Impella Versus Intra‐Aortic Balloon Pump in Patients With Cardiogenic Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation: An Observational Study

Background Venoarterial extracorporeal membrane oxygenation (VA‐ECMO) is increasingly used for patients with cardiogenic shock. Although Impella or intra‐aortic balloon pump (IABP) is frequently used for left ventricular unloading (LVU) during VA‐ECMO treatment, there are limited data on comparative outcomes. We compared outcomes of Impella and IABP for LVU during VA‐ECMO. Methods and Results Using the Nationwide Readmissions Database between 2016 and 2020, we analyzed outcomes in 3 groups of patients with cardiogenic shock requiring VA‐ECMO based on LVU strategies: extracorporeal membrane oxygenation (ECMO) only, ECMO with IABP, and ECMO with Impella. Of 15 980 patients on VA‐ECMO, IABP and Impella were used in 19.4% and 16.4%, respectively. The proportion of patients receiving Impella significantly increased from 2016 to 2020 (6.5% versus 25.8%; P ‐trend<0.001). In‐hospital mortality was higher with ECMO with Impella (54.8%) compared with ECMO only (50.4%) and ECMO with IABP (48.4%). After adjustment, ECMO with IABP versus ECMO only was associated with lower in‐hospital mortality (adjusted odds ratio [aOR], 0.83; P =0.02). ECMO with Impella versus ECMO only had similar in‐hospital mortality (aOR, 1.09; P =0.695) but was associated with more bleeding (aOR, 1.21; P =0.007) and more acute kidney injury requiring hemodialysis (aOR, 1.42; P <0.001). ECMO with Impella versus ECMO with IABP was associated with greater risk of acute kidney injury requiring hemodialysis (aOR, 1.49; P =0.002), higher in‐hospital mortality (aOR, 1.32; P =0.001), and higher 40‐day mortality (hazard ratio, 1.25; P <0.001). Conclusions In patients with cardiogenic shock on VA‐ECMO, LVU with Impella, particularly with 2.5/CP, was not associated with improved survival at 40 days but was associated with increased adverse events compared with IABP. More data are needed to assess Impella platform‐specific comparative outcomes of LVU.