Ankle brachial pressure index but not brachial-ankle pulse wave velocity is a strong predictor of systemic atherosclerotic morbidity and mortality in patients on maintenance hemodialysis

Background: Ankle brachial pressure index (ABPI) and pulse wave velocity (PWV) have been widely recognized as a marker of systemic atherosclerosis. We examined whether ABPI and brachial-ankle PWV (baPWV) predict individual cardiovascular events in patients on maintenance hemodialysis (HD). Methods: We prospectively followed-up 445 HD patients undergoing both ABPI and baPWV measurements for up to 5 years. They were divided into 2 groups [group with ABPI >0.9 to ≤1.3 (n= 328) and group with ABPI ≤0.9 or >1.3 (n= 117)] and were also divided into tertiles according to the baPWV level (T1: <1850. cm/s; T2: 1850-2310. cm/s and T3: ≥2310. cm/s). Results: During the follow-up period (mean 43 ± 17 months), 206 cardiovascular events [cardiac event: 125 (28.1%), cerebrovascular events: 39 (8.8%), and peripheral arterial events: 42 (9.4%)] occurred, and 36 (8.1%) and 42 (9.4%) patients experienced cardiovascular and non-cardiovascular deaths, respectively. Cox multivariable analysis showed that presence of ABPI ≤0.9 or >1.3 was a significant predictor of cardiac events [hazard ratio (HR) 1.78, 95% confidential interval (CI) 1.27-2.49, p= 0.0008], cerebrovascular event (HR 1.95, 95%CI 1.13-3.36, p= 0.017), peripheral arterial event (HR 3.64, 95%CI 2.10-6.29, p< 0.0001), composite endpoint of cardiovascular events (HR 2.22, 95%CI 1.64-2.99, p< 0.0001), cardiovascular mortality (HR 2.42, 95%CI 1.44-4.06, p= 0.0008) and all-cause mortality (HR 1.52, 95%CI 1.03-2.25, p= 0.037). However, baPWV did not predict cardiovascular events on multivariate analysis. Conclusion: ABPI but not baPWV is useful for risk stratification of systemic atherosclerotic morbidity and mortality in HD patients. Furthermore, ABPI could predict not only individual peripheral arterial events but also cardiac and cerebrovascular events.