Objective: Data regarding the long-term efficacy of carotid artery stenting (CAS) are still scarce. As demonstrated by several major randomized controlled trials (RCT) comparing the efficacy of carotid endarterectomy (CEA) vs medical therapy, even after successful carotid revascularization late ipsilateral stroke occurs in 5-13% at 5 years. Therefore, major concerns also remain about the durability of the CAS procedure in terms of stroke prevention. The purpose of this study was to review long-term results after carotid stent implantation in a large cohort of patients.
Methods: This retrospective investigation involved 3179 CAS procedures performed at four European carotid high-volume centers. Echo-duplex scan using modified velocity criteria to recognize in-stent restenosis (ISR) and neurological examinations of all patients were carried out every 6 months after the procedure. Life-table analysis was used to determine freedom from mortality, stroke-related death, ipsilateral fatal/major stroke, and any ipsilateral stroke. Freedom from ISR and from reintervention were also reported. The secondary aim was to identify predictive risk factors for neurological complications and ISR.
Results: At 5 years freedom from mortality, stroke-related death, ipsilateral fatal/major stroke, and any stroke rate were 82%, 93.5%, 93.3%, and 91.9%, respectively. The only predictor for neurological complications was the presence of neurological symptoms before CAS (hazard ratio 1.38 [CI 1.05, 1.82] P = .02). Freedom from restenosis at 1, 3, and 5 years was, respectively, 98.4%, 96.1%, and 94%. Uni- and multi-variate analyses showed that stent characteristics (material/design/free-cell area) were not significantly associated with time to in-stent restenosis or time to reintervention.
Conclusion: Our long-term results in a large cohort of patients validated CAS as a durable procedure for stroke prevention. The annual rate of neurological complications after CAS was comparable to that of conventional surgery as demonstrated by large RCTs involving both symptomatic patients (North American Symptomatic Carotid Endarterectomy Trial [NASCET] and European Carotid Surgery Trial [ECST]) and asymptomatic patients (Asymptomatic Carotid Atherosclerosis Study [ACAS] and Asymptomatic Carotid Surgery Trial [ACST]).