Impella as unloading strategy during VA-ECMO: systematic review and meta-analysis

Area of Science:

• Cardiology
• Mechanical Circulatory Support
• Critical Care Medicine

Background:

• Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) provides circulatory support but increases left ventricle (LV) afterload in cardiogenic shock (CS).
• Impella, a percutaneous micro axial pump, offers a direct LV unloading strategy during VA-ECMO.
• Optimizing VA-ECMO in CS requires evaluating the efficacy and safety of concurrent Impella use.

Approach:

• A meta-analysis systematically searched Medline, Scopus, and Cochrane Library for studies comparing VA-ECMO with and without Impella (ECPELLA) in CS patients.
• The primary endpoint was short-term all-cause mortality.
• Secondary endpoints included major bleeding, hemolysis, renal replacement therapy (RRT), and cerebrovascular accident (CVA).

Key Points:

• The ECPELLA group demonstrated improved survival compared to VA-ECMO alone (RR: 0.86; 95% CI: 0.76, 0.96; p = 0.009).
• LV unloading with Impella during VA-ECMO was associated with significantly reduced mortality, even in homogeneous comparator groups (RR: 0.85; 95% CI: 0.75, 0.97; p = 0.01).
• Higher rates of hemolysis (RR: 1.70; 95% CI: 1.35, 2.15; p < 0.00001) and RRT (RR: 1.86; 95% CI: 1.07, 3.21; p = 0.03) were observed in the ECPELLA group.

Conclusions:

• LV unloading with Impella during VA-ECMO in CS patients is associated with improved survival.
• This strategy increases the incidence of hemolysis and the need for RRT.
• The combination of VA-ECMO and Impella does not appear to increase the risk of major bleeding or CVA.