mRNA vaccine-associated myocarditis resolves in time without clinical events

Promising follow-up data from two small series show that myocarditis that develops after mRNA vaccination against SARS-CoV-2 resolves or shows signs of resolution approximately 6 months after initial diagnosis. indicates that there is

In an initial series involving 9 male patients (mean age 22 years) who developed myocarditis after 2 doses of Pfizer/Biontech or Moderna vaccines, cardiac MRI of one patient showed late gadolinium enhancement (LGE). ) resolved completely, and the remaining 8 patients had persistent but resolved LGE.

“Myocardial edema resolved in all cases after repeated cardiac MRIs for 3 to 6 months, meaning there was no more active inflammation,” said lead investigator Yash Patel, MD. , MPH (Warren Alpert Medical School at Brown University, Providence), RI) told TCTMD. “Regarding clinical follow-up, none showed adverse cardiovascular outcomes. There were no recurrences of myocarditis, arrhythmias, heart failure, or hospitalizations.”

In a second report based on seven male patients (mean age 30 years) who developed myocarditis after receiving either the first or second Pfizer/BioNTech vaccine, absolute LGE decreased in one patient and fully recovered in one. Median follow-up he is 212 days. In addition, she had an increased left ventricular ejection fraction in 5 of 7 patients and no adverse cardiovascular events, including readmission, arrhythmia, or death.

“This is good news. Italian Studies have shown that follow-up MRI is very important in predicting long-term outcome in these patients. Of course, long-term clinical follow-up is needed, but this follow-up cardiac MR study confirms that long-term outcomes in patients with vaccine-associated myocarditis are very good. “

Second Series Principal Investigator, Ashraf Hamdan, M.D., Rabin Medical Center, agreed. “These findings support the relatively favorable clinical course and outcomes of these patients,” he said in an email.

Both studies last week JACC: Cardiovascular Imaging.

good prognosis

Several case reports and case series have low risk of myocarditis Associated with mRNA vaccines, especially in young men, Risk tends to be slightly higher with Moderna vaccineCardiac imaging suggested that these cases resembled ‘classic’ myocarditis and tended to be relatively mild. Resolution without clinical impactthese studies have shown increased LVEF and LGE resolution in cardiac MR.

Israeli researchers previously published data Record mainly mild myocarditis After vaccination of 54 patients. In their original analysis, the cumulative incidence of myocarditis he had was low at 2.13 cases per 100,000. However, in men aged 16 to his 29 years, the cumulative incidence he had was approximately 11 cases per 100,000.

Of the 54 original patients, 15 underwent cardiac MR scans at a median of 4 days after diagnosis. In a follow-up study that included her 7 patients who underwent her MRI after a median of just over 7 months, there was a statistically significant improvement in her LVEF between the 2 MR studies. (56.8% to He 59.4%; P. = 0.046). LGE also decreased during MR scans and all patients showed signs of improvement or resolution.

“We still need long-term clinical follow-up,” said Shiyovich, adding that the initial MR imaging data are very encouraging. “This helps us treat these patients and get them back to work and physical activity. Much of this damage is actually reversible. but in this context it’s probably not fibrosis, it’s edema, not scarring.

In a US study, nine men diagnosed with myocarditis after receiving the Pfizer/BioNTech (n = 7) or Moderna (n = 2) vaccine had a follow-up cardiac MR scan at a median of 94 days after diagnosis. I was. As Patel noted, follow-up had his MR evidence of myocardial recovery and no clinical events, evidenced by measurements of global longitudinal strain and global circumferential strain. As such, there were also indications that some mild abnormalities persisted.

Like Shiyovich, Patel said that mRNA vaccination-associated myocarditis is very similar to classical myocarditis and has a comparable LGE scarring pattern.

“This is good because we can extrapolate the viral myocarditis data to this group of patients,” he said. “Most patients with COVID-19 vaccination-induced myocarditis had LGE in the lateral wall of the left ventricle, but not in the septum. If it is in the septum, the prognosis is poor.” From what is known so far, “I think the cases of vaccination-related myocarditis are following a benign course,” Patel said.