18F-Fluorodeoxyglucose positron emission tomography for detection of acute cellular rejection after heart transplantation: A single–center retrospective study

Background Although histopathological evaluation of myocardium is essential for detecting both acute cellular rejection (ACR) and antibody-mediated rejection (AMR) following heart transplantation, indeterminate results and complication risks associated with repeated endomyocardial biopsies remain serious problems. We investigated the clinical utility of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) to detect rejection. Methods This retrospective single-center study reviewed the clinical data of heart-transplant recipients at our institution between 2008 and 2022. Patients who underwent 18 F-FDG PET/CT scans post-transplant were enrolled. Scans were performed following a high-fat, low-carbohydrate diet initiated 24 hours before imaging and an 18-hour fasting period. FDG uptake was represented as cardiac metabolic volume (CMV), maximum standard uptake value (SUVmax), and total lesion glycolysis (TLG). Results During the study period, 132 18 F-FDG PET/CT scans in 40 heart-transplant recipients were identified. Age at transplant was 53 [43–62] years old, and 29 patients (73%) were male. We found 10 scans at the time of significant ACR. No patients experienced AMR. At the time of ACR, CMV (88.2 [22.5–275.8] vs. 0.0 [0.0–7.3] mL, P