[The use of preoperative intra-aortic balloon in myocardial revascularization surgery associated to severe...

To evaluate the effectiveness of prophylactic intra-aortic balloon (IAB) in elective myocardial revascularization surgery (MRS), to prevent trans or post-operative infarction and reduce intra-hospital mortality in patients with low left ventricular ejection fraction.

Using a cohort study model, 239 patients with left ventricular ejection fraction < or = 40%, submitted to elective MRS with extracorporeal circulation (ECC) were evaluated from March 1995 to February 2001.

Of these, 58 patients received preoperative IAB and the remainder underwent surgery without circulatory assistance (control group). The two groups of patients had similar characteristics regarding factors associated to the pertaining outcomes. There were five demises (8.6%) in the group with IAB and 21 (11.6%) in the control group (non-significant difference). There were 2 (3.4%) infarctions in the IAB group and 28 (15.5%) in the control group (p< 0.05), relative risk of 0.22 with an interval of confidence of 95% from 0.05 to 0.85.

The use of pre-operative IAB can significantly reduce the risk of trans or post-operative acute myocardial infarction (AMI) in patients with decreased systolic function, without increasing vascular complications. In this same situation, the IAB does not significantly decrease mortality. Randomized studies are necessary to establish more precise conclusions.