Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly used for refractory cardiogenic shock (CS). Although guidelines have downgraded the recommendations for intra-aortic balloon pump (IABP) in CS, escalation from IABP to ECMO (IABP-ECMO) is still common in CS patients. This study aims to determine the association between IABP-ECMO and outcomes for patients undergoing VA-ECMO.

Methods: Adults who received IABP before VA-ECMO (IABP-ECMO group) or did not receive IABP before ECMO (direct ECMO group) from January 1, 2017, through August 31, 2022 were extracted from the Chinese Extracorporeal Life Support (CSECLS) registry. The primary outcome was in-hospital mortality. Multivariable logistic regression analyses were performed to assess the association between IABP-ECMO and in-hospital outcomes.

Results: Among 4607 patients meeting study inclusion, 655(14.2%) received IABP before VA-ECMO. Patients in the IABP-ECMO group were older (age 61 vs 55 years), more often had acute myocardial infarction (68.7% vs 39.1%), and less often had cardiac arrest before ECMO (25.8% vs 41.4%) (all p<0.001). In-hospital mortality (57.1% vs 51.4 %, p=0.007) occurred more frequently in the IABP-ECMO group which persisted in multivariable modeling (adjusted OR [aOR], 1,34; 95% CI, 1.08-1.67; P =0.008; Figure 1). Escalation from IABP to ECMO was also associated with on-support mortality (aOR, 1.50; 95% CI, 1.19-1.88; P =0.001) and limb ischemia (adjusted OR, 2.20; 95% CI, 1.62-2.99; P <0.001).

Conclusions: Among adults receiving VA-ECMO, escalation from IABP to ECMO was associated with increased in-hospital mortality and limb ischemia rate.