A coronary artery bypass graft (CABG) procedure is performed to improve circulation to the heart muscle by creating one or more alternative routes for blood to flow around blockages in the coronary arteries (a technique called revascularization ). To accomplish this, blood vessels from other parts of the body are grafted between the aorta and the coronary arteries. During a conventional bypass surgery, the heart is temporarily stopped and connected to a cardiopulmonary bypass pump. This machine performs the functions of the heart and lungs during the surgery, and gives the surgeon a stationary field in which to work.

During off-pump coronary artery bypass (OPCAB), on the other hand, the surgeon uses a special device to stabilize only the part of the heart being operated on, while the rest of the heart continues to beat.

A number of studies have shown that OPCAB results in fewer complications, shorter hospital stays, and lower costs than conventional CABG. However, others have shown that patients undergoing OPCAB require a second revascularization procedure more often than those receiving conventional bypass. This is often blamed on the fact that OPCAB is a more technically difficult procedure than conventional CABG. In an attempt to settle this argument, researchers designed a study that directly compared the two techniques. The results of this study, which were published in the April 21, 2004 issue of The Journal of the American Medical Association, suggest that OPCAB may be equally as successful and less costly than CABG.

About the Study

The researchers enrolled 197 adult participants who were randomly assigned to receive either OPCAB or CABG. A single surgeon, highly skilled in both OPCAB and CABG performed all the procedures.

To ensure that all the grafts were still open and functioning properly, a follow up coronary angiography was performed at the time each participant was discharged from the hospital and again after one year. Additionally, each participant completed an in person or telephone interview regarding any adverse events, complications, hospital admissions, or revascularization procedures they had required both 30 days and one year after their surgery.

The Findings

The researchers found that grafts performed during OPCAB and conventional CABG were still open and functioning well at one month and one year after surgery, and that there was no significant difference between the two groups. They also found that the risk of death, or a secondary cardiovascular event, such as stroke, heart attack, angina, or the need for a second revascularization procedure were similar in both groups over the same time periods. There were no significant differences in the health-related quality of life for any of the participants.

The average cost upon discharge for each participant undergoing OPCAB was $2,272 less than that of participants receiving CABG. After one year OPCAB was still saving an average of $1,955 over CABG.

How Does This Affect You?

The researchers concluded that off-pump coronary artery bypass surgery was equally effective and less expensive than its conventional counterpart and that the time may have come for OPCAB to become the new standard of care for performing coronary artery bypass procedures.

An editorial published in the same issue of the Journal tends to agree, but raises an important concern. All of the procedures in this trial were performed by a single surgeon with extensive experience in performing off-pump surgery. Changing the standard of care would require all surgeons, many of whom do not have the same level of expertise as the surgeon in the study, to master a new and technically challenging procedure. Therefore, the authors of the editorial call for a large, multicenter, randomized trial comparing CABG and OCAB before any changes to the standard of care are made.

Still, if you or a family member has been advised to undergo coronary artery bypass grafting, be sure to discuss the off-pump option with the surgeon. If he or she has had a lot experience with the procedure, it may turn out to be the best treatment for you.