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"Carotid Endarterectomy for Moderate Stenosis".The New England Journal of Medicine. Date. Volume(Issue):pages.
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1 Clinical Question
2 Bottom Line
3 Major Points
4 Guidelines
5 Design
6 Population
6.1 Inclusion Criteria
6.2 Exclusion Criteria
6.3 Baseline Characteristics
7 Interventions
8 Outcomes
8.1 Primary Outcomes
8.2 Secondary Outcomes
9 Criticisms
10 Funding
11 Further Reading

Clinical Question

Does carotid endarterectomy in patients with symptomatic moderate carotid stenosis reduce the risk of stroke, and is the benefit of endarterectomy in patients with severe stenosis durable over eight years of follow-up?

Bottom Line

Carotid endarterectomy in patients with symptomatic moderate carotid stenosis (50 to 69 percent) provided a moderate reduction in the risk of stroke. No benefit was observed in patients with less than 50 percent stenosis. For severe stenosis (≥70 percent), the benefit of endarterectomy was durable at eight-year follow-up.

Major Points

The study assessed the efficacy of carotid endarterectomy in patients with symptomatic moderate carotid stenosis (defined as <70 percent) and confirmed the long-term benefit in patients with severe stenosis over an eight-year period. A moderate risk reduction was noted in the moderate stenosis group, requiring 15 patients to be treated to prevent one stroke over five years. There was no significant benefit in patients with less than 50 percent stenosis, while the benefit remained substantial and durable for those with severe stenosis.

Guidelines

Current guidelines for carotid endarterectomy should take this study into account, especially for patients with moderate stenosis where the benefit is more modest and dependent on risk factors as well as the skill and experience of the surgical team.

Design

- Multicenter, randomized, controlled trial.
- N=2226 patients.
- Stratification according to stenosis severity (50 to 69 percent vs. <50 percent).
- Interventions: Carotid endarterectomy (1108 patients) or medical care alone (1118 patients).
- Mean follow-up of 5 years.

Population

- Patients who had transient ischemic attacks or nondisabling strokes ipsilateral to moderate carotid stenosis within 180 days before study entry were included.
- Patients over 80 years were excluded initially but were included later.
- Patients with severe stenosis were enrolled in the first phase and followed throughout the trial.

Inclusion Criteria
- Focal cerebral ischemia symptoms ipsilateral to less than 70 percent stenosis in the internal carotid artery within 180 days before enrollment.
- Nondisabling stroke (Rankin score <3) or transient symptoms persisting less than 24 hours.

Exclusion Criteria
- Lack of angiographic visualization of the symptomatic artery, significant intracranial stenosis, other life-limiting diseases, severe infarction, nonatherosclerotic carotid disease, risk of cardioembolism, or previous ipsilateral endarterectomy.

Baseline Characteristics
- Well-balanced between surgical and medical groups.

Interventions

- Carotid endarterectomy versus medical therapy.
- Medical therapy included antiplatelet medication, antihypertensive and lipid-lowering drugs as indicated.
- Surgical technique was left to surgeon's discretion.

Outcomes

Primary Outcomes
- Five-year rate of any ipsilateral stroke.
- Moderate stenosis (50 to 69 percent): surgical group 15.7%, medical group 22.2% (P=0.045).
- Less than 50 percent stenosis: no significant difference between groups.

Secondary Outcomes
- Durability of benefit in severe stenosis group: death or disabling ipsilateral stroke rate at 30 days was 2.1%, increasing to only 6.7% at 8 years.

Criticisms

- The modest benefit in the moderate stenosis group highlights the importance of careful patient selection and surgical expertise for positive outcomes.
- Nonvalidated use of ultrasonography and other noninvasive methods for measuring stenosis severity is a potential concern.

Funding

- Funded by a grant from the National Institute of Neurological Disorders and Stroke.