Studies Find Heart Scarring Detected More Than 1 Year After COVID-19 Vaccination
Two long-term studies discovered evidence of fibrosis in individuals who experienced heart inflammation following receiving a COVID-19 vaccine.
Damage to the heart was detected over a year after COVID-19 vaccination in individuals who experienced myocarditis following vaccination, according to researchers in new studies.
A third of 60 patients who underwent follow-up cardiac imaging over 12 months after their myocarditis diagnosis displayed persistent late gadolinium enhancement (LGE), which often indicates heart scarring, as reported by Australian researchers in a preprint of a new study published on March 22.
Myocarditis is a type of heart inflammation.
The average time from receiving a vaccine to follow-up imaging was 548 days, with the longest interval being 603 days.
“We found that the occurrence of persistent myocardial fibrosis is notable, observed in nearly one-third of patients at more than 12 months post-diagnosis, which could impact the management and prognosis of this mainly young group,” the researchers wrote.
Researchers in a prior study found that LGE served as a “robust predictor” of negative outcomes in myocarditis patients.
Before the new examinations, nine patients were definitively diagnosed with myocarditis, while 58 patients were considered probable cases of myocarditis. The discovery of persistent LGE led to reclassifying 16 cases from probable to definite myocarditis.
Patient exclusions included those who were pregnant or had allergies to agents used in gadolinium testing.
Out of a subgroup of 20 patients who underwent imaging shortly after vaccination, 19 exhibited LGE. In subsequent imaging, LGE was no longer visible in 10 patients, reduced in five, and unchanged in four.
The study was carried out by Andrew Taylor, a professor at Monash University’s Central Clinical School, and his colleagues by recruiting patients diagnosed with myocarditis associated with COVID-19 vaccination between August 2021 and March 2022. The patients were offered imaging at Alfred Hospital or Royal Children’s Hospital in Melbourne, Australia.
The study group with follow-up imaging comprised 44 adults and 16 adolescents.
The majority of patients had received a Pfizer-BioNTech vaccine, with a minority receiving Moderna or AstraZeneca vaccinations. The companies did not respond to requests for comment.
Limitations of the study, which was published before peer review, included potential selection bias since participation in the study was voluntary. The authors disclosed no conflicts of interest or funding.
In another recent paper, Canadian researchers reported that around half of patients referred for imaging due to possible post-vaccination myocarditis exhibited persistent LGE in follow-up imaging.
The retrospective study involved a total of 60 patients. Among them, seven reported ongoing symptoms.
In a subset of 21 patients with available follow-up MRIs, 10 showed persistent LGE, while left ventricle function had normalized in all patients.
The research found that the persistent LGE likely indicates replacement fibrosis, or heart scarring, according to Dr. Kate Hanneman of the University of Toronto’s Department of Medical Imaging and her team. They referenced some of the same studies mentioned by the Australian researchers and a study on the implications of finding LGE on MRI in myocarditis patients.
They emphasized the need for additional studies to assess patients with persistent LGE and a recovered left ventricle.
The study included adult patients referred to a hospital network with suspected myocarditis and new cardiac symptoms within 14 days of COVID-19 vaccination. All patients had received either Pfizer or Moderna vaccines.
The study’s limitations included a lack of biopsy-confirmed myocarditis.
The authors disclosed no funding and only one competing interest – that an author serves as an associate editor of the journal.
The corresponding authors for both papers did not respond to requests for comment.
“My concern after reading these two studies is that myocardial damage and scarring are present in a significant number of individuals who experienced adverse effects from COVID vaccines up to 18 months after vaccination. This suggests the potential for permanent heart damage from the vaccines,” said Dr. Danice Hertz, the research lead for the U.S. group React19.
The new studies contribute to earlier research indicating that LGE remains in some individuals for months following a COVID-19 vaccination.
For instance, researchers in Washington state reported in 2022 that LGE persisted in children up to eight months after vaccination. The U.S. Centers for Disease Control and Prevention (CDC) later confirmed that over half of 151 patients with follow-up imaging displayed residual LGE, indicative of myocardial scarring.
The CDC possesses longer-term patient data but has not yet published another paper detailing that data. The CDC, which failed to alert the public to the risk of post-vaccination myocarditis, declined to comment on the new Australian and Canadian studies.
Researchers in Hong Kong in 2023 reported that roughly half of 40 patients who underwent follow-up MRIs months after vaccination showed LGE.
Symptoms also persisted in individuals with post-vaccination myocarditis.
Preliminary updated results from the CDC’s long-term study in early 2023 indicated that some patients still had symptoms over a year after vaccination. Australian researchers in late 2023 reported that symptoms persisted for at least six months in a majority of patients they monitored. Some patients also reported lingering health issues years after vaccination.
