Reverse Remodeling in Pediatric Myocarditis With DCM Phenotype Impact of rASD and PAB

BACKGROUND: Myocarditis progressing to a dilated cardiomyopathy (DCM) phenotype carries a high risk of end-stage heart failure in early childhood. OBJECTIVES: Given the age-dependent regenerative capacity of the immature myocardium, we evaluated a staged, pathophysiology-guided strategy combining left atrial decompression and pulmonary artery banding (PAB) to promote myocardial recovery in selected infants and young children. METHODS: We retrospectively analyzed 31 children <3 years (55% female; median age 312 days) with biopsy-proven myocarditis and a DCM phenotype treated between 2013 and 2024. All underwent standardized multimodal assessment, including echocardiography, cardiac magnetic resonance imaging, invasive hemodynamic assessment, and endomyocardial biopsy. RESULTS: At presentation, all patients were in Ross functional class > III; median BNP was 2,258 pg/mL (IQR: 770-4331), and 90% required inotropic support. The mean echocardiography-derived left ventricular (LV) ejection fraction at admission was 24% ± 6.2% with marked LV dilatation (mean z-score +5). The median LV end-diastolic pressure (was 20 mm Hg (IQR: 15-23), indicating elevated filling pressures. A restrictive atrial communication (restrictive atrial septal defect or patent foramen ovale dilatation) was created in 17 patients for atrial decompression. Seventeen patients met the predefined criteria for surgical PAB, including severely reduced LV ejection fraction (mean 19% ± 6%), marked LV dilatation (z-score +6 ± 1.6), and preserved right ventricular function. During a median follow-up of 2 years (IQR: 1-7) overall survival was 90%. Heart transplantation was required in 19%; mechanical circulatory support in 6%. Among patients selected for PAB, 76% achieved sustained functional recovery. CONCLUSIONS: A staged, pathophysiology-guided strategy incorporating left atrial decompression and PAB may promote myocardial recovery in selected young children with myocarditis-associated DCM.