Myopericarditis After COVID-19 mRNA Vaccination Among Adolescents and Young Adults: A Systematic Review and Meta-analysis

Abstract

Importance: Published data on COVID-19 mRNA vaccine-associated myopericarditis in adolescents and young adults have been derived from small case series, national population-based studies, or passive reporting systems. Pooled evidence from a larger, international cohort is scarce.

Objective: To investigate the clinical features and early outcomes associated with myopericarditis after COVID-19 mRNA vaccination in a heterogeneous population of adolescents and young adults.

Data sources: PubMed and EMBASE were searched through August 2022. Language restrictions were not 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 investigators extracted relevant data from each study. One-group meta-analysis in a random effects model was performed. The Preferred Reporting Items for Systematic Reviews and Meta-analysis and Meta-analysis of Observational Studies in Epidemiology reporting guidelines were followed.

Main outcomes and measures: The primary outcomes were clinical features and early outcomes for COVID-19 mRNA vaccine-associated myopericarditis, including incident rate, cardiac findings, hospitalization, intensive care unit (ICU) admission, and in-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. Male sex was predominant, at 90.3% (95% CI, 87.3%-93.2%) of individuals. The incident rate was higher after the second dose than the first dose, with 74.4% (95% CI, 58.2%-90.5%) of events occurring after the second dose. Most 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%), most (14.1% [95% CI, 10.2%-18.1%]) were mild (ie, LVEF 45%-54%), and only 1.3% (95% CI, 0%-2.6%) of patients had severe LV systolic dysfunction (ie, LVEF<35%). Interestingly, cardiac magnetic resonance imaging 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 patients died or required mechanical support, and the hospital length of stay was 2.8 (95% CI, 2.1-3.5) days.

Conclusions and relevance: This systematic review and meta-analysis found 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.

Figure 1.. Flowchart of Study Selection

Of 454 identified articles, 23 studies^{,,,,,,,,,,,,,,,,,,,,,,} reporting clinical characteristics and outcomes of myopericarditis following COVID-19 vaccination in adolescents and young adults were included for a systematic review and meta-analysis.

Figure 2.. Forest Plots Showing the Prevalence of Echocardiogram and Cardiac Magnetic Resonance Findings

The pooled estimates of echocardiogram and CMR findings of myopericarditis after COVID-19 mRNA vaccination in adolescents and young adults were calculated using 1-group meta-analysis in random-effects model. LV indicates left ventricular; LVEF, left ventricular ejection fraction; diamond, total estimate with 95% CI.

Figure 3.. Forest Plots Showing the Pooled Estimates of Early Outcomes

The pooled estimates of the prevalence of early outcomes of myopericarditis after COVID-19 mRNA vaccination in adolescents and young adults were calculated using 1-group meta-analysis in random-effects model. ICU indicates intensive care unit; diamond, total estimate with 95% CI.