Predictive value of ankle–brachial index for long-term events of ischemic stroke in hemodialysis patients

Abstract

Objectives The ankle–brachial index is a noninvasive modality to evaluate atherosclerosis and is a predictive role for future cardiovascular events and mortality. However, few studies have evaluated its relation to long-term future ischemic stroke in hemodialysis patients. Therefore, we examined the relationship between ankle–brachial index and ischemic stroke events among hemodialysis patients in a seven-year follow-up. Methods A total of 84 patients were enrolled. Ankle–brachial index was assessed in January 2009. Primary outcomes included ischemic stroke. An ankle–brachial index < 0.9 was considered abnormal and 1.4 ≥ ankle–brachial index ≥ 0.9 to be normal ankle–brachial index. Results Mean values for ankle–brachial index were 0.98 ± 0.21at study entrance. In addition, 28 patients encountered ischemic stroke in the seven-year follow-up. In univariate Cox regression analysis, old age (hazard ratio (HR): 1.065, 95% confidence interval (CI): 1.030–1.102, p < 0.001), low seven-year averaged serum phosphate levels (HR: 0.473, 95% CI: 0.306–0.730, p = 0.001), and abnormal ankle–brachial index (HR: 0.035, 95% CI: 0.009–0.145, p < 0.001) were risk factors for ischemic stroke. In multivariate Cox regression analysis for significant variables in univariate analysis, abnormal ankle–brachial index (HR: 0.058, 95% CI: 0.012–0.279, p < 0.001) and low seven-year averaged serum phosphate levels (HR: 0.625, 95% CI: 0.404–0.968, p = 0.035) remained the risk factors for ischemic stroke. The risk of ischemic stroke was 3.783-fold in patients with abnormal ankle–brachial index compared with patients with normal ankle–brachial index (HR: 3.783, 95% CI: 1.731–8.269, p = 0.001). Conclusions These findings suggest that ankle–brachial index is an impressive predictor of future ischemic stroke among hemodialysis patients.