Key points What are the frequency, clinical characteristics, and early outcomes associated with myopericarditis after COVID-19 mRNA vaccination in adolescents and young adults? Findings In this systematic review and meta-analysis of 23 studies, including 854 patients aged 12 to 20 years with vaccine-associated myopericarditis, the incidence of myopericarditis was higher in men after the second dose. Although 15.6% of patients had left ventricular (LV) systolic dysfunction, only 1.3% had severe LV systolic dysfunction (ejection fraction <35%); late gadolinium enhancement was found in 87.2% and 23.2% required admission to the intensive care unit; however, no in-hospital mortality was observed. Meaning These findings suggest largely favorable outcomes of COVID-19 vaccine-associated myopericarditis in adolescents and young adults. |
Summary
Importance
Published data on COVID-19 mRNA vaccine-associated myopericarditis in adolescents and young adults were derived from small case series, national population-based studies, or passive reporting systems. Pooled evidence from a larger international cohort is scarce.
Aim
To investigate the clinical characteristics and early outcomes associated with myopericarditis after COVID-19 mRNA vaccination in a heterogeneous population of adolescents and young adults.
PubMed and EMBASE data sources were searched up to August 2022. No language restrictions were applied.
Study selection
Observational studies and case series describing COVID-19 vaccine-associated myopericarditis in adolescents and young adults aged 12 to 20 years and reporting clinical characteristics and early outcomes were included.
Data extraction and synthesis
Two independent researchers extracted relevant data from each study. A one-group meta-analysis was performed in a random effects model. The reporting guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analyses of Observational Studies in Epidemiology were followed.
Main results and measures
The primary outcomes were the clinical characteristics and early outcomes of COVID-19 mRNA vaccine-associated myopericarditis, including incidence rate, cardiac findings, hospitalization, intensive care unit (ICU) admission, and hospital mortality.
Results
A total of 23 observational studies were identified, including 854 individuals (mean age, 15.9 [95% CI, 15.5-16.2] years) with COVID-19 vaccine-associated myopericarditis. The male sex predominated, in 90.3% (95% CI, 87.3%-93.2%) of the individuals.
The incident rate was higher after the second dose than the first, with 74.4% (95% CI, 58.2%-90.5%) of events occurring after the second dose.
The majority of patients (84.4% [95% CI, 80.5%-88.3%] of patients) had preserved left ventricular (LV) function. Of the 15.6% (95% CI, 11.7%-19.5%) of patients with LV systolic dysfunction (LV ejection fraction [LVEF] <55%), the majority (14.1% [CI 95%, 10.2%-18.1%]) mild (i.e., LVEF 45% to 54%) and only 1.3% (95% CI, 0% to 2.6%) of Patients had severe LV systolic dysfunction (i.e., LVEF <35%).
Interestingly, cardiac MRI revealed late gadolinium enhancement in 87.2% (95% CI, 79.8%-94.7%) of patients. Although 92.6% (95% CI, 87.8%-97.3%) of patients were hospitalized and 23.2% (95% CI, 11.7%-34.7%) of patients required ICU admission, inotropes were used in only 1.3% (95% CI, 0%-2.7%) of patients, no patient died or required mechanical support, and hospital stay was 2. 8 (95% CI, 2.1-3.5) days.
Conclusions and relevance
This systematic review and meta-analysis found a low incidence rate and largely favorable early outcomes of COVID-19 mRNA vaccine-associated myopericarditis in adolescents and young adults from a wide range of populations. These findings are reassuring, but continued follow-up is warranted.
