Treating Pediatric Myocarditis with High Dose Steroids and Immunoglobulin.
Schauer J, Newland D, Hong B, Albers E, Friedland-Little J, Kemna M, Wagner T, Law Y. Pediatr Cardiol. 2022 Sep 12:1-10. doi: 10.1007/s00246-022-03004-w. PMID: 36097060
Take home points:
- There is considerable variability in practice among pediatric centers for treatment of myocarditis.
- Median duration of IV steroids was 7 days (IQR 4–12) followed by an oral taper. Median cumulative dose of IV immunoglobulin (IVIG) was 2 g/kg. Overall transplant free survival was 92.5% with median follow-up of 1 year and by 3 months from diagnosis, 70% of patients regained normal left ventricular function.
- High dose steroids in conjunction with IVIG to treat acute myocarditis can be safe without significant infections or long-term side effects.
Commentary from Dr. Manoj Gupta (New York City, NY, USA), chief section editor of Pediatric & Fetal Cardiology Journal Watch.
Introduction
In the real world, most pediatric myocarditis diagnoses are based on clinical presentation, incorporating echocardiography, electrocardiography and cardiac specific biomarkers. Best practice for treating myocarditis remains controversial. IVIG and steroids are frequently used in other inflammatory diseases in children such as Kawasaki disease as well as for treatment of rejection after cardiac transplantation.
Materials and Methods
This is a single center retrospective study of children less than 21 years of age diagnosed with myocarditis from January 2004-April 2021 at Seattle Children’s Hospital. Patients with myocarditis are managed or consulted on by the Heart Failure, Transplant, and Mechanical Circulatory Support (HF/TXP/MCS) service. Our standard myocarditis treatment protocol includes 2 g/kg IVIG based on actual body weight given over 48 h and an initial high dose steroid “pulse” that is tapered over 10–12 weeks. (Table 3)
Results
An initial medical record query for the diagnosis of myocarditis revealed 112 patients. Forty patients ultimately met inclusion criteria. The initial echocardiogram showed severe LV systolic dysfunction (EF < 35%) in 21 patients (54%), moderate LV systolic dysfunction (EF 35–44%) in 6 patients (15%), and mild LV systolic dysfunction (EF 45–55%) in 4 patients (10%). Eight patients (21%) had a normal ejection fraction but with significant left ventricular dyskinesis or hypokinesis on echocardiogram. Median initial LV end-diastolic dimension z score was 0.02 (IQR − 0.87 to 1.79). Twenty-two patients (65%) had at least mild mitral valve regurgitation, and 21 patients (53%) had at least mild tricuspid valve regurgitation on initial echocardiogram. Nine patients (23%) had at least a mild pericardial effusion.
Treatment with high dose steroids was initiated within 48 h of admission for 65.8% of patients. Intravenous Immunoglobulin (IVIG) was received by all patients. Thirty-two (80%) patients required inotropic support, the majority of which received milrinone. Thirty-eight patients (95%) received conventional heart failure therapy (including angiotensin converting enzyme inhibitors (ACE-I) or angiotensin II receptor blockers (ARB), mineralocorticoid receptor antagonists (MRA), digoxin, beta blockers or isosorbide dinitrate/hydralazine) during their inpatient stay.
Outcomes
Of the cohort, 10 (25%) required mechanical circulatory support (MCS) during their initial hospitalization with extracorporeal membrane oxygenation (ECMO) being the most common form (n=6; median 11 days, range 4–25 days). Three patients were supported with a left ventricular assist device (LVAD). All but one patient was cannulated onto MCS prior to initiation of steroids. The remaining patient was cannulated within 12 h of steroid initiation. Three patients (7.5%) either died or required transplantation.
Complications during hospital stay: (Table 6)
Follow up Echocardiographic Data
The majority of patients showed improvement in left ventricular function over time with 42% (13 out of 31) showing normalization of ejection fraction by 1 week, 65% (22 out of 34) by 1 month, and 70% (14 out of 21) by 1 year.
Discussion
Under this regimen, transplant free survival in our cohort was 92.5% over a median follow up period of 1 year (IQR 0.5–3), with improvement in multiple echocardiographic indices of myocardial function observed over time.
Conclusion
Use of high dose steroids with IVIG to treat myocarditis in a contemporary cohort can be safe and was not associated with any apparent propagation of viral infection affecting clinical outcome. The cohort had excellent recovery of ventricular function and survival without transplant (94%). Prospective comparison of a combination of high dose steroids with IVIG versus either therapy alone is needed.
