Diagnostic Accuracy of Stress Myocardial Perfusion Imaging in Indian Diabetic Patients: A Single Centre Experience

Diabetics have around 2-4 times increased risk of coronary artery disease(CAD) and it is the most important cause of mortality in these patients. This study was carried out to compare the sensitivity, specificity and accuracy of MPI-SPECT among diabetics and non-diabetics in the Indian population. This retrospective study included 261 patients; 213 males and 48 females, with 75 diabetic and 186 non-diabetic patients. Only type II diabetics and non-diabetic patients were included in the study. Only patients who had coronary angiography (CAG) done within 6 months of the stress ^99mTc-sestamibi MPI-SPECT study were included in the study. Two arbitrary cut off points on CAG ≥ 50% and ≥ 70% were used for determination of extent of CAD. Considering coronary angiography as gold standard with ≥ 50% coronary stenosis as a cut off criteria for significant stenosis the sensitivity and specificity respectively, of myocardial perfusion SPECT was 83% and 72% in diabetics and 81% and 69% in non-diabetic pateints (p value not significant). For ≥ 70% coronary stenosis as a cut off criteria for significant stenosis the sensitivity and specificity respectively, of myocardial perfusion SPECT was 87% and 61% in diabetics and 88% and 58%in non-diabetics (p value not significant). No significant difference was found in the sensitivity, specificity and accuracy of LAD, LCx and RCA coronary vessels among diabetics and non-diabetics for both ≥ 50% and ≥ 70% coronary stenosis as cut off criteria. Diabetic patients had a lower incidence of SVD compared to the non-diabetic patients. They also had a higher incidence of TVD and MVD compared to the non-diabetic patients with both ≥ 50% and ≥ 70% diameter stenosis criteria (p value significant). Sensitivity and specificity of ^99mTc-sestamibi myocardial perfusion imaging is similar in diabetic and non-diabetic patients in Indian population.