The Diagnostic Value of Tc-99m MIBI Gated Myocardial Perfusion SPECT in Detection of Silent Myocardial Ischemia in Asymptomatic Patients with Type 2 Diabetes Mellitus.

OBJECTIVE In this study, we aimed to evaluate the diagnostic value of Technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) gated myocardial perfusion SPECT (MPS) in the detection of coronary artery disease (CAD) and silent myocardial ischemia (SMI) in patients with asymptomatic type 2 diabetes mellitus (DM). MATERIALS AND METHODS For this purpose, 35 patients with type 2 DM and 15 volunteers with no cardiac symptoms (control group) were included in this study. Exercise tolerance tests (ETT), echocardiography and Tc-99m MIBI gated MPS were performed in patients and volunteers. Computed tomography coronary angiography (CTCA) was performed in patients with coronary ischemia or infarct detected by Tc-99m MIBI gated MPS. The results were analyzed and compared visually and statistically. RESULTS The present study revealed a high rate of silent myocardial ischemia (25.71%, N=9) in 35 patients with type 2 DM. Severe CAD in CTCA was detected in four of nine patients with ischemia or infarct by Tc-99m MIBI gated MPS (44.4%). Left ventricular diastolic dysfunction, ischemic pattern and high risk of CAD were detected in the same four patients by echocardiography, ETT and biochemical analysis, respectively. At the end of the statistical evaluation, we found that Tc-99m MIBI gated MPS showed significant correlations with CTCA, echocardiography, ETT, Hba1c level, risk of CAD and diabetic age in diabetic patients with CAD. CONCLUSION We propose that Tc-99m MIBI gated MPS is a reliable and non-invasive method that can be used to detect silent myocardial ischemia and CAD in patients with type 2 DM.