Silent coronary artery disease in patients with type 2 diabetes mellitus

The purpose of this study was to estimate the prevalence and risk factors of silent CAD in asymptomatic type 2 diabetic patients aged over 40 years. A total of 172 asymptomatic type 2 diabetic patients, mean age 54.42 years, with normal resting electrocardiogram were included in the study. Technetium-99m (Tc-99m) tetrofosmin cardiac single photon emission computed tomography myocardial scintigraphy with exercise testing or dipyridamole injection was performed on all patients. If this test was positive, coronary angiography was carried out and was considered to be positive with a stenosis of greater than or equal to70%. Abnormal perfusion pattern was found in 14 patients (8.14%). Significant coronary artery stenosis was found in 13 subjects (7.56%), confirming a high positive predictive value (92.86%) of this diagnostic procedure. A significant correlation was observed between silent CAD and male sex, retinopathy, hypertension, post-prandial blood glucose level, and low HDL-cholesterol level. Sex (OR=4.026; 95% CI, 1.187-13.659), hypertension (OR=5.564; 95% CI, 1.446-21.400) and retinopathy (OR=3.766; 95% CI, 1.096-12.948) were risk factors for CAD. Overall, 14.06% of asymptomatic male patients with type 2 diabetes mellitus presented silent CAD with significant angiographically documented coronary stenosis. This finding, along with the high positive predictive value of a noninvasive technique, indicates that routine screening for silent CAD would be useful in this patient subgroup especially when they have retinopathy or hypertension.