Reoperative coronary artery bypass grafting with and without cardiopulmonary bypass: determinants of perioperative morbidity and mortality.

Background: This retrospective study evaluates perioperative results of reoperative coronary artery bypass grafting (CABG) with and without cardiopulmonary bypass (CPB).

Methods: From January 1995 to March 1999 reoperative CABG was performed on 581 patients: 307 (52.84%) patients were operated upon on-CPB and 274 (47.16%) off-CPB. Median sternotomy was used in all patients on-CPB. Median sternotomy or alternative surgical approaches were used in the off-CPB group. Data was retrospectively reviewed. To identify the variables independently related to perioperative mortality and adverse outcome, multivariate analysis was performed in the overall population of 581 patients.

Results: Preoperative risk factors were comparable in the two groups. Critical lesions of the right and left circumflex coronary artery were more common in the on-CPB group (p < 0.005). A total of 2.7 grafts/patient was performed in the on-CPB group versus 1.3 grafts/patient in the off-CPB group (p = NS). Freedom from postoperative complications was higher in the off-CPB group (72% versus 90.9%, p < 0.005). Perioperative stroke and respiratory failure rates were more common in the on-CPB group (3.9% versus 0.7% and 5.9% versus 2.2% respectively, p < 0.005). Actual mortality was 5.9% in the on-CPB group and 3.6% in the off-CPB group (p = NS). Risk adjusted mortality was 2.2% and 1.3% in the on-CPB and off-CPB groups respectively. Although CPB was found to be independently related to adverse outcome (odds ratio (OR) = 2.89, p-value < 0.005), no correlation was found between mortality and CPB.

Conclusions: Avoidance of CPB independently reduces adverse outcomes in reoperative CABG without affecting mortality rate.