Clinical outcomes of impella compared with intra-aortic balloon pump support in cardiogenic shock: a systematic review and meta-analysis

Cardiogenic shock remains associated with mortality despite advances in revascularization and critical care. Although Impella provides greater hemodynamic support than intra-aortic balloon pump (IABP), comparative outcomes remain uncertain. We conducted a systematic review and meta-analysis comparing Impella with IABP in adults with cardiogenic shock. PubMed/MEDLINE, Embase, and Cochrane CENTRAL were searched from inception through August 2026. Randomized controlled trials and observational studies comparing Impella with IABP were included. Secondary outcomes included recurrent myocardial infarction, renal replacement therapy (RRT), major bleeding, stroke, vascular complications, and mortality with major bleeding. Random-effects models generated pooled risk ratios (RRs) with 95% confidence intervals (CIs). Prespecified subgroup analyses examined study design and Impella device type. Eleven studies comprising 36,023 participants were included. Impella was associated with higher all-cause mortality than IABP (RR 1.32, 95% CI 1.17–1.48; I 2 = 90.7%). Mortality did not differ significantly in randomized trials, with differences between study-design subgroups ( P = 0.0022). Impella was associated with increased RRT (RR 2.56, 95%CI 1.27–5.18), major bleeding (RR 1.64, 95% CI 1.42–1.90), stroke (RR 1.47, 95%CI 1.25–1.74), and vascular complications (RR 3.30, 95% CI 2.68–4.06). Mortality with major bleeding was also higher with Impella (RR 1.34, 95%CI 1.17–1.54). Recurrent myocardial infarction did not differ significantly (RR 0.76, 95%CI 0.40–1.46). Impella was associated with higher mortality and adverse outcomes compared with IABP. However, the mortality association was not observed in randomized evidence, highlighting potential confounding in observational studies. Further randomized comparisons of contemporary Impella CP and IABP are warranted. PROSPERO ID: (CRD420261428842).