Coronary calcium score in symptomatic patients referred for a coronary computed tomographic angiography. Influence of diabetes

The benefit of the coronary artery calcium score (CACS) measured by cardiac CT is well documented in asymptomatic patients at intermediate risk, however is not known in symptomatic patients. The coronary CT angiography (CCTA) allows an anatomical evaluation of the coronary arteries. The objective was to determine, in symptomatic patients, with diabetes or not, the predictive value of CACS for the presence of significant coronary stenosis (CS > 50%) detectable by CCTA. The study included 52 patients (36 wemen/16 men), mean age 61 years (35–79 years), including 22 diabetics, who had a CACS measurement and a CCTA with a 64-slice cardiac CT with an atypical chest pain syndrome and without history of ischemic heart disease, revascularization by coronary angioplasty or coronary artery bypass grafting. The patients were divided into 5 groups according to the CACS: 0, 1–10, 11–100, 101–400, > 400 AU. The prevalence of CACS in patients was 65%. The CACS was: 0, 1–10, 11–100, 101–400, > 400 respectively in 18, 14, 5, 8, 8 patients. Fifteen patients (29%) had CS on the CCTA. The percentage of diabetics was somewhat higher among these patients than among the 37 without CS (60% vs. 37%, P = 0.09). CS was present in 2 of 18 patients with CACS = 0, 1/13 with CACS 1–10, 1/5 with CACS 11–100, 3/8 with CACS 101–400, and 8 patients with CACS > 400. Thus the prevalence of CS was 11% and 69% respectively among patients with CACS ≤ 100 or > 100 ( P < 0.001). Among patients with CACS > 100, CS was found in 7 diabetics and 4 of 9 non-diabetics. These data suggest that about 30% of patients with suspected angina have coronary stenosis detectable by CCTA, when a CACS is > 100 its predicts the presence of CS with a positive predictive value of 100% in diabetics (vs. 44% in no diabetics), while CS is present in approximately 10% of patients with CACS < 10, suggesting an atheroma with no or little calcification.