Stroke Trials Registry

NASCET
North American Symptomatic Carotid Endarterectomy Trial

Principal Investigator
Henry J. M. Barnett, M.D.

PI Address
University of Western Ontario, London, ON, Canada.

Contact Address
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada and John P. Robarts Research Institute, London, ON, Canada

Sponsor

Trial Phase:	Phase III
Study Size Actual:	2226
Centers Actual:	106
Max Time from onset:	120 Days

Status:
Trial complete. Initial results published 8/91.

Purpose:
To test the potential benefit of endarterectomy in patients with moderate or severe stenosis.

Interventions:

Endarterectomy, carotid
Surgical therapy to remove atherosclerotic plaque in narrowed carotid arteries.

Year Published: 1991

Design:
Multi-center, randomized, controlled trial of 2226 patients at 106 centers.

Inclusion Criteria
Hemispheric or retinal transient ischemic attack or a nondisabling stroke within 120 days of entry.

Exclusion Criteria
Failure to provide informed consent, lack of angiographic visualization of the symptomatic artery, intracranial stenosis more clinically significant than cervical lesion, other disease limiting life expectancy to less than 5 years, cerebral infarction eliminating useful function in the affected arterial territory, nonartherosclerotic carotid disease, cardiac lesions likely to cause cardioembolism, history of ipsilateral endarterectomy.

Patient Involvement:
Patients were divided into two predetermined categories based on the severity of carotid stenosis: 30-69% and 70-99%. Patients were then randomly assigned to receive carotid endarterectomy or medical care alone. All patients received optimal medical care, including antiplatelet therapy.

Primary Outcome:
Fatal or nonfatal stroke ipsilateral to the stenosis for which the patient underwent randomization. Assessment was made at 1, 3, 6, 9, and 12 months and every 4 months thereafter.

Secondary Outcome:
All strokes and deaths.

Results:
The risk of ipsilateral stroke was reduced significantly (p=0.045) in patients with carotid stenosis 50-69% who received carotid endarterectomy. Patients with stenosis of 70-99% showed the most significant reduction (p < 0.001) in the rate of ipsilateral stroke while patients with stenosis of <50% did not show a significantly lower rate of ipsilateral stroke.

Source of Information:
Published reports 1991, 1998.

Web Links and Publications:

Reanalysis of the final results of the European Carotid Surgery Trial
Stroke 2003;34:514-523

Prognosis after transient monocular blindness associated with carotid-artery stenosis.
N Engl J Med. 2001 Oct 11;345(15):1084-90.

Causes and severity of ischemic stroke in patients with internal carotid artery stenosis.
JAMA. 2000 Mar 15;283(11):1429-36.

The causes and risk of stroke in patients with asymptomatic internal-carotid-artery stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators.
N Engl J Med. 2000 Jun 8;342(23):1693-700.

The North American Symptomatic Carotid Endarterectomy Trial : surgical results in 1415 patients.
Stroke 1999 Sep;30(9):1751-8.

Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators.
N Engl J Med 1998 Nov 12;339(20):1415-25

The risks and benefits of carotid endarterectomy in patients with near occlusion of the carotid artery. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Group.
Neurology 1997 Apr;48(4):911-915

Prevention of functional impairment by endarterectomy for symptomatic high-grade carotid stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators.
JAMA. 1994 Apr 27;271(16):1256-9.

North American Symptomatic Carotid Endarterectomy Trial. Methods, patient characteristics, and progress.
Stroke 1991 Jun;22(6):711-20.

Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators.
N Engl J Med 1991 Aug 15;325(7):445-453

This information last updated on: 11/30/2000

Reviewed on: 08/20/2008.

UID: 22