Introduction: Intra-aortic balloon pump (IABP) is a mechanical device that increases cardiac output by increasing diastolic blood flow to the coronary arteries and lowers the afterload of the left ventricle in systole. IABP is primarily used in acute heart failure, that includes patients that have to undergo coronary artery bypass grafting (CABG). Its usage, however, in cardiac surgery has been declining with ongoing controversy regarding its benefits. The aim of this study was to assess the use and indications and outcome of IABP related to CABG surgery.

Material and Methods: The study was retrospective and included 2177 patients that underwent CABG at Landspítali during 2001-2018. We compared those who received an IABP with controls, using uni- and multivariate analysis. Long term survival and complications (major adverse cardiovascular and cerebral events, MACCE) was estimated with Kaplan-Meier method.

Results: A total of 99 (4.5%) patients received an IABP. The incidence was highest in 2006 (8.9%) and lowest in 2001 (1.7%), but the incidence did not change during the study period (p=0.90). Most patients received the pump before (58.6%) or during (34.3%) CABG, but only 6.1% after surgery. Complication rate was 14.1%, with bleeding from the insertion site in the groin being the most common complication. Thirty day mortality was higher in the IABP group compared with controls (22.2% vs 1.3%, p<0.001) and both 5-year survival (56.4% vs 91.5%, 95% CI: 0.47-0.67) and 5-year MACCE-free survival (46.9% vs 83.0%, 95% CI: 0.38-0.58) were inferior.

Conclusions: Less than 5% of patients received IABP in relation to CABG in Iceland and the rate hasn't changed much for the last 18 years. Both the complication rate and 30-day mortality was higher in patients in IABP group and both the long term and MACCE-free survival was much worse, probably mostly related to worse overall clinical condition of the patient that received IABP.

Table I . Comparison of background factors between groups. Mean ± standard deviation or number of cases (%) are shown.

Table II . Comparison of primary risks of coronary artery disease and operation related factors. Mean ± standard deviation or number of cases (%) are shown.

Table III . Predictors of intra-aortic balloon pump insertion, determined with logistic regression. Odds ratios (OR) and 95% confidence interval (CI) are shown.

Table IV . Comparison of short term complications, total hospital stay and 30-day mortality. Mean ± standard deviation or number of cases (%) are shown.

Table V . Incidence of complications related to the insertion or use of IABP. Number of patients is shown (%). No patients had more complications simultaneously.

Figure 1. Intra aortic balloon pump (IABP) is usually insterted via femoral artery and the tip of the balloon positioned below the left subclavian artery. The balloon is deflated in systole and inflated in diastole.

Figure 2a. Incidence of IABP usage in cardiac surgery per year during 2001-2018. The incidence did not change significantly during the study-period (p=0.896)

Figure 2b. Time of IABP insertion.

Figure 3. Comparison of overall survival in IABP and control group (Kaplan Meier) ( p <0,001, log-rank test).

Figure 4. Comparison of MACCE-free survival between groups (Kaplan Meier) (p <0,001, log-rank test).