Long-Term Results of Stenting versus Endarterectomy for Carotid-Artery Stenosis

Abstract

Background: In the Carotid Revascularization Endarterectomy versus Stenting Trial, we found no significant difference between the stenting group and the endarterectomy group with respect to the primary composite end point of stroke, myocardial infarction, or death during the periprocedural period or any subsequent ipsilateral stroke during 4 years of follow-up. We now extend the results to 10 years.

Methods: Among patients with carotid-artery stenosis who had been randomly assigned to stenting or endarterectomy, we evaluated outcomes every 6 months for up to 10 years at 117 centers. In addition to assessing the primary composite end point, we assessed the primary end point for the long-term extension study, which was ipsilateral stroke after the periprocedural period.

Results: Among 2502 patients, there was no significant difference in the rate of the primary composite end point between the stenting group (11.8%; 95% confidence interval [CI], 9.1 to 14.8) and the endarterectomy group (9.9%; 95% CI, 7.9 to 12.2) over 10 years of follow-up (hazard ratio, 1.10; 95% CI, 0.83 to 1.44). With respect to the primary long-term end point, postprocedural ipsilateral stroke over the 10-year follow-up occurred in 6.9% (95% CI, 4.4 to 9.7) of the patients in the stenting group and in 5.6% (95% CI, 3.7 to 7.6) of those in the endarterectomy group; the rates did not differ significantly between the groups (hazard ratio, 0.99; 95% CI, 0.64 to 1.52). No significant between-group differences with respect to either end point were detected when symptomatic patients and asymptomatic patients were analyzed separately.

Conclusions: Over 10 years of follow-up, we did not find a significant difference between patients who underwent stenting and those who underwent endarterectomy with respect to the risk of periprocedural stroke, myocardial infarction, or death and subsequent ipsilateral stroke. The rate of postprocedural ipsilateral stroke also did not differ between groups. (Funded by the National Institutes of Health and Abbott Vascular Solutions; CREST ClinicalTrials.gov number, NCT00004732.).

Figure 1. Cumulative Proportions of Patients with the Primary Composite End Point, Stroke or Death, and Any Stroke, According to Treatment Group

Shown are Kaplan–Meier estimates of event rates for the primary end point (a composite of stroke, myocardial infarction, or death from any cause during the periprocedural period or ipsilateral stroke within 10 years after randomization) (Panel A), any stroke or death during the periprocedural period or ipsilateral stroke afterward (Panel B), and any stroke (regardless of relationship with the target artery) (Panel C). The curves are shown separately for patients who were randomly assigned to carotid-artery stenting and those who were randomly assigned to carotid endarterectomy. Insets show the same data on an enlarged y axis.

Figure 2. Subgroup Analyses of the Primary Composite End Point and the End Point of Stroke or Death

Hazard ratios and associated 95% confidence intervals are shown for the primary composite end point of any stroke, death, or myocardial infarction during the periprocedural period plus ipsilateral stroke within 10 years after randomization (Panel A) and for any stroke or death during the periprocedural period plus ipsilateral stroke within 10 years after randomization (Panel B). Severe stenosis was defined as stenosis of at least 70% of the diameter of the artery, and moderate stenosis as less than 70%. The sizes of the boxes are proportional to the numbers of patients in the strata, and horizontal lines indicate 95% confidence intervals.

Figure 3. Estimated Rate of Restenosis

Restenosis was defined by the first observation of stenosis of 70% or more of the diameter of the artery on duplex ultrasonography or by ipsilateral revascularization. Ultrasonography was performed at annual visits, and therefore a restenosis reported at year 1 was observed at the 1-year clinic visit (which was performed within a 30-day window). The inset shows the same data on an enlarged y axis.