Objective: This study compares preoperative risk factors, estimated, observed, and risk adjusted mortality, and postoperative complications in patients undergoing coronary artery bypass grafting. Patients were divided in two groups depending on operative method: Group A patients had coronary artery bypass grafting using cardiopulmonary bypass. In group B cardiopulmonary bypass was not utilized. Patients operated on between January 1 1995 and August 31 1996 were compared. Group A consisted of 1829 patients and Group B 172.
Methods: Patients were selected to undergo coronary artery bypass grafting without the use of cardiopulmonary bypass either because the surgeon felt that there were contraindications to--or no need for the heart-lung machine. The decision to avoid the use of cardiopulmonary bypass was taken pre-operatively by the individual surgeon. Median sternotomy, formal left thoracotomy or left anterior small thoracotomy were used. The data was collected and validated by the hospital's professional data collectors. Data-analysis was performed using the NY-state database.
Results: Previous heart surgery and extensively calcified ascending aorta were significantly more common in Group B as was estimated and observed mortality. This resulted in identical risk-adjusted mortality of 2.8%. When reoperations were reviewed separately risk adjusted mortality was lower in Group B (2.1 versus 3.1%) but this difference was not statistically significant. Cardiovascular-and other-complications were higher in group A patients. In reoperative patients this difference was significant (P = 0.05). The need for postoperative mechanical assistance was also reduced (Group A: 14.9% versus Group B: 1.3% P = 0.01).
Conclusion: We conclude that coronary artery bypass surgery can be done safely in selected patients without cardiopulmonary bypass. Mortality is unchanged and complications are less frequent. Cost and hospital utilization are decreased. The greatest benefit is observed in reoperations.