The FDA has approved the NexStent carotid stent and monorail delivery systems, and the FilterWire EZ Embolic Protection System (EPS) for use in patients with carotid artery disease who are at high risk for surgery.
The NexStent Carotid Stent is manufactured by EndoTex Interventional Systems and has been distributed exclusively by Boston Scientific outside the US since receiving European CE mark approval in 2005. Boston has since acquired EndoTex, under the terms of the companies’ existing agreements (following FDA approval).
The NexStent Carotid Stent is a laser-cut, nitinol stent with a rolled sheet design that enables one stent size to adapt to multiple diameters in tapered or non-tapered vessel configurations. Its self-sizing feature is designed to provide adaptability when treating lesions in the carotid arteries, and its closed-cell configuration is designed to increase lesion coverage and provide a smooth inner lumen to help facilitate delivery and retrieval of ancillary devices. Accordin to Boston, the NexStent Carotid Stent provides an effective, low profile option for physicians who want a high degree of flexibility and plaque stabilisation.
FilterWire EZ is a low-profile embolic filter mounted on a 0.014″ guide wire that is delivered through a monorail exchange delivery catheter. The FilterWire EX System is Boston Scientific’s first-generation embolic protection product. It is also the first filter-based system cleared for treatment of saphenous vein graphs in the US.
“This is an innovative stenting system that interventionalists in the US have been waiting for,” said Dr Subbarao Myla, co-principal investigator of the CABERNET Trial, of Hoag Memorial Hospital in Newport Beach, CA. “Study results demonstrate excellent outcomes at one month – when there is the greatest risk of procedure-related stroke – through one year in patients with a wide range of lesions and vessel anatomy.”
Boston’s FilterWire EZ Embolic Protection System was studied together with the NexStent, in the Carotid Stent in the Carotid Artery Revascularization Using the Boston Scientific FilterWire EX/EZ and the EndoTex NexStent (CABERNET) clinical trial.
Principal Investigator Dr L Nelson Hopkins, Professor & Chairman of Neurosurgery at the University at Buffalo, State University of New York, said, “These results compare very favourably with other similar US high risk carotid artery stenting trials and appear competitive with the major carotid endarterectomy trials.”
According to Boston, interim data presented from the CABERNET study as well as data from other carotid stent studies has begun to demonstrate that carotid stenting in conjunction with embolic protection may have efficacy that is comparable to or better than surgical interventions. CABERNET was designed to evaluate the safety and efficacy of carotid artery stenting as a minimally invasive alternative for treating carotid artery disease and reducing the risk of stroke in patients either ineligible or at high risk for surgery. The trial was a prospective, non-randomised, multi-centre, single-arm clinical study. It was performed to demonstrate the safety and efficacy of the devices when used to treat high-risk, surgical and non-surgical, symptomatic (> or = 50% stenosis) and asymptomatic (> or = 80% stenosis) subjects with disease in the internal carotid artery. A total of 454 patients were enrolled at 19 clinical sites (15 in the US and four international sites). CABERNET patients were also grouped according to whether they were symptomatic (24.4%) or asymptomatic (75.6%).
In patients enrolled in the study, the 30-day composite major adverse event (MAE) rate, defined as all-cause stroke, death and myocardial infarction (MI) — was 3.8%. This corresponds to a per-patient breakdown of MAE events to include: death, 0.5%; stroke, 3.4%; and MI, 0.2%, and compares favorably to other high-risk carotid artery stenting trials. The NexStent device success, defined as successful delivery and placement of the stent at the intended target site was 96.9%. The device success for the FilterWire EX and EZ, defined as FilterWire successfully placed within the target vessel, was 99.1%. Both reported device success rates correspond to a per-patient assessment.
The composite endpoint score of all death, all stroke and all MI (3.8%) in the CABERNET study is comparable to the 5.4% rate reported in the BEACH study and the 7.8% rate reported in both the SAPPHIRE and ARCHER 2 studies.
The results show that the composite major adverse event (MAE) rate at one-year (defined as any death, stroke or MI < or = 30 days post-procedure plus any ipsilateral stroke including any death as a result of an ipsilateral stroke from 31-365 days) was 4.5% (death 0.5%, stroke 4.0%, MI 0.2%).
“We are pleased to now offer US physicians the benefits of the FilterWire EZ System in conjunction with the NexStent Carotid Stent to offer a less-invasive alternative to treating carotid artery disease and help reduce the devastating effects of stroke,” said John Pedersen, president of Boston Scientific’s Peripheral Interventions business. “With its second cleared indication, the FilterWire EZ System offers innovation and versatility to treat a variety of lesions and cases seen in every day practice.”