Myocarditis and pericarditis following mRNA vaccination in autoimmune inflammatory rheumatic disease patients: A single-center experience.

Introduction: The mRNA vaccines Comirnaty (Pfizer/BioNTech) and Spikevax (Moderna) are considered safe and highly effective against SARS-COV2. However, they are also associated with a small increased risk of pericarditis and myocarditis. There is concern about an increased risk of these complications in patients with autoimmune inflammatory rheumatic diseases (AIRD).

Case Report: We describe three patients with pre-existing AIRD who developed myocarditis or pericarditis shortly after receiving their first dose of the Pfizer-BioNTech vaccine. The first case is a 31-year-old female with systemic lupus erythematosus (SLE) and anti-phospholipid syndrome (APLS) who presented 7 days after receiving the Pfizer-BioNTech vaccine and was diagnosed with myopericarditis following a positive troponin and abnormal transthoracic echocardiogram (TTE). The second case is a 29-year-old man with seronegative inflammatory arthritis and APLS who presented 7 days after receiving the first dose of the Pfizer-BioNTech vaccine. His troponin and TTE were unremarkable however his ECG showed widespread ST elevation. Lastly, the third case is a 34-year-old man with Behcet's disease with a history of recurrent pericarditis. He developed a recurrence of symptoms approximately 7 days after his Pfizer-BioNTech vaccine and self-commenced prednisolone at home. He had normal laboratory and radiological findings. All patients received prednisolone resulting in a quick recovery and resolution of symptoms.

Discussion: In this review we discuss the association between myocarditis, pericarditis and mRNA COVID-19 vaccines, those who are at greatest risk and current clinical considerations. We also discuss the possible increased risk in AIRD patients and the current research supporting this.