Abstract Body (Do not enter title and authors here): Introduction: Impella CP (Abiomed, Danvers, MA) microaxial flow pumps are commonly used in acute myocardial infarction (AMI) and heart failure (HF) cardiogenic shock (CS). Contemporary data from large, unselected populations are needed to understand differences between these groups.

Hypothesis: Differences in patient and hospitalization characteristics such as device exposure and shock complications may contribute to differences in outcomes between those with AMI-CS compared to HF-CS.

Methods: The Cardiogenic Shock Working Group (CSWG) registry enrolls patients with CS at 36 international sites. We analyzed patients with CS and Impella CP enrolled from 2019-2024, categorized by CS etiology and mechanical support device exposure. Baseline characteristics, complications, and outcomes were compared. Outcomes included survival to discharge, native heart survival, and heart replacement therapy. Multivariable analysis was performed to identify predictors of mortality and complications.

Results: 1486 patients with CS (34.9% HF-CS, 57.9% AMI-CS) and Impella CP were analyzed. Patients with HF-CS were younger (60 vs 64 years), more often had chronic kidney disease (26.4% vs 13.6), less commonly had cardiac arrest (13.3% vs 27.6%), and less commonly had CSWG-SCAI stage E CS (45.7% vs 57.2%) than those with AMI-CS (p<0.001 for all). Impella CP alone was used in 38.3%. Multi-device strategies (sequential or concurrent) included CP+IABP in 9.8%, CP+Impella 5.0/5.5 in 8.3%, CP+ECMO in 23.1%, and CP+≥2 other devices in 20.4%. Impella CP alone was the most common device strategy in both HF-CS (37.9%) and AMI-CS (38.9%) followed by CP+ECMO (26.4% and 20.8%). Acute kidney injury and renal replacement therapy were more common in HF-CS than AMI-CS (66.5% vs 59.7%, p=0.03 for AKI; 40.5% vs 32.7%, p=0.002 for RRT). Acute limb ischemia was less common in HF-CS than in AMI-CS (11.0% vs 14.4%; p=0.05), with no difference in bleeding (36.8% vs 41.7%; p=0.08). Survival to discharge was 53.4% and was higher in HF-CS than AMI-CS (59.7% vs 49.8%; p<0.001). Patients supported by Impella CP+≥2 other devices had the lowest survival (43.8%). Multivariable modeling revealed several factors that were significantly associated with mortality, limb ischemia, and bleeding (Figure).

Conclusion:
Differences in baseline characteristics, shock severity, mechanical device exposure, and hospital complications between patients with HF-CS and AMI-CS supported by Impella CP may influence outcomes.