Myocarditis after COVID-19 vaccination and cardiac MRI findings
USA: A recent study in the American Journal of Roentgenology (AJR) suggests radiologists be aware of the possible occurrence of myocarditis following COVID-19 mRNA vaccination. Also, to recognize the role of cardiac MRI for assessing suspected myocarditis postvaccination.
According to the study authors, in the small case series, all patients with myocarditis following COVID-19 vaccination were adolescent males and had a favorable initial clinical course. All patients showed cardiac MRI findings typical of myocarditis of other causes. Late gadolinium enhancement (LGE) persisted in two patients undergoing repeat MRI.
Lydia Chelala, University of Chicago Medicine, Chicago, Illinois, and colleagues aimed to describe cardiac MRI findings in patients with myocarditis after COVID-19 mRNA vaccination.
Chelala and team's retrospective study included patients who underwent cardiac MRI between May 14, 2021, and June 14, 2021, for suspected myocarditis within 2 weeks of COVID-19 mRNA vaccination—without known prior COVID-19. With clinical presentation, hospital course, and postdischarge events recorded, the cardiac MRI examinations were reviewed in consensus by a cardiothoracic radiologist and cardiothoracic imaging fellow.
Of the 52 patients who underwent cardiac MRI during the study period, Chelala and colleagues identified 5 male patients (age range, 16–19 years; mean age, 17.2 years) who presented within 4 days of the second dose of COVID-19 mRNA vaccine. After a mean hospitalization length of 4.8 days, all 5 patients were discharged in stable condition with improved or resolved symptoms. However, two patients underwent repeat cardiac MRI that showed persistent, albeit decreased, LGE.
Key findings include:
- Troponin levels were elevated in all patients (mean peak troponin I, 6.8±4.1 ng/mL). Alternate possible causes of myocarditis were deemed clinically unlikely based on medical history, physical examination, myocarditis viral panel, and toxicology screen.
- Cardiac MRI findings were consistent with myocarditis in all 5 patients based on Lake Louise criteria, including early gadolinium enhancement (EGE) and late gadolinium enhancement (LGE) in all patients and corresponding myocardial edema in 4 patients.
- All 5 patients had a favorable hospital course and were discharged in stable condition with improved or resolved symptoms after mean hospitalization length of 4.8 days.
- Two patients underwent repeat cardiac MRI that showed persistent, though decreased, LGE.
- Three patients reported mild intermittent self-resolving chest pain after discharge; 2 patients had no recurrent symptoms after discharge.
Acknowledging that their article is the first report to describe additional results of short-term follow-up in this patient population, the authors of this AJR article also conceded, "the observations do not establish causality."
Reference:
The study titled, "Cardiac MRI Findings of Myocarditis After COVID-19 mRNA Vaccination in Adolescents," is published in the American Journal of Roentgenology.
DOI: https://www.ajronline.org/doi/10.2214/AJR.21.26853
