CRF: EXCEL trial to test superiority of PCI vs. CABG for left main
A clinically controlled trial will determine whether PCI in appropriate patients with left main (LM) disease is as good or superior to CABG, said Gregg W. Stone, MD, of the Columbia University Medical Center in New York City, during a presentation at the fourth annual Left Main and Bifurcation Summit April 29 in Seoul, South Korea, sponsored by the Cardiovascular Research Foundation (CRF).
The EXCEL trial will expand on the results of the SYNTAX trial, which found similar rates of major adverse cardiovascular events (MACE) in patients with left main or triple vessel disease treated with either CABG or PCI.
During the SYNTAX trial, rates of mortality were recorded at 7.9 percent for patients who underwent CABG and 2.7 percent for those who were treated with PCI, said Stone.
While this was a small subgroup, it does show that in patients who weren’t at “excessively high risk, PCI was actually superior,” Stone said.
In response to the SYNTAX results, the American College of Cardiology (ACC) and the American Heart Association (AHA) changed the indication for stenting these patients from class III to class IIb.
While the class IIb indication is better than the procedure being contraindicated, it still is not a “ringing endorsement for PCI, but at least its allowing more people to go ahead and perform it in appropriate patients,” Stone said.
The ACC/AHA guidelines say that “stenting of the left main coronary artery as an alternative to CABG may be considered in patients with anatomic conditions that are associated with a low risk of PCI procedural complications and clinical conditions that predict an increased risk of adverse surgical outcomes."
Due to these classifications and prior data, Stone said that the researchers at Columbia will begin in early September to enroll patients into the EXCEL trial -- an informative trial that will evaluate the outcomes in patients who undergo PCI with the Xience Prime stent (Abbott Vascular) or CABG.
One of the intentions of the EXCEL trial is to help create protocols for clinicians including how to optimize PCI techniques, how to properly treat distal bifurcations and when to use intravascular ultrasound (IVUS) and fractional flow reserve (FFR).
Additionally, the trial will provide the best possible techniques to perform CABG on these patients, as well as include ways to minimize waiting time or maximize pan-arterial revascularization.
The trial will use death, stroke and MI as its primary endpoint and will enroll 2,500 patients who have SYNTAX scores less than or equal to 32. Patients will be randomized at a 1:1 ratio.
The patients will undergo follow-up at 30 days, six months and once every year for five years.
Stone said that the trial will only include patients with “significant” diagnosed left main disease—angiographic digital subtraction (DS) of 70 percent or greater or equal to 50 percent to 70 percent.
“The left main is the hardest part of the coronary tree for operators and core laboratories to agree on stenosis severity even when the stenosis severity is around 100 percent,” said Stone.
“There are many situations in the left main where there are other diseases or absences of diseases in the main circulation other than the left main that can lead to false positives or false negatives,” he said.
Because of this problem, researchers are recommending the use of IVUS rather than FFR, even though FFR is “known as the gold standard for the detection of ischemia.”
Compared to the stent used in the SYNTAX trial (Taxus, Boston Scientific), the Xience Prime is “superior” and will be more deliverable and flexible with shorter balloon tapers, Stone said.
"I don’t think this stent is going to be better than the Taxus stent in the left main itself,” Stone said. However, he added, it will provide better results in all other lesions in the LAD and right coronary and should improve MACE outcomes.
The EXCEL trial will expand on the results of the SYNTAX trial, which found similar rates of major adverse cardiovascular events (MACE) in patients with left main or triple vessel disease treated with either CABG or PCI.
During the SYNTAX trial, rates of mortality were recorded at 7.9 percent for patients who underwent CABG and 2.7 percent for those who were treated with PCI, said Stone.
While this was a small subgroup, it does show that in patients who weren’t at “excessively high risk, PCI was actually superior,” Stone said.
In response to the SYNTAX results, the American College of Cardiology (ACC) and the American Heart Association (AHA) changed the indication for stenting these patients from class III to class IIb.
While the class IIb indication is better than the procedure being contraindicated, it still is not a “ringing endorsement for PCI, but at least its allowing more people to go ahead and perform it in appropriate patients,” Stone said.
The ACC/AHA guidelines say that “stenting of the left main coronary artery as an alternative to CABG may be considered in patients with anatomic conditions that are associated with a low risk of PCI procedural complications and clinical conditions that predict an increased risk of adverse surgical outcomes."
Due to these classifications and prior data, Stone said that the researchers at Columbia will begin in early September to enroll patients into the EXCEL trial -- an informative trial that will evaluate the outcomes in patients who undergo PCI with the Xience Prime stent (Abbott Vascular) or CABG.
One of the intentions of the EXCEL trial is to help create protocols for clinicians including how to optimize PCI techniques, how to properly treat distal bifurcations and when to use intravascular ultrasound (IVUS) and fractional flow reserve (FFR).
Additionally, the trial will provide the best possible techniques to perform CABG on these patients, as well as include ways to minimize waiting time or maximize pan-arterial revascularization.
The trial will use death, stroke and MI as its primary endpoint and will enroll 2,500 patients who have SYNTAX scores less than or equal to 32. Patients will be randomized at a 1:1 ratio.
The patients will undergo follow-up at 30 days, six months and once every year for five years.
Stone said that the trial will only include patients with “significant” diagnosed left main disease—angiographic digital subtraction (DS) of 70 percent or greater or equal to 50 percent to 70 percent.
“The left main is the hardest part of the coronary tree for operators and core laboratories to agree on stenosis severity even when the stenosis severity is around 100 percent,” said Stone.
“There are many situations in the left main where there are other diseases or absences of diseases in the main circulation other than the left main that can lead to false positives or false negatives,” he said.
Because of this problem, researchers are recommending the use of IVUS rather than FFR, even though FFR is “known as the gold standard for the detection of ischemia.”
Compared to the stent used in the SYNTAX trial (Taxus, Boston Scientific), the Xience Prime is “superior” and will be more deliverable and flexible with shorter balloon tapers, Stone said.
"I don’t think this stent is going to be better than the Taxus stent in the left main itself,” Stone said. However, he added, it will provide better results in all other lesions in the LAD and right coronary and should improve MACE outcomes.