Incidence of Thromboembolic Stroke and of Major Bleeding in Patients with Atrial Fibrillation and Chronic Kidney Disease Treated with and Without Warfarin

The objective was to investigate the incidence of thromboembolic stroke in patients with chronic kidney disease (CKD) and atrial fibrillation (AF) treated with and without warfarin. We investigated the incidence of thromboembolic stroke and of major bleeding in 399 unselected patients with CKD and AF treated with warfarin to maintain an international normalized ratio (INR) between 2.0 and 3.0 (N = 232) and without warfarin (N = 167). Of the 399 patients, 93 (23%) were receiving hemodialysis, and 132 (33%) had an estimated glomerular filtration rate (GFR) of <15 mL/min/1.73 m(2) At the 31-month follow-up of patients treated with warfarin and 23-month follow-up of patients not treated with warfarin, thromboembolic stroke developed in 21 of 232 patients (9%) treated with warfarin and in 43 of 167 patients (26%) not treated with warfarin (P < 0.001). Major bleeding occurred in 32 of 232 patients (14%) treated with warfarin and in 15 of 167 patients (9%) not treated with warfarin (P not significant). Stepwise Cox regression analysis showed that significant independent predictors of thromboembolic stroke were use of warfarin (odds ratio, 0.28; P < 0.0001) and prior stroke or transient ischemic attack (odds ratio, 2.9; P < 0.05). In conclusion, this observational study showed that CKD patients with AF treated with warfarin to maintain an INR between 2.0 and 3.0 had a significant reduction in thromboembolic stroke and an insignificant increase in major bleeding.