Research presented in a six-hour symposium on carotid artery disease at the 29th Annual Scientific Meeting of the Society of Interventional Radiology showed carotid artery stenting to be safe and effective for highrisk patients.
Currently, the standard of care for stroke prevention in patients with moderate to severely blocked carotid arteries is carotid endarterectomy surgery. The ARCHeR trials treated patients who were high-risk surgical candidates with carotid artery stenting with and without embolic protection, a device to capture debris that may break off during the procedure.
This multi-center study at 48 sites in the U.S., Europe and Argentina included 581 consecutive patients in a series of three, single arm trials. The ARCHeR 1 trial used just the stent, the ARCHeR 2 trial included the stent plus embolic protection, and the ARCHeR 3 used a newer version of the catheters for delivering the stent and embolic filter, known as the rapid exchange system.
The 30-day adverse event rate counting all strokes, deaths or heart attacks were 7.6, 8.6, and 8.3 percent for ARCHeR 1, 2, and 3 respectively. The incidence of major stroke or death in the first 30 days was low in all trials; 3.8, 2.5 and 2.8 percent, for ARCHeR 1, 2, and 3 respectively.
One-year data is available for ARCHeR 1 and 2 and this composite endpoint includes the 30-day event rate for stroke, death and heart attack plus stroke on the same side as the carotid stent (ipsilateral stroke) up to 12 months. At one year, the major adverse event rate (MAE) was 8.3 percent and 10.2 percent for ARCHeR 1 and 2, respectively. The one-year data is still being collected for ARCHeR 3.
The studies, sponsored by Guidant Corporation, used the ACCULINK stent and the ACCUNET embolic protection filter. The comparative rates for the surgery, using the same composite endpoint for one year, is 14.5 percent, based on the rates in the published medical literature for both carotid endarterectomy surgery and for medical therapy in high-surgical risk patients. This literature control was used so that patients at high risk for surgery were not subjected to surgery.
“This study shows that carotid stenting is safe, even in the high-risk group,” says interventional radiologist Mark Wholey, M.D., an ARCHeR trial principal investigator presenting this data at the Society of Interventional Radiology’s Annual Scientific Meeting. Because the carotid surgery is an established safe treatment, the study only included those patients who were high risk because they were too sick for surgery or anatomically would not have been good surgical candidates. “We are excited that we are getting proof of carotid stenting in the high-risk group, and we look forward to the results of studies like CREST that are studying stenting in lower risk populations; although we certainly expect it to be safer than surgery in low-risk populations, too,” says Wholey.
The rate at which the artery became reblocked and required a repeat procedure at one year was low, at 2.2 percent for ARCHeR 1 and 2.8 percent for ARCHeR 2. “This is quite good because the known published rate for the artery to reblock after the surgery is 4 to 7 percent. So carotid stenting is a durable procedure that is more effective than the surgery in keeping the vessel open, with less need for retreatment.