Chronic Kidney Disease as an Independent Risk Factor for Thromboembolism in Patients with Atrial Fibrillation

Oh, Gyu Chul; Cha, Myung Jin; Kang, Do Yoon; Kim, Ji Yeong; Sung, Young Jun; Yoon, Jung Han; Lee, Dong Won; Lee, Min Ho; Choe, Wonseok; Choi, Eue Keun; Oh, Seil

Abstract

BACKGROUND/AIMS
The CHADS2 scoring system has been widely used to stratify thromboembolic risk associated with atrial fibrillation. Chronic kidney disease (CKD) is associated with increased risk of stroke in patients with atrial fibrillation (AF) but has not yet been included in risk-scoring systems. We analyzed the difference in thromboembolic risk of patients with AF and a moderate risk of stroke according to the presence of CKD.
METHODS
Of 1,952 patients with AF, 451 with a CHADS2 score of 1 were divided into two groups according to the presence of CKD, and thromboembolic events were analyzed. Each group was further classified by the antithrombotic regimen used: warfarin or aspirin.
RESULTS
Of the 451 patients, 94 with CKD had a significantly higher risk for thromboembolic complications than the 357 patients without CKD (hazard ratio [HR], 3.630; 95% confidence interval [CI], 1.565-8.422; p = 0.003). Patients with CKD who were on aspirin had a higher risk for thromboembolic events than those on warfarin (HR, 5.203; 95% CI, 1.056-25.633, p = 0.043). However, in patients without CKD, the aspirin group did not have a higher risk of thromboembolic events than the warfarin group (HR, 0.803; 95% CI, 0.225-2.867, p = 0.735).
CONCLUSIONS
In Korean patients with AF and a CHADS2 score of 1, CKD may be an independent thromboembolic risk factor. In patients with CKD, warfarin may be superior to aspirin for lowering thromboembolic risk.