SAN FRANCISCO—On- and off-pump CABG remained neck-and-neck at the one-year mark in the CORONARY trial. One-year results released March 11 at the American College of Cardiology scientific session showed similar outcomes in patients treated with either approach, akin to findings at 30-days.
CORONARY (Coronary Artery Bypass Grafting Surgery Off or On Pump Revascularization Study) is a large, international trial designed to compare the effects of on- and off-pump bypass procedures in patients undergoing isolated CABG. Andre Lamy, MD, of McMaster University in Ontario, reported 30-day results at ACC.12 in Chicago. Researchers found no significant difference in the primary outcome—a composite of death, MI, stroke and new renal failure requiring dialysis. The off-pump group experienced a higher rate of repeat revascularization at 30 days but had lower rates of bleeding, acute kidney injury and respiratory complications.
The 2013 presentation focused on one-year results, which included measures on quality of life and neurocognitive function. The New England Journal of Medicine simultaneously published the results online.
CORONARY enrolled 4,752 patients with coronary artery disease between 2006 and 2011 who were to undergo CABG at one of 79 facilities in 19 countries. Patients were randomized to either off-pump (2,375 patients) or on-pump (2,377) procedures done by expert surgeons. Besides conducting one-year analyses, they looked at outcomes between 31 days and one year. These analyses did not include patients who experienced a primary outcome at 30 days.
The overall study is designed to extend over a five-year period.
At baseline, patient characteristics were well balanced. Patients had a mean age of 67 years old and 87 percent were male. Breakdown by European System for Cardiac Operative Risk Evaluation (EuroSCORE) showed 1,339 patients were low risk (0-2 score), 2,516 were moderate risk (3-5) and 828 were high risk (greater than 5).
“We found no difference between the two groups,” Lamy said, referring to the primary outcome. At one year, the rate of the composite outcome was 12.1 percent in the off-pump group and 13.3 percent in the on-pump group. Nor did they detect any differences in the components of the primary outcome.
The rates also were similar at 31 days and one year. Repeat revascularization occurred in 1.4 percent of the off-pump group and 0.8 percent of the on-pump group at one-year. The quality of life and neurocognitive function measures were similar for both groups.
Quality of life was similar at baseline and increased at 31 days and at one year in both groups. “I found it reassuring personally that quality of life of the patient increased after cardiac surgery, “ Lamy said at a press conference following his presentation. “But it is a very neutral trial so far.”
Panelist Michael J. Mack, MD, medical director of cardiovascular surgery at Baylor Healthcare in Plano, Texas, pointed out that less than half of the patients took the neurocognitive tests. “These tests take up a lot of time and some centers had a difficulty with that, so we made the test optional,” Lamy explained.
Lamy said that their analysis found that the patients who refused to take the tests tended to be sicker than those who did agree to undergo neurocognitive testing. Several panelists suggested that created a selection bias, which Lamy challenged.
A post-hoc analysis has shown that patients with a lower EuroSCORE tended to have better results with the on-pump approach while patients with higher scores tended to fare better with off-pump, Lamy said.
“We know that EuroSCORE is one of the main drivers,” he said in the press conference. He added that he will explore which patients benefit and don’t benefit from off-pump surgery. “In my personal practice, it is not unusual for me to do an off-pump in a frail patient and do an on-pump in a younger, more robust patient.”
Lamy recommended that surgeons become competent in both approaches. “The message here is surgeons should know both techniques and be able to adjust their surgical practice [to the patient] rather than be a one-trick pony,” Lamy said.