[Diabetes mellitus type 2: coronary calcifications as a predictor of coronary artery disease]

Abstract

Background and purpose: Patients with diabetes mellitus have an increased risk of developing cardiovascular disease. Therefore, coronary artery disease (CAD) is the most common cause of mortality in these patients. The early and reliable diagnosis of coronary atherosclerosis is crucial for an effective treatment. Determination of coronary calcifications with multislice computed tomography offers the possibility to detect coronary calcifications as a sign of early coronary atherosclerosis. The present study examined the possibility to predict CAD in patients with diabetes mellitus by determination of coronary calcifications.

Patients and methods: 632 patients (417 men, 215 women, age 54.6 +/- 17.3 years) with diabetes mellitus and suspected CAD were examined. All patients underwent coronary angiography. Coronary stenoses with lumen narrowing > 50% were regarded as significant CAD. Within 3 days coronary multislice computed tomography (Sensation 4, Siemens Medical Solutions, Forchheim, Germany) was performed and coronary calcifications were quantified using the volume score. Sensitivity, specificity, negative and positive predictive value for prediction of CAD were determined for different cutpoints.

Results: 440 patients showed a significant CAD, 315 patients underwent coronary transluminal angioplasty and 57 patients coronary artery bypass surgery. Mean volume score was 421 +/- 461. Volume score increased from 2 +/- 6 for patients < 40 years to 751 +/- 801 for patients > 70 years. Women showed a significantly lower score in all age groups. The mean volume score was significantly higher in patients with CAD compared to those without CAD (587 +/- 642 compared to 40 +/- 53; p < 0.01). In all patients without coronary calcifications, CAD could be ruled out angiographically. Using score 0, 10, 100 as cutoff points for the prediction of CAD, a sensitivity of 100%, 97%, and 87% at a specificity of 25%, 69%, and 82% was calculated. Best results were achieved using the 75th percentile as cutoff point with a sensitivity of 91% and a specificity of 84%. In total, CAD could be diagnosed correctly by quantification of coronary calcifications in 94% of all patients.

Conclusion: Determination of coronary calcifications by multislice computed tomography could be used in patients with diabetes mellitus to detect coronary atherosclerosis and allows the early and exact diagnosis of CAD.