A Case of Post-Vaccine Myocarditis Mimicking Long Covid

ABSTRACT

Myocarditis is a rare complication following mRNA-based COVID vaccinations. While the risk appears to be greatest in adolescent males, increased rates of myocarditis following COVID vaccination have been documented in both sexes and across multiple age groups.In this case, a 59- year-old woman with history of mild COVID infection developed unexplained fatigue, diminished exercise capacity, and intermittent chest discomfort several days after receiving her first dose of the Pfizer-BioNTech COVID-19 vaccine. She was seen in the emergency department at the onset of symptoms and found to have a dynamic troponin elevation peaking at 177 ng/L. A comprehensive workup including regadenoson stress testing, CT scan of the chest with contrast, and ambulatory cardiac monitoring failed to demonstrate an etiology. She subsequently received a second dose of the COVID-19 vaccine which resulted in worsening cardiopulmonary symptoms that persisted over the next several months. Her symptoms were initially attributed to long COVID, and she was provided supportive care and an SSRI for anxiety. After reevaluation in the Cardiology clinic, the patient underwent cardiac MRI revealing edema in the basal lateral wall and late gadolinium enhancement in a subepicardial distribution, suggestive of myocardial inflammation. She was treated with prednisone 50 mg daily and colchicine 0.6 mg twice daily resulting in resolution of chest pain. A repeat MRI performed two weeks later showed complete resolution of myocardial edema with residual subepicardial LGE in the basal lateral wall consistent with prior myocarditis.This case demonstrates the pitfalls of relying on a diagnosis of 'long COVID' to explain concerning cardiac symptoms of uncertain etiology and highlights post-vaccine myocarditis as an important differential in the COVID-19 era. At this time, it is unclear how many patients experience persistent cardiopulmonary symptoms following COVID vaccination and whether a subset of these patients have undiagnosed myocarditis. It is important for clinicians to be alert to the possibility of post vaccine myocarditis in patients presenting with persistent symptoms following vaccination, regardless of demographic profile.