Renal Protection and Hemodynamic Improvement by Impella® Microaxial Pump in Patients with Cardiogenic Shock

Acute kidney injury is one of the most frequent and prognostically relevant complications in cardiogenic shock. The purpose of this study was to evaluate the potential effect of the Impella® pump on hemodynamics and renal organ perfusion in patients with myocardial infarction complicating cardiogenic shock. Between January 2020 and February 2022 patients with infarct-related cardiogenic shock supported with the Impella® pump were included in this single-center prospective short-term study. Changes in hemodynamics on different levels of Impella® support were documented with invasive pulmonal arterial catheter. As far as renal function is concerned, renal perfusion was assessed by determining the renal resistive index (RRI) using Doppler sonography. A total of 50 patients were included in the analysis. The increase in the Impella® output by a mean of 1.0 L/min improved the cardiac index (2.7 ± 0.86 to 3.3 ± 1.1 p < 0.001) and increased central venous oxygen saturation (62.6 ± 11.8% to 67.4 ± 10.5% p < 0.001). On the other side, the systemic vascular resistance (1035 ± 514 N·s/m5 to 902 ± 371 N·s/m5p = 0.012) and the RRI were significantly reduced (0.736 ± 0.07 to 0.62 ± 0.07 p < 0.001). Furthermore, in the overall cohort, a baseline RRI ≥ 0.8 was associated with a higher frequency of renal replacement therapy (71% vs. 39% p = 0.04), whereas the consequent reduction of the RRI below 0.7 during Impella® support improved the glomerular filtration rate (GFR) during hospital stay (15 ± 3 days; 53 ± 16 mL/min to 83 ± 16 mL/min p = 0.04). Impella® support in patients with cardiogenic shock seems to improve hemodynamics and renal organ perfusion. The RRI, a well-known parameter for the early detection of acute kidney injury, can be directly influenced by the Impella® flow rate. Thus, a targeted control of the RRI by the Impella® pump could mediate renal organ protection.