Background/Aim: The global COVID-19 vaccination campaign has raised concerns about potential side effects, including cardiac involvement or axillary lymphadenopathy. This study investigated the relationship between COVID-19 vaccination and thallium-201 myocardial perfusion imaging (Tl-201 MPI) findings, aiming to elucidate the impact of the vaccine impact on cardiac health. Patients and Methods: This retrospective analysis enrolled patients referred for MPI examination post-COVID-19 vaccination between June 2021 and January 2022. Eligible participants included symptomatic individuals without prior coronary artery disease (CAD) or with stable CAD, experiencing symptoms within one-month post-vaccination. MPI was conducted post dipyridamole-stress testing, and positive stress test results were further evaluated by cardiac catheterization. The association between vaccination and MPI results, including axillary lymphadenopathy presence, was assessed. Results: Sixty-four patients were included, with a mean age of 54.7 years, and a predominance of males (64.3%). A notable incidence of positive MPI findings and axillary lymphadenopathy was observed, particularly in patients vaccinated with mRNA vaccines. Among the 15 patients with positive MPI, visible axillary lymphadenopathy was observed in 4 cases (26.7%), compared with 6 of 49 patients (12.2%) with negative MPI. Although this difference was not statistically significant, it suggests a possible trend toward a higher prevalence in the MPI-positive subgroup. Most patients with positive MPI findings had received the Moderna vaccine. Conclusion: Our findings indicate a potential link between mRNA COVID-19 vaccination and cardiac issues detected via MPI, as well as an increase in axillary lymphadenopathy. Although further prospective studies are warranted to establish causality, our findings underscore the importance of post-vaccination monitoring, particularly in symptomatic patients, and the need of continued efforts to comprehensively assess vaccine safety to help reduce mortality rates.
CHEN et al. (Fri,) studied this question.