Feasibility and application of trimetazidine in 18F-FDG PET myocardial metabolic imaging of diabetic mellitus patients with severe coronary artery disease: A prospective, self-controlled study

18F-FDG PET myocardial metabolic imaging (MMI) is sometimes uninterpretable due to background activity from uncontrolled glucose homeostasis in diabetic mellitus (DM) patients. Trimetazidine is an oral medication that promotes the transformation of myocardial energy supply from free fatty acids to glucose. We aimed to investigate the feasibility and application of trimetazidine in 18F-FDG PET MMI of DM patients. With DM patients exhibiting severe coronary artery disease (CAD) symptoms serving as self-controls, the effects of trimetazidine on PET MMI image quality, myocardial viability assessment, quantitative analytical parameters, and 18F-FDG uptake of different myocardial segments were elucidated. The image quality of 18F-FDG MMI was graded visually as good, moderate, and uninterpretable. After trimetazidine, grades of good, moderate, and uninterpretable were observed in 14 (60.9%), 8 (34.8%), and 1 (4.3%) patients, respectively, and in 4 (17.4%), 15 (65.2%), 4 (17.4%) patients without trimetazidine. The myocardial SUV and myocardial to blood pool SUV ratio (M/B ratio) were significantly higher after trimetazidine administration than those before (3.11 ± 1.07 vs 2.32 ± 1.00, 2.67 ± 1.41 vs 1.81 ± 0.75, P all < 0.01). 6 (3, 7) viable myocardium segments were detected with a mismatch score of 10 (6, 17) after trimetazidine, significantly higher than those before trimetazidine [5 (2, 7) and 8 (2, 17), P < 0.05]. Meanwhile, the 18F-FDG uptake in myocardial segments with decreased and normal perfusion showed different ranges of increase (by 15.30%-57.77%). Trimetazidine is feasible and effective in DM patients with severe CAD before 18F-FDG PET MMI, which can significantly improve the image quality and increase the number of viable myocardium segments detected. The study was registered in the Chinese Clinical Trial Registry (ChiCTR2000038559).