A majority of young Americans who suffered heart inflammation after receiving a COVID-19 vaccine had abnormal MRI results, according to a new study from the U.S. Centers for Disease Control and Prevention (CDC).
CDC researchers have been following youth who experienced myocarditis, a form of heart inflammation, after receipt of the Pfizer or Moderna COVID-19 vaccines, both of which utilize messenger RNA (mRNA) technology.
Some 81 percent of the included patients were considered by health care providers to be fully recovered or "probably fully recovered" from myocarditis. However, nearly half of the patients continued to report symptoms, including chest pain. And among the 151 patients who had follow-up cardiac MRI results, 54 percent had an abnormal finding, such as swelling and scarring.
"The meaning of the cardiac MRI findings among the subset of patients who received cardiac imaging is unclear. Evidence of ongoing myocarditis on follow-up cardiac MRIs based on modified Lake Louise criteria was uncommon," the CDC researchers wrote. "However, consistent with the few published case series of myocarditis after mRNA COVID-19 vaccination, we observed that nearly half of patients (71/151) with follow-up cardiac MRIs had residual late gadolinium enhancement, suggestive of myocardial scarring."
In some of the patients, initial cardiac imaging was normal, but the follow-up imaging after several months was abnormal, which may indicate that the condition worsens over time.
"The CDC is conducting additional follow-up on patients who were not considered recovered at least 12 months since symptom onset, to better understand their longer term outcomes," the researchers said.
Cardiologists Weigh InDr. Anish Koka, a cardiologist in Pennsylvania, said that the study "should dispel the ludicrous notion that clinical myocarditis—a disease entity that comes to light when you have chest pain because cells in your heart are dying—is mild."
Koka, writing on Substack, said that many of the abnormalities detected on the MRIs are "very likely" related to myocarditis.
The CDC has said current evidence supports a causal link between the mRNA-based vaccines and two forms of heart inflammation: myocarditis and pericarditis.
"These are very likely to be real scars. The valid, open question is what these scars mean long term. And the best answer is that we don’t know," Koka said.