Atrial fibrillation and risk of stroke in dialysis patients.

PURPOSE: Both stroke and chronic atrial fibrillation (AF) are common in dialysis patients, but uncertainty exists in the incidence of new strokes and the risk conferred by chronic AF.

METHODS

A cohort of dually eligible (Medicare and Medicaid) incident dialysis patients was constructed. Medicare claims were used to determine the onset of chronic AF, which was specifically treated as a time-dependent covariate. Cox proportional hazards models were used to model time to stroke.

RESULTS

Of 56,734 patients studied, 5629 (9.9%) developed chronic AF. There were 22.8 ischemic and 5.0 hemorrhagic strokes per 1000 patient-years, a ratio of approximately 4.5:1. Chronic AF was independently associated with time to ischemic (hazard ratio [HR], 1.26; 99% confidence interval [CI], 1.06-1.49; P = .0005), but not hemorrhagic, stroke. Race was strongly associated with hemorrhagic stroke: African Americans (HR, 1.46; 99% CI, 1.08-1.96), Hispanics (HR, 1.64; 99% CI, 1.16-2.31), and others (HR, 1.76; 99% CI, 1.16-2.78) had higher rates than did Caucasians (all P < .001).

CONCLUSIONS

Chronic AF has a significant, but modest, association with ischemic stroke. Race/ethnicity is strongly associated with hemorrhagic strokes. The proportion of strokes owing to hemorrhage is much higher than in the general population.