The arterial stiffness changes in hemodialysis patients with chronic kidney disease: The impact on mortality

Background. Patients with kidney disease suffer from high cardiovascular risk due to classic and disease-specific risk factors. Arterial stiffness is a novel cardiovascular risk factor whose role is yet to be established. High-resolution echo-tracking is a developing method for the assessment of local arterial stiffness. Objectives. To assess carotid stiffness in patients on long-term hemodialysis (HD) using high-resolution echo-tracking and to analyze the impact of arterial stiffness on mortality in the mid-term follow-up. Materials and methods. Fifty-eight HD patients (28 female (F), 30 male (M)) underwent clinical examination, laboratory tests and carotid stiffness assessment. Local arterial stiffness parameters such as beta stiffness index (beta), Young's modulus (Ep), arterial compliance (AC), and one-point pulse wave velocity (PWV beta) were measured both before and after HD, allowing to calculate their change (Delta). The survival of patients was analyzed up to 48 months. The multivariate analysis of survival with the use of Cox proportional hazard stepwise regression was performed to determine the factors significantly correlated with the survival. Results. After 48 months, 33 patients were alive (16 F, 17 M) and 25 patients (12 F, 13 M) died. The deceased group was significantly older (66.5 +/- 12.3 years compared to 56.6 +/- 17.8 years), had more pronounced coronary artery disease (percutaneous coronary intervention (PCI) 36% compared to 9%, p < 0.05, respectively). Deceased patients had significantly higher Delta AC than survivors. The results showed that age, history of PCI, left ventricular ejection fraction (LVEF), Delta AC, fasting glucose, serum total protein, sodium level after HD, and potassium level before HD were significantly associated with mortality. Conclusions. Echo-tracking-based arterial stiffness assessment in patients with chronic kidney disease (CKD) yields the clinical information regarding mid-term mortality risk. A paradoxical increase in AC is among independent risk factors for mid-term mortality in patients undergoing maintenance HD. The proper estimation of the correlations among vascular, hemodynamic and sympathetic-dependent changes in a given patient with kidney failure is complex.