Prognostic Significance of Abnormal Ankle–Brachial Index Among Long-term Hemodialysis Patients in Kinshasa, the Democratic Republic of the Congo

Abstract

Objective Early identification of atherosclerosis using a non-invasive tool like ankle–brachial index (ABI) could help reduce the risk for cardiovascular disease among long-term hemodialysis patients. The study objective was to assess the frequency and impact of abnormal ABI as a marker of subclinical peripheral artery disease (PAD) in chronic hemodialysis patients. Methods This was a historic cohort study of kidney failure patients on long-term hemodialysis for at least 6 months. The ABI, measured with two oscillometric blood pressure devices simultaneously, was used to assess subclinical atherosclerosis of low limb extremities. Abnormal ABI was defined as ABI 1.3 (PAD present). Survival was defined as time to death. Independent factors associated with abnormal ABI were assessed using multiple logistic regression analysis. Kaplan–Meier method (log-rank test) was used to compare cumulative survival between the two groups; a P value <0.05 was statistically significant. Results Abnormal ABI was noted in 50.6% (n=43) of the 85 kidney failure patients included in the study; 42.4% (n=36) had a low ABI, and 8.2% (n=7) had a high ABI. Factors associated with PAD present were cholesterol (adjusted odds ratio [AOR], 1.02; 95% confidence interval [CI], 1.01–1.04; P=0.019), inflammation (AOR, 9.44; 95% CI, 2.30–18.77; P=0.002), phosphocalcic product (AOR, 6.25; 95% CI, 1.19–12.87; P=0.031), and cardiac arrhythmias (AOR, 3.78; 95% CI, 1.55–7.81, P=0.009). Cumulative survival was worse among patients with PAD present (log-rank; P=0.032). Conclusion The presence of PAD was a common finding in the present study, and associated with both traditional and emerging cardiovascular risk factors as well as a worse survival rate than patients without PAD.

Keywords

• ankle-brachial index
• hemodialysis
• subclinical peripheral arterial disease