Current use of preoperative intra-aortic balloon counterpulsation in high-risk cardiac surgery: a cohort study

To determine whether preoperative introduction of intra-aortic balloon counterpulsation (IABC) reduced mortality in high-risk patients undergoing coronary artery bypass graft (CABG) surgery.

This was a retrospective cohort study of prospectively collected data on all patients who underwent cardiac surgery at a university hospital in Sydney, New South Wales, between 1 January 2002 and 20 August 2007. High risk was defined as the presence of two or more recognised risk factors. We compared the observed mortality to the mortality predicted by the EuroSCORE, and conducted a logistic regression analysis to determine the effect of preoperative IABC on mortality.

Among 358 patients deemed high risk, 36 underwent preoperative IABC. This group had higher EuroSCORE-predicted mortality than the group that did not undergo IABC (38% v 18%, P = 0.008). Despite this, observed mortality was similar for those with and without preoperative IABC (both 2.8%) and was significantly lower than predicted in both groups. This equates to a riskadjusted reduction in mortality associated with the use of preoperative IABC (hazard ratio, 0.47; 95%CI, 0.26-0.84; P = 0.005). This result was not confirmed in the logistic regression analysis, with an adjusted odds ratio for mortality of 0.85 (95% CI, 0.09-7.6; P = 0.88). Rates of postoperative complications, including limb ischaemia, were low and similar in both groups.

In this study of high-risk CABG patients, the use of preoperative IABC in the group with higher predicted mortality was associated with a relative reduction in observed mortality. These data provide cautious support for the use of preoperative IABC in selected high-risk patients.