Big trials show no advantage to using off-pump CABG
Quality of life and neurocognitive tests showed significant difference between the two groups.
However, neurocognitive testing was declared optional because it's so time consuming, and many patients opted out. For example, only 1,273 of the original 4,752 patients returned to take the Montreal Cognitive Assessment at 1 year, noted Dr. Lamy, a heart surgeon at the Population Health Research Institute at McMaster University in Hamilton, Ont.
Discussant Dr. Bernard Gersh zeroed in on the incomplete neurocognitive testing. "I think this is really a significant limitation. There's a huge bias. If there's any advantage to off-pump CABG, it may be in neurocognitive dysfunction," commented Dr. Gersh, professor of medicine at the Mayo Clinic, Rochester, Minn.
In response to questioning as to where off-pump CABG fits into clinical practice in light of the disappointing CORONARY and GOPCABE findings, Dr. Diegeler said he remains convinced that some high-operative-risk patients - those with aortic calcification or other evidence of generalized vascular disease - do benefit preferentially from off-pump surgery when performed by expert surgeons.
Dr. Lamy said a post hoc analysis of the CORONARY data showed that low-operative-risk patients as defined by a EuroScore of 0-2 tended to do better with on- than off-pump CABG, while the converse was true in those with moderate- or high-risk scores.
"In my personal practice now, my low-risk patients go on-pump and my moderate- and high-risk patients go off-pump," he added.
Dr. Jan Hlavicka presented the results of the PRAGUE-6 trial, in which 206 patients at high operative risk - a EuroScore of 6 or greater - were randomized to off- or on-pump CABG at Charles University, Prague. The operations were performed by five surgeons proficient in both procedures. The 30-day primary composite endpoint comprising death, MI, stroke, or new renal failure requiring dialysis occurred in 20.6% of the on-pump group, compared with 9.2% of off-pump patients.
The off-pump group required significantly fewer RBC transfusions. There were no significant differences between the two groups in terms of average hospital length of stay, wound infection rates, or total hospital costs.
Dr. Gersh noted that the only significant difference between the two groups in the individual components of the primary endpoint was in acute MI rates: 12.1% in the on- vs. 4.1% in the off-pump CABG group. He took issue with the Czech investigators? use of the 2004 Society of Thoracic Surgeons definition of acute MI. That's not sufficiently stringent. It surely captures many patients who don't really have an acute MI. The data should be reanalyzed using a contemporary definition which requires new Q waves, he added.
Dr. Hlavicka, Dr. Lamy, and Dr. Diegeler declared no conflicts.
