The analysis comprised 2,544 patients, 1,637 of whom were randomized to stenting, and 907 of whom were randomized to endarterectomy. The population included more than 1,000 patients with 3-year follow-up and more than 500 with 4-year follow-up. Patients randomized to stenting were slightly younger, but the percentage of patients older than age 65 was similar between groups. Current cigarette smoking was slightly more common among patients randomized to stenting. The groups were well balanced by sex, race, and risk factors such as hypertension, hyperlipidemia, and diabetes.
The rate of primary endpoint events was 5.3% in the stenting arm and 5.1% in the endarterectomy arm (hazard ratio with stenting, 1.02; 95% confidence interval, 0.7-1.5; P = .91). The rate of periprocedural stroke was 2.7% in the stenting arm and 1.5% in the endarterectomy arm (P = .07). The rate of periprocedural myocardial infarction was 0.6% in the stenting arm and 1.7% in the endarterectomy arm (P = .01). The rate of periprocedural stroke and death was 2.7% in the stenting arm and 1.6% in the endarterectomy arm (P = .07). The rate of 4-year ipsilateral stroke was 2.3% in the stenting arm and 2.2% in the endarterectomy arm (P = .97).
A secondary analysis indicated that the cumulative, 4-year rate of stroke-free survival was 93.2% in the stenting arm and 95.1% in the endarterectomy arm (P = .10). “Almost all this difference is the initial periprocedural hazard difference,” said Dr. Matsumura. The rate of cumulative 4-year survival was 91% in the stenting arm and 90.2% in the endarterectomy arm.
The results of the pooled analysis do not support the perception that stenting entails an increased risk of periprocedural stroke. “The majority of trials have been in symptomatic patients,” said Dr. Matsumura. “We’re studying asymptomatic patients. We’re also studying them in the context of second-generation devices.” The results may reflect the amount of device-related training that the researchers undertook, as well as the decision to use single-stent dedicated carotid systems, he added.
Sponsors of the analysis included the University of Wisconsin, Massachusetts General Hospital, the Medical University of South Carolina, the University of Alabama at Birmingham, Cardiovascular Associates, and Mayo Clinic Jacksonville.