Noninvasive assessment of plaque characteristics with multislice computed tomography coronary angiography in symptomatic diabetic patients.

OBJECTIVE: Cardiovascular events are high in patients with type 2 diabetes, whereas their risk stratification is more difficult. The higher risk may be related to differences in coronary plaque burden and composition. The purpose of this study was to evaluate whether differences in the extent and composition of coronary plaques in patients with and without diabetes can be observed using multislice computed tomography (MSCT). RESEARCH DESIGN AND METHODS: MSCT was performed in 215 patients (86 [40%] with type 2 diabetes). The number of diseased coronary segments was determined per patient; each diseased segment was classified as showing obstructive (> or = 50% luminal narrowing) disease or not. In addition, plaque type (noncalcified, mixed, and calcified) was determined. Plaque characteristics were compared in patients with and without diabetes. Regression analysis was performed to assess the correlation between plaque characteristics and diabetes.
RESULTS: Patients with diabetes showed significantly more diseased coronary segments than nondiabetic patients (4.9 +/- 3.5 vs. 3.9 +/- 3.2, P = 0.03) with more nonobstructive (3.7 +/- 3.0 vs. 2.7 +/- 2.4, P = 0.008) plaques. Relatively more noncalcified (28 vs. 19%) and calcified (49 vs. 43%) and less mixed (23 vs. 38%) plaques were observed in patients with diabetes (P < 0.0001). Diabetes correlated with the number of diseased segments and nonobstructive, noncalcified, and calcified plaques.
CONCLUSIONS: Differences in coronary plaque characteristics on MSCT were observed between patients with and without diabetes. Diabetes was associated with higher coronary plaque burden. More noncalcified and calcified plaques and less mixed plaques were observed in diabetic patients. Thus, MSCT may be used to identify differences in coronary plaque burden, which may be useful for risk stratification.