Venoarterial extracorporeal membrane oxygenation with and without left ventricular unloading in patients with cardiac arrest: A nationwide analysis from the United States.

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) using veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a promising strategy for refractory cardiac arrest. However, the role of left ventricular (LV) unloading during ECPR remains uncertain.

Methods: We queried the United States National Inpatient Sample (2016-2021) to identify adult patients with out-of-hospital (OHCA) and in-hospital cardiac arrest (IHCA) who received ECPR. Patients were stratified based on the use of either VA-ECMO only or VA-ECMO with intra-aortic balloon pump (IABP) or VA-ECMO with Impella (ECPELLA) for ventricular unloading. Multivariable logistic regression was used to compare in-hospital outcomes between the groups.

Results: Among 6915 patients receiving ECPR, VA-ECMO alone was used in 5147 (74.4 %), VA-ECMO-IABP in 811 (11.7 %), and ECPELLA in 957 (13.9 %). In IHCA patients, ECPELLA was associated with 50 % lower odds of in-hospital mortality compared to VA-ECMO alone (adjusted odds ratio [aOR] 0.50, 95 % CI 0.31-0.81, p < 0.01). No significant difference was found in OHCA patients. VA-ECMO-IABP was not associated with a mortality benefit vs. VA-ECMO alone in either OHCA or IHCA.

Conclusion: LV mechanical unloading with ECPELLA was associated with improved survival in IHCA patients but not in OHCA patients compared to VA-ECMO alone. The addition of an IABP to VA-ECMO was not associated with a mortality benefit.