Background and purpose: Carotid intimal medial thickness (IMT) is a measure of subclinical atherosclerosis and is predictive of future cardiovascular events. The purpose of this study was to determine the significance and magnitude of association between IMT and atherosclerotic calcification of the carotid arteries.
Methods: Forty-five subjects underwent electron beam computed tomography of the neck to ascertain the extent of atherosclerotic calcification in the carotid arteries followed by B-mode carotid ultrasonography for IMT.
Results: The mean age, BMI and total cholesterol to HDL ratio were 61.4, 26.2 and 4.3, respectively. Forty-one percent were women. The overall mean IMT was 0.91 mm with the mean for the right and left being 0.93 and 0.87 mm, respectively. The median total carotid calcium score (CCS) was 48.4 [range: 0-973]. Age-adjusted correlations were significant between the overall mean IMT and total CCS (r=0.53, p<0.01), mean right IMT and right CCS (0.31, 0.05), mean left IMT and left CCS (0.31, 0.05), right common carotid IMT and right CCS (0.53, <0.01) and left common carotid IMT and left CCS (0.31, 0.05). The mean IMT was 0.14 mm greater in subjects with any carotid calcification adjusted for risk factors. A 0.05 mm increase in the carotid IMT was associated with an approximate 3-fold increase in risk for the presence of atherosclerotic calcification.
Conclusions: Carotid IMT is significantly correlated with and predictive of atherosclerotic calcification. Conversely, individuals with any carotid calcification have significantly greater intimal medial thicknesses.