Abstract 18693: Effect of Mechanical Unloading on Cardiogenic Shock Severity in Venoarterial Extracorporeal Membrane Oxygenation Patients

Abstract

Introduction: Mechanical unloading (MU) with Intra-aortic balloon pump (IABP) or Impella is commonly used to prevent left ventricular (LV) distension in VA-ECMO patients, but its impact on shock severity is not well described. Methods: Patients treated with VA-ECMO in our hospital between 2016-2022 for cardiogenic shock (CS) due to LV failure not related to cardiac surgery were included if no MU was used or it was instituted within 24h of ECMO cannulation. Patients were grouped according to MU: ECMO alone, ECMO + IABP or ECMO + Impella. Linear mixed effects models adjusting for age, sex, hypertension, acute myocardial infarction (AMI) etiology of shock and pre-ECMO cardiac arrest (CA) were used to assess the impact of MU on hemodynamic and perfusion markers. R version 4 was used for analysis. Results: Among 68 patients included, 18 received ECMO alone, 17 ECMO + IABP, and 33 ECMO + Impella. Age and CA were similar across groups. The Impella group had a higher proportion of men and patients with AMI. Pulmonary artery diastolic pressure was unchanged in all groups. Compared to ECMO alone, MU did not enhance lactate clearance (interaction: IABP p=0.7, Impella p=0.22), but it did improve the vasopressor-inotropic score (IABP p=0.03, Impella p=0.01), serum creatinine (IABP p=0.03, Impella p=0.04), and alanine transaminase (IABP only p=0.02). Survival to decannulation was similar in patients with ECMO alone (50%), Impella (64%) and IABP (65%) (p=0.68). Conclusions: In adults treated with VA-ECMO for CS unrelated to cardiac surgery, LV MU can lead to improvements in CS severity.