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

70%. 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.
Key words
Type 2 diabetes mellitus - Silent coronary artery disease - Myocardial scintigraphy - Tetrofosmin - SPECT