Carotid artery stenting (CAS) is as effective over the long term for high-risk patients as a surgery called endarterectomy, according to a study published this week in the New England Journal of Medicine.
However, the studies authors note that carotid endarterectomy (CEA) — the surgical removal of plaque from the artery — will continue to be the treatment of choice for the 70% to 80% of the patients who are not classified as high-risk.
According to the study, three-year data from the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) study in patients with severe blocked carotid arteries, the main blood vessels in the neck leading to the brain, who underwent carotid artery stenting with the Precise Nitinol Stent and the Angioguard Emboli Capture Guidewire both developed by the Cordis (Miami Lakes, Florida) unit of Johnson & Johnson (New Brunswick, New Jersey) — were comparably protected from stroke, heart attack, death, and repeat revascularization procedures as patients who underwent the surgical endarterectomy procedure.
The report describes a three-year follow-up of the SAPPHIRE study — funded by Cordis — that compared stenting with endarterectomy in 334 people who had narrowing of the carotid artery and were at high risk of complications from surgery.
Data on 260 of the participants showed that the incidence of heart attacks, strokes and death was about the same in the two groups, occurring in 24.6% (41 of the 167 patients) of those who were stented and 26.9% (45 of 167 patients) of those who had surgery.
There was no statistical significance between these groups. A procedure to re-open the blocked arteries (target-vessel revascularization) was infrequent in both groups. The pre-specified major secondary endpoint at three years was a composite of death, stroke, or myocardial infarction within 30 days after the procedure or death or ipsilateral stroke (occurring on the same side) between 31 days and three years.
"Patients who are undergoing a procedure want to know that they'll be protected long-term from stroke, and that the procedure is safe," Hitinder Gurm, MD, at interventional cardiologist at the University of Michigan (UM; Ann Arbor) and the study's lead author, told Medical Device Daily. "This is the first study to suggest that stents do just as well long-term as surgery, in high-risk patients."
While he views the result as a positive, Gurm took a conservative stance on the study's implication. He said that the surgical approach would still be better for the majority of patients at this time who are not high-risk candidates "Surgery has been around for 50 years — it's better to go with something you know more about," he said.
And so for translating the benefits of CAS to a broader patient population, Gurm said, "We don't have the data now."
However, he said that his personal bias as an interventional cardiologist leads him to believe "that probably [carotid] stenting will replace endarterectomy, but we just don't know that yet."
Participants were at high risk because of the location of the potential blockage (either very high or very low in the carotid artery); because they had radiation therapy; or because they had undergone a previous endarterectomy, Gurm said. Someone with very serious heart or lung disease might also be at risk from surgery, he said.
Senior study senior author Donald Cutlip, MD, an associate professor of medicine at Harvard Medical School (Boston) agreed with Gurm concerning how far the procedure should be extended to patients. It's not yet possible to extend the SAPPHIRE results to people who are not at high risk.
"You can't answer that question on the basis of our study," Cutlip said. "What we can say is that the results are similar in high-risk patients at one-year and now at three-year outcomes."
"Clinical trials are now under way to determine the relative risks and benefits of stenting and endarterectomy in average-surgical-risk patients, and to compare different stent procedures," said Gurm, noting that two such trials are under way at UM.
Gurm said he believes that the trial that could really break things open for carotid stenting is the National Institute of Neurological Disorders and Stroke (NINDS; Bethesda, Maryland)-sponsored trial known as the Carotid Revascularization Endarterectomy Stenting Trial (CREST). The study randomized moderate-risk, symptomatic patients to either CEA or CAS. Patients in the latter arm received the Acculink stent and the Accunet embolic protection device, both manufactured by the company formerly known as Guidant.
A total of 2,332 patients from 60 North American centers were enrolled in CREST, though that study was delayed from its intended commencement date of 1999 until 2000 and has suffered interminable delays. Gurm said he expects to see results from this study in the next two to three years.
Until then, the resolution of the controversy of CEA vs. CAS in moderate-risk, symptomatic patients will be delayed a bit longer.
So, in the meantime, Gurm said that the use of carotid stenting by physicians should be limited.
"Outside of trials, I do not think a person with average surgical risk should undergo stenting. But for high-risk patients, we can now be certain that they will have a similar long-term outcome from stenting as they would have had from surgery."
While the company certainly hopes that CAS will eventually be available to a broader patient population, Sidney Cohen, MD, PhD, VP of Clinical Research at Cordis, said that the current long-term study results of SAPPHIRE "are important to the approximately one-third of patients who have severe carotid artery stenosis and require a less invasive, but effective treatment option, because they are poor candidates for surgery."