Objectives: Mortality rates in patients with acute myocardial infarction and cardiogenic shock (AMI-CS) remain persistently high despite advances over the past decade in percutaneous mechanical circulatory support. This systematic review aims to analyse the existing literature to compare mortality outcomes in patients mechanically supported by intra-aortic balloon pump or percutaneous Impella 2.5/CP© for AMI-CS undergoing emergency revascularisation. Methods: The following MeSH terms were applied to the databases Ovid Medline, Ovid Embase, Cochrane and Web of Science: ‘Intra-aortic balloon pump’, ‘Impella’, ‘Cardiogenic shock’, ‘Myocardial Infarction’ and ‘Mortality’. This yielded 2643 studies. Using predefined inclusion and exclusion criteria, the studies were initially screened by title and abstract before full text analysis. Results: Fourteen studies met eligibility criteria: two randomised controlled trials (RCTs) and 12 observational studies. Data from a total of 21,006 patients were included across the studies. Notably, one study claimed reduced mortality with IABP versus control, and one study concluded that Impella© improved survival rates over the IABP. The average 30-day all-cause mortality in patients supported by IABP was 38.1%, 54.3% in Impella© groups and 39.4% in control groups. Conclusion: AMI-CS presents an important cohort of patients in whom conducting RCTs is difficult. As a result, the literature is limited. Analysis of the available literature suggests that there is insufficient evidence to support superior survival in those supported by IABP or Impella© when compared to control despite suggestions that the Impella© offers superior haemodynamic support. Limitations of the studies have been discussed to outline suggestions for future research.
Intra-aortic balloon pump in patients with cardiogenic shock complicating myocardial infarction: a systematic review and meta-analysis of randomized trials (protocol)
