Arterial stiffness predicts cardiovascular death independent of arterial thickness in a cohort of hemodialysis patients

Objective: Both arterial thickness and stiffness are predictors of cardiovascular disease (CVD). Although these arterial changes develop in parallel, no study has ever tested a hypothesis that arterial stiffness can predict mortality from CVD independent of arterial thickness. This study tested this possibility. Methods: This was an observational cohort study in 423 hemodialysis patients (CKD stage 5D). We simultaneously measured intima-media thickness (CA-IMT) and stiffness parameter beta(CA-beta) by carotid ultrasonography at baseline, and the cohort was followed-up for a mean period of 70 months. Results: During the follow-up, 216 all-cause deaths occurred including 124 deaths from CVD. Univariate analyses indicated both CA-IMT and CA-beta were signi. cant predictors for CVD death. Kaplan-Meier analysis, in which the total subjects were divided into four groups by the medians of CA-IMT and CA-beta, showed that the hazards ratio (95% con. dence interval) was 5.87 (3.43-10.05) for the group with higher CA-IMT/higher CA-beta as compared to the group with lower CA-IMT/lower CA-beta. The hazards ratios for the group with lower CA-IMT/higher CA-beta (2.22, 1.16-4.25) and the group with higher CA-IMT/lower CA-beta (2.85, 1.52-5.33) were comparable. Multivariate Cox analysis revealed that both CA-IMT and CA-beta were independently predictive of CVD mortality even after adjustment for other relevant covariates. Conclusion: Increased arterial stiffness predicted cardiovascular mortality independent of arterial thickness in this cohort, implicating the distinct roles of stiffness and thickness of arterial wall in the pathogenesis of CVD. (C) 2009 Elsevier Ireland Ltd. All rights reserved.