MODERNA mRNA-1273 vaccine-associated myopericarditis in a patient with a subclinical autoimmune predisposition.

We present a rare case of myopericarditis developing one day after the injection of the second dose of the MODERNA mRNA-1273 vaccine (Cambridge, MA, USA). The patient complained of typical positional chest pain with initial laboratory results significant for elevated troponin, erythrocyte sedimentation rate, and C-reactive protein. Autoimmune predisposition was suggested by elevated anti-nuclear antibodies and anti-Sjögren's-syndrome-related antigen A autoantibodies titers. Subsequent cardiac magnetic resonance imaging (cMRI) revealed mild global hypokinesis with an ejection fraction of 48%, diffuse pericardial hyperenhancement suggestive of acute pericarditis, and T2-weighted short tau inversion recovery apical septal hyperenhancement suggestive of myocardial edema. Based on clinical, laboratory, and cMRI findings, a diagnosis of acute myopericarditis was made and the patient was treated with colchicine and ibuprofen with prompt resolution of symptoms. Vaccine-associated myopericarditis is rare, however, there have been reports of myocarditis developing after smallpox vaccination. The American College of Rheumatology has expressed concern about flaring or development of autoimmune inflammatory rheumatic disease (AIIRD) after COVID vaccination. Further studies are required to quantify AIIRD flaring/development including myopericarditis after mRNA-1273 vaccination. < With the recent reports of myocarditis developing after COVID vaccination, our case report highlights the need for further studies to investigate a possible link between the mRNA-1273 vaccine and autoimmune inflammatory rheumatic disease development including myopericarditis. In addition to clinical findings and laboratory workup, our case also assesses the clinical utility of cardiac magnetic resonance imaging for the diagnosis of myopericarditis.>.