Prevalence of subclinical atherosclerosis in asymptomatic diabetic patients by 64-slice computed tomography

Patients with diabetes have a 2-fold to 4-fold higher risk of a cardiovascular event than nondiabetic patients. Thus there is a need to identify patients with diabetes who are at risk of cardiovascular events before the onset of symptoms. We studied the prevalence of coronary artery disease in asymptomatic diabetic patients compared with asymptomatic nondiabetic patients by 64-slice computed tomography (CT).

From 425 asymptomatic patients with coronary risk factors but without known coronary artery disease who underwent 64-slice CT, we identified 93 asymptomatic diabetic patients (diabetic group) and 93 age-matched and sex-matched asymptomatic nondiabetic patients.

Clinical characteristics were not significantly different between the two groups. Total coronary calcium score was significantly higher in diabetic group than that in nondiabetic group (median 117 vs. 53.5, P<0.0001). No coronary calcium was detected in 30.0% of nondiabetic group compared with 15.1% of diabetic group (P=0.0022). Coronary calcium score more than 400 was detected in 9.7% of nondiabetic group compared with 36.6% of diabetic group (P<0.0001). Coronary plaques were found in 67.7% of nondiabetic group compared with 91.4% of diabetic group (P<0.0001). Multiple plaques were detected in 57.0 and 77.4% of patients in nondiabetic and diabetic group, respectively (P=0.0030). Significant coronary stenosis was found in 16.1% of nondiabetic group compared with 33.3% of diabetic group (P=0.0065).

Our results show that the prevalence of coronary plaques detectable by 64-slice CT in asymptomatic diabetic patients is very high.