An echolucent carotid artery intima-media complex is a new and independent predictor of mortality in an elderly male cohort.

BACKGROUND

The echogenicity of atherosclerotic plaques is a measure of their lipid content and predicts cardiovascular disease. We hypothesized that the echogenicity of the non-plaque-affected arterial wall may be prognostically important as well, and more easily used as not all subjects carry plaques. We investigated the prognostic value of intima-media (IM) echogenicity (measured as the grey scale median [GSM]) for mortality compared with intima-media thickness (IMT) in a population-based sample of elderly men.

METHODS

A cohort from a community-based sample of 491 men was investigated with carotid artery ultrasound at age 75. IMT and GSM for IM and plaques were measured in the far wall of the common carotid artery being apparently free of plaque. Cox proportional hazard analysis models were used to investigate linear and non-linear relations of IM-GSM to mortality, adjusted for IMT, body mass index, cholesterol, HDL-cholesterol, triglycerides, systolic blood pressure, antihypertensive treatment, CRP, diabetes, current smoking, pack years of smoking, and previous cardiovascular disease.

RESULTS

Seventy-seven subjects died during a median follow-up time of 5.1 years. Participants were divided in tertiles by IM-GSM. In unadjusted analysis, IM-GSM predicted mortality in a U-shaped manner. In Cox proportional hazard analyses, an echolucent IM-GSM was a predictor of all-cause mortality (HR: 3.23; CI: 1.60-6.54; p<0.05) and CVD mortality (n=30, HR: 8.29; CI: 2.03-33.92; p<0.05) independently of IMT and established risk factors. These associations were still significant following adjustment for plaque occurrence and plaque echogenicity.

CONCLUSION

An echolucent intima-media complex is a predictor of all-cause and CVD mortality in elderly men independently of plaque occurrence, plaque GSM, IMT and established risk factors, suggesting the echogenicity of the apparently plaque-free intima-media complex provides novel prognostic information regarding mortality after age 75.