Stress/rest gated-spect imaging in asymptomatic diabetics with suspected coronary artery disease

Abstract

It's known that that in the routine use of diagnostic imaging, the stratification of asymptomatic diabetics patients (pts) is not widely accepted. The aim of present study was to evaluate the use of gated stress/rest myocardial perfusion imaging (gMPI) in asymptomatic diabetic population at increased risk of CAD. Methods: From January 2003, 214 diabetic (163 males, age 61±6 ys) without history of CAD performed gMPI. The cardiovascular risk score (CVRS) was calculated following Italian Health Ministry charts and it was always ≥20% (that is multiple risk factors). To perform gated-SPECT study we adopted a dual-day stress/rest protocol. Both post-exercise and resting images were gated and acquired 20–30 minutes after injection of technetium 99m-tetrofosmin at peak of exercise using a dual-head camera. Perfusion quantitation (SSS, SRS, SDS), and left ventricular global ejection fraction (LVEF) were automatically calculated by using Autoquant™ software package. Results: 115 pts (54%) had abnormal gMPI for perfusion parameters with a SSS ≥8, and in 12 of these pts the post-stress LVEF was abnormal (LVEF < 45%). About the left ventricular function, was normal in all remaning 202 pts, moreover were not differences about RAS between normal and abnormal gMPI. 77 pts (67%) because of an abnormal MPI with a SSS > 13 were referred to angiography and 67 pts (87%) showed significant CAD. 51/67 (76%) demonstrated left descending artery stenosis > 70% and/or significant 3-vessel disease (> 70% stenosis). All pts with abnormal LVEF revealed 3-vessel disease. Thus the rate of revascularization of this cohoort of asymptomatic diabetic subjects without a standard indication for stress testing who had abnormal MPI was 24%. Conclusions: In a population of asymptomatic diabetic males, the incidence of abnormal gMPI was substantial and clinical assessment alone did not result predictive of abnormal MPI. The potential routine use of screening test with gMPI may provide additional value in asymptomatic diabetics at increased CVRS with a good cost/effective profile.