Impella Support Versus Intra-Aortic Balloon Pump in Acute Myocardial Infarction Complicated by Cardiogenic Shock: A Meta-Analysis

Background: Acute myocardial infarction complicated by cardiogenic shock (AMICS) is associated with high mortality rates. Data has shown that intra-aortic balloon pump (IABP) support does not provide a survival benefit over optimal medical therapy in AMICS. Despite lack of supportive evidence, IABP is still commonly used in these clinical situations. The Impella percutaneous ventricular assist device (PVAD) (Abiomed, Denver, MA) rapidly deploys superior mechanical circulatory support (MCS) in patients with AMICS. However, the safety and efficacy of Impella in AMICS is a matter of ongoing investigation, and its role in AMICS management is not yet fully established. Methods: The databases of Pubmed, EMBASE and Cochrane Central databases were searched from inception to March 2020. Relevant randomized trials and observational studies comparing Impella versus IABP in AMICS were identified and a meta-analysis was performed using the random effect model. The efficacy endpoint of interest was short-term mortality (defined as in-hospital or 30-day mortality). The safety endpoints of interest were major bleeding, limb complications, stroke and hemolysis. Results: A total of 2 randomized trials and 5 observational studies with 3921 patients were included. No difference in short-term mortality between the two groups [RR 1.08, 95% CI 0.87–1.33, P = 0.49] was found. For safety endpoints, Impella was associated with significantly higher incidence of major bleeding [RR: 2.03, 95% CI 1.56–2.64, P < 0.0001], limb complications [RR: 3.67, 95% CI 1.56–8.65, P = 0.003] as well as hemolysis [RR: 9.46, 95% CI 1.75–51.22, P = 0.009] compared with IABP. No significant difference was observed for the incidence of stroke [RR: 1.07 95% CI 0.34–3.31 P = 0.91]. Conclusion: Impella support in AMICS patients was associated with a significantly increased risk of bleeding, limb complications and hemolysis without an improved short-term survival advantage compared with IABP. © 2021