Endocrine Abstracts

Purpose: Coronary artery disease (CAD) is more common and severe in diabetic patients. The aim of this study is to assess the frequency of silent myocardial ischemia in asymptomatic diabetitics by myocardial perfusion scintigraphy and to correlate the results with risk fators.

Methods: We prospectively studied 50 (25 men and 25 women) diabetic patients asymptomatic and without known history of CAD. The minimum duration of diabetes was 15 years for the type 1, 10 years for type 2. The average age was 61.4 years ranging from 43 to 80 years. All these patients had a first stress Myocardial Tomoscintigraphy (MTS) 99mTc-MIBI. MTS has enabled a study of myocardial perfusion, wall motion abnormalities and LV function. If MTS showed severe ischemia, further exploration was carried out by coronary angiography. It was performed in 5 patients in our study. These patients were recruited over a period of 8 months and have received specialized follow-up of 12 months post MTS.

Results: Positive MTS screening results were obtained in 20 patients (40% of cases) and showed ischemia in 65%, necrosis in 20% and mixed abnormalities in 15% of cases. lschemia is minimal in 8 patients (40%), moderate in 4 patients (20%) and severe in 8 patients. In the latter two cases there were at least 4 factors of cardiovascular risks. For the 8 patients with severe ischemia, the stress test (ST) was positive in only 10% of cases. Perfusion abnormalities sit at the inferior wall in 43%, concern the right coronary artery in 53%, and reach a single territory in 55% of cases. Coronary angiography was normal in one case, while the MTS objectified hypo perfusion. Moreover, the MTS abnormalities observed were consistent with coronary angiography. For six negative MTS, ST was negative in 80% of cases and doubtful in 20% of cases. Positive MTS patients have had therapy reinforcement or revascularization procedures. The SMI was more frequent in the group of male subjects, aged over 60 years for type 2 diabetes and over 45 years for the type 1, unbalanced, smoking, dyslipidemic.

Conclusions: MTS is a reliable tool for diabetic SMI screening. Its prognostic value can stratify the cardiac risk and guide therapeutic strategy. Improving this prognosis is based more on the intensive correction of risk factors than on possible revascularization procedure. Through better management of radiation risks, MTS is most appropriate.