November 1, 2009Open Access
Incidence of thromboembolic stroke and of major bleeding in patients with atrial fibrillation and chronic kidney disease treated with and without warfarin
Key Result
Warfarin use in patients with CKD and AF significantly reduced thromboembolic stroke (9% vs 26%; OR 0.28, P<0.0001) with an insignificant increase in major bleeding.
Study Design
Type
Observational (n=399)
Structured PICO
Does warfarin reduce thromboembolic stroke in patients with atrial fibrillation and chronic kidney disease?
P
Population
399 unselected patients with chronic kidney disease (CKD) and atrial fibrillation (AF), including 93 (23%) receiving hemodialysis and 132 (33%) with an estimated glomerular filtration rate (GFR) of <15 mL/min/1.73 m2
I
Intervention
Warfarin to maintain an international normalized ratio (INR) between 2.0 and 3.0 (N = 232)
C
Comparator
No warfarin treatment (N = 167)
O
Outcome
Incidence of thromboembolic strokehard clinical
In patients with atrial fibrillation and chronic kidney disease, warfarin therapy targeted to an INR of 2.0-3.0 significantly reduces thromboembolic stroke without a significant increase in major bleeding.
Main Result
Effect estimate: OR 0.28
Absolute Event Rate: 9% vs 26%
p-value: p=<0.0001
Abstract
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.