The Adapt carotid stent, when used in conjunction with the FilterWire EZ embolic protection device, is a safe and effective treatment option for patients with carotid artery stenosis who are at high risk for surgery, Dierk Scheinert, Center of Vascular Medicine, Park Hospital Leipzig, Germany, told delegates at the LINC conference.
The ASTI trial has been designed to answer whether carotid artery stenting and, specifically, the Adapt stent in combination with FilterWire EZ (both from Boston Scientific), is a safe and effective solution in patients at high risk for endarterectomy, who require revascularisation to treat extracranial carotid stenosis.
ASTI is a prospective, multicentre, single-arm trial, with 100 patients enrolled in 11 centres in Belgium, Germany and Spain. Follow-up was scheduled at 30 days and 12 months and includes clinical and neurological assessments and duplex ultrasound. The primary endpoint is a composite rate of death, stroke and myocardial infarction up to 30 days after the procedure. The principal investigator is Marc Bosiers, AZ St Blasius Hospital in Dendermonde, Belgium.
“Long-term safety and effectiveness of NexStent carotid stent (Boston Scientific), used in conjunction with FilterWire EZ embolic protection device, was demonstrated in the CABERNET trial. The Adapt carotid stent is the second generation of the NexStent, which is no longer commercialised,” Scheinert said.
The Adapt Monorail device is a self-expanding nitinol stent, with a closed cell design and is a “one size fits all” in terms of diameter as it can be adapted to 4–9mm diameter. He noted that improvements in the Adapt device include additional lengths (21 and 40mm) and markers at the proximal and distal ends to enhance visibility. The delivery system has also been enhanced for improved placement accuracy, with an improved tip design for increased security. Of the 100 patients enrolled in ASTI, 32 were symptomatic and 63 asymptomatic. At 30 days, 92 patients were available for follow-up. All the lesions were located in the interior carotid artery and the mean length was 14.4±5.6mm.
The results at 30 days showed a 5.4% event rate for the composite endpoint of death, stroke and myocardial infarction. All the events were ipsilateral strokes – 2.2% were major, haemorrhagic strokes; 3.2% were minor, ischaemic strokes. By symptom status, the stroke rate was 3.6% in the symptomatic group and 6.7% among asymptomatic patients. A total of 2.2% of patients had transient ischaemic attacks and 1.1% had stent thrombosis.
In conclusion, Scheinert noted, the use of the Adapt stent with the FilterWire EZ produced a low and acceptable rate of major adverse events through 30 days postprocedure. “Results from the ASTI trial suggest that stenting with embolic protection is, in general, a safe alternative to carotid endarterectomy for patients with high surgical risk,” he said.