Safety and mid-term outcomes of impella compared to intra-aortic balloon pumping in patients who required mechanical cardiac support

Abstract Background Impella (Abiomed USA) is a promising alternative to improve prognosis in patients with cardiogenic shock requiring mechanical cardiac support (MCS). Despite of its advanced hemodynamic profile, its superiority regarding prognosis has not been established yet. Aims The aims of this study were to investigate safety and mid-term outcomes of Impella compared to IABP in patients who required MCS. Methods In this single-center study, consecutive 205 patients who required IABP or Impella from January 2017 to June 2023 were evaluated retrospectively. The primary outcome was 180-day mortality. Secondary outcomes were the rate of complications including hemolysis, thrombocytopenia, bleeding, limb ischemia, acute kidney impairment and stroke. Major complication was defined as major bleeding (BARC 3-5), limb ischemia and stroke. Results Of all patients, 62 (30.2%) received Impella and 143 (69.8%) IABP. The rate of patients required extracorporeal membrane oxygenation (ECMO) support was not significantly different between two groups (31.4 % vs 38.7%; p=0.34. There were no significant differences in 180-day mortality between two groups (36.2% vs 31.1%; p=0.55). Further investigation according to SCAI classification demonstrated that the mortality rate in SCAI C group was significantly lower in Impella than IABP group (34.1% vs 6.7%; p=0.02), whereas there were not significant differences in mortality between two groups in SCAI D and E groups (54.8% vs 61.4%; p=0.71). The rate of major complications was significantly higher in Impella group (54.4% vs 72.1%; p=0.02). The rate of hemolysis (19.6% vs. 58.1%, p<0.01), thrombocytopenia (19.6% vs. 58.1%, p<0.01), limb ischemia (4.3% vs. 17.7%, p<0.01), acute kidney impairment (37.7% vs 64.5%, p<0.01) and initiation of renal replacement therapy (13.8% vs 29%, p=0.02) were significantly higher in Impella group. Multivariate analysis adjusting for Impella use, out of hospital cardiopulmonary arrest (OHCPA), initial lactate ≥60 md/dL and major complication, revealed that age ≥70 (hazard ratio (HR): 3.1, 95%CI: 1.73-5.61) and use of ECMO (HR: 4.3, 95%CI: 2.54-7.31) were independent predictor of mortality. The mortality rate arose up to 83.3% in patients with age ≥70, OHCPA and use of ECMO (HR: 9.7, 95%CI: 4.07-23.02). Conclusion The mortality rate did not differ between Impella and IABP, however Impella was associated with improved mortality in patients with SCAI C group. The complications were high likely seen in patients with Impella compared to IABP. Our findings indicate that Impella results in better outcomes with careful selection of patients, defining its indication and appropriate care. A further investigation would be of value to elucidate whether Impella improve prognosis.