding (5 studies, RR 1.13, 95% CI 0.83 to 1.52, P=0.44). Conclusion: This meta-analysis of cohort studies suggests warfarin use is neither beneficial nor unsafe in patients with ESRD and AF. However, randomized controlled trials are needed to definitively clarify the effects of anticoagulant agents in this patient population.