Acute myocarditis after administering the BNT162b2 (Pfizer-BioNTech) vaccine against COVID-19 in an adolescent patient

Abstract

Myocarditis is a multifactorial inflammatory condition of the myocardium. Recently myocarditis has been recognized as an adverse event in patients vaccinated against COVID-19 with Pfizer-BioNTech and Moderna (mRNA vaccines), mainly in adolescents and young adults. Cardiac magnetic resonance (CMR) allows the characterization of myocardial tissue and cardiac function and has become the non-invasive diagnostic gold standard in patients with suspected acute myocarditis. The authors present a 16-year-old male case with stabbing chest pain after the second dose of immunization against SARS-CoV-2 with the BNT162B2 (Pfizer-BioNTech) vaccine. The electrocardiogram (ECG) showed disclosed ST-segment elevation, and increased myocardial injury markers were also observed. Angio tomography (AngioCT) showed subtle signs of myocardial hypoperfusion and left ventricular dysfunction. Gadolinium CMR was performed, identifying global hypokinesis of the left ventricle (LV), myocardial edema hyperemia and late gadolinium enhancement (LGE) as evidence of myocardial injury, and markers of non-ischemic intramyocardial inflammatory lesion. Having excluded other etiologies, this presentation of acute myocarditis is proposed to be an adverse reaction associated with the BNT162b2 vaccine against COVID-19. The long-term risks of the COVID-19 vaccine in children, adolescents and young adults are still unknown, and further investigation will be needed.