The American Heart Association (AHA) has released a scientific statement on the effectiveness of off-pump versus on-pump coronary artery bypass grafting (CABG) for myocardial revascularization. The Council on Cardiovascular Surgery and Anesthesia collaborated with the Interdisciplinary Working Group on Quality of Care and Outcomes Research to review clinical data from retrospective studies, meta-analyses, and randomized trials that compared the two methods. The full report was published in the May 31, 2005, issue of Circulation.

Off-pump CABG does not use cardiopulmonary bypass or cardioplegia, while standard on-pump CABG involves the use of a heart-lung machine and medication to arrest the heart. On-pump CABG has been the gold standard for managing myocardial revascularization; however, it has been unclear whether outcomes with standard CABG are superior to outcomes with off-pump CABG.

Although the AHA report did not determine that one method was superior to the other, it showed trends that were associated consistently with each.

POSITIVE TRENDS ASSOCIATED WITH OFF-PUMP CABG

• Less bleeding

• Less renal dysfunction

• Less short-term neurocognitive dysfunction, especially with a calcified aorta

• Shorter overall hospitalization

POSITIVE TRENDS ASSOCIATED WITH ON-PUMP CABG

• Less technically demanding

• Shorter learning curve for surgeon

• Better long-term graft patency

• Easier to graft posterior (circumflex) bypass targets

• More bypass grafts constructed

The AHA concludes that patients receiving CABG have excellent outcomes regardless of the method. However, outside factors (e.g., surgeon skill, hospital quality, systems approach) are significant in determining the outcome after coronary revascularization. Further large-scale prospective randomized trials are needed to definitively answer whether one method is more effective than the other. In the meantime, the AHA recommends choosing the method with which the surgeon is most comfortable and most skilled.