Intraaortic balloon pump in patients with cardiogenic shock complicating myocardial infarction. A systematic review and meta-analysis of randomized trials

INTRODUCTION: Cardiogenic shock is associated with significant mortality, particularly when caused by myocardial infarction. Intraaortic balloon pump (IABP) is the primary hemodynamic adjunct in patients with cardiogenic shock; however, evidence suggests that IABP may not improve mortality in this population. METHODS: We conducted an electronic search of the Medline, EMBASE, and Cochrane trial registry databases. Two reviewers independently screened citations and identified eligible trials. The same reviewers abstracted data independently. We pooled the data using a fixed effect model and reported dichotomous outcomes as risk ratios (RRs) with 95% confidence intervals (CIs). Subsequently, we used the GRADE approach to judge the quality of evidence. RESULTS: We included 4 randomized trials with 735 patients. The use of IABP did not reduce the risk of death in patients with cardiogenic shock secondary to cardiac ischemia when compared with usual care (RR, 0.94; 95% CI, 0.79-1.13; P = 0.52; I² = 0%; moderate confidence). The use of IABP was not associated with an increased risk of stroke (RR, 0.77; 95% CI 0.22-2.69; P = 0.68; I² = 48%; very low confidence), limb ischemia (RR, 1.24; 95% CI, 0.59-2.59; P = 0.58; I² = 0%; low confidence), or major bleeding (RR, 0.76; 95% CI, 0.34-1.72; P = 0.52; I² = 0%; low confidence). CONCLUSIONS: The use of IABP in patients with cardiogenic shock complicating myocardial ischemia does not reduce mortality (moderate confidence) and is not associated with a higher risk of complications (very low to low confidence). The results should be interpreted with caution owing to limitations such as imprecision, risk of bias, and clinical heterogeneity.