Prognostic Value of Aortic Stiffness and Calcification for Cardiovascular Events and Mortality in Dialysis Patients

Abstract

Radiographic calcification and arterial stiffness each individually are predictive of outcome in dialysis patients. However, it is unknown whether combined assessment of these intermediate endpoints also provides additional predictive value. Scoring of abdominal aortic calcification (AAC) using plain lateral abdominal x-ray and measurement of carotid-femoral pulse wave velocity (PWV) were performed in a cohort of 1084 prevalent dialysis patients recruited from 47 European dialysis centers. During a follow-up of 2 years, 234 deaths and 91 nonfatal cardiovascular (CV) events occurred. Compared with the lowest tertile of AAC, the risk of an event was increased by a factor 3.7 in patients with a score of 5 to 15 (middle tertile), and by a factor 8.6 in patients with scores of 16 to 24. Additionally, each 1-m/s increase in PWV was associated with a 15% higher risk. At higher AAC (scores ≥ 5), the effect of PWV was attenuated because of a negative PWV × AAC interaction (hazard ratio [HR]: 0.895 and 0.865 for middle and upper AAC tertiles). After accounting for age, diabetes, and serum albumin, AAC and PWV remained independent predictors of outcome. AAC and central arterial stiffness are independent predictors of mortality and nonfatal CV events in dialysis patients. The risk associated with an increased PWV is less pronounced at higher levels of calcification. Assessment of AAC and PWV is feasible in a clinical setting and both may be used for an accurate CV risk estimation in this heterogeneous population.