Prevalence, Interventions, and Outcomes in Hospitalized Children With Myocarditis: A 25-Year Study

Introduction: Myocarditis is an uncommon inflammatory disease of the myocardium and is associated with significant morbidity and mortality. The study was aimed at evaluating prevalence trends, demographic characteristics, associated interventions, and mortality in children hospitalized with myocarditis.


Methods: A retrospective analysis of Kids’ Inpatient Database from 1997 to 2022 was performed. Hospitalized children < 20 years were selected using ICD-9 and ICD-10 diagnosis codes for myocarditis. Univariate analyses were performed for inferential statistics. Trend analysis was performed to evaluate the prevalence of myocarditis and associated complications.


Results: Among 60,791,449 discharges from 1997 to 2022, a total of 10,508 children were hospitalized with myocarditis (Prevalence 17.1 per 100,000 discharges). Trend analysis demonstrates an increase in prevalence (p < 0.001) and a decrease in mortality (p < 0.001) over 25 years. Myocarditis was more frequent in early adolescents (46%), males (68.9%), and in teaching facilities (90.5%). Interventions included invasive mechanical ventilation (IMV) (16.7%), cardiovascular surgery (CV surgery) (8.9%), ECMO (4.2%), VAD (1.5%), and heart transplant (0.8%). Overall mortality from myocarditis was 4.1%, among those who died the median age was significantly lower 6 (IQR: 1-15) years (p < 0.001). Mortality was higher when associated with female sex 6.4% (OR:2.1, 95% CI: 1.7-2.5), CHD 7.7% (OR:2.1, 95%CI: 1.6-2.7), CV surgery 8.9 % (OR:2.6, 95% CI: 2.1-3.3), IMV 17.7% (OR:14.8, 95% CI: 11.9-18.4), vasopressor infusion 17.8% (OR:5.4, 95% CI: 3.9-7.6), VAD 18.6% (OR:5.6, 95% CI: 3.7-8.4), ECMO 28.0% (OR:12.2, 95% CI: 9.6-15.5) and cardiopulmonary resuscitation 44.4% (OR:24.3, 95% CI: 18.5-32.1). Association of myocarditis with CHD, and the use of ECMO, VAD, and heart transplant has shown an upward trend (P < 0.001).


Conclusions: There is an increase in trend and a decrease in mortality among hospitalized children with myocarditis over the last 25 years. Younger age, female sex, and the need for interventions are associated with poor outcomes. An increased use of ECMO, VAD, and heart transplantation signifies temporal changes in management, and their association with improved outcomes needs further evaluation.