Carotid intima-media thickness as an independent predictor of coronary artery disease

Abstract

Background: A noninvasive technique of measuring carotid artery intima-media thickness has recently generated considerable interest as a marker of atherosclerosis and in the prediction of clinical coronary events and coronary artery disease. The present study evaluated the association of carotid artery intima-media thickness in the prediction of coronary artery disease in a western Indian population.

Methods and results: Carotid artery intima-media thickness was measured with a B-mode scan in an ongoing study of 266 patients, who were further subdivided into 4 subgroups: those with non-insulin dependent diabetes mellitus; hypertension; diabetes mellitus with hypertension; and those without diabetes or hypertension (labeled as controls). The maximal intima-media thickness greater than 0.8 mm at the far wall of the common carotid artery, excluding raised lesions and plaques, was selected as the highest value for comparison. The subgroups were further divided into those with and without apparent coronary artery disease. A statistically significant intima-media thickness greater than 0.8 mm was observed in 59.2% of the subjects with coronary artery disease as against 40.8% in those without the disease on univariate analysis. A higher incidence of intima-media thickness of more than 0.8 mm was observed in all subgroups with coronary artery disease as against those without the disease, which was most marked in the hypertensive group (22.2% v. 3.6%) and contributed to the increased arterial thickness in diabetics with concomitant hypertension. Multivariate regression analysis revealed carotid artery intima-media thickness to be associated with coronary artery disease with an odds ratio of 2.40.

Conclusions: Carotid artery intima-media thickness is a simple, noninvasive and reproducible clinical tool to evaluate atherosclerosis and predict coronary artery disease in Indian subjects. Prospective studies in a larger number of subjects, particularly in those undergoing coronary angiography, will help in establishing the role of this technique.