The effect of treatment srategy for acute myocardial infarction complicated by cardiac shock using Impella in accordance with institutional protocol

Abstract Backgrounds Team-based care for cardiogenic shock (CS) using mechanical circulatory support (MCS) including Impella in accordance with standardized protocol was reported to improve the prognosis of patients with CS. Methods Between February 2018 and September 2022, we performed percutaneous coronary intervention (PCI) in 63 patients with acute myocardial infarction (AMI) complicated by CS using Impella. We introduced institutional protocol (Figure 1) to standardize the treatment strategy for CS from June 2019, in which early Impella implantation preceding PCI was recommended. We retrospectively examined the incidence of Impella implantation preceding PCI, in-hospital outcomes including the rates of survival to Impella weaning and to discharge, and the incidence of major cardiovascular events (MACE) including all death, MI, and hospitalization for heart failure at 1-year before and after protocol introduction. Results The patients have a mean age of 67.1±13.2 years and 53 patients (84.1%) were male. The patients in preceding period were 16 cases, while 47 in latter period. The rate of Impella implantation preceding PCI was significantly higher in latter period than that in preceding period (61.7% vs. 25%, p=0.027) (Figure 2A). The rate of survival to Impella weaning was significantly higher in latter period than that in preceding period (83% vs. 56.3%. p=0.043). There was no difference in the rate of survival to discharge between each period (50% in preceding period vs. 68.1% in latter period, p=0.236). However, the cumulative MACE free survival rate was significantly higher in latter period than that in preceding period (56.9% vs. 31.3%, Log-rank p=0.020) (Figure 2B). Conclusion The introduction of institutional standardized protocol of MCS use might improve 1-year outcomes of patients with AMI complicated by CS treated with Impella.Figure 1Figure 2