Abstract 3402: Predictive Value of Coronary Calcifications for Future Cardiac Events in Asymptomatic Patients with Diabetes mellitus: A Prospective Study in 502 patients over 8 Years
To establish an efficient prophylaxis of coronary artery disease a reliable risk stratification is crucial, especially in the high risk population of patients suffering from diabetes mellitus. This prospective study determined the predictive value of coronary calcifications for future cardiovascular events in asymptomatic patients with diabetes mellitus. We included 502 patients suffering from diabetes mellitus (306 men, 196 women, age 53.7 ± 15.2 years) in this study. On study entry all patients were asymptomatic and had no history of coronary artery disease. In addition all patients showed no signs of coronary artery disease in ECG, stress ECG or echocardiography. Coronary calcifications were determined with the Imatron C 150 XP electron beam computed tomograph. For quantification of coronary calcifications we calculated the volume score. After a mean observation period of 8.1 ± 1.1 years patients were contacted and the event rate of cardiac death (CD) and myocardial infarction (MI) was determined During the observation period 92 patients suffered form MI, 31 patients died from acute CD. 19 patients died because of non cardiac death. The initial volume score in patients that suffered from MI (483 ± 199) or died from CD (641 ± 279) was significantly higher compared to those without cardiac events (189 ±167, p < 0.01). A volume score above the 75. percentile was associated with an significantly higher annualised event rate for MI (3.9 % versus 1.4 %, p < 0.05) and for CD (2.9 % versus 0.7%, p < 0.05) compared to patients with scores below the 75. percentile. No cardiac events were observed in patients with exclusion of coronary calcifications. The relative risk of future MI increased with the volume score and showed a high correlation to the volume score with a correlation coefficient of 0.91. Compared to the ATP III risk score the volume score showed a significant higher diagnostic accuracy in the prediction of MI with an area under the ROC curve of 0.77 versus 0.68, p < 0.01. By determination of coronary calcifications patients at risk for future MI and CD could be identified within an asymptomatic population of patients with diabetes mellitus. On the other hand future events could be excluded in patients without coronary calcifications.