article61

ACT I

"Carotid-Artery Stenting versus Endarterectomy in Asymptomatic Patients".The New England Journal of Medicine. 2016. 374:1011-1020.PubMed•Full text•PDF

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 Outcome
8.2 Secondary Outcomes
9 Criticisms
10 Funding
11 Further Reading

Clinical Question

In asymptomatic patients 79 years or younger with severe carotid stenosis who are not considered at high risk for surgical complications, is carotid-artery stenting with embolic protection noninferior to carotid endarterectomy?

Bottom Line

Carotid-artery stenting with embolic protection is noninferior to carotid endarterectomy with respect to the primary composite end point of death, stroke, or myocardial infarction at 1 year in asymptomatic patients with severe carotid stenosis who were not at high risk for surgical complications. Overall survival and stroke rates did not differ significantly between the two groups over a period of up to 5 years.

Major Points

Carotid endarterectomy has been considered the standard treatment for reducing the risk of stroke in patients with significant carotid artery stenosis. However, carotid-artery stenting has emerged as a less invasive alternative. The Asymptomatic Carotid Trial (ACT) I sought to compare the outcomes of these two treatments in patients that were asymptomatic and at standard surgical risk.

Guidelines

As of the study's knowledge cutoff in 2016, guidelines stated that carotid revascularization is reasonable in asymptomatic patients with stenosis greater than 70% if the perioperative risk is low.

Design

Prospective multicenter randomized trial comparing carotid-artery stenting with embolic protection versus carotid endarterectomy in patients at standard risk.

Population

Patients included were 79 years of age or younger, asymptomatic with severe carotid stenosis (70-99%), and not considered high risk for surgical complications. A total of 1453 patients were enrolled in the study.

Inclusion Criteria
- Candidates for stenting and endarterectomy
- 79 years of age or younger
- Asymptomatic from neurological events at least 180 days before enrollment
- Bifurcation carotid stenosis of 70 to 99%

Exclusion Criteria
- High risk for operative complications
- Presence of substantial contralateral carotid stenosis (>60%)

Baseline Characteristics
Similar baseline demographic and medical history characteristics were noted across both groups with an average patient age of 68 years.

Interventions

Patients were randomized to undergo either carotid stenting with embolic protection or carotid endarterectomy.

Outcomes

Primary Outcome
- Composite of death, stroke, or myocardial infarction within 30 days of the procedure or ipsilateral stroke within 365 days.

Secondary Outcomes
- Composite measure of complications within 30 days postprocedure.
- Freedom from clinically driven target-lesion revascularization at 6 months, 1 year, and up to 5 years.
- Overall survival rate at 5 years.
- Freedom from non–procedure-related ipsilateral stroke and all strokes up to 5 years.

Criticisms

- Lack of comparison with contemporary medical therapy alone.
- Absence of characterization for the population screened but not enrolled.
- Trial termination before reaching planned enrollment, resulting in a reduced power of 75%.
- Inclusion of myocardial infarction in the primary composite end point, which could affect the interpretation of stenting versus endarterectomy results.

Funding

The study was supported by Abbott Vascular.