The Carotid Intima-Media Thickness as a Screening Test for Coronary Artery Disease

ABSTRACT

BACKGROUND AND OBJECTIVES: This study was performed to evaluate the clinical usefulness of the carotid intima-media thickness (IMT) as a screening test for coronary artery disease (CAD), and evaluate the differences in the carotid IMT in CAD patients with age- and sex-matched healthy subjects and hyperlipidemic hypertensive patients. SUBJECTS AND METHODS: The study was conducted on a total of 609 subjects; 229 patients with CAD (mean age; 53 yrs, 148 males), 207 age- and sex-matched hyperlipidemic hypertensive patients (mean age; 52 yrs, 115 males) and 173 age and sex matched healthy subjects (mean age; 52 yrs, 100 males). The carotid IMT was semi-automatically measured using high-resolution ultrasound. The clinical variables and carotid IMT in the study subjects were compared, and the data analyzed. RESULTS: The mean carotid IMT in patients with CAD (0.87+/-0.19 mm) was significantly higher than that in hyperlipidemic hypertensive patients (0.72+/-0.14 mm, p<0.001) and the healthy subjects (0.66+/-0.11 mm, p<0.001). Also, the carotid IMT in the hyperlipidemic hypertensive patients was significantly higher than that in the healthy subjects (p=0.001). The prevalence of carotid plaques was also significantly different between the CAD, hyperlipidemic hypertensive and healthy groups; 29.3, 18.4 and 8.7%, respectively (p<0.001). The cutoff values for differentiating CAD patients from healthy subjects and hyperlipidemic hypertensive patients were both 0.754 mm, with sensitivities and specificities of 72 and 80% and 72 and 66%, respectively, inform an ROC curve analysis. CONCLUSION: The carotid IMT was more increased in patients with coronary artery disease than in the hyperlipidemic hypertensive patients and healthy subjects. Therefore, the cutoff value (0.754 mm) of the carotid IMT could be a clinically useful screening test for predicting significant CAD and for differentiating high risk patients.