Carotid Stent Fractures Are Not Associated With Adverse Events: Results From the ACT-1 Multicenter Randomized Trial (Carotid Angioplasty and Stenting Versus Endarterectomy in Asymptomatic Subjects Who Are at Standard Risk for Carotid Endarterectomy With Significant Extracranial Carotid Stenotic Disease).

BACKGROUND: The impact of carotid artery stent fractures on the incidence of adverse clinical events remains unclear. The objective of this study is to report the stent fracture rate and its association with in-stent restenosis and adverse outcomes in the ACT-1 trial (Carotid Angioplasty and Stenting Versus Endarterectomy in Asymptomatic Subjects Who Are at Standard Risk for Carotid Endarterectomy With Significant Extracranial Carotid Stenotic Disease).

METHODS: ACT-1 is a prospective multicenter trial of patients who have standard surgical risk with severe asymptomatic carotid artery stenosis randomly assigned to carotid artery stenting or carotid endarterectomy (Abbott Vascular). The primary end point was a composite of death, stroke, or myocardial infarction during the 30 days after the procedure or ipsilateral stroke during the 365 days after the procedure. After 771 patients were enrolled, successively randomly assigned patients were required to undergo annual radiographic (x-ray) analysis for stent fracture. Images were independently adjudicated by a core laboratory.

RESULTS: Of 1021 patients treated with carotid artery stenting during a mean follow-up of 3.1±1.6 years, 939 had at least 1 x-ray during the follow-up period. Stent fracture was reported in 51 (5.4%) patients. With a maximum follow-up period of 5 years, adverse clinical outcomes occurred in 39 patients with at least 1 x-ray during the follow-up. Of 826 (80.9%) subjects who underwent both duplex ultrasound and x-ray, 822 (99.5%) were interpretable. There was no association between stent fracture and the primary end point ( P =0.86) or with restenosis ( P =0.53).

CONCLUSIONS: In this large, independently adjudicated, multicenter study, the stent fracture rate was low and not associated with major adverse clinical events or in-stent restenosis.

CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00106938.