Condition category
Circulatory System
Date applied
23/10/2000
Date assigned
23/10/2000
Last edited
18/09/2017
Prospective/Retrospective
Retrospectively registered
Overall trial status
Ongoing
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Carotid stenosis is a condition where one or both of the carotid arteries (the main blood vessels that supply the head and neck) become narrowed due to a build-up of fatty deposits (plaque). This increases the risk of having a stroke, when the blood supply to part of the brain is cut off. The aim of this study is to compare carotid surgery (carotid endarterectomy or CEA) with the best medical treatment (BMT) in patients with carotid stenosis but no symptoms. The aim of this study is to find out whether CEA and BMT together improve stroke-free survival time when compared to BMT alone. The study also aims to identify high-risk groups for whom the benefits of surgery and of BMT are increased and the long-term follow-up is looking at whether carotid endarterectomy reduces the risk of dementia in the long-term.

Who can participate?
Patients whose carotid stenosis has not caused symptoms for at least 6 months, and who have no past history of stroke

What does the study involve?
Participants are randomly allocated to be treated with either CEA plus BMT or BMT alone, unless symptoms develop requiring a CEA. Fatal and non-fatal stroke and death rates are compared between the two groups. For long-term follow-up the UK and Swedish participants' health records are also analysed for rates of stroke, death and dementia in the long-term. Relatives or friends of the UK participants are also asked to complete a postal questionnaire about the participant’s cognitive (mental) function.

What are the possible benefits and risks of participating?
There is no direct benefit to taking part but the information gained may help doctors to treat patients with asymptomatic carotid disease better in the future. There is no additional risk to taking part in this study.
Long-term follow-up: there is no direct benefit to taking part but this follow-up may contribute to a wider benefit if carotid surgery is found to reduce the risk of developing later memory and thinking problems. The long-term follow-up does not involve any additional physical risk to the participants or does not provide any risk in relation to loss of anonymity.

Where is the study run from?
John Radcliffe Hospital (UK)

When is the study starting and how long is it expected to run for?
April 1993 to December 2018

Who is funding the study?
1. Medical Research Council (MRC) (UK)
2. Alzheimer’s Society (UK)

Who is the main contact?
Alison Halliday
acst@nds.ox.ac.uk

Trial website

http://acst-2.org/acst-1%20long%20term%20follow-up.html

Contact information

Type

Scientific

Primary contact

Miss Alison Halliday

ORCID ID

http://orcid.org/0000-0001-9828-3579

Contact details

ACST Trials Office
Level 6
West Wing
John Radcliffe Hospital
Headley Way
Oxford
OX3 9DU
United Kingdom
+44 (0)1865 223073
acst@nds.ox.ac.uk

Type

Public

Additional contact

Ms Mary Sneade

ORCID ID

http://orcid.org/0000-0002-8860-0363

Contact details

ACST trials office
Richard Doll Building
Old Road Campus
Roosevelt Drive
Oxford
OX3 7LF
United Kingdom
+44 (0) 1865 617978
acst@nds.ox.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

G9408332

Study information

Scientific title

Asymptomatic Carotid Surgery Trial (ACST-1)

Acronym

ACST-1

Study hypothesis

The aim is to determine whether CEA and BMT improve stroke-free survival time when compared to BMT alone. The trial will also help identify high-risk groups in whom the benefits of surgery and of BMT would be increased.

Added 21/02/2017:
Primary objective: In participants with carotid stenosis, does carotid endarterectomy reduce the long-term risk of dementia, stroke or death related to carotid stenosis?
Secondary objective: In patients with carotid stenosis, does the long-term risk of dementia, stroke or death in recorded electronic records vary by duration of follow up, or participant characteristic recorded at baseline?

Ethics approval

London Research Ethics Committee, 11/11/1998, ref: 98/2/92

Study design

Randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Treatment

Patient information sheet

Not available in web format, please use contact details to request a participant information sheet

Condition

Carotid stenosis

Intervention

CEA and best medical treatment (BMT) vs BMT alone

Added 19/08/2008: follow-up is a minimum of 5 years

Added 21/02/2017:
No further treatment interventions are planned as part of the long-term follow-up study.
Phase 1: Analysis of long-term data from UK and Swedish ACST-1 participant’s health records through electronic data linkage (NHS digital, UK; Socialstyrelsen, Sweden) for specific outcomes of incident stroke, death and dementia (16/SC/0406). The trialists will also be applying to the equivalent regulatory authorities in Scotland and Northern Ireland.
Phase 2: A relative or friend of the ACST-1 UK participants will be invited to complete a postal questionnaire (Informant Questionnaire on Cognitive decline in the Elderly-IQCODE) on the participant’s cognitive function.

Intervention type

Other

Phase

Not Specified

Drug names

Primary outcome measures

Fatal and non-fatal stroke and death rates

Added 10/03/2017:
Long-term follow-up to determine specific outcomes of stroke and cognitive decline:
1. Long-term risk of dementia, stroke or death, measured using participant’s health records through electronic data linkage (NHS digital, UK; Socialstyrelsen, Sweden) at least 14 years post enrolment
2. Cognitive function, measured using the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), MoCA and TICS-N, at least 14 years post enrolment

Secondary outcome measures

Subsidiary analyses in an effort to identify high and low risk groups will include the effect of risk factors such as presence or absence of silent cerebral infarction on clinical outcome

Overall trial start date

01/04/1993

Overall trial end date

31/12/2018

Reason abandoned

Eligibility

Participant inclusion criteria

1. Patients whose carotid stenosis has not caused symptoms for at least 6 months
2. No past history of ipsilateral disabling or severe contralateral stroke
3. No clear indications or contraindications to carotid endarterectomy (CEA)

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

3120; 1601 for long-term follow-up

Participant exclusion criteria

1. Patients with a small likelihood of worthwhile benefit e.g. those with major life-threatening disease.
2. Patients who have had recent myocardial infarct, intracerebral neoplasia or aneurysm, or restenosis of an artery following previous CEA

Recruitment start date

19/04/1993

Recruitment end date

01/05/2003

Locations

Countries of recruitment

Austria, Belgium, Brazil, Bulgaria, Canada, Croatia, Cyprus, Czech Republic, Finland, France, Germany, Greece, Hungary, Ireland, Israel, Italy, Netherlands, New Zealand, Norway, Poland, Portugal, Russian Federation, Slovenia, Spain, Sweden, Switzerland, Tunisia, United Kingdom, United States of America

Trial participating centre

John Radcliffe Hospital
Oxford
OX3 9DU
United Kingdom

Trial participating centre

123 other centres
-

Sponsor information

Organisation

Medical Research Council (MRC) (UK)

Sponsor details

20 Park Crescent
London
W1B 1AL
United Kingdom
+44 (0)20 7636 5422
clinical.trial@headoffice.mrc.ac.uk

Sponsor type

Research council

Website

http://www.mrc.ac.uk

Organisation

University of Oxford

Sponsor details

Research Services
Clinical Trials and Research Governance (CTRG)
Joint Research Office
Block 60
Churchill Hospital
Headington
Oxford
OX3 7LE
United Kingdom
-
ctrg@admin.ox.ac.uk

Sponsor type

University/education

Website

Funders

Funder type

Research council

Funder name

Medical Research Council (MRC) (UK)

Alternative name(s)

MRC

Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government

Location

United Kingdom

Funder name

Alzheimer's Society

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

professional associations and societies

Location

United Kingdom

Results and Publications

Publication and dissemination plan

The long-term follow-up results are anticipated to be published end of 2017-2018 in peer-reviewed journals and relevant scientific forums and conferences.

IPD sharing plan
The datasets generated during and/or analysed during the current study are not expected to be made available.

Intention to publish date

01/10/2018

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

2004 results in: http://www.ncbi.nlm.nih.gov/pubmed/15135594
2010 results in: http://www.ncbi.nlm.nih.gov/pubmed/20870099
2013 results in: http://www.ncbi.nlm.nih.gov/pubmed/23632980
2016 results in: http://www.ncbi.nlm.nih.gov/pubmed/27435205
2016 results in: http://www.ncbi.nlm.nih.gov/pubmed/27322379
2016 results in: http://www.ncbi.nlm.nih.gov/pubmed/27111809
2016 results in: http://www.ncbi.nlm.nih.gov/pubmed/26725253

Publication citations

  1. Results

    Halliday A, Mansfield A, Marro J, Peto C, Peto R, Potter J, Thomas D, , Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: randomised controlled trial., Lancet, 2004, 363, 9420, 1491-1502, doi: 10.1016/S0140-6736(04)16146-1.

  2. Results

    Halliday A, Harrison M, Hayter E, Kong X, Mansfield A, Marro J, Pan H, Peto R, Potter J, Rahimi K, Rau A, Robertson S, Streifler J, Thomas D, , 10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trial., Lancet, 2010, 376, 9746, 1074-1084, doi: 10.1016/S0140-6736(10)61197-X.

Additional files

Editorial Notes

18/09/2017: Contact details updated. 21/02/2017: The following changes were made to the trial record: 1. The overall trial end date was changed from 31/03/2004 to 31/12/2018. 2. The target number of participants was changed from '3120' to '3120; 1601 for long-term follow-up'. 3. Alzheimer’s Society was added as a funder for the long-term follow up. 4. The acronym was changed from ACST to ACST-1. 5. Austria, Belgium, Brazil, Bulgaria, Canada, Croatia, Cyprus, Czech Republic, Finland, France, Germany, Greece, Hungary, Ireland, Israel, Italy, New Zealand, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, Netherlands, Tunisia and USA were added to the countries of recruitment. 6. University of Oxford was added as a sponsor. 27/01/2017: Publication references added.