Background:

Acute myocarditis can result in severe hemodynamic compromise requiring venoarterial extracorporeal membrane oxygenation (VA-ECMO). Outcomes and factors associated with mortality among myocarditis patients are not well described in the modern ECMO era.

Methods:

We queried the Extracorporeal Life Support Organization registry from 2011 to 2020 for adults with suspected acute myocarditis undergoing peripheral VA-ECMO support. The primary outcome was in-hospital mortality and was compared to all-comers receiving VA-ECMO in the registry over the same period. Secondary outcomes were rates of bridging to advanced therapies and ECMO complications. We used multivariable logistic regression to examine factors associated with in-hospital mortality.

Results:

Among 850 patients with suspected acute myocarditis receiving peripheral VA-ECMO, the mean age was 41 years, 52% were men, 39% Asian race, and 14.8% underwent extracorporeal cardiopulmonary resuscitation. During the study period, in-hospital mortality steadily declined and was 58.3% for all all-comers receiving VA-ECMO compared with 34.9% for patients with myocarditis (P<0.001). After multivariable modeling, risk factors for mortality were earlier year of support, older age, higher weight, Asian race, need for extracorporeal cardiopulmonary resuscitation, sepsis, and lower mean arterial pressure and pH prior to ECMO initiation. ECMO complications including bleeding, limb ischemia, infections and ischemic stroke were more common among nonsurvivors and significantly declined during the study period.

Conclusions:

Compared with all-comers supported with VA-ECMO, in-hospital mortality for patients with acute myocarditis is significantly lower, with nearly two-thirds of patients surviving to discharge. Major modifiable risk factors for mortality were ongoing cardiopulmonary resuscitation requiring ECMO and markers of illness severity prior to ECMO.