Is low ejection fraction safe for off-pump coronary bypass operation?

Background: Does the manipulation of the heart during off-pump coronary artery bypass (OPCAB) procedure further compromise the hemodynamic stability of a patient with depressed left ventricular function compared with the conventional coronary artery bypass (CCAB) approach? Does this manipulation induce a more dramatic hypoperfused state that may contribute to an increase in the incidence of related complications or mortality? This retrospective review of data attempted to answer the above concern.

Methods: Between January 1, 1998, and June 30, 1999, 177 patients with ejection fractions of 30% or less underwent full sternotomy coronary artery bypass grafting at our institution. Of these patients, 45 underwent OPCAB procedures and 132 patients underwent CCAB. Pre-, intra-, and postoperative variables as identified by The Society of Thoracic Surgeons National Cardiac Surgery Database were compared using univariate and logistical regression analysis.

Results: Despite recognized hemodynamic derangement during cardiac displacement, these groups of OPCAB patients appeared to tolerate the procedure well. Univariate analysis of cardiac enzyme leak and blood loss was statistically significant in the OPCAB patients. Utilizing regression analysis, cardiopulmonary bypass was the only predictor for all postoperative complications.

Conclusions: Multivessel coronary artery bypass utilizing the OPCAB approach in patients with depressed left ventricular function of equal to or less than 30% is appropriate and applicable. Analysis of CCAB and OPCAB variables was nonsignificant except for operative and postoperative blood loss and peak cardiac enzyme leak. Attention to intraoperative detail and hemodynamic management could be credited for the success with OPCAB.