TCT 2016: EXCEL, NOBLE present conflicting findings on eluting stents, bypass surgery

Two new trials on eluting heart stents designed to treat unprotected left main coronary artery disease were presented at the Transcatheter Cardiovascular Therapeutics (TCT) 2016 conference, and they have left cardiologists stumped over their conflicting findings.

In one trial titled Excel, Gregg W. Stone, MD, the director of cardiovascular research and education at Columbia University Medical Center in New York, and his team conducted a trial comparing Abbott Vascular’s Xience everolimus-eluting metallic stent to a coronary artery bypass graft (CABG) surgery in patients with left main coronary artery disease. The full study was published online Oct. 31 in the New England Journal of Medicine.

Results showed that patients with low or intermediate SYNTAX scores with Xience implants had fewer adverse events 30 days after the procedure and comparable rates of stroke, death and MI after three years.

"A stenting procedure with Xience may be an acceptable way to increase blood flow to the heart for certain patients with left main coronary artery disease, taking into account a patient's individual circumstances," said Charles A. Simonton, MD, chief medical officer for Abbott's vascular business, in a statement to Cardiovascular Business. "This is important news for patients because in addition to improved safety, stenting procedures are much less invasive than open heart surgery, potentially reducing recovery time and healthcare costs." 

But the Excel findings contradict those in a separate study titled Noble, done by Evald H. Christiansen, MD, PhD, a cardiologist at Aarhus University Hospital in Denmark.

The Noble study, published Oct. 31 in the Lancet, compared the effectiveness of a Biomatrix Flex biolimus-eluting stent to bypass graft surgery. Results showed that patients had higher rates of adverse cardiac and cerebrovascular events after five years when compared with a CABG surgery. Additionally, stroke rates were higher among patients who underwent a CABG procedure at 30 days, but were numerically higher among patients with the stent after five years.

With the Excel study making a case that PCI may be a better treatment option over CABG for patients with left main coronary artery disease and Noble saying the opposite, cardiologists are left to wonder what that means for practice going forward.

David J. Cohen, MD, a cardiologist at Saint Luke’s Health System in Kansas City, Missouri, said at a TCT press conference that though the trials conflict with each other in certain areas, there are still significant similarities.

“I don’t see them as quite so different,” Cohen said. “I think the biggest difference is the striking finding that the SYNTAX score didn’t seem to matter, which was very surprising based on the data from the SYNTAX trial where it seemed to work so well, and I think that needs to be examined more closely.”