Abstract 5626: Incidence of Thromboembolic Stroke and of Major Bleeding in Patients With Chronic Kidney Disease Treated With and Without Warfarin

Background: The incidence of thromboembolic (TE) stroke and of major bleeding in patients with chronic kidney disease (CKD) and atrial fibrillation (AF) have not been investigated in controlled clinical trials. Purpose: To investigate the incidence of TE stroke and of major bleeding in patients with CKD and AF treated with and without warfarin. Methods: We investigated the incidence of TE stroke and of major bleeding in 399 unselected patients with chronic CKD and AF treated with warfarin to maintain an International Normalized Ratio 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 of <15 mL/min/1.73 m 2 . Results: New TE stroke occurred in 21 of 232 patients (9%) treated with warfarin at 31-month follow-up and in 43 of 167 patients (26%) treated without warfarin at 23-month follow-up (p<0.001). Of the 21 TE strokes on warfarin, 9 (43%) occurred when the International Normalized Ratio was <2.0. Stepwise Cox regression analysis using 19 variables showed that significant independent variables for predicting TE stroke were prior stroke or transient ischemic attack (odds ratio = 2.9; 95% CI, 1.2–6.7) and use of warfarin (odds ratio = 0.28; 95% CI, 0.16–0.50). In hemodialysis patients, new TE stroke occurred in 5 of 51 patients (10%) treated with warfarin and in 16 of 42 patients (38%) not treated with warfarin (p<0.005). In patients with an estimated glomerular filtration rate <15 mL/min/1.73 m 2 , new TE stroke occurred in 8 of 78 patients (10%) treated with warfarin and in 20 of 54 patients (37%) 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). Conclusions: CKD patients with AF treated with warfarin to maintain an International Normalized Ratio between 2.0 and 3.0 had a significant reduction in TE stroke and an insignificant increase in major bleeding.