Intima-media thickness of the common carotid artery is the significant predictor of angiographically proven coronary artery disease.

BACKGROUND

Previous studies have shown a relationship between intima-media thickness (IMT) of the common carotid artery and coronary artery disease (CAD). The role of IMT in the prediction of significant CAD has not been established.

OBJECTIVES

To investigate the diagnostic accuracy of IMT measurement and the detection of carotid plaques in relation to cardiovascular risk factors in the prediction of significant CAD.

PATIENTS AND METHODS

One hundred and seventy patients (121 men and 49 women; average age 58 +/- 11 years) undergoing selective coronary angiography were examined by carotid ultrasound. IMT was measured. Plasma lipid concentrations and other risk factors were determined.

RESULTS

Angiographically proven significant CAD was found in 138 (81%) of all patients. Carotid plaques were detected in 98 (58%) of all patients. Presence of carotid plaques in common carotid artery (P<0.001) and male sex (P<0.005) were found to be categorical risk factors for significant CAD but in multiple regression analysis only age (P=0.15), IMT (P<0.01), high density lipoprotein (HDL) cholesterol (P=0.02) and, less significantly, total cholesterol (P=0.09) were found to be independent parameters for the prediction of significant CAD. IMT of 0.75 mm was determined as a cut-off point for the detection of significant CAD (sensitivity 78%, specificity 79%, positive predictive value 95%, negative predictive value 41%, odds ratio 12.9, 95% CI 3.5 to 47.6).

CONCLUSION

The increase in IMT is the significant positive predictor of angiographically proven CAD; other predictors are high age, low HDL cholesterol and, less significantly, high total cholesterol. Presence of carotid plaques and male sex do not add any new information for the prediction of CAD once the predictors are considered.