Rate of ankle-brachial index decline predicts cardiovascular mortality in hemodialysis patients

Abstract

Chronic kidney disease is a risk factor for cardiovascular mortality and morbidity of cardiovascular events (CVEs). We obtained baseline data regarding blood biochemistry, ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV) and echocardiographic parameters from 300 patients on hemodialysis in 2005. We also measured ABI and baPWV annually from June 2005 until June 2012 and calculated rates of changes in ABI and baPWV to identify factors associated with CVEs. Seventy-three patients died of cardiovascular disease and 199 CVEs occurred in 164 patients during the study period. Cardiac, cerebrovascular and peripheral artery disease (PAD) events occurred in 124, 43 and 32 patients, respectively, and 30 patients had more than two types of CVEs. Analysis using the Cox proportional hazards model showed that a higher rate of decline in ABI (hazard ratio [HR], 4.034; P < 0.001) was the most significant risk factor for decreased patient survival. Multivariate Cox analysis revealed that a higher rate of ABI decline (HR, 2.342; P < 0.001) was a significant risk factor for cardiac events, and that a lower baseline ABI was a risk factor for cerebrovascular (HR, 0.793; P = 0.03) and PAD (HR, 0.595; P < 0.0001) events. Our findings suggested that the rate of a decline in ABI and the baseline ABI value are potent correlation factors for survival and CVE morbidity among patients on hemodialysis in Japan.

Keywords: Ankle-brachial index; Cardiovascular events; Hemodialysis; Mortality.