Timing of initiation of intra‐aortic balloon pump in patients with acute myocardial infarction complicated by cardiogenic shock: A meta‐analysis

BACKGROUND: For patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) undergoing primary percutaneous coronary intervention (PCI), the optimal timing of the initiation of intra‐aortic balloon pump (IABP) therapy remains unclear. Therefore, we performed the first meta‐analysis to compare the outcomes of IABP insertion before vs after primary PCI in this population. METHODS: Electronic databases of PubMed, EMBASE, and Cochrane Library were comprehensively searched from inception to April 1, 2019, to identify the eligible studies. The main outcomes were short‐term (in‐hospital or 30 days) and long‐term (≥ 6 months) mortality. In addition, pooled analysis of risk‐adjusted data were also performed to control for confounding factors. RESULTS: Seven observational studies and two sub‐analysis of randomized controlled trials involving 1348 patients were included. Compared to patients inserted IABP after PCI, patients who received IABP therapy before primary PCI had similar risks of short‐term (odds ratio [OR] 0.88, 95% CI 0.49 to 1.59) and long‐term (OR 0.99, 95% CI 0.58 to 1.68) all‐cause mortality. Moreover, a pooled analysis of risk‐adjusted data also found similar effects of the two therapies on short‐term (OR 0.65, 95% CI 0.34 to 1.25) and long‐term (OR 0.68, 95% CI 0.17 to 2.72) mortality. Besides, no significant difference was found between the two groups with respect to reinfarction, repeat revascularization, stroke, renal failure, and major bleeding. CONCLUSIONS: The timing of the initiation of IABP therapy does not appear to impact short‐term and long‐term survival in patients with AMI complicated by CS undergoing primary PCI.