Arterial stiffness in hemodialysis: which parameter to measure to predict cardiovascular mortality?

Abstract

In previous studies, different parameters of arterial stiffness were related to cardiovascular mortality in hemodialysis patients, but their relative prognostic value has not previously been evaluated in 1 cohort. Carotid-femoral pulse wave velocity (PWV), the carotid augmentation index, carotid pulse pressure (CPP) and carotid-brachial pulse pressure amplification (AMP) were measured in 98 patients before and after hemodialysis. Patients were followed for a median of 29 months (1-34) and the association of these parameters with cardiovascular mortality were assessed using log-rank tests and Cox proportional hazards regressions. During follow-up, 25 patients died of cardiovascular causes. Increasing pre- and postdialysis PWV tertiles and decreasing predialysis AMP tertiles were significantly related to cardiovascular mortality (p = 0.012 and 0.011 for PWV, respectively; < 0.001 for AMP). Neither the carotid augmentation index nor carotid pulse pressure were related to cardiovascular mortality. The adjusted hazard ratios for 1 m/s higher pre- and postdialysis PWV were 1.24 (1.07-1.44) and 1.17 (1.06-1.28), respectively. The hazard ratio for 10% lower predialysis AMP was 1.41 (1.03-1.92). When included in the same model, both predialysis PWV and AMP remained significantly associated with cardiovascular mortality. Among different stiffness parameters, PWV is consistently related to cardiovascular mortality, irrespective of the timing of measurement. Predialysis AMP seems to provide additional prognostic information.