Impact of Diabetes on Coronary Stenosis and Coronary Artery Calcification Detected by Electron-Beam Computed Tomography in Symptomatic Patients

Abstract

OBJECTIVE—Ischemic heart disease is a pivotal complication for diabetic patients. Electron-beam computed tomography (EBCT) represents the only noninvasive method that allows for accurate quantification of coronary artery calcification that reflects underlying atherosclerotic disease. Although coronary calcium score (CCS) cut points that predict the presence of angiographic stenosis have been established in nondiabetic individuals, it is not known whether coronary calcifications in diabetic patients are associated with the presence of significant coronary stenoses. In this study, we evaluated the relationship between coronary calcifications and angiographic stenosis in symptomatic patients with or without type 2 diabetes. RESEARCH DESIGN AND METHODS—In this study, 282 patients (204 men and 78 women) with chest pain, including 101 diabetic patients and 181 nondiabetic patients (mean age 63 ± 9.6 years), underwent coronary angiography and EBCT with determination of CCS using Agatston’s method. Luminal stenosis ≥ 50% was defined as significant coronary stenosis. RESULTS—Angiography identified 205 patients with significant stenoses (89 of 101 diabetic patients, 114 of 181 nondiabetic patients). The sensitivity and specificity of EBCT to detect significant coronary stenosis were not significantly different between diabetic and nondiabetic patients. In diabetic patients, a CCS ≥90 was associated with 75% sensitivity and 75% specificity, whereas a CCS ≥200 was associated with 64% sensitivity and 83% specificity. CONCLUSIONS—We demonstrated that calcification of the coronary arteries in symptomatic diabetic patients is well associated with severity of coronary stenosis, as in nondiabetic patients.