Stenting, endarterectomy equally effective for carotid stenosis

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Carotid stenting and carotid endarterectomy may be equally effective for symptomatic carotid artery stenosis, according to long-term data from a randomized trial.

At a median follow-up of more than four years, the number of disabling strokes and deaths in the two groups, and the functional outcomes as assessed by the modified Rankin stroke disability scale, were similar.

When choosing which procedure to use, doctors should consider the procedure-related risks and characteristics of each patient, the study authors advised in a paper online October 14 in The Lancet.

"Now that we have shown that the long-term results of the two treatments are similar, more patients should be offered carotid stenting after a transient ischemic attack or minor stroke caused by carotid narrowing," wrote senior author and chief study investigator Dr. Martin M. Brown of University College London Institute of Neurology, in email to Reuters Health.

"Stenting is a reasonable choice for otherwise suitable younger patients, while endarterectomy is usually the safer choice for older patients," he said. "In other publications, we have shown that the risk of stroke during the procedure is no higher for stenting than for endarterectomy in younger patients under 70 years of age and in those who do not have extensive white matter disease on computed tomography (CT) or magnetic resonance imaging (MRI) brain scans."

"One treatment might also be better for anatomical reasons," he added. "For example, in some patients, getting the stent threaded up the artery toward the stenosis can be hazardous, so surgery is better. Alternatively, if the patient's narrowing is high in the neck, caused by radiotherapy or recurrence after previous endarterectomy, stenting is better."

In their International Carotid Stenting Study (ICSS), Dr. Brown and colleagues randomly assigned 1,713 patients with symptomatic carotid stenosis to either open treatment with stenting (n=855) or to endarterectomy (n=858) at 50 medical centers worldwide. The researchers followed the patients for a median of 4.2 years, to a maximum of 10.0 years, and they looked for fatal or disabling stroke from baseline through follow-up in any territory.

The number of fatal or disabling strokes (52 vs 49) and the cumulative five-year risk between the stenting and endarterectomy groups, respectively, did not differ significantly (6.4% vs 6.5%; p=0.77). Any stroke was more frequent in the stenting group (119 vs 72 events; ITT population, 5-year cumulative risk 15.2% vs 9.4%, HR 1.71; p<0.001; per-protocol population, 5-year cumulative risk 8.9% vs 5.8%, HR 1.53; p=0.04).

Strokes were were mainly non-disabling, however, and the modified Rankin scale score distribution at one year, five years, and final followup did not differ significantly between the groups.

"I think everyone expected that the excess of strokes associated with stenting compared to surgery would lead to long-term differences in physical functioning and quality of life, but our long-term results show that in fact there was no long-term impact of these extra strokes that we could measure on patient outcomes," Dr. Brown wrote in an email.

The authors acknowledge that carotid stenting was a relatively new procedure when the study began. Since then, surgeons have become more experienced, technology has advanced and the risks associated with endarterectomy have declined; and the trial wasn't powered to detect variations in treatment effects between patient subgroups.

Dr. Salomeh Keyhani of the University of California, San Francisco, wrote in an email, "Understanding the differences between the two procedures is important because carotid artery stenting is a rapidly growing treatment modality sometimes replacing carotid endarterectomy for the treatment of symptomatic carotid stenosis.

"While the authors emphasize no difference between the procedures I am not so sure about their interpretation. While the rate of disabling or fatal stroke was no different between the two revascularization methods, the 'any stroke' rate was lower in the carotid endarterectomy group. 'Any stroke' is a much more meaningful outcome to any patient (i.e., it is a more patient-centric outcome) so I think there is a real difference between the two procedures that matters to patients. Second, given the higher 'any stroke' rate and the higher periprocedural stroke rate in the stenting arm, the importance of comparing stenting to medical therapy (which has never been done) in a clinical trial is highlighted," wrote Dr. Keyhani, who was not involved in the study.

Dr. John R. Laird, medical director of the University of California, Davis Vascular Center in Sacramento, who was also not involved in the study, wrote in an email, "The results of this trial are consistent with other randomized trials of carotid stenting and endarterectomy that demonstrated that once you get beyond the 30-day periprocedural period, the procedures are equally effective in preventing stroke. The main limitation of carotid stenting vs endarterectomy has been a slightly higher risk of small, non-disabling periprocedural strokes. Carotid endarterectomy, though, carries a slightly higher risk of perioperative myocardial infarction and a small risk of permanent cranial nerve injury from the surgery."

"Hopefully the results of this study will help physicians keep an open mind regarding carotid stenting. Future randomized trials will continue to shed light on the role of this procedure compared to medical therapy and carotid endarterectomy for severe, asymptomatic carotid stenosis," he added.

Dr. Brown also called for innovation to make stenting safer, such as better stent design and better protection devices, in an email.

SOURCES: https://bit.ly/1vG4WH4

Lancet 2014.

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