Contemporary Outcomes of Pediatric Patients with Acute Fulminant Myocarditis Supported with Extracorporeal Membrane Oxygenation

Abstract

<h3>Purpose</h3> Despite extracorporeal membrane oxygenation (ECMO) utilization in up to 20% of cases, there are limited outcome data in pediatric patients with acute fulminant myocarditis (AFM) requiring mechanical circulatory support. <h3>Methods</h3> Retrospective cohort of patients <18 years with AFM admitted to a single center cardiac ICU and supported with ECMO from 1997-2021. Patients had ≤14 days of symptoms, rapid cardiogenic shock, and normal LV size. We compared clinical variables in patients who survived to discharge without heart transplant (HT) to those who did not. In addition, we assessed long-term LV function in survivors. <h3>Results</h3> Among 29 patients (median age 9 years; IQR 3,14), 22 (76%) survived to discharge without HT. Patients were supported on ECMO for a median of 6 days (IQR 5,8). Three patients were bridged to HT with durable ventricular assist devices (VAD). Four patients died, 2 of whom were supported with VAD. At presentation, 7 patients (24%) had high grade or complete atrioventricular block and 8 (28%) had ventricular tachycardia. CPR prior to ECMO occurred in 22 (76%) including all patients in the death/HT group. The death/HT group had higher peak troponin levels (12.5 vs 0.9 ng/mL, p=0.01). All patients underwent cardiac catheterization. Initial LA pressure was higher in the death/HT group (27 vs 18 mmHg, p=0.02) and LA decompression was performed in 23 patients (79%). Twenty-two (76%) had biopsy findings consistent with AFM. Among transplant-free survivors, 19 (86%) had normalization in LV function (median 16 days from presentation, IQR 9,449); the remaining 3 patients had persistent mild LV dysfunction at last follow up. Nine patients underwent cardiac MRI (median 752 days post-diagnosis), among whom 4 exhibited late gadolinium enhancement. <h3>Conclusion</h3> Transplant-free survival of pediatric patients with AFM supported on ECMO was 76% and associated with lower initial LA pressure. Recovery of ventricular function among survivors was rapid and durable.