Myocarditis developed following anti-Covid vaccination presents fewer cardiovascular complications than those with other origins, notably coronavirus infection.
- Patients with myocarditis after mRNA Covid-19 vaccination have fewer cardiovascular complications (5.7%) at 18 months than others, according to a new study.
- In fact, the rate of complications in patients with myocarditis attributable to Covid-19 is 12.1%.
- The research also confirmed that young men were most at risk of developing myocarditis after receiving a COVID-19 vaccine.
The occurrence of myocarditis within a week of receiving an mRNA vaccine (Comirnaty or Spikevax), particularly in young men after the second dose, has been one of the identified adverse effects of covid-19 vaccination.
However, the conclusions of a study carried out by the GIS Epi-Phare, published in the Journal of the American Medical Association (Jama), are intended to be reassuring.
People who developed this disorder following vaccination against Covid-19 have half as many cardiovascular complications in the medium term as those suffering from myocarditis of other origins.
Myocarditis: twice as many complications in Covid patients
To assess the medium- and long-term consequences of post-vaccination myocarditis, the researchers used information from the National Health Data System (SNDS). They observed the frequency of occurrence of cardiovascular complications (readmission to hospital for myopericarditis, hospitalization for another cardiovascular event, including heart failure/rhythm disorders/cardiomyopathy, etc.) as well as patient care (diagnostic procedures and medications dispensed) 18 months after diagnosis depending on the origin of the myocarditis.
A total of 4,635 confirmed cases of myocarditis were identified in people aged 12 to 49 hospitalized in France between December 27, 2020 and June 30, 2022. Of these, 558 cases occurred after administration of an mRNA vaccine, 298 following infection with SARS-CoV-2 and 3,779 myocarditis cases were linked to other causes.
“Patients with myocarditis after mRNA vaccination against Covid-19 had fewer cardiovascular complications (5.7%) at 18 months than patients with myocarditis attributable to Covid-19 or other causes (12.1% and 13.2% respectively)”explain the authors in their press release.
Post-vaccination myocarditis: mainly healthy young men
The study also confirmed that post-vaccination myocarditis mainly affected “healthy young men”. The latter could require medical care for up to several months after their discharge from hospital. However, the researchers point out that the number of cases of post-vaccination myocarditis (558) appears “uncommon given the high number of doses administered.” 54 million people have been vaccinated in France.
For them, their work on the medium-term clinical consequences of myocarditis associated with mRNA vaccines against Covid-19 complements other international studies confirming a benefit-risk ratio in favor of vaccination.
