Some children who experienced heart inflammation after COVID-19 vaccination had scarring on their hearts months later, a new long-term study found.
Researchers followed a group of 40 patients aged 12 to 18 for up to one year after the children were diagnosed with myocarditis, or heart inflammation, following vaccination with one of the messenger RNA shots from Pfizer or Moderna. They performed a series of tests, including echocardiograms.
Cardiac magnetic resonance imaging, or cardiac MRIs, was performed on 39 of the 40 patients. Abnormal results came in for 26 of those who were imaged, including 19 who had late gadolinium enhancement, or signs of scarring.
The patients with abnormal results returned for follow-up cardiac MRIs at least five months after the initial tests and 15, or 58 percent, had residual late gadolinium enhancement (LGE). The one patient without an initial scan also had mild late gadolinium enhancement when scanned during a follow-up visit.
“Persistence of LGE in a significant subset of patients with up to 1 year of follow-up was observed,” Dr. Yiu-fai Cheung, with Hong Kong Children’s Hospital, and the other researchers wrote.
They said that the implications of the persistence remain unclear, but that given it is an indicator of subclinical heart dysfunction and scarring, “there exists a potential long-term effect on exercise capacity and cardiac functional reserve during stress.”