Abstract 4343939: COVID-19 Vaccine-Induced Cardiac Inflammation: A Review of 103 Cases and Appraisal of VAERS Database

Introduction/Background: The COVID-19 vaccines has been pivotal in controlling SARS-CoV-2 transmission and reducing hospitalization and mortality. Authorized vaccines, including mRNA-based and adenoviral vector platforms, have demonstrated strong safety and efficacy profiles. However, post-marketing surveillance has identified rare cases of vaccine-associated myocarditis and pericarditis, predominantly among young males following mRNA vaccines. Understanding these occurrences is essential to inform risk-benefit analyses and guide clinical management. Research Questions/Hypothesis: What is the clinical presentation and outcome of myocarditis and related cardiologic manifestations following COVID-19 vaccination? Goals/Aims: This review aims to evaluate the frequency, clinical characteristics, diagnostic findings, and short-term outcomes of myocarditis, pericarditis, and myopericarditis following COVID-19 immunization. Methods/Approach: A systematic search was conducted across PubMed, PMC, Embase, Google Scholar, and the VAERS database to identify relevant literature between March 2020 and April 2022. A total of 98 studies were screened, and 75 met the inclusion criteria, including 47 primary studies (case reports/series) detailing 103 individual cases. English-language studies involving adverse cardiac events temporally related to COVID-19 vaccination in the U.S. were included. Results/Data: Of the 103 reported cases, myocarditis was most prevalent (n=88, 85.4%), followed by myopericarditis (n=10) and pericarditis (n=5). Most cases (n=90, 87.4%) involved male patients, particularly aged 16–30. The BNT162b2 (Pfizer) vaccine was associated with the highest number of cases (n=67), followed by mRNA1273 (Moderna, n=29), and Ad26.COV2.S (J&J, n=4). The average symptom onset was 3.5 days post-vaccination, with chest pain (90.9%) being the most common symptom. Elevated troponin (89.7%), ECG abnormalities (80.6%), and cardiac MRI findings consistent with myocarditis (70.4%) were frequently reported. Clinical outcomes were favorable in 93.1% of cases, with symptom resolution and discharge. Five deaths were reported.