Patients with Fulminant Myocarditis Supported with Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis of Short-Term Mortality and Impact of Risk Factors

Purpose Fulminant myocarditis (FM) is a rare disease that may progress rapidly to refractory cardiogenic shock requiring temporary mechanical circulatory support. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been used to provide biventricular support in these patients, however, studies have demonstrated conflicting results, likely due to small sample size. We conducted a systematic review and meta-analysis to evaluate short-term mortality after VA-ECMO in patients with FM. Methods Seven relevant databases were systematically searched on June 1st, 2019 to identify studies evaluating death at 30 days and/or hospital discharge (short-term mortality) after VA-ECMO support for FM. We included studies with n≥5, published after 2009. Mortality risk was meta-analyzed using random effect models. We performed a meta-regression analysis to explore heterogeneity based on a priori defined factors. We assessed the quality of the evidence using the GRADE approach. Results We included 12 retrospective studies (Figure) with 859 patients, mean age 38 ± 12 years to 59 ± 17 years, proportion of female patients ranged from 40% to 60%. In 5 studies (n=144), FM was verified by biopsy. In 4 studies (n=67), the reported use of steroids ranged from 13% to 41%, and in 4 studies (n=207), co-therapy with IABP ranged from 65% to 96%. The pooled short-term mortality was 41% (95% CI 34-47%; I2=64%). The exploration of heterogeneity showed that age and sex significantly impacted short-term mortality after VA-ECMO with lowest mortality in studies with younger populations and higher proportion of female patients. Conclusion In patients with rapidly progressive FM, short-term mortality was 41%. Mortality might be even lower in younger and in female patients. Cardiopulmonary support with VA-ECMO provides an invaluable tool in the treatment of fatal FM, where appropriate patient selection can further improve their outcomes.