Patients in the off-pump group had worse composite outcomes and poorer graft patency compared with patients undergoing coronary artery bypass grafting (CABG) with the use of a cardiopulmonary bypass machine at one year of follow up, according to a study in Thursday’s issue of the New England Journal of Medicine.
Traditionally, CABG has been performed with the use of a cardiopulmonary bypass machine (on-pump CABG). However, researchers have begun to speculate whether CABG without the cardiopulmonary bypass machine (off-pump CABG) might reduce the number of complications related to the heart-lung machine.
A. Laurie Shroyer, PhD, from the Northport VA Medical Center in Northport, N.Y., and colleagues randomly assigned 2,203 patients—2,189 of whom were men—scheduled for urgent or elective CABG to either on- or off-pump procedures.
According to the researchers, the primary short-term endpoint was a composite of death or complications (reoperation, new mechanical support, cardiac arrest, coma, stroke or renal failure) before discharge or within 30 days after surgery. The primary long-term endpoint was a composite of death from any cause, a repeat revascularization procedure or a nonfatal MI within one year after surgery.
The investigators did not find any significant difference between off-pump and on-pump CABG in the rate of the 30-day composite outcomes (7 and 5.6 percent, respectively). The rate of the one-year composite outcome was higher for off-pump than for on-pump CABG (9.9 vs. 7.4 percent).
Shroyer and colleagues found that the proportion of patients with fewer grafts completed than originally planned was higher with off-pump CABG than with on-pump CABG (17.8 vs. 11.1 percent).
Follow-up angiograms in 1,371 patients who underwent 4,093 grafts revealed that the overall rate of graft patency was lower in the off-pump group than in the on-pump group (82.6 vs. 87.8 percent), according to the authors.
Despite early literature that indicated that off-pump approaches could improve neuropsychological outcomes, they did not find any treatment-based differences or differences in short-term use of major resources between the two groups.
Shroyer and colleagues concluded that their results “did not show any overall advantage to the use of the off-pump as compared with the on-pump cardiac surgical approach for coronary bypass.”