Prognostic value of coronary artery calcium screening in subjects with and without diabetes.
OBJECTIVE
The study was done to determine the interaction of coronary artery calcium and diabetes mellitus for prediction of all-cause death.


BACKGROUND
Diabetes is a strong risk factor for coronary artery disease (CAD) and is associated with an elevated overall mortality. Electron beam tomography (EBT) provides information on the presence of subclinical atherosclerosis and may be useful for risk stratification.


METHODS
We followed 10,377 asymptomatic individuals (903 diabetic patients) referred for EBT imaging. Primary end point was all-cause mortality, and the average follow-up was 5.0 +/- 3.5 years. Cox proportional hazard models, with and without adjustment for other risk factors, were developed to predict all-cause mortality.


RESULTS
Patients with diabetes had a higher prevalence of hypertension and smoking (p < 0.001) and were older. The average coronary calcium score (CCS) for subjects with and for those without diabetes was 281 +/- 567 and 119 +/- 341, respectively (p < 0.0001). Overall, the death rate was 3.5% and 2.0% for subjects with and without diabetes (p < 0.0001). In a risk-factor-adjusted model, there was a significant interaction of CCS with diabetes (p < 0.00001), indicating that, for every increase in CCS, there was a greater increase in mortality for diabetic than for nondiabetic subjects. However, patients suffering from diabetes with no coronary artery calcium demonstrated a survival similar to that of individuals without diabetes and no detectable calcium (98.8% and 99.4%, respectively, p = 0.5).


CONCLUSIONS
Mortality from all causes is increased in asymptomatic patients with diabetes in proportion to the screening CCS. Nonetheless, subjects without coronary artery calcium have a low short-term risk of death even in the presence of diabetes mellitus.
Raggi
Paolo
P
Section of Cardiology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA. praggi@tulane.edu
Shaw
Leslee J
LJ
Berman
Daniel S
DS
Callister
Tracy Q
TQ
D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002118:Calcium / Q000378:metabolism*; D002423:Cause of Death; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*; D003925:Diabetic Angiopathies / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014057:Tomography, X-Ray Computed
D015415:Biomarkers; D002118:Calcium