Forearm reactive hyperemia and mortality in end-stage renal disease

Background. Reports on the general population indicated that decreased endothelial-mediated vasodilation has a prognostic impact on cardiovascular (CV) morbidity and mortality. Flow-dependent vasodilation of conduit arteries and ischemia-induced forearm reactive hyperemia are impaired in end-stage renal disease (ESRD). Whether deterioration of vasodilator function in ESRD patients has a prognostic impact has not been documented. The aim of this study was to determine whether the impaired forearm postischemic vasodilation is an independent predictor of mortality in ESRD patients, independently from CV end-organ damages, which are usually associated with decreased vasodilatory response. Methods. Common carotid artery intima-media thickness (CCA-IMT), aortic stiffness (pulse wave velocity - PWV), and LV mass (LVM) were determined for 78 stable ESRD patients on hemodialysis. Forearm postischemic vasodilation [flow debt repayment (FDR)] was measured by venous plethysmography. All-cause mortality served as the outcome variable over a median follow-up of 60 +/- 27 months. Results. Twenty-four deaths occured (16 of CV origin). According to Cox regression adjusted for age, CCA-IMT, LVM, and PWV, all-cause mortality was independently associated with decreased FDR (RR 0.69 for every 10% increase; 95% CI 0.56- 0.85; P = 0.0006) and increased aortic PWV (RR 1.16 for 1 m/s increase; 95% CI 1.04-1.29; P = 0.0091). Conclusion. Our data indicate that lower postischemic forearm reactive hyperemia is associated with all-cause mortality of ESRD patients, independently of the presence of end-organ damage such as LVH or arteriosclerosis.