Acute Coronary SyndromePhase 4NCT03252249

Duration of Dual Anti-Platelet Therapy (DUAL-ACS)

A Phase 4 study testing 3 months dual anti-platelet therapy and 12 months dual anti-platelet therapy in people with Acute Coronary Syndrome and Coronary Artery Disease, run by University of Edinburgh at 49 sites in 2 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

Who is it for?: Ages 18 years and older
Conditions the study is for: Acute Coronary Syndrome, Coronary Artery Disease
What is being tested?: 3 months dual anti-platelet therapy and 12 months dual anti-platelet therapy
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 5,094 participants
Where: 49 sitesin 2 countries
Study dates: 26 Apr 2018to 4 Feb 2023
Phase: Phase 4
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Aged ≥18 years
Clinical diagnosis of Type 1 myocardial infarction within 12 weeks
In the opinion of the attending clinician requires dual anti-platelet therapy with aspirin and a P2Y12 receptor antagonist
Resident in the country of recruitment with their unique health identifier
The attending clinician has equipoise regarding the duration of therapy
Provision of informed consent

Who cannot join

Clear indication for specific duration of dual anti-platelet therapy
Type 2 myocardial infarction
Contraindication to aspirin or P2Y12 receptor antagonist
Non-resident in the country of recruitment
Previous recruitment into the trial
Inability or unwilling to give informed consent

Trial locations and contacts

49 sites in 2 countries.

Country

City, postcode or hospital

49 sites in 2 countries

United Kingdom44 sites

Aberdeen Royal Infirmary
Aberdeen, AB25 2XN
University Hospital Monklands
Airdrie, ML6 0JS
William Harvey Hospital
Ashford, TN24 0LZ
University Hospital
Ayr, KA6 6DX
Blackpool Victoria Hospital
Blackpool, FY3 8NR
Royal Bournemouth Hospital
Bournemouth, BH7 7DW
Bradford Royal Infirmary
Bradford, BD9 6RJ
Bristol Heart Institute
Bristol, BS2 8ED
Cumberland Infirmary and West Cumberland Hospital
Carlisle, CA2 7HY
Northumbria Specialist Emergency Care Hospital
Cramlington, NE23 6NZ
Dorset County Hospital
Dorchester, DT1 2JY
Dumfries and Galloway Royal Infirmary
Dumfries, DG2 8RX
Ninewells Hospital
Dundee, DD2 1GZ
University Hospital Hairmyres
East Kilbride, G75
Western General Hospital
Edinburgh, EH4 2XU
Edinburgh Royal Infirmary
Edinburgh
Royal Devon and Exeter Hospital
Exeter, EX2 5DW
Glasgow Royal Infirmary
Glasgow, G4 0SF
Queen Elizabeth University Hospital
Glasgow, G51 4TF
Golden Jubilee National Hospital
Glasgow, G81 4HX
Inverclyde Royal Hospital
Greenock, PA16 0XN
Conquest Hospital
Hastings, TN37 7HS
Wycombe Hospital
High Wycombe, HP11 2TT
Raigmore Hospital
Inverness, IV2 3UJ
West Middlesex University Hospital
Isleworth, TW7 6AF
University Hospital Crosshouse
Kilmarnock, KA2 0BE
Victoria Hospital
Kirkcaldy, KY2 5AH
Forth Valley Royal Hospial
Larbert, FK5 4WR
St John's Hospital
Livingston, EH54 6PP
Royal Free Hospital
London, NW3 2QG
St Thomas' Hospital
London, SE1 7EH
Macclesfield District General Hospital
Macclesfield, SK10 3BL
Borders General Hospital
Melrose, TD6 9BS
James Cook Hospital
Middlesbrough, TS4 3BW
John Radcliffe Hospital
Oxford, OX3 9DU
Royal Alexandra Hospital
Paisley, PA2 9PN
Perth Royal Infirmary
Perth, PH1 1NX
Royal Berkshire Hospital
Reading, RG1 5AN
Northern General Hospital
Sheffield, S5 7AU
Southampton General Hospital
Southampton, SO16 6YD
Torbay Hospital
Torquay, TQ2 7AA
Royal Albert Edward Infirmary
Wigan, WN1 2NN
University Hospital
Wishaw, ML2 0DP
Yeovil District Hospital
Yeovil, BA21 4AT

Other trials in United Kingdom

New Zealand5 sites

Auckland City Hospital
Auckland, 1023
Middlemore Hospital
Auckland, 2025
Christchurch Hospital
Christchurch, 8011
Rotorua Hospital
Rotorua, 3010
Tauranga Hospital
Tauranga, 3112

Other trials in New Zealand

About this study

Official title: Duration of Dual Anti-Platelet Therapy in Acute Coronary Syndrome

Despite substantial evidence supporting the use of dual anti-platelet therapy in patients with acute coronary syndrome, there remains major uncertainty regarding the optimal duration of therapy. Recent evidence suggests that shorter durations of dual anti-platelet therapy are superior because the avoidance of atherothrombotic events is counterbalanced by the greater risks of excess major bleeding with apparent increases in all-cause mortality with longer durations. We here propose an international randomised controlled trial of 18,318 patients with type 1 myocardial infarction allocated to differing durations of dual anti-platelet therapy. We will use electronic health record linkage to track duration of therapy and clinical outcomes in a real-world, real-time, efficient and highly cost-effective trial. This has the potential to define treatment duration, settle a major outstanding international controversy, and influence modern cardiology practice across the world.

Conditions: Acute Coronary Syndrome, Coronary Artery Disease
Being tested: 3 months dual anti-platelet therapy, 12 months dual anti-platelet therapy
Medical subject headings: Acute Coronary Syndrome, Coronary Artery Disease

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

3 months dual anti-platelet therapyOther
Patients with acute coronary syndrome will be randomised to 3 months dual anti-platelet therapy.
12 months dual anti-platelet therapyOther
Patients with acute coronary syndrome will be randomised to 12 months dual anti-platelet therapy.

Study groups in NCT03252249
Study group	Role	What they receive
3 months dual anti-platelet therapy	Active comparator	3 months dual anti-platelet therapy. Receives: Other: 3 months dual anti-platelet therapy
12 months dual anti-platelet therapy	Active comparator	12 months dual anti-platelet therapy. Receives: Other: 12 months dual anti-platelet therapy

What is being measured

The primary outcome is the main question the study is designed to answer.

Time-to-event: All-cause Mortality
Restricted Mean Survival Time
Measured: Date of index MI to 15 months
Incidence: All-cause Mortality
Occurrence of event
Measured: Date of index MI to 15 months

Secondary outcomes (21)

Time-to-event: Non-cardiovascular Death (Including Fatal Bleeding) and Major Non-fatal Bleeding
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Non-cardiovascular Death (Including Fatal Bleeding) and Major Non-fatal Bleeding
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Non-cardiovascular Death (Including Fatal Bleeding)
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Non-cardiovascular Death (Including Fatal Bleeding)
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Major Fatal and Non-fatal Bleeding
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Major Fatal and Non-fatal Bleeding
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Gastrointestinal Bleeding
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Gastrointestinal Bleeding
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Cardiovascular Death and Non-fatal Myocardial Infarction
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Cardiovascular Death and Non-fatal Myocardial Infarction
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Cardiovascular Mortality (Cardiac and Non-cardiac)
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Cardiovascular Mortality (Cardiac and Non-cardiac)
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Myocardial Infarction (Fatal and Non-fatal)
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Myocardial Infarction (Fatal and Non-fatal)
Occurrence of event
Measured: Date of MI to 15 months
Incidence: Intracranial Haemorrhage
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Coronary Revascularisation
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Coronary Revascularisation
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Stent Thrombosis
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Stent Thrombosis
Occurrence of event
Measured: Date of MI to 15 months
Time-to-event: Thrombotic Stroke
Restricted Mean Survival Time
Measured: Date of MI to 15 months
Incidence: Thrombotic Stroke
Occurrence of event
Measured: Date of MI to 15 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

26 Apr 20184 Feb 2023

First posted17 Aug 2017
Study start26 Apr 2018
Primary completion4 Feb 2023
Study completion4 Feb 2023

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Acute Coronary SyndromeStudies of the same condition, open and under way.
More trials run by University of EdinburghThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 4
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 5,094 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03252249
Sponsor's protocol ID: AC16104
Status last verified: Jan 2026
First submitted: 9 Aug 2017
Last updated: 3 Nov 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Acute Coronary Syndrome trials

Study at a glance

From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Duration of Dual Anti-Platelet Therapy in Acute Coronary Syndrome
ClinicalTrials.gov ID: NCT03252249
Acronym / sponsor ID: AC16104
Conditions: Acute Coronary Syndrome, Coronary Artery Disease
Phase: Phase 4
Study type: Interventional
Recruitment status: Completed
Enrolment: 5,094 participants (actual)
Lead sponsor: University of EdinburghUniversity, hospital or other
Collaborators: British Heart Foundation
Study start: 26 Apr 2018 (actual)
Primary completion: 4 Feb 2023 (actual)
Study completion: 4 Feb 2023 (actual)
First posted: 17 Aug 2017 (actual)
Results: Posted 28 Jan 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
3 months dual anti-platelet therapy	Active comparator	Other: 3 months dual anti-platelet therapy3 months dual anti-platelet therapy.
12 months dual anti-platelet therapy	Active comparator	Other: 12 months dual anti-platelet therapy12 months dual anti-platelet therapy.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (6 listed)

Aged ≥18 years
Clinical diagnosis of Type 1 myocardial infarction within 12 weeks
In the opinion of the attending clinician requires dual anti-platelet therapy with aspirin and a P2Y12 receptor antagonist
Resident in the country of recruitment with their unique health identifier
The attending clinician has equipoise regarding the duration of therapy

Key exclusion criteria (6 listed)

Clear indication for specific duration of dual anti-platelet therapy
Type 2 myocardial infarction
Contraindication to aspirin or P2Y12 receptor antagonist
Non-resident in the country of recruitment
Previous recruitment into the trial

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
3 months dual anti-platelet therapyPatients with acute coronary syndrome will be randomised to 3 months dual anti-platelet therapy.	Other	3 months dual anti-platelet therapy
12 months dual anti-platelet therapyPatients with acute coronary syndrome will be randomised to 12 months dual anti-platelet therapy.	Other	12 months dual anti-platelet therapy

Primary outcome

Time-to-event: All-cause Mortality
Time frame: Date of index MI to 15 months
Restricted Mean Survival Time
Incidence: All-cause Mortality
Time frame: Date of index MI to 15 months
Occurrence of event

21 secondary outcomes

Time-to-event: Non-cardiovascular Death (Including Fatal Bleeding) and Major Non-fatal Bleeding
Time frame: Date of MI to 15 months
Incidence: Non-cardiovascular Death (Including Fatal Bleeding) and Major Non-fatal Bleeding
Time frame: Date of MI to 15 months
Time-to-event: Non-cardiovascular Death (Including Fatal Bleeding)
Time frame: Date of MI to 15 months
Incidence: Non-cardiovascular Death (Including Fatal Bleeding)
Time frame: Date of MI to 15 months
Time-to-event: Major Fatal and Non-fatal Bleeding
Time frame: Date of MI to 15 months
Incidence: Major Fatal and Non-fatal Bleeding
Time frame: Date of MI to 15 months
Time-to-event: Gastrointestinal Bleeding
Time frame: Date of MI to 15 months
Incidence: Gastrointestinal Bleeding
Time frame: Date of MI to 15 months
Time-to-event: Cardiovascular Death and Non-fatal Myocardial Infarction
Time frame: Date of MI to 15 months
Incidence: Cardiovascular Death and Non-fatal Myocardial Infarction
Time frame: Date of MI to 15 months
Time-to-event: Cardiovascular Mortality (Cardiac and Non-cardiac)
Time frame: Date of MI to 15 months
Incidence: Cardiovascular Mortality (Cardiac and Non-cardiac)
Time frame: Date of MI to 15 months
Time-to-event: Myocardial Infarction (Fatal and Non-fatal)
Time frame: Date of MI to 15 months
Incidence: Myocardial Infarction (Fatal and Non-fatal)
Time frame: Date of MI to 15 months
Incidence: Intracranial Haemorrhage
Time frame: Date of MI to 15 months
Time-to-event: Coronary Revascularisation
Time frame: Date of MI to 15 months
Incidence: Coronary Revascularisation
Time frame: Date of MI to 15 months
Time-to-event: Stent Thrombosis
Time frame: Date of MI to 15 months
Incidence: Stent Thrombosis
Time frame: Date of MI to 15 months
Time-to-event: Thrombotic Stroke
Time frame: Date of MI to 15 months
Incidence: Thrombotic Stroke
Time frame: Date of MI to 15 months

Results and safety

Results posted to the registry on 28 Jan 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
3 Months Dual Anti-platelet Therapy	2,526	2,526
12 Months Dual Anti-platelet Therapy	2,526	2,526

Primary outcome: Time-to-event: All-cause Mortality

Time frame: Date of index MI to 15 months. Mean (Standard Error). Unit: days

Measure	3 Months Dual Anti-platelet Therapy n = 2526	12 Months Dual Anti-platelet Therapy n = 2526
Value	447.337 (1.0542)	445.196 (1.1741)

Population analysed: Intention to Treat Population. Patients were analysed according to their allocated intervention, irrespective of whether the patient's actual management complied with the allocated intervention.

Primary outcome: Incidence: All-cause Mortality

Time frame: Date of index MI to 15 months. Count of participants. Unit: Participants

Measure	3 Months Dual Anti-platelet Therapy n = 2526	12 Months Dual Anti-platelet Therapy n = 2526
Value	68	87

3 Months Dual Anti-platelet Therapy vs 12 Months Dual Anti-platelet Therapy: Hazard Ratio (HR): 0.78 (95% CI 0.57 to 1.07), p = 0.1232, Regression, Cox

21 secondary outcomes are reported in the full results.

Adverse events

Time frame: 15 months from date of randomisation.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
3 Months Dual Anti-platelet Therapy	0 of 2,526 (0%)	0 of 2,526 (0%)	68 of 2,526
12 Months Dual Anti-platelet Therapy	0 of 2,526 (0%)	0 of 2,526 (0%)	87 of 2,526

Limitations and caveats (from the sponsor): The major limitation is that early trial termination meant the target sample size was not achieved, leaving an underpowered trial which was unable to address its primary endpoint. The recruitment suspension due to COVID-19, and the subsequent delays in re-opening of the study sites and lack of staff capacity significantly affected recruitment.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Acute Coronary Syndrome

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

David Newby principal investigator

University of Edinburgh

49 sites in 2 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 3 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 49 sites in United Kingdom, New Zealand. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 28 Jan 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Time-to-event: All-cause Mortality (time frame: Date of index MI to 15 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03252249.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2026.