Peripheral artery disease and blood pressure profile abnormalities in hemodialysis patients.

Abstract

Patients undergoing chronic hemodialysis (HD) are at increased risk for peripheral artery disease (PAD). Both ankle-brachial index (ABI) and ambulatory blood pressure monitoring (ABPM) in the interdialytic period have been shown to be strong predictors of all-cause mortality. This cross-sectional study investigated the relationship between ABPM profile and ABI in 81 HD patients. ABPM was measured throughout a 44-h midweek interdialytic period. Pre-dialysis ABI was evaluated with a BOSO ABI device. An ABI value <0.9 or ≥1.3 was defined as abnormal. In the whole study group (72% males, mean age 67±14years), there was an increase in BP (p<0.05) and in systolic BP night/day ratio (n/dSR, p=0.01) during the interdialytic period. Patients with abnormal ABI (n=29) more frequently had a positive history for cerebrovascular accident and PAD and higher proBNP values than those with normal ABI (n=52). No difference was detected among ABPM-derived components except for the n/dSR (p=0.02). Patients with abnormal ABI showed a significantly increased n/dSR (p=0.02) and ambulatory arterial stiffness index (AASI) (p=0.006) on the second day compared to the first. Patients with n/dSR >1 during day 2 (n=34) were older, showed significantly higher proBNP and AASI and were more likely to reveal abnormal ABI compared to those with a lower n/dSR (p=0.006). Abnormal ABI in HD patients is associated to changes in interdialytic ABPM pattern, namely higher n/dSR on day 2. These data may indicate the pathophysiological mechanisms underlying the worse outcome observed in HD patients.