Off-pump CABG is just as safe and effective as on-pump surgery, according to findings from the anticipated five-year follow up of the CABG Off or On Pump Revascularization Study (CORONARY) – but the experience of the surgeon plays the biggest role in off-pump surgery outcomes the findings reveal.
“CORONARY has shown that when you have surgeons experienced in off pump techniques you can get the same level of revascularisation, an equal number of grafts per patient and equal graft patency, and you can therefore expect to see the same degree of long-term survival as on pump CABG,” said Professor Paul Bannon, president of the Australian and New Zealand Society of Cardiothoracic Surgeons and study investigator.
According to Professor Bannon the long-awaited findings debunk previous trials that showed sub optimal results with off-pump CABG and associated the technique with incomplete revascularisation, poorer anastomoses, and no reduction in morbidity and mortality compared to conventional CABG.
“These trials have since been criticised because the off-pump procedures had been carried out by surgeons who, although were experienced in on-pump CABG, were less experienced in off-pump techniques,” he told the limbic.
“CORONARY was designed to specifically address this – the investigators had to have at least 100 cases of off-pump surgeries under their belts before they were allowed to be contributors to the CORONARY trial in the off-pump arm,” Professor Bannon noted.
The trial is the first to examine the long-term outcomes of using or not using a pump during CABG. It looked at 4,752 patients aged 75 to 90 years at 79 hospitals from 19 countries from November 2006 through October 2011, half of who underwent CABG on-pump and half-off.
Follow-ups conducted nearly five years after the surgery found “no significant difference” between the groups in terms of death, nonfatal strokes, heart attacks and kidney failure, and repeated procedures.
The researchers also found no significant differences in costs or quality of life.
However patients with diabetes did experience fewer adverse events with off-pump CABG (22.7% versus 26.1% for on-pump surgery, HR 0.85, 95% CI 0.72-1.00), the authors said.
Professor Bannon said a drawback of the trial is that it did not look at aortic, or no touch, off-pump surgery, which he said offers better outcomes in terms of stroke.
“Other trials have shown that the best off-pump operation is where you do a single mammary to the left anterior descending artery – you don’t touch the aorta and you’ve got that long-term survival benefit of the mammary,” he told the limbic.
Professor Bannon’s own group has recently concluded a meta analyses involving data from more than 37,000 patients that shows a clear benefit of stroke rate in no touch off-pump surgery.
“If you have an experienced set of hands performing aortic off pump surgery, which gets the same amount of grafts per patient and the same amount of graft patency, you’ll get the same improved survival as bypass surgery but with a very low stroke rate – around 0.4% which is the same as PCI. That’s the gold standard we should be aiming for,” he told the limbic.
Subgroups of patients who would benefit from aortic off-pump surgery are those with ascending aortic disease and high stroke risk such as diabetic patients and patients with vascular nephropathy, he added.
“The screening is fairly simple – what frightens me is the lack of screening of the ascending aorta prior to surgery,” he told the limbic.
“We should be trying to identify those patients at high risk of stroke and looking to see if there’s another technique or another surgery that could be done to avoid that.”
“There is enough information out there to be able to identify these patients but I do think added training is required and I think the CORONARY trial proves that.”