Conclusion:
Physician adjudicated etiology and origin of cardiac arrest, even when considered along with arrest rhythm, may not be predictive of survival to discharge in ECPR. Patients who are younger, arrested in the emergency department, and arrested from a pulmonary embolism may represent a population who benefits from ECPR that warrants future study. The excellent neurological status of those who survive to discharge demonstrated in this study serves as a justification for its continued use and optimization.
The lack of correlation between etiology, origin, rhythm, and outcome is indicative of the underlying heterogeneity of arrest patients. This heterogeneity poses a fundamental challenge to studying the appropriateness of ECPR across the diverse care settings and patient populations. Ultimately, ECPR survival may depend more on resuscitation metrics such as CPR duration or quality than patient- or arrest-specific characteristics. In order to determine who may benefit most, we must focus on improving our ability to clinically phenotype peri-arrest patients, as well as understanding how the epidemiology of in-hospital cardiac arrest is changing over time as medical advances continue to alter the natural history of many common underlying conditions and risk factors. Further studies are needed to elucidate the factors that can help determine who will derive the greatest benefit from ECPR in order to better guide institutions on how to deploy this resource-intensive but potentially life-saving therapy.