Left Ventricular Unloading With Impella Versus Intra‐Aortic Balloon Pump in Cardiogenic Shock Requiring Venoarterial Extracorporeal Membrane Oxygenation

BACKGROUND: Optimal unloading strategies for patients with cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation remain uncertain, particularly when comparing Impella and intra-aortic balloon pump (IABP). We aimed to compare outcomes of patients receiving Impella or IABP during venoarterial extracorporeal membrane oxygenation and evaluate cause-specific differences. METHODS: In this retrospective cohort study using the nationwide JROAD-DPC (Japanese Registry of All Cardiac and Vascular Diseases-Diagnosis Procedure Combination) database from 2012 to 2023, patients with cardiogenic shock treated with venoarterial extracorporeal membrane oxygenation and either Impella or IABP were analyzed. Propensity score-based inverse probability of treatment weighting was applied to adjust baseline differences. RESULTS: Among 18 906 patients (Impella, n=1688; IABP, n=17 218), overall in-hospital mortality was 57.3% with Impella and 67.2% with IABP. Impella use was associated with lower in-hospital mortality compared with IABP (odds ratio OR, 0.86 95% CI, 0.75-0.99). Cause-specific analyses showed significantly lower mortality with Impella in heart failure (OR, 0.66 95% CI, 0.47-0.91) and arrhythmia (OR, 0.62 95% CI, 0.42-0.91). Impella use was also associated with longer hospital stay (median, 22 versus 12 days), longer support duration (7 versus 4 days), and higher total costs (56.1 versus 27.3 thousand USD). CONCLUSIONS: In this nationwide cohort, Impella unloading during venoarterial extracorporeal membrane oxygenation was associated with lower in-hospital mortality than IABP in the overall cohort, particularly in selected causes, at the expense of prolonged hospitalization and higher costs. Further studies are needed to define optimal cause-specific unloading strategies in cardiogenic shock.