Carotid Artery Plaque Burden, Stiffness, and Mortality Risk in Elderly Men

Abstract

Background— Indicators of carotid atherosclerosis may confer additional prognostic value and guide clinicians in cardiovascular risk assessment. Carotid artery morphology (plaque burden) and function (stiffness indexes) as predictors of all-cause and cardiovascular mortality were prospectively evaluated in elderly men. Methods and Results— Cardiovascular risk profile was measured in 367 independently living men (mean± SD age, 78±4 years). The number of carotid plaques was assessed by B-mode ultrasound, and arterial stiffness was quantified with a wall tracker system. During 48 months of follow-up, 70 deaths (28 cardiovascular) occurred. The total number of carotid plaques was the parameter most closely related to prognosis. In the age-adjusted multivariate Cox model, all-cause mortality was predicted by number of plaques (hazard ratio [HR] per 1-unit increase, 1.35; 95% confidence interval [CI], 1.12 to 1.64). Predictors of cardiovascular mortality in the respective model were number of plaques (HR, 1.18; 95% CI, 1.04 to 1.33) and Young’s elastic modulus (HR, 1.68; 95% CI, 1.26 to 2.26). Number of plaques improved the prognostic utility in any prognosis model when added to commonly available cardiovascular risk information. In contrast, stiffness indexes offered no consistent additive value. Conclusions— In elderly men, carotid artery plaque burden is a strong independent predictor of all-cause and cardiovascular mortality in the years to come. The additional value of carotid artery stiffness measurements as a pathophysiologically related entity appears to be limited in this age group and, if anything, confined to cardiovascular mortality risk.