Epidemiologic Trends, Risk Factors and Outcomes for Pediatric Myocarditis in the Covid Era

Background and Aim: During the peak of the COVID pandemic, there was a high degree of awareness around myocarditis as a potential manifestation. However, it is not very clear if hospitalizations related to myocarditis increased pre- and during the COVID era. We hypothesize that there has not been an increase in hospitalizations for pediatric myocarditis in between 2019-2022 compared to the prior era and the outcomes for patients hospitalized for COVID myocarditis are inferior to those admitted for non-COVID myocarditis.Methods:PHIS database was utilized to identify patients diagnosed with myocarditis from 2006-2022 using appropriate diagnostic codes. To assess and compare the outcomes such as in-hospital mortality, ICU hospitalization and length of stay (LOS), mixed model multivariable logistic regression analysis was performed.Results:A total of 5,084 patients were diagnosed with myocarditis from 2006-2022. The incidence of myocarditis patients increased significantly from 4.23% in 2006 to 15.2% in 2021 (p<0.001) Specifically, during the post-covid era from 2020 to 2022, the incidence of myocarditis (n=1298, 28.7%) increased significantly. Out of which, one-third (n=366, 28.1%) of the patients were also diagnosed with covid-19. Patients having covid-19 along with myocarditis had two times (OR: 2.13 (95% CI: 1.55-2.92) and patients utilizing mechanical ventilation had 13 times higher odds of ICU hospitalization. In contrast, patients vising ED had 35% lower odds of ICU hospitalization. Although patients diagnosed with COVID and myocarditis are twice as likely to be hospitalized in the ICU, there were comparable rates of discharge mortality between COVID era and non-COVID era among pediatric myocarditis cases.Conclusion: Despite increase in the incidences of the myocarditis patients and increased hospitalizations during post-covid era, rates of mortality among these patients were comparable.