Impact of Steroid Therapy on Outcomes in Fulminant Myocarditis Requiring V-A ECMO: An International Multicenter Analysis

Purpose: Fulminant myocarditis (FM) can progress to refractory cardiogenic shock requiring venoarterial extracorporeal life support (V-A ECLS). The role of corticosteroids in this setting remains uncertain. We evaluated whether steroid therapy is associated with improved short- and long-term outcomes. Methods: This was a retrospective analysis of patient-level data from studies identified in a systematic review conducted by our center on adults with FM supported with V-A ECLS. Among 16 centers (440 patients), we included those with complete documentation of therapies, left ventricular assist device (LVAD) implantation, heart transplantation (HTx), and complications. Multivariable Cox proportional hazard models, adjusted for age, sex, cardiac arrest, and arrhythmias, evaluated the association between steroid use and mortality at 30 days and the composite of death, LVAD implantation, or HTx at 30 days and 1 year. Between-group differences in major complications were assessed using chi-square tests. Results: Of 440 patients, 278 had complete data. The median age was 45 years [25th-75th percentiles 32-58 years], 132 patients (48%) were male, 96 patients (35%) had a cardiac arrest, and 82 patients (30%) had unstable brady- or tachyarrhythmias. Overall, 107 patients (38.5%) received steroids, with no significant differences in the baseline characteristics between groups. Among steroid-treated patients, 36 (35%) received IVIG and 11 (12%) received other immunosuppressive therapies. At 30 days, 90 patients (32%) died, 13 (5%) received an LVAD, and 10 (4%) underwent HTx. At 1 year, 113 (41%) had died, 15 (5%) received an LVAD, and 13 (5%) underwent HTx. Multivariable Cox regression showed no significant association between steroid use and 30-day (HR 1.10, 95% CI 0.73-1.64, p = 0.67) or 1-year mortality (HR 1.15, 95% CI 0.79-1.67, p = 0.47) or the composite end-point. Rates of major bleeding, neurologic complications, limb ischemia, sepsis, liver and kidney failure were also similar between groups (p> 0.05). Conclusion: Among patients with FM requiring V-A ECLS, steroid therapy was not associated with improved survival or reduced rates of LVAD or HTx at 30 days or 1 year. In this critically ill population, steroids were neither beneficial nor harmful, underscoring the need for prospective studies to define optimal immunomodulatory strategies in FM.