Influence of timing of impella insertion on the prognosis of acute myocardial infarction complicated with cardiogenic shock requiring ECPELLA
Authors: Shimamoto K S , Nishikawa R N , Watanabe S W , Ono K O 
Published: October 2024

Abstract

Background/Introduction
In patients with cardiogenic shock (CS), a combination of Impella-a percutaneous ventricular assist device with a catheter-type micro-axial heart pump-and venoarterial extracorporeal membrane oxygenation (ECPELLA) has been reported to have a better prognosis compared to venoarterial extracorporeal membrane oxygenation (VA-ECMO) alone, although it was associated with more complications. In contemporary clinical practice, ECPELLA has often been used in place of VA-ECMO alone. However, in many cases of acute myocardial infarction (AMI) with CS, there is controversy regarding the prioritization of Impella or VA-ECMO installation.

Purpose
The current study aims to clarify the factors of Impella use before VA-ECMO, the impact of the timing of Impella insertion (before or after VA-ECMO) for 30-day mortality, and major adverse events (MAEs) in the two groups.

Methods
The Japanese registry for Percutaneous Ventricular Assist Device (J-PVAD) Registry is a nationwide registry enrolling 5,718 consecutive Japanese patients treated with Impella between February 2020 and December 2022. The current study population consisted of 1,082 patients with AMI complicated by CS excluding cardiopulmonary arrest on arrival or using only Impella, who were divided into 2 groups; Impella use before and after VA-ECMO.

Results
Among the current study population, 323 patients (30%) used Impella before VA-ECMO, and 759 patients (70%) used Impella after VA-ECMO. Patients who used Impella before VA-ECMO were older (72 vs. 68 years old, P&lt;0.0001) and had higher left ventricular ejection fraction (LVEF) (30 vs 20 %, P&lt;0.0001), lower lactate level (5.6 vs 9.1 mmol/L, P&lt;0.0001), and more often ST-elevation myocardial infarction (MI) (82% vs 76%, P&lt;0.0001), whereas those patients had less often out-of-hospital cardiac arrest (OHCA) (13% vs 45%, P&lt;0.0001), in-hospital cardiac arrest (IHCA) (27% vs 63%, P&lt;0.0001), and prior heart failure (9.5% vs 16%, P=0.006). The factors of Impella use before VA-ECMO were 75 years or older, dyslipidemia, the absence of OHCA, the absence of IHCA, the absence of prior MI, and the absence of LVEF less than 30%. The cumulative 30-day incidence of all-cause death was 46.2% in patients with Impella use before VA-ECMO and 53.4% in those with Impella use after VA-ECMO (Log-rank P=0.02). After adjusting confounders, there was no excess risk of Impella use before VA-ECMO relative to Impella use after VA-ECMO (adjusted HR, 0.87; 95%CI, 0.55-1.37; P=0.55). Regarding major adverse events, hemolysis was significantly more frequent in patients with Impella use before VA-ECMO, while stroke was significantly more common in patients with Impella use after VA-ECMO.

Conclusions
The prognosis with AMI complicated by CS requiring ECPELLA remained poor. The 30-day mortality was lower in patients with Impella use before VA-ECMO compared to after VA-ECMO. However, after adjusting for confounders, there was no difference between the two groups.