Cardiac Safety of COVID-19 Vaccines: A Longitudinal Study of Health Checkup Subjects Using Multi-Modal Imaging

Purpose The aim of this study was to assess myocardial metabolic activity and cardiac function in asymptomatic health checkup subjects before and after vaccination COVID-19 vaccination. Materials and methods We retrospectively analyzed clinical records of 67 asymptomatic subjects who underwent whole-body FDG PET/CT before and after COVID-19 vaccination. Cardiac metabolic activity was assessed using myocardial standardized uptake value (SUVmax). Echocardiography and cardiac MRI, including cine-based strain analysis, were used to evaluate cardiac function. The Wilcoxon signed-rank test and Bland-Altman plots were applied to assess changes between pre- and post-vaccination data. Results No significant differences in myocardial FDG uptake (SUVmax: 3.29 [IQR: 2.84–6.45] vs. 3.21 [IQR: 2.76–7.25], P = 0.63) was observed. Similarly, echocardiographic parameters, including LVEF, LVEDV, and LVESV, remained unchanged. MRI-based circumferential strain also showed no significant alterations (-21.27 ± 3.63 vs. -21.90 ± 3.60, P = 0.088). Conclusions This study, the first to systematically evaluate myocardial FDG uptake alongside MRI strain analysis in the same subjects pre- and post-vaccination, demonstrates no significant impact of COVID-19 vaccination on myocardial metabolic activity or cardiac function. These findings support the cardiac safety of COVID-19 vaccination and provide a robust basis for future research in broader populations.