Background and Objectives: Carotid intima-media thickness (CIMT) and plaque are both important in primary prevention. However, it is still unclear which one is more important in prognosis in patients with coronary artery disease (CAD).

Subjects and Methods: The study population, consists of 1473 consecutive patients with CAD, was followed up for a mean of 40.7 months (maximum 126 months). Study population was divided into 4 groups according to the CIMT (≥0.79mm, median value) and the presence of carotid plaque.

Results: Patients with plaque and thick CIMT (n=309, 21.0%) were older and had higher prevalence of hypertension and diabetes mellitus than those with plaque and thin CIMT (n=140, 9.5%), those without plaque and thick CIMT (n=429, 29.1%) and those without plaque and thin CIMT (n=595, 40.4%). In univariate analysis, patients with plaque and thick CIMT had higher mortality (8.1% vs. 5.7%, 2.1% and 2.0%, respectively, p<0.001), restenosis (15.2% vs. 12.1%, 12.4% and 5.4%, respectively, p<0.001), hospitalization for congestive heart failure (4.5% vs. 2.1%, 2.3% and 1.0%, respectively, p=0.005) and total MACE (35.0% vs. 27.1%, 22.6% and 12.3%, respectively, p<0.001) than the other groups. Multivariate Cox regression analysis showed that the independent predictors of total MACE were carotid ultrasound findings (HR 1.4.6, 95% CI 1.276 to 1.549, p<0.001) and diabetes mellitus (HR 1.360, 95% CI 1.066 to 1.736, p=0.013).

Conclusion: Carotid ultrasound findings are important predictor in patients with CAD. Presence of carotid plaque is more important than CIMT in prognostic power.