Off-Pump Versus On-Pump Coronary Artery Bypass Surgery: A Case-Matched Comparison of Clinical Outcomes and Costs

Abstract

Background: Results of off-pump coronary artery bypass (OPCAB) surgery have demonstrated trends toward fewer complications, faster recoveries and lower costs compared with on-pump coronary artery bypass (ONCAB) surgery. The validity of such comparisons, however, may be impacted by differences in preoperative risk factors between the two surgeries.

Methods: A total of 76 OPCAB surgery patients were case-matched (by age, sex and Society of Thoracic Surgeons’ risk scores) with an equal number of patients who underwent ONCAB surgery by the same surgeon. Postoperative clinical parameters (time on mechanical ventilation, number of blood transfusions, peak cardiac enzyme levels and metabolic acidosis) and outcomes data (intensive care unit and overall in-hospital lengths of stay, perioperative myocardial infarction, atrial fibrillation, stroke, reoperation for bleeding and mortality) were analyzed, and the variable and total costs for each patient were calculated.

Results: OPCAB patients required less mechanical ventilation and fewer blood transfusions and had lower peak creatinine phosphokinase levels, as well as a reduced incidence of metabolic acidosis. There were trends toward both shorter intensive care unit and overall in-hospital lengths of stay for OPCAB patients. The average total cost for this group was 20.5% less than for ONCAB patients. There were no differences in rates of atrial fibrillation, myocardial infarction, reoperation for bleeding, stroke or mortality.

Conclusions: By reducing the need for mechanical ventilation, transfusions and intensive care unit and overall in-hospital lengths of stay, OPCAB surgery decreases the use of limited and costly resources without increasing risks. These advantages do not appear to be related to patient selection.