Long-Term Outcomes in Survivors of Fulminant Myocarditis Supported with Venoarterial Extracorporeal Membrane Oxygenation by Discharge Cardiac Function

Background: Fulminant myocarditis (FM) is a life-threatening cause of cardiogenic shock. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is often employed as a bridge to recovery, but data on long-term outcomes and prognostic markers post-discharge remain limited. We described long-term outcomes and explored the association between discharge left ventricular ejection fraction (LVEF) and post-discharge events. Methods: This retrospective, international, multicentre cohort study included adult FM patients who required VA-ECMO and survived to hospital discharge. Patients were stratified by LVEF ≥ 50% or < 50% at discharge. Cox proportional hazards models were used to assess the association between discharge LVEF and the primary composite endpoint of death, heart transplantation, or durable mechanical circulatory support postdischarge. Results: A total of 106 patients from 11 centres were included, with a median age of 43 years (interquartile range 29-57); 42% were male. At discharge, LVEF was ≥ 50% in 69 patients and < 50% in 37 patients. Over a median follow-up of 4.4 years (interquartile range 1.6-7.9), 3 patients (2.8%) experienced the composite outcome (2 deaths, 1 left ventricular assist device implantation). Compared with patients discharged with an LVEF ≥ 50%, those with an LVEF < 50% had a numerically higher risk of the composite endpoint (hazard ratio 2.9, 95% confidence interval 0.19-42.9), although this difference was not statistically significant. Conclusions: Given the low number of postdischarge events, this study was underpowered to assess the prognostic value of discharge LVEF. However, long-term outcomes were favourable among survivors of FM supported with VA-ECMO, regardless of their LVEF at discharge.