New French data suggest that myocarditis attributed to COVID-19 mRNA vaccination is associated with fewer cardiovascular complications compared to conventional myocarditis or myocarditis attributed to SARS-CoV-2 infection itself. However, the findings emphasize the need for follow-up care in more severe cases.
Previous studies have confirmed that vaccine-related myocarditis is rare and usually resolves quickly, but it seems to affect some groups more than others. While the new data are consistent with previous findings, they underscore the need for “medical disease management for up to several months after hospital discharge” in certain affected patients, write the researchers.
Peter Liu, MD, who was not involved in the study, said it’s “reassuring” that vaccination-related myocarditis is usually mild, but agreed that the medical community must remain vigilant in following up with these patients, especially given their young age and unknowns about how this condition can affect them years later.
The analysis included 4,635 individuals aged 12 to 49 years hospitalized for myocarditis in France between December 2020 and June 2022. Patients were allocated to the postvaccine or post-COVID-19 infection myocarditis groups based on whether they had received a COVID-19 mRNA vaccine or experienced a COVID-19 infection within the last 7 or 30 days.
Compared to conventional myocarditis, the standardized incidence of the primary composite endpoint of hospital readmission for myopericarditis, other cardiovascular events, or all-cause death at 18 months was lower following postvaccine myocarditis. However, the risk was similar with post-COVID-19 myocarditis.
Liu said the classification of 18 months in these patients as long term is “reasonable,” adding that more data out to 4 or 5 years are still needed, especially because mRNA vaccines and treatments continue to be developed for conditions other than COVID-19.
In conclusion, while the new data are reassuring, they emphasize the importance of follow-up care for patients with vaccine-related myocarditis, particularly those with severe symptoms or comorbidities.
Continued monitoring and research are necessary to fully understand the long-term implications of this condition.