Cohort study
COVID-19 vaccination-related myocarditis: a Korean nationwide study
- Nationwide cohort study
- adjudicated cases
Authors' conclusion
Although COVID-19 VRM was rare and showed relatively favorable clinical courses, severe VRM was found in 19.8% of all VRM cases.
Study context
- Population
- Individuals with at least 1 dose of COVID-19 vaccination, Korea
- Participants
- 44,276,704 individuals
- Outcome
- Incidence and clinical course of COVID-19 vaccination-related myocarditis (VRM), confirmed by expert adjudication
Main finding
As reported in the abstract
VRM incidence
Confirmed vaccination-related myocarditis (VRM) cases
480
VRM incidence, overall
1.08 cases per 100 000 persons
Observational data: associations, not effects.
Further findings
| Outcome | Values | P value |
|---|---|---|
| VRM incidence by sex | Men 1.35 per 100 000 persons · Women 0.82 per 100 000 persons | P < 0.001 |
| VRM incidence by vaccine type | mRNA vaccines 1.46 per 100 000 persons · Other vaccines 0.14 per 100 000 persons | P < 0.001 |
VRM incidence by age and sex
cases per 100 000 persons
- Highest: males aged 12–17 years
- 5.29
- Lowest: females over 70 years
- 0.16
Safety
Severe VRM and outcomes among VRM cases
- Severe VRM
- 95 cases (19.8% of total VRM, 0.22 per 100 000 vaccinated persons)
- ICU admission
- 85 (17.7%)
- Fulminant myocarditis
- 36 (7.5%)
- ECMO therapy
- 21 (4.4%)
- Deaths
- 21 (4.4%)
- Heart transplantation
- 1 (0.2%)
- Sudden cardiac death (SCD) attributable to VRM (autopsy-proven), of 21 deaths
- 8
- all SCD cases aged under 45 years and received mRNA vaccines
Original publication
COVID-19 vaccination-related myocarditis: a Korean nationwide study. Eur Heart J. Published 2 June 2023. doi:10.1093/eurheartj/ehad339
Summarised from the published abstract; every number is checked against it