162 - Viral Myocarditis in the Age of COVID: A Retrospective Analysis of the Impact of the COVID-19 Pandemic on Rates of Heart Failure and Death associated with Viral Myocarditis

Poster Number: 162
Publication Number: 162.3063

Background: Rates and outcomes associated with myocarditis prior to the start of the COVID-19 pandemic compared to during the pandemic have not been studied. This study aimed to describe the incidence and associated outcomes of COVID-19 and non-COVID-19 related viral myocarditis in pediatric and adult patients before and after the start of the COVID-19 pandemic in 2020.

Objective: This study aimed to describe the incidence and associated outcomes of COVID-19 and non-COVID-19 related viral myocarditis in pediatric and adult patients before and after the start of the COVID-19 pandemic in 2020.

Design/Methods: Data was gathered using a cloud-based database (TriNetX™) which collected de-identified patient information from over 50 healthcare organizations in the United States. A total of 2,649 pediatric patients and 15,451 adult patients were identified as having viral myocarditis. Patients were identified by age (pediatric patients ≤ 17 years, adult patients >18 years), time of diagnosis (pre-COVID: 01/2018-03/2020, post-COVID: 03/2020-12/2022) and COVID-19 ICD-10 codes and COVID-19 laboratory results. These groups were analyzed by measures of association, and odds ratios were calculated for heart failure (HF) and death.

Results: For both populations, more cases of viral myocarditis were identified after the start of the pandemic (pediatric 855 pre vs 1,794 post, 67.7%; adult 5,334 pre vs 10,117 post, 65.5%).

Pediatric patients had a higher risk of mortality (OR 1.918) and HF (OR 1.863) associated with viral myocarditis pre- vs post-pandemic. There was no difference in risk of mortality (OR 1.786) and HF (OR 1.012) when comparing COVID-19 vs non-COVID associated myocarditis in the post- pandemic group.

Adult patients had an increased risk of HF with viral myocarditis pre- vs post-pandemic (OR 1.284). There was no significant difference in rates of HF when comparing COVID-19 associated and non-COVID associated myocarditis (OR 1.047). There was no significant difference in risk of death for when comparing pre- and post-pandemic myocarditis (OR 0.874). There was increased risk of death in adult viral myocarditis patients with COVID compared to those without (OR 2.65).

Conclusion(s): In both adult and pediatric populations, there was higher incidence of viral myocarditis after the start of the COVID-19 pandemic. Pediatric patients with viral myocarditis had lower associated rates of heart failure and death after the start of the COVID-19 pandemic regardless of COVID-19 status. Adult patients with COVID-19 associated viral myocarditis had higher risk of death compared to those without COVID-19.