Maximum carotid intima-media thickness improves the prediction ability of coronary artery stenosis in type 2 diabetic patients without history of coronary artery disease.

OBJECTIVE: Carotid intima-media thickness (CIMT), a marker of early atherosclerosis and vascular remodelling, is one of the independent predictors of coronary artery disease (CAD). However, it is unknown whether ultrasonic assessment of carotid atherosclerosis, including CIMT, improves the prediction ability for CAD over and above conventional coronary risk factors in the diabetic patients.

METHODS: Ultrasonic scanning of the common carotid artery (CCA), the carotid bulb (Bul), and the internal carotid artery (ICA) was performed. The site with the greatest IMT, including plaque lesions, was sought along the arterial walls and max-IMT (the greatest IMT in the observation-possible areas of the CCA, Bul and ICA) was measured. The association of max-IMT with coronary artery stenosis assessed by coronary computed tomography angiography and the incremental effect of adding max-IMT to the conventional risk factors for predicting coronary artery stenosis were evaluated in 241 asymptomatic type 2 diabetic patients.

RESULTS: Multiple logistic regression analyses showed that max-IMT was significantly associated with coronary artery stenosis even after adjustment for conventional risk factors. ROC curve analysis revealed that the AUC significantly increased after addition of max-IMT to conventional coronary risk factors [from 0.64 (95% CI; 0.57-0.71) to 0.74 (95% CI; 0.67-0.80), p = 0.020]. The addition of max-IMT to conventional coronary risk factors increased the AUC in obese patients (from 0.58 to 0.76, p = 0.012) but not in non-obese patients (from 0.68 to 0.72, NS).

CONCLUSIONS: In type 2 diabetic patients without apparent cardiovascular disease, the addition of max-IMT to conventional risk factors substantially improves the risk stratification for CAD.