Abstract 9449: Extracorporeal Membrane Oxygenation versus Impella in Patients with Cardiogenic Shock from Inferior Wall Myocardial Infarction: Analysis from the National Inpatient Sample

Abstract

Introduction: Since the IABP-SHOCK II trial, extracorporeal membrane oxygenation (ECMO), and the percutaneous ventricular assist device, Impella have emerged as the preferred mechanical circulatory assist devices for cardiogenic shock (CS). Studies have shown similar clinical outcomes with Impella and ECMO in patients with CS from unspecified myocardial infarction (MI) locations; however, data in patients with inferior wall MI is lacking. Hypothesis: ECMO is associated with an increased likelihood of adverse inpatient complications and medical costs compared to Impella in patients with CS from an inferior wall MI. Methods: We queried the National Inpatient Sample (NIS) from 2016-2018 to identify patients 18 years and older with a discharge diagnosis of CS from inferior wall MI who underwent ECMO or Impella placement. To mitigate selection bias, 8-to-1 propensity scoring was used to select matched samples between patients with ECMO and patients with Impella. The scoring was based on a multivariate logistic regression model accounting for age, gender, race, hospital type, income, and medical comorbidities. Results: We identified 638 patients with inferior wall MI resulting in CS, 15% (n=96) underwent ECMO and 85% (n=542) received Impella. ECMO was not associated with increased inpatient mortality (52% vs 50.7%; p=0.86) or cardiac arrest (24% vs 15%, p=0.09) when compared to Impella. After applying the multivariate logistic regression model, ECMO was not associated with an increased risk for acute kidney injury (OR 0.67; 95% CI 0.28-1.6, p=0.36), cerebrovascular events (OR 1.06; 95% CI 0.33-3.36, p=0.92), cardiac tamponade (OR 6.85; 95% CI 0.89-52.83, p=0.06) or CPR (OR 1.89; 95% CI 0.9-3.98; p=0.09). However, ECMO was associated with increased blood transfusions (OR 3.56; 95% CI 0.26-10.06, p=0.02), increased length of hospitalization (13.2 days vs 9.4 days; p<0.0001), and medical costs ($501,435 vs 403,120, p<0.0001). Conclusions: Our study demonstrates that ECMO is not associated with increased mortality in patients with CS from inferior wall MI compared to Impella, although Impella remains the more cost-effective choice in these patients. Future randomized studies are warranted comparing these circulatory assist devices in patients with CS.