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

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.