Off-Pump Coronary Artery Bypass Graft Is Associated with Similar Outcomes at One Year as On-Pump Surgery in Patients with Coronary Artery Disease

One-year results from a planned five-year trial show little difference in outcomes among patients with coronary artery disease who undergo on-pump vs. off-pump coronary artery bypass graft surgery. Lead study author Andre Lamy, MD, professor in the division of cardiac surgery at McMaster University, Hamilton, Ontario, presented results from the CORONARY trial at ACC.13, the 62nd Annual Scientific Session & Expo of the American College of Cardiology.

This late-breaking parallel trial evaluated the one-year performance of patients who underwent coronary artery bypass graft (CABG) surgery on-pump vs. those who underwent CABG off-pump.

From November 2006 through October 2011, 4,752 patients were screened at 79 centers in 19 countries. Patients with multi-vessel coronary artery disease undergoing CABG were randomized to have the procedure off-pump (2,375) versus on-pump (2,377).

Eligible patients over age 70 who underwent CABG had one or more of the following risk factors: peripheral arterial disease, cerebrovascular disease or carotid stenosis over 70%, and/or renal insufficiency.

Participants between age 60 and 69 years had one or more of the following risk factors: diabetes, urgent revascularization, and/or smokers within the past year. Patients between age 55 and 59 had two or more of the same risk factors.

Exclusions were made for planned valve surgery, contraindication to or decision against off-pump or on-pump CABG, limited life expectancy, emergency or repeat CABG, or previous enrollment in the trial.

Primary endpoints were death, non-fatal myocardial infarction (MI), stroke, or renal failure requiring dialysis at 30 days. Secondary endpoints included all of the above, plus repeat revascularization at five years, blood transfusion, recurrent angina, or cardiovascular death.

Participants averaged nearly 68 years of age, 20% were women, 47% were diabetic, and 34% had prior MI. The primary endpoint occurred in 9.8% of the off-pump group versus 10.3% of the on-pump group (P=0.59). For the study, surgeons performing CABG were required to have more than two years of experience and to have performed more than 100 of each procedure type.

At thirty days, the off-pump and on-pump groups demonstrated similar outcomes: death (off-pump 2.5% vs. on-pump 2.5%), MI (6.7% vs. 7.2%), stroke (1.0% vs. 1.1%), and renal failure requiring dialysis (1.2% vs. 1.1%).

At one year, the off-pump and on-pump groups again showed similar outcomes: death: (off-pump 5.1% vs. on-pump 5.0%), MI (6.8% vs. 7.5%), stroke (1.5% vs. 1.7%), and need for repeat revascularization (1.4% vs. 0.8%). There was no significant difference between the two techniques in primary outcomes, revascularization, quality of life, or neurocognitive function.

Among patients with multi-vessel CAD undergoing CABG, the off-pump technique did not improve primary endpoints up to one year of follow-up. Hard clinical outcomes were not improved. However, off-pump CABG reduced the need for transfusion, reoperation for bleeding, acute kidney injury, and respiratory complications within 30 days. Fewer bypass grafts were performed with off-pump CABG. There was no reduction in stroke with off-pump CABG, possibly due to 102 crossovers from the on-pump group to the off-pump group due to a calcified aorta.

In conclusion, off-pump CABG is a viable technique for surgical revascularization. Both techniques are reasonable options, in experienced hands. “It’s a neutral trial so far, but we still have to see,” said Lamy. Cardiosurgeons can do off-pump surgery without difficulty, and in the future, investigators must determine which patients benefit more (or less) from the procedure.