Gated 99mTc-MIBI Myocardial Perfusion SPECT in Patients with Chronic Myocardial Infarction Stratified by Risk Factors

Abstract

Quantitative electrocardiogram-gated single-photon emission computed tomography (SPECT) myocardial imaging (MI) provides useful information about the extent and severity of perfusion abnormalities (PA) and global left ventricular (LV) function in patients with coronary artery disease. The aim of this study was to evaluate by gated SPECT-MP, perfusion scores and LV function stress / rest in patients with chronic myocardial infarction (CMI). Materials and methods: between 2019-2021 110 consecutive patients (age 65 ±10) with CMI 82 with and 28 without percutaneous coronary intervention, undergoing one-day stress-rest gated-SPECT-MP with 99mTc-MIBI. A summed stress score (SSS), a rest score (SRS) and SDS (SSS-SRS), SMS and thickening (STS) score were calculated. SDS >3 indicated myocardial ischemia. Results: Forty-nine (45%), of the patients showed normal, and 61 (55%) abnormal perfusion,
with 21 (34%) with fixed defect and 40 (66%) with ischemic defect. There was significant poststress increase of SSS, extent of myocardial hypoperfusion, STS, and diastolic and systolic volume of LV in patients with CMI with ischemia, in comparison with patients with fixed defect. Decrease of post-stress EF in rest was found in 5 (12%) of 40 patients with CMI with ischemia, indicating
stunning. Normal and abnormal imaging were stratified into low-risk (54%), low to intermediate risk 10% and high risk 35%. Conclusion: Gated SPECT myocardial imaging has an important role in the evaluation of perfusion and LV function in patients with CMI especially in patients with additional ischemia.