Occurrence of Myopericarditis Following COVID-19 Vaccination Among Adults in the Eastern Region, Saudi Arabia: A Multicenter Study.

Abstract

Evidence supporting the possible causal association of myopericarditis with the coronavirus disease (COVID-19) vaccine has mainly come from case reports. Epidemiological evidence indicating an increased relative risk for myopericarditis after COVID-19 vaccination is lacking. Therefore, this study aimed to identify and assess all confirmed COVID-19 vaccine- related cases of myopericarditis presenting to major cardiac centers in the Eastern Region of Saudi Arabia, before and after the introduction of the COVID-19 vaccine. According to case definition, the hospital's information system database detected all confirmed cases at two main cardiac centers. Of the 18 confirmed myocarditis and myopericarditis cases detected after the administration of COVID-19 vaccines, three were possibly related to COVID-19 immunization. The first case was of myopericarditis following a third dose of mRNA-1273. The second case was myocarditis, which occurred seven days after the first dose of AstraZeneca. The third case was myocarditis, which occurred 12 days after the third dose of BNT162b2. A cardiologist carefully evaluated the cases using recognized protocols and case definitions to demonstrate a direct relationship with vaccination consequences rather than coincidence. We found no difference in the occurrence of myocarditis and myopericarditis after the COVID-19 vaccine compared with the background rate during a similar period (P = 0.9783). The incidences of myocarditis and myopericarditis following immunization were low. The advantages of the COVID-19 vaccination outweigh the risk of myopericarditis.