Impella <i>vs</i> intra-aortic balloon pump in patients with acute myocardial infarction complicated with cardiogenic shock: an updated systematic review and meta-analysis

Cardiogenic shock (CS) is a major cause of mortality in patients with acute myocardial infarction (AMI). Mechanical circulatory support devices like Impella and Intra-Aortic Balloon Pump (IABP) manage AMI-CS, but their comparative effectiveness remains unclear. We conducted a meta-analysis following Cochrane and PRISMA guidelines. From the database inception until March 2024, we searched databases including PubMed, Google Scholar, and the Cochrane Library for studies comparing Impella and IABP in AMI-CS patients. Risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes were calculated using a random-effects model. Nine studies involving 18,289 patients were included and the mean age of patients in the Impella group was 64.79 years, and 64.75 years in the IABP group. Short-term mortality showed no significant difference between Impella and IABP (RR: 1.13, 95% CI: 0.84-1.52, p=0.42, I²=76%). Impella was associated with higher risks of hemolysis (RR: 9.46, p=0.009), limb ischemia (RR: 3.65, p=0.003), transfusion (RR: 2.03, p< 0.0001), and acute kidney injury (RR: 1.22, p=0.04). Meta-regression indicated that peripheral arterial disease, prior PCI, and left ventricular ejection fraction were significant covariates for short-term mortality. Our meta-analysis found no significant difference in short-term mortality between Impella and IABP in AMI-CS patients. In contrast, Impella is associated with higher risks of hemolysis, limb ischemia, transfusion needs, and acute kidney injury. Peripheral arterial disease, prior PCI, and lower LVEF were significantly associated with short-term mortality, with PAD and prior PCI increasing risk, while higher LVEF demonstrated a protective effect.