ABSTRACT
Ultrasound detected intima-media thickness [IMT] of the carotid artery and thoracic aorta are possible screening tests to assess the risk of coronary artery disease [CAD] in asymptomatic individuals. Objective: Aim of the study was to assess the utility of carotid and aortic IMT as a predictor of CAD and to assess the extent of IMT with severity of CAD in a South Indian population. A cross-sectional and analytical study was carried out among 40 cases, who had angiographic evidence of CAD against 30 healthy control subjects with a normal treadmill test. At plaque-free regions, the carotid IMT was evaluated by B-mode ultrasonography and thoracic aorta IMT was evaluated by trans-esophageal echocardiography [TEE]. The significance of difference in means between two groups was analyzed using one-way ANOVA F-test and the significance of difference in proportions by Chi-square test. Multiple comparisons were done by Bonferroni t test. The correlation between IMT and severity of CAD was assessed by Spearman's method. There were 38 males and 2 females among cases with age 51.7 +/- 8.3 years, and 28 males and 2 females among control subjects with age 52.2 +/- 7.1 years. Increased carotid IMT was noted among 24 cases and 2 control subjects, and the association was significant for CAD [P<0.001, Chi-square=20.89, odds ratio [OR]=21.00, and 95% confidence interval [CI]=4.78-89.59]. Similarly, 19 cases and one control subject had abnormal IMT with positive correlation for CAD [P<0.001, Chi-square=16.39, OR=28.24, and 95% CI=4.06-163.21]. There was no association between IMT and diabetes, hypertension, or smoking; however, IMT was significantly associated with age and dyslipidemia. Also, there was no correlation between extent of IMT and severity of CAD. IMT of the carotid and thoracic aorta is strongly associated with risk of CAD in a South Indian population, and may be used as a non-invasive screening tool for coronary atherosclerosis in resource-limited settings. The presence of dyslipidemia influenced IMT and may be used as a tool to follow patients on hypolipidemic drugs