IABP before cardiac surgery: clinical benefit compared to intraoperative implantation

The aim of this study was to determine whether preoperative compared to intraoperative intra-aortic balloon counterpulsation (IABP) is advantageous regarding 30-day and 2-year survival in high-risk patients (acute myocardial infarction, severely impaired left ventricular ejection fraction (LVEF), low output syndrome) undergoing coronary surgery.

In the years 2004 to 2008, 156 consecutive patients undergoing coronary surgery with IABP support (119 preoperative, 37 intraoperative IABP) were observed. Applying Fisher's exact test, as well as Wilcoxon and median tests, possible group differences were evaluated. After univariate analysis, models of logistic regression and Cox-regression were built.

Preoperative hemodynamic state and risk profile of the two patient groups were comparable: patients with preoperative IABP showed a similar level of urgency (21.9% vs. 18.9% emergencies), cardiogenic shock (8.4% vs. 10.8%), inotropes (8.4% vs. 8.1%), impaired LVEF (30.3% vs. 29.7%) and ventilation (5.9% vs. 5.4%) compared to patients with intraoperative IABP. Nevertheless, patients with intraoperative IABP demonstrated a significantly higher 30-day mortality rate (37.8% vs. 5.9%) and 2-year mortality rate (54.0% vs. 18.1%) compared to patients with preoperative IABP. Logistic regression revealed that patients with intraoperative IABP have a 16-times higher 30-day mortality rate after coronary surgery (OR: 16.386, 95% CI: 4.858-55.266) than patients with preoperative IABP. Two-year mortality (OR: 9.317, 95% CI: 3.430 to 25.311) and survival time were significantly better in patients with preoperative IABP therapy.

Considering the significant benefit for patients with preoperative compared to intraoperative IABP and the absence of vascular problems after IABP insertion, the results of this study indicate a more liberal indication for IABP in high-risk patients before coronary bypass surgery.