Scholte AJHA et al. (2008) 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. Heart 94: 290–295

Patients with type 2 diabetes mellitus (T2DM) are at high risk of developing coronary artery disease (CAD). Furthermore, in these patients CAD has often reached an advanced stage by the time of diagnosis. Scholte et al. investigated the prevalence of CAD in asymptomatic patients with T2DM by multislice CT (MSCT), which permits noninvasive angiography and assessment of the coronary artery calcium burden.

The analysis included 70 patients with T2DM, none of whom had symptoms of CAD. MSCT identified CAD in 56 (80%) patients, including 18 (26%) patients with obstructive CAD. An elevated calcium score was found in 39 (56%) patients. Analysis of plaque morphology in 322 segments of diseased coronary artery revealed 39% calcified plaques, 20% mixed plaques and 41% noncalcified plaques. There was a direct relationship between coronary artery calcium score and incidence of obstructive CAD; however, CAD was present in 17 of the 31 patients with a calcium score below 10, and 3 of these patients had obstructive CAD.

The authors conclude that the prevalence of CAD is high in asymptomatic patients with T2DM, and that, because of the high prevalence of noncalcified plaques in this population, calcium scoring alone is of limited value in assessing CAD. Routine MSCT angiography may provide additional information.