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 vaccines from Pfizer or Moderna. They performed a series of tests, including echocardiograms.
Cardiac MRIs were 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 the implications of the persistence remain unclear but that given it’s an indicator of subclinical heart dysfunction and scarring, “there exists a potential long-term effect on exercise capacity and cardiac functional reserve during stress.”
The study was published by Circulation. The authors reported no funding or disclosures.
Dr. Peter McCullough, an American cardiologist and president of the McCullough Foundation, said the new data is consistent with what cardiologists are seeing in clinical practice.
“Serious cases of COVID-19 vaccine-induced myocarditis are not resolved by cardiac MRI at one year of followup in the majority of cases. At some point, we must assume that late gadolinium enhancement represents a scar or permanent damage,” Dr. McCullough, who wasn’t involved in the research, told The Epoch Times via email.
“COVID-19 vaccines should be pulled from the market immediately until further notice. Large-scale research programs should be commissioned immediately on subclinical and clinical COVID-19 vaccine induced myocarditis with initial aims at risk stratification and mitigation for cardiac arrest.”
Dr. Anish Koka, another American cardiologist who wasn’t involved in the study, said the persistent LGE signifies a scar that replaced the initially inflamed heart muscle.
“The good news is that the amount of scar is small. The bad news is that there is scar,” Dr. Koka wrote on X, formerly known as Twitter.
He said the level of scarring indicates there likely wouldn’t be a long-term impact but that even small levels of scarring could be a foundation for future arrhythmias, with exercise serving as a trigger.
“All these kids (even those without scar) would need exercise stress tests at 6 months to attempt to prognosticate this,” Dr. Koka said.
Pfizer and Moderna didn’t respond to requests for comment on the study on myocarditis, a known side effect of both of the companies’ COVID-19 vaccines.
Myocarditis after COVID-19 vaccination was first detected in early 2021, and an increasing number of studies have undercut claims from officials in the United States that the heart inflammation is mild and resolves without treatment.
A study from the U.S. Centers for Disease Control and Prevention (CDC), published in 2022, reported that among patients with follow-up cardiac MRIs, 54 percent had at least one abnormal finding, such as scarring.
The study relied on surveys from health care providers who examined the patients.
The providers later told the CDC that five to 13 months after the initial diagnosis, 14 percent of patients still weren’t cleared for all physical activity and that multiple patients still had abnormal cardiac MRI findings. And in a separate set of surveys, many patients reported experiencing one or more symptoms beyond one year.
Also in 2022, Rhode Island doctors reported that 8 out of 9 patients who were scanned a median of 94 days after initial diagnosis had persistent LGE, while U.S. researchers reported in 2023 that 3 out of 7 patients who were imaged a median of 107 days after diagnosis had persistent LGE.
Myocarditis can cause deaths, including sudden deaths, and deaths from myocarditis after vaccination have been confirmed in a number of countries, including South Korea, the United States, and Germany.
South Korean researchers reported in June that vaccine-induced myocarditis caused eight sudden deaths, all in people aged 45 or younger, and a new meta-analysis found that COVID-19 vaccination was linked with an increased risk of cardiac-related death.
Vaccine-induced myocarditis primarily affects young people, particularly young males.
Some critics say that all people, or certain people, don’t need a vaccine, noting the risks as well as the high percentages of people who have been vaccinated, infected, or both.
The CDC still recommends that people of all ages receive a COVID-19 vaccine, despite the risk of heart inflammation and other side effects and even as the effectiveness of the vaccines has become worse. In its most recent benefit-risk assessment, the CDC estimated that a million doses in children aged 12 to 17 would prevent up to 136 hospitalizations and one death. According to previous estimates from the CDC, a million second doses would lead to 48 cases of myocarditis in children aged 12 to 15 and 84 cases in children aged 16 or 17.