At American College of Cardiology Scientific Sessions in New Orleans, Guidant presented positive results for its ACCULINK for Revascularisation of Carotids in High Risk Patients (ARCHeR) series of clinical trials.

The ARCHeR trials were 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 ARCHeR trials treated high-risk patients and featured Guidant's ACCULINK carotid stent systems and ACCUNET embolic protection systems, devices designed specifically for use in the carotid artery. The prospective, non-randomised, single-arm trials enrolled 581 registry patients at 48 sites in North America, Europe and Argentina. The trials enrolled symptomatic patients with occlusions of 50% or greater and asymptomatic patients with occlusions of 80% or greater. All the patients had at least one risk factor that made them either ineligible for surgery or a high-risk surgical candidate, and approximately 42% of the patients had two or more of these risk factors.

Final one-year results for ARCHeR 1 and ARCHeR 2, and final 30-day results for ARCHeR 3 were presented at the American College of Cardiology Scientific Sessions 2004 meeting in New Orleans by William Gray, Director of Endovascular Care at the Swedish Medical Center in Seattle, Washington, and an Executive Committee member overseeing the ARCHeR trials.

ARCHeR 1 and 2: The trials enrolled 158 and 278 high-risk patients, respectively. Patients in ARCHeR 1 were treated with the over-the-wire ACCULINK carotid stent system. Patients in ARCHeR 2 received the over-the-wire ACCULINK carotid stent system and the over-the-wire ACCUNET embolic protection system, which is designed to trap particles of atherosclerotic plaque. The 12-month composite primary endpoint of all death, stroke and myocardial infarction (MI) in the first 30 days, plus any ipsilateral stroke (strokes in the same territory of the lesion) between 31 days and one year was 8.3% in ARCHeR 1 and 10.2% in ARCHeR 2. By comparison, the data associated with the high-risk surgical historical control group indicated a rate of incidence of these events of 14.5%.

ARCHeR 3: This trial enrolled 145 high-risk patients and was designed to show equivalence in the safety and performance of the next-generation rapid exchange (RX) versions of ACCULINK and ACCUNET with the first-generation over-the-wire devices used in ARCHeR 2. The combined death, stroke and myocardial infarction rate at 30 days was 8.3%, establishing equivalence with the devices used in ARCHeR 2.

An important safety parameter in any stroke prevention trial is the rate of major stroke and death. At 30 days, the rate of major stroke and death across ARCHeR 1, 2 and 3 was 3.8%, 2.5%, and 2.8%, respectively. From 31 days to one year, there were no major ipsilateral strokes in ARCHeR 1, and only one in ARCHeR 2.

"Results from the ARCHeR trials point to the potential of carotid artery stenting as an effective therapy for the thousands of patients with carotid artery disease who, because of their risk and co-morbidity factors, are not well-treated by standard carotid surgery," said Dr Gray. "Carotid stenting appears poised to become a realistic treatment option for these high-risk patients."

In addition to the ARCHeR trials, Guidant is participating in the CREST (Carotid Revascularisation Endarterectomy vs. Stent Trial) study of carotid artery stenting versus surgery in a patient population at lower risk than those studied in the ARCHeR trials. Sponsored by the National Institute of Neurological Disorders and Stroke (NINDS), and the National Institutes of Health (NIH), CREST is a randomised clinical trial to evaluate the efficacy of carotid artery stenting as compared to carotid endarterectomy surgery in preventing stroke, myocardial infarction and death in the 30-day period immediately following the procedure, and ipsilateral stroke during a multi-year follow-up. Guidant supports CREST by supplying ACCULINK and ACCUNET devices that are used to treat patients enrolled in the trial. The University of Medicine and Dentistry of New Jersey is responsible for the IDE sponsorship, management of trial sites and all FDA submissions for CREST.