Prevalence of coronary artery disease and plaque morphology assessed by multi-slice computed tomography coronary angiography and calcium scoring in asymptomatic patients with type 2 diabetes.

OBJECTIVE: The purpose of the study was to evaluate the prevalence of CAD as well as plaque morphology in asymptomatic patients with type 2 diabetes using multi-slice computed tomography (MSCT). In addition, the relation between calcium score and MSCT findings was explored.

DESIGN: In 70 patients, coronary calcium scoring and non-invasive coronary angiography were performed. Angiograms showing atherosclerosis were further classified as obstructive (> or =50% luminal narrowing) CAD or not. Plaque type (non-calcified, mixed and calcified) was determined. Finally, the relation between calcium score and MSCT findings was explored.

RESULTS: A calcium score <10 was observed in 31 (44%) patients. A calcium score of 10-100 was observed in 14 (20%) patients while a score of 101-400 or >400 was identified in 12 (17%) and 13 (19%) patients respectively. Non-invasive coronary angiography showed CAD in 56 (80%) patients. 322 coronary segments with plaque were identified, of which 132 (41%) contained non-calcified plaques, 65 (20%) mixed plaques and 125 (39%) calcified plaques. The percentage of patients with obstructive CAD paralleled increasing calcium score. The presence of CAD was noted in 17 (55%) patients with no or minimal calcium (score <10).

CONCLUSIONS: MSCT angiography detected a high prevalence of CAD in asymptomatic patients with type 2 diabetes. A relatively high proportion of plaques were non-calcified (41%). Importantly, a calcium score <10 did not exclude CAD in these patients. MSCT might be a useful technique to identify CAD in asymptomatic patients with type 2 diabetes with incremental value over calcium scoring.