A Systematic Review and Meta‐Analysis of the Efficacy and Safety of Combined Mechanical Circulatory Support in Acute Myocardial Infarction Related Cardiogenic Shock

Background
Acute myocardial infarction-related cardiogenic shock (AMICS) is a severe complication associated with exceedingly high mortality rates. While mechanical circulatory support (MCS) has emerged as a potential intervention, the evidence base for independent MCS use remains weak. In contrast, systematic reviews of observational studies have revealed significant mortality reduction when a combination of MCS was used: VA-ECMO in conjunction with a left ventricular (LV) unloading device (Impella or IABP). The ongoing dilemma concerning the selection between two LV unloading devices (VA-ECMO + Impella vs. VA-ECMO + IABP) warrants further investigation and clarification.

Aim
This is the first systematic review and meta-analysis assessing the short-term efficacy and safety of VA-ECMO + Impella versus VA-ECMO + IABP in treatment of AMICS.

Methods
A systematic search was performed on the EMBASE, MEDLINE, and Cochrane databases. Studies reporting the short-term (30-day/inpatient) mortality and complications of adult patients with AMICS treated with VA-ECMO + Impella and VA-ECMO + IABP were included. Subgroup analysis was performed including studies with ACS predominant CS (CS etiology 100% by AMI).

Results
Four observational studies with 14,247 patients were included. There was no significant difference in mortality between VA-ECMO + Impella and VA-ECMO + IABP (56.5% vs. 66.5%; OR, 0.90; 95% CI, 0.79−1.02; p = 0.09). However, VA-ECMO + Impella was associated with significantly lower mortality in patients with ACS predominant CS (53.2% vs. 67.7%; OR, 0.72; 95% CI, 0.62−0.85; p < 0.0001). VA-ECMO + Impella was concomitantly associated with a significantly higher risk of complications.

Conclusions
When comparing LV unloading devices in patients with AMICS requiring a combination of MCS, VA-ECMO + Impella was superior in mortality reduction only in the cohort where 100% of CS was caused by AMI.