Abstract 3: Restenosis following Carotid Artery Stenting and Endarterectomy in the Carotid Revascularization Endarterectomy versus Stenting Trial

Abstract

Objectives The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) showed no difference in the composite endpoint of stroke, myocardial infarction, or death between carotid artery stenting (CAS) and carotid endarterectomy (CEA) in patients with symptomatic or asymptomatic carotid stenosis (CS). We compared restenosis or occlusion, and repeat revascularization, between CAS and CEA over 2 years of follow-up. Methods Restenosis, occlusion, and repeat revascularization were assessed at 1, 6, 12 and 24 months post-randomization. Hemodynamically significant restenosis (≥70% diameter reduction) was defined by a peak systolic velocity (PSV) ≥300 cm/second on standardized duplex ultrasonography (DUS), occlusion by an absence of flow within the target artery on DUS, and repeat revascularization by any additional procedure (CEA, angioplasty or CAS) performed on the index artery. Studies were performed in CREST-certified laboratories and interpreted in the CREST Ultrasound Core Lab. Patients included in this report were those who received their assigned treatment within 30 days of randomization and had an ultrasound reviewed at the Core Lab (n=2191). Treatment differences were assessed using proportional hazards models adjusting for age, sex, and symptomatic status. Results In the analytic cohort, 1086 patients received CAS and 1105 received CEA. Over 2 years 113 patients developed restenosis, 56 (rate 5.8%) in the CAS group and 57 (rate 5.8%) in the CEA group; and 8 developed an occlusion, 3 (rate 0.3 %) in the CAS group and 5 (rate 0.5%) in the CEA group. The combined restenosis-occlusion rate was 6.0% (n=58) for CAS and 6.3% (n=62) for CEA (HR=0.90, 95% CI=0.63-1.29, p=0.58). Forty-three patients of the 2191 underwent repeat revascularization (20 CAS, 23 CEA, p=0.69) of which 28 had restenosis by our criteria and so were included ( Figure ). Stroke occurred in 13 (4 CAS; 9 CEA) of the 120 patients with restenosis or occlusion; 1 of the 4 CAS strokes occurred after restenosis was detected, and 5 of 9 CEA strokes occurred after restenosis was detected. Conclusions This analysis of carotid restenosis is the largest reported to date from any randomized clinical trial. Restenosis and occlusion were infrequent and similar up to 2 years following CAS or CEA among 2191 patients. The rates of revascularization likewise did not differ between CAS and CEA. Follow-up out to 10 years is ongoing. Figure. Kaplan-Meier curves of restenosis and occlusion over 2 years.