Graft Patency Rates Lower With Off-Pump CABG

In a prospective randomized study, patients who underwent coronary artery bypass surgery (CABG) without cardiopulmonary bypass and cardiac arrest (off-pump CABG) had lower graft patency rates at three months than those who underwent conventional on-pump CABG.

This finding “arouses concern about the long-term outcome of this approach, and further clinical trials with longer follow-up are needed,” Dr. Natasha E. Khan from Royal Brompton Hospital in London and colleagues write in the January 1st edition of The New England Journal of Medicine.

In the study, 50 patients underwent on-pump CABG receiving a mean of 3.4 grafts, and 54 underwent the off-pump procedure receiving a mean of 3.1 grafts. The surgical and anesthetic techniques were the same in both groups. The average age of the patients was 63 years.

Off-pump CABG was as safe as on-pump CABG, although the off-pump surgery caused less myocardial damage as evidenced by higher troponin T levels during the first 72 hours postop in the on-pump than off-pump group (p = 0.02).

According to Dr. Khan and colleagues, coronary angiography performed three months after CABG showed that 127 of 130 grafts were patent in the on-pump group (98%) compared with 114 of 130 in the off-pump group (88%).

“The patency rate was higher for all graft territories in the on-pump group than in the off-pump group,” the team reports. “Radial-artery grafts appear to be the most vulnerable conduit in the off-pump group,” they add.

In their paper, the team discusses various possible explanations for these findings, but come to no firm conclusions.

Writing in an editorial, two cardiac surgeons from Boston emphasize that off-pump CABG is not for everyone. “Methods of treatment should not compete for patients but should be selected according to individual patients’ needs in order to optimize their care,” Drs. Thomas E. MacGillivray and Gus J. Vlahakes from Massachusetts General Hospital write.

Off-pump CABG is a “valuable technique” that may benefit patients at high-risk for pump-related complications such as those with diffusely diseased aortas, pulmonary disease, hepatic dysfunction, or bleeding diatheses, they add.

N Engl J Med 2004;350:3-4,21-28.