Preoperative intra-aortic balloon pump in patients with ST-elevation myocardial infarction undergoing urgent cardiac bypass surgery

Background: In patients with ST-elevation myocardial infarction (STEMI), either with or without cardiogenic shock, mechanical circulatory support with an intra-aortic balloon pump (IABP) is not associated with lower mortality. However, in STEMI patients undergoing urgent coronary artery bypass grafting (CABG), preoperative insertion of an IABP has been suggested to reduce mortality. In this study, the effect of preoperative IABP use on mortality in STEMI patients undergoing urgent CABG was investigated.

Methods: All consecutive STEMI patients undergoing urgent CABG in a single centre between 2000 and 2018 were studied. The primary outcome, 30-day mortality, was compared between patients with and without a preoperative IABP. Subgroup analysis and multivariable analysis using a propensity score and inverse probability treatment weighting were performed to adjust for potential confounders.

Results: A total of 246 patients were included, of whom 171 (69.5%) received a preoperative IABP (pIABP group) and 75 (30.5%) did not (non-pIABP group). In the pIABP group, more patients suffered from cardiogenic shock, persistent ischaemia and reduced left ventricular function. Unadjusted 30-day mortality was comparable between the pIABP and the non-pIABP group (13.3% vs 12.3%, p = 0.82). However, after correction for confounders and inverse probability treatment weighting preoperative IABP was associated with reduced 30-day mortality (relative risk 0.52, 95% confidence interval 0.30-0.88).

Conclusion: In patients with STEMI undergoing urgent CABG, preoperative insertion of an IABP is associated with reduced mortality.