Left ventricular unloading and survival outcomes in pediatric acute fulminant myocarditis patients receiving extracorporeal membrane oxygenation: A systematic review and meta-analysis

Background Acute fulminant myocarditis (AFM) is a severe condition in pediatric patients. Extracorporeal membrane oxygenation (ECMO) is often used as a supportive therapy, but survival rates and the impact of adjunctive therapies like left ventricular (LV) unloading and bridge-to-heart transplantation remain unclear. This meta-analysis evaluates survival outcomes in pediatric AFM patients treated with ECMO and assesses the influence of these strategies. Methods This systematic review and meta-analysis followed PRISMA guidelines. Databases, including PubMed, Embase, and the Cochrane Library, were searched for studies published in the last 10 years. Inclusion criteria were studies reporting survival rates of pediatric AFM patients treated with ECMO. Data were analyzed using fixed and random-effects models. Subgroup and univariable meta-regression analyses identified factors associated with survival. Results From 2308 articles, 10 studies met the inclusion criteria, totaling 210 pediatric patients. The pooled survival rate was 67% (95% CI: 37%-97%). Subgroup analyses showed higher survival in patients receiving LV unloading (82% vs 63%; p < .01) and those bridged to heart transplantation, though not statistically significant. Univariable meta-regression identified LV unloading as a significant predictor of survival ( p = .02). Other factors, such as age, gender, and cardiac arrest before ECMO, showed no significant associations with survival. Cumulative meta-analysis indicated an improving trend in survival over the years. Conclusions This meta-analysis suggests an association between ECMO and improved survival in children with AFM. While LV unloading may offer benefits, the retrospective nature of the included studies, along with potential confounding factors, necessitates cautious interpretation. Further well-designed prospective studies are required to establish its optimal role, indications, and timing in pediatric ECMO patients with AFM.