Comparative Effectiveness of Intravenous Immunoglobulin vs Steroids in the Treatment of Pediatric Acute (Non-COVID) Myocarditis: A Pediatric Health Information Systems Database Study.

OBJECTIVE

To describe the epidemiology of acute, non-COVID-19 myocarditis in hospitalized children and to evaluate the association of administration of intravenous immunoglobulin (IVIg) and/or steroids with hospital mortality.

STUDY

DESIGN

We conducted a retrospective cohort study using the Pediatric Health Information System database. Children (ages 0-18 years) coded for myocarditis from 2012 to 2022 were included. Patients missing pharmacy data or those with a diagnosis of COVID-19 were excluded. Data included demographics, complex chronic conditions, medications, and clinical course. Patients were divided into 4 treatment categories: (1) no IVIg or steroids, (2) steroids, (3) IVIg, and (4) both IVIg and steroids.

RESULTS

A total of 2294 children were included. Treatment groups were (1 - none) 8% (189/2294); (2-steroids) 20% (450/2294); (3-IVIg) 25% (578/2294); and (4-IVIg and steroids) 47% (1077/2294). In-hospital mortality was 8%. The proportion of patients who received IVIg alone decreased significantly over the study period (tau = -0.527, P = .03). After adjusting for sex, race, hospital region, age at admission, length of stay, need for intensive care, presence of a complex chronic condition, and use of antiarrhythmic medication, the receipt of IVIg alone (OR 0.24, 95% CI 0.13-0.42) or the combination of IVIg and steroids (OR 0.60, 95% CI 0.42-0.87) was independently associated with decreased mortality compared with steroid use alone. These associations were also seen in a subgroup of children with acute fulminant myocarditis.

CONCLUSIONS

In-hospital mortality from acute myocarditis in children remains significant. Although IVIg use has decreased over time, IVIg with or without steroids is associated with improved survival.