Durability of Surgery, Stenting for Symptomatic Carotid Stenosis Good for Up to a Decade

HONOLULU, HI—Results of carotid revascularization with either surgery or stenting stand up well over the long term, with very low rates of stroke through up to a decade of follow-up, new data from the Carotid Stenosis Trialists’ Collaboration show.

In pooled data from four randomized trials, the annual rate of ipsilateral stroke per person-year starting 120 days after revascularization then moving forward was 0.60% with carotid endarterectomy and 0.64% with stenting, a nonsignificant difference (HR 1.06; 95% CI 0.73-1.54).

“Really this is what kind of surprised us with all of these studies was that once the patients underwent their successful endarterectomy or stent there was an especially low rate of subsequent ipsilateral stroke,” Thomas Brott, MD (Mayo Clinic, Jacksonville, FL), said here at the International Stroke Conference. The findings were published simultaneously online in the Lancet Neurology.

But, as was already known, risk of periprocedural events—stroke or death within 120 days for this analysis—was lower with surgery. Due to this early separation, the overall risk during long-term follow-up was greater with stenting (HR 1.45; 95% CI 1.20-1.75).

What that shows, Brott said, is “a safety advantage of carotid surgery over carotid stenting but an equivalent durability.”

He noted that the last stenting procedure in any of the four trials included in the analysis occurred more than a decade ago, in 2008. Thus, he said, “if stenting has become safer over the intervening decade, stenting and surgery could be comparable, or nearly so, for the combined outcomes of periprocedural stroke and death plus postprocedural ipsilateral stroke.”

Though newer stenting techniques—including access through the carotid artery with flow reversal to avoid showering the brain with microemboli—could be safer, the message from this study “is that you’re better off with endarterectomy,” commented J. David Spence, MD (Robarts Research Institute, London, Canada).

“Because the periprocedural risk all happens at the beginning and then [the curves are] level,” he told TCTMD, “stenting should be reserved for selected patients with particular factors that make stenting safer, such as a very high stenosis, previous radiation or surgery causing fibrosis and scarring in the region of the surgery, and very high periprocedural risk like unstable angina.” He guessed that select group would represent about 25% of patients with symptomatic carotid stenosis.

What’s the Impact of Revascularization?

Brott underscored the importance of looking at the longer-term durability of carotid revascularization by noting that at age 70, average life expectancy is 15 years.

This study was a preplanned analysis of pooled individual patient data from four trials that have compared stenting and endarterectomy for patients with symptomatic carotid artery stenosis. That includes a total of 4,754 patients from CREST, EVA-3S, ICSS, and SPACE. Patients were followed for up to 12.4 years, with the median length of follow-up ranging from 2.0 to 6.9 years across trials.

The main outcome of interest, according to Brott, was the risk of postprocedural ipsilateral stroke between 121 days and 10 years after revascularization. “The idea being we wanted to compare these two procedures—surgery to stenting—with regard to clinical durability,” he said.

The study showed that the comparable postprocedural durability between the two techniques was consistent across various subgroups.

Brott additionally reported that the annual rates of nonipsilateral stroke in the postprocedural period per person-year—0.78% for stenting and 0.85% for surgery—were not significantly different from rates of ipsilateral stroke.

“Because stroke outside the territory of the treated carotid is not lower, the low rates of ipsilateral stroke may in part be from the endarterectomy and from the stent and not just from advances in medical management and the decline in cigarette smoking,” Brott said.

He highlighted the declining stroke rates in carotid revascularization trials over time. In NASCET, which was published in 1999, the annual rate of any postprocedural stroke with endarterectomy was 4.5%. In comparison, the rate in this pooled analysis was 1.4% for endarterectomy and 1.5% for stenting; in general population data from REGARDS, it was 0.6%.

Thus, not all of the decline in stroke rates over time is due to revascularization, Brott said. “How much is medicine? How much is declining cigarette smoking? How much is from the procedures themselves? We can’t tell,” he said.

Revascularization Choice

Asked after his presentation how he would decide between endarterectomy or stenting, Brott indicated that it is important to look at patient characteristics.

“Today it’s hard to know because of the potential improvements in safety,” he said. “Carotid surgery between 1980 and 1990 improved quite a bit with regard to safety. But, clearly, older patients have a higher risk with carotid stenting. So first of all, how old is the patient? How much arterial tortuosity is there? How much calcification is there in the arterial tree? If those factors are favorable, then I think stenting and endarterectomy today are likely comparable.”

In an accompanying editorial, however, Spence maintains that endarterectomy should be the way to go in most patients with symptomatic carotid stenosis.

“Brott and colleagues express the hope that improvements in carotid artery stenting will reduce periprocedural risks, but passing catheters through stiff, tortuous, and craggy arteries that have a high plaque burden is hazardous and probably explains the higher risk of stenting in older patients (> 70 years),” he writes, pointing to microemboli dislodged as the catheter moves through the ascending aorta and the stent is deployed.

Spence concludes by saying that “patients are likely to prefer a less invasive procedure, so they should be informed that outcomes with carotid endarterectomy are generally better than with carotid artery stenting.”