Ankle brachial index as a predictor for mortality in patients with chronic kidney disease and undergoing haemodialysis

Aim: The ankle brachial index (ABI) is a marker for peripheral artery disease and can predict mortality in advanced chronic kidney disease (CKD) and haemodialysis patients, respectively. However, it is seldom studied in Taiwan, an area with high prevalence of CKD and end-stage renal disease. The aim of this study was to investigate the predictors for mortality by using ABI value in patients with CKD and undergoing haemodialysis in Taiwan. Methods: One hundred and sixty-nine patients with CKD stage 3-5 and 231 haemodialysis patients were enrolled in one regional hospital. The mean follow-up period was 23.3 +/- 3.3 months. Patients were stratified into three groups according to ABI value (< 0.9, >= 0.9 to < 1.3, and >= 1.3). The relative mortality risk was analyzed by Cox-regression methods. Results: In multivariate analysis, an ABI of 1.3 or more (hazard ratio, 3.846; P = 0.043) and coronary artery disease (P = 0.012) were positively associated with overall mortality, and serum low-density lipoprotein cholesterol level (P = 0.042) was negatively associated with overall mortality. In addition, an ABI of less than 0.9 (P = 0.049), an ABI of 1.3 or more (P = 0.033), coronary artery disease (P = 0.024) and haemodialysis treatment (P = 0.043) were strong predictors for cardiovascular mortality. Conclusion: Our findings show that an ABI of 1.3 or more predicts for both overall and cardiovascular mortality, and an ABI of less than 0.9 predicts for cardiovascular mortality in CKD and haemodialysis patients. Screening patients with chronic renal failure by means of ABI may help to identify a high-risk group for increased mortality.