Long-term results of carotid stenting versus endarterectomy in high-risk patients

Current concepts in the management of carotid stenosis

Several large randomized clinical trials in North America and Europe concluded over a decade ago that carotid endarterectomy plus medical management was significantly better than medical management alone for stroke prevention in either symptomatic or asymptomatic patients with severe carotid stenosis. Percutaneous carotid angioplasty now represents another treatment option that currently seems most appropriate either in the context of prospectively randomized trials or for patients who are at a higher than average risk for conventional surgical treatment.

Carotid artery stenting versus carotid endarterectomy: current status

Carotid occlusive disease remains an important cause of ischemic stroke. The results of large, randomized, clinical trials have established the benefit of surgical revascularization in patients with symptomatic or asymptomatic carotid stenosis. The introduction of balloon angioplasty and stenting of the extracranial carotid artery as a potential alternative to surgery has been received with enthusiasm by patients and physicians. Whether or not this enthusiasm is justified fully has yet to be determined. This article reviews established and emerging data from clinical trials evaluating the safety and efficacy of carotid endarterectomy, carotid angioplasty, and stenting.

Carotid stenting with embolic protection: evolutionary advances

Stroke is one of the most significant causes of death and morbidity worldwide. Atherosclerotic stenosis of the extracranial internal carotid artery has been invoked as a common causative factor for stroke in over 20% of patients. Although medical therapy can help to prevent the onset and progression of carotid arteriosclerosis, open surgical carotid endarterectomy has been the gold standard for treating severe blockage. Carotid artery stenting has recently demonstrated efficacy in stroke prevention from atherosclerosis, and in high-risk surgical subgroups, has been shown to be associated with a reduction in the risk of myocardial infarction. The controversy for carotid stenting surrounds the incidence of periprocedural stroke. Will embolic protection devices (EPDs) decrease this risk? EPDs continue to evolve with various engineering strategies directed at increasing the efficiency of protection. There are two major categories of EPDs: distal occlusion, either with balloons (e.g., Percusurge, Medtronic Corporation, MN, USA); or distal filtration (e.g., Angioguard, Cordis Corporation, NJ, USA). The second method is proximal protection (e.g., MoMA device, Invatec Corporation, Brescia, Italy). We review the results of trials currently evaluating carotid stenting with both distal and proximal embolic protection.

The optimal treatment of carotid atherosclerosis: a 2008 update and literature review

Carotid and cerebrovascular disease have major public health implications given the associated morbidity and mortality. However, the best treatment for this disease is uncertain. Carotid endarterectomy has proven useful in primary and secondary prevention of strokes for patients with significant internal carotid artery stenoses. Many patients are considered at high risk for such surgical procedures and therefore have relatively few treatment options. Carotid stenting is currently being investigated as an alternative therapeutic intervention for these patients. This article reviews the literature pertaining to carotid intervention and its current status in 2008.

Carotid artery stenting has increased rates of postprocedure stroke, death, and resource utilization than does carotid endarterectomy in the United States, 2005

OBJECTIVE

Carotid endarterectomy (CEA) remains the procedure of choice for treatment of patients with severe carotid artery stenosis. The role of carotid artery stenting (CAS) in this patient group is still being defined. Prior single and multicenter studies have demonstrated economic savings associated with CEA compared with CAS. The purpose of this study was to compare surgical outcomes and resource utilization associated with these two procedures at the national level in 2005, the first year in which a specific ICD-9 procedure code for CAS was available.

METHODS

All patient discharges for carotid revascularization for the year 2005 were identified in the Nationwide Inpatient Sample based on ICD9-CM procedure codes for CEA (38.12) and CAS (00.63). The primary outcome measures of interest were in-hospital mortality and postoperative stroke; secondary outcome measures included total hospital charges and length of stay (LOS). All statistical analyses were performed using SAS version 9.1 (Cary, NC), and data are weighted according to the Nationwide Inpatient Sample (NIS) design to draw national estimates. Univariate analyses of categorical variables were performed using Rao-Scott chi(2), and continuous variables were analyzed by survey weighted analysis of variance (ANOVA). Multivariate logistic regression was performed to evaluate independent predictors of postoperative stroke and mortality.

RESULTS

During 2005, an estimated 135,701 patients underwent either CEA or CAS nationally. Overall, 91% of patients underwent CEA. The mean age overall was 71 years. Postoperative stroke rates were increased for CAS compared with CEA (1.8% vs 1.1%, P < .05), odds ratio (OR) 1.7; (95% confidence interval [CI] 1.2-2.3). Overall, mortality rates were higher for CAS compared with CEA (1.1% vs 0.57%, P < .05) this difference was substantially increased in regard to patients with symptomatic disease (4.6% vs 1.4%, P < .05). By logistic regression, CAS trended toward increased mortality, OR 1.5; (95% CI .96-2.5). Overall, the median total hospital charges for patients that underwent CAS were significantly greater than those that underwent CEA ($30,396 vs $17,658 P < .05).

CONCLUSIONS

Based on a large representative sample during the year 2005, CEA was performed with significantly lower in-hospital mortality, postoperative stroke rates, and lower median total hospital charges than CAS in US hospitals. As the role for CAS becomes defined for the management of patients with carotid artery stenosis, clinical as well as economic outcomes must be continually evaluated.

Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial: results up to 4 years from a randomised, multicentre trial

BACKGROUND

Carotid stenting is a potential alternative to carotid endarterectomy but whether this technique is as safe as surgery and whether the long-term protection against stroke is similar to that of surgery are unclear. We previously reported that in patients in the Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial, the rate of any stroke or death within 30 days after the procedure was higher with stenting than with endarterectomy. We now report the results up to 4 years.

METHODS

In this follow-up study of a multicentre, randomised, open, assessor-blinded, non-inferiority trial, we compared outcome after stenting with outcome after endarterectomy in 527 patients who had carotid stenosis of at least 60% that had recently become symptomatic. The primary endpoint of the EVA-3S trial was the rate of any periprocedural stroke or death (ie, within 30 days after the procedure). The prespecified main secondary endpoint was a composite of any periprocedural stroke or death and any non-procedural ipsilateral stroke during up to 4 years of follow-up. Other trial outcomes were any stroke or periprocedural death, any stroke or death, and the above endpoints restricted to disabling or fatal strokes. This trial is registered with ClinicalTrials.gov, number NCT00190398.

FINDINGS

262 patients were randomly assigned to endarterectomy and 265 to stenting. The cumulative probability of periprocedural stroke or death and non-procedural ipsilateral stroke after 4 years of follow-up was higher with stenting than with endarterectomy (11.1%vs 6.2%, hazard ratio [HR] 1.97, 95% CI 1.06-3.67; p=0.03). The HR for periprocedural disabling stroke or death and non-procedural fatal or disabling ipsilateral stroke was 2.00 (0.75-5.33; p=0.17). A hazard function analysis showed the 4-year differences in the cumulative probabilities of outcomes between stenting and endarterectomy were largely accounted for by the higher periprocedural (within 30 days of the procedure) risk of stenting compared with endarterectomy. After the periprocedural period, the risk of ipsilateral stroke was low and similar in both treatment groups. For any stroke or periprocedural death, the HR was 1.77 (1.03-3.02; p=0.04). For any stroke or death, the HR was 1.39 (0.96-2.00; p=0.08).

INTERPRETATION

The results of this study suggest that carotid stenting is as effective as carotid endarterectomy for middle-term prevention of ipsilateral stroke, but the safety of carotid stenting needs to be improved before it can be used as an alternative to carotid endarterectomy in patients with symptomatic carotid stenosis.

Results of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study to treat symptomatic stenoses at 2 years: a multinational, prospective, randomised trial

BACKGROUND

The SPACE trial is a multinational, prospective, randomised study to test the hypothesis that carotid artery stenting is not inferior to carotid endarterectomy for treating patients with severe symptomatic carotid artery stenosis. We did not prove non-inferiority of carotid artery stenting compared with carotid endarterectomy for the 30-day complication rate, and we now report the results at 2 years.

METHODS

Between March, 2001, and February, 2006, patients with symptomatic, severe (>or=70%) carotid artery stenosis were recruited to this non-inferiority trial and randomly assigned with a block randomisation design to have carotid artery angioplasty with stenting or carotid artery endarterectomy. 2-year endpoints include several clinical endpoints and the incidence of recurrent carotid stenosis of at least 70%. Clinical and vascular follow-up was done by a certified neurologist. Analyses were by intention to treat and per protocol. This trial is registered with ISRCTN, number 57874028.12.

FINDINGS

1 214 patients were randomly assigned (613 were randomly assigned to carotid angioplasty with stenting and 601 were randomly assigned to carotid endarterectomy). In both the intention-to-treat and per-protocol analyses the Kaplan-Meier estimates of ipsilateral ischaemic strokes up to 2 years after the procedure and any periprocedural stroke or death do not differ between the carotid artery stenting and the carotid endarterectomy groups (intention to treat 9.5%vs 8.8%; hazard ratio (HR) 1.10, 95%CI 0.75 to 1.61; log-rank p=0.62; per protocol 9.4%vs 7.8%; HR 1.23, 95%CI 0.82 to 1.83; log-rank p=0.31). In both the intention-to-treat and per-protocol populations, recurrent stenosis of 70% or more is significantly more frequent in the carotid artery stenting group compared with the carotid endarterectomy group, with a life-table estimate of 10.7% versus 4.6% (p=0.0009) and 11.1% versus 4.6% (p=0.0007), respectively. Only two incidences of recurrent stenoses after carotid artery stenting led to neurological symptoms.

INTERPRETATION

After 2 years' follow-up, the rate of recurrent ipsilateral ischaemic strokes reported in the SPACE trial is similar for both treatment groups. The incidence of recurrent carotid stenosis at 2 years, as defined by ultrasound, is significantly higher after carotid artery stenting. However, it cannot be excluded that the degree of in-stent stenosis is slightly overestimated by conventional ultrasound criteria.