Preoperative Intra-Aortic Balloon Pumps in Cardiac Surgery: A Propensity Score Analysis

Introduction: The role of intra-aortic balloon pumps (IABP) in high-risk patients undergoing coronary artery bypass graft (CABG) surgery remains controversial. We report the 5-year experience from a new Australian centre. Methods: We retrospectively analysed 690 patients undergoing urgent isolated CABG surgery at a Western Australian tertiary centre from February 2015 to May 2020. De-identified data was obtained from the Australia & New Zealand Society of Cardiothoracic Surgeons database. Patients were stratified according to preoperative IABP use. A propensity score was created for the probability of IABP use and a propensity adjusted analysis was performed using logistic regression. The primary outcome was 30-day mortality. Secondary outcomes were postoperative inhospital outcomes. Results: Preoperative IABP was used in 78 patients (11.3%). After propensity score adjustment, in a subgroup of patients with reduced ejection fraction or left main disease, 30-day mortality (7.0% vs 2.0%, OR 6.03, 95% CI 1.89–19.28, p=0.002) was significantly higher in the IABP group. Red blood cell transfusions (19.7% vs 12.6%, OR 1.86, 95% CI 1.02–3.35, p=0.039), prolonged inotrope use (78.9% vs 50.9%, OR 6.11, 95% CI 2.77–13.48, p<0.001), prolonged invasive ventilation (28.2% vs 3.4%, OR 20.2, 95% CI 8.24–49.74, p<0.001), mesenteric ischaemia (2.8% vs 0%, OR 4.52, 95% CI 1.15–17.77, p=0.031) and multisystem organ failure (1.3% vs 0.7%, OR 25.68, 95% CI 2.55–258.34, p=0.006) were significantly higher in the IABP group. Conclusion: In patients undergoing isolated CABG surgery, preoperative IABP use was associated with increased 30-day mortality and adverse outcomes. Large randomised controlled trials are required to confirm our findings.