Atrial FibrillationCOAST-AF RCTNCT03347227
Characterization of Arrhythmia Substrate to Ablate Persistent Atrial Fibrillation
A study testing Catheter ablation in people with Atrial Fibrillation, run by Ottawa Heart Institute Research Corporation at 14 sites in Canada.
Trial summary
A multicentre, parallel group, two arm, single-blinded randomized clinical trial, assessing the efficacy of a patient-tailored catheter ablation (CA) strategy guided by atrial low voltage area mapping in addition to pulmonary vein isolation (PVI) when compared to PVI alone in patients with persistent atrial… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Fibrillation
- What is being tested?
- Catheter ablation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 510 participants
- Where
- 14 sitesCanada
- Study dates
- 24 Aug 2018to Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- Age ≥18 years;
- Subjects with symptomatic persistent AF AND clinically indicated catheter ablation for AF;
- Persistent AF defined as a sustained episode beyond 3 months in duration;
- At least one episode of AF must have been documented on 12-lead ECG, Holter monitor, loop monitor or trans-telephonic monitor (TTM) within 36 months of enrollment in the study;
- Modified DR-FLASH score >=3
- 4. Subjects must be able to provide informed consent.
Who cannot join
- History of previous catheter ablation for AF or left atrial flutter;
- History of previous surgical ablation for AF;
- Known intracardiac thrombus;
- Contraindication to systemic oral anticoagulation therapy;
- Reversible causes of AF;
- Hypertrophic cardiomyopathy;
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- Severe valvular disease (mitral/aortic stenosis or regurgitation);
- Subjects that are pregnant or breastfeeding;
- Comorbid condition with life expectancy < 1 year
Trial locations and contacts
14 sites in 1 country.
14 sites in 1 country
Canada14 sites
Libin Cardiovascular Institute
Calgary, Alberta
QEII Health Sciences Centre, Nova Scotia Health Authority
Halifax, Nova Scotia, B3H 1V7
Hamilton General Hospital
Hamilton, Ontario
London Health Sciences Centre
London, Ontario
Centre Hospitalier de l'Universite de Montreal (CHUM)
Montreal, Quebec, H2W 1T8
McGill University Health Centre
Montreal, Quebec
Montreal Heart Institute
Montreal, Quebec
Southlake Regional Health Centre
Newmarket, Ontario, L3Y 2P9
University of Ottawa Heart Institute
Ottawa, Ontario, K1Y 4W7
Institute Universitaire de Cardiologie et Pneumologie du Quebec (IUCPQ)
Québec, Quebec, G1V 4G5
CIUSSS de L'Estrie-CHUS-Hopital Fleurimont
Sherbrooke, Quebec, J1H 5N4
St. Michael's Hospital
Toronto, Ontario, M5B 1W8
Rouge Valley Regional Heart Centre
Toronto, Ontario
Vancouver General Hospital
Vancouver, British Columbia
About this study
Official title: Characterization of Arrhythmia Substrate to Ablate Persistent Atrial Fibrillation (Coast-AF) Randomized Clinical Trial
A multicentre, parallel group, two arm, single-blinded randomized clinical trial, assessing the efficacy of a patient-tailored catheter ablation (CA) strategy guided by atrial low voltage area mapping in addition to pulmonary vein isolation (PVI) when compared to PVI alone in patients with persistent atrial fibrillation (AF).
Read the detailed description
The optimal CA strategy for persistent AF remains unknown. Current data highlight the need for a better understanding of the substrate and mechanisms of arrhythmia maintenance in this population. Atrial low voltage area (LVA)-based catheter ablation has recently emerged as a promising strategy for ablation of AF. However, the available data has limitations that preclude definitive conclusions regarding the utility of this strategy (no data from multicenter, randomized studies available). Further research is needed to assess the role of LVA-based ablation for persistent AF.
The Investigators hypothesize that catheter ablation of persistent AF (PeAF) tailored to abolish abnormal atrial substrate identified by intracardiac atrial (LVA) mapping in addition to pulmonary vein isolation (PVI) will result in higher procedural success rates when compared to PVI alone.
The study will recruit 502 patients with PeAF (251 per treatment arm) who are candidates for CA ablation of AF according to the treating physician (and in agreement with current practice guidelines). Subjects will be recruited over a 42-month period. The total duration of the study is 60 months.
Prior to undergoing catheter ablation subjects will be seen by the investigator/ research assistant and the following data will be collected:
- Age and sex ii. Structural heart disease if present iii. CHADS2VASc score iv. DR-FLASH score v. NYHA class vi. Current medications vii. Duration of uninterrupted AF viii. Height and weight ix. Echocardiogram and other cardiac imaging results (within previous 24 months, including assessment of left ventricular ejection fraction, left atrial volume and valve function) x. ECG, Holter or loop monitor recording (within past 36 months) documenting AF.
Subjects will be randomly assigned in a 1:1 ratio to undergo wide area circumferential ablation for pulmonary vein isolation (PVI- control arm) or wide area circumferential ablation PVI and atrial LVA ablation (experimental arm). Randomization will be stratified by centre and by sex. Subjects will be randomized prior to the procedure.
Enrolled subjects will have a clinical follow-up visit at 3, 6, 12, 18, 24 and 36 months after the ablation procedure, defined as Holter monitoring with equipment capable of recording 14 days of continuous ambulatory ECG. Patients will be followed for 36 months or until the last recruited patient completes the mandatory 18-month follow-up visit. The results of monitoring will be interpreted at a centralized core lab, and the results will be adjudicated by an arrhythmia specialist blinded to treatment group. A total of three questionnaires will be administered throughout the study, each at a specific time point. The Quality of Life (EQ-5D), CCS-Severity of AF scale, and Atrial Fibrillation Effect on Quality of life (AFEQT) will be completed at baseline, and at the 12-month and 18-month visit.
Concomitant medical therapy will be selected according to the treating physician. All subjects will be maintained on systemic oral anticoagulation for at least 2 months following catheter ablation.
- Conditions
- Atrial Fibrillation
- Being tested
- Catheter ablation
- Keywords
- AF ablation, Pulmonary vein isolation, Atrial scar ablation
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Catheter ablationProcedure or surgery
Also called Atrial Fibrillation Ablation
Wide area circumferential catheter ablation for pulmonary vein isolation of persistent atrial fibrillation
| Study group | Role | What they receive |
|---|---|---|
| Pulmonary Vein Isolation | Active comparator | Wide area circumferential catheter ablation for pulmonary vein isolation Receives: Procedure: Catheter ablation |
| Pulmonary Vein Isolation and atrial low voltage area ablation | Experimental | Wide area circumferential catheter ablation for pulmonary vein isolation and atrial low voltage area ablation Receives: Procedure: Catheter ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of documented (>30s) AF, atrial flutter or atrial tachycardia occuring from day 91 to 18 months post ablation
Documented AF, Aflutter or AT by ECG, holter or external loop monitoring and has a duration of at least 30 seconds
Measured: day 91 post ablation to 18 months
Secondary outcomes (10)
Composite safety endpoints
Procedure related complications at any time (stroke, PV stenosis, pericarditis, cardiac perforation, major bleeding) and/or death
Measured: Up to 18 months
AF burden
Documented assessment of AF burden
Measured: At 12 months and 18 months
Need for repeat ablation procedure for AF, AFl or AT
Documented by ECG, holter or ECG loop recorder
Measured: Up to 18 months
Need for emergency room visits or hospitalization
Hospital admission for > 24 hours and emergency room admission
Measured: Up to 18 months
Quality of Life assessment with EQ5D
Assess the participants quality of life
Measured: Baseline to 18months
Time to first recurrence at 18 months according to sex and atrial low voltage area extent
Recurrence of AF, AFl or AT
Measured: 18 months
Total ablation delivery time
RF ablation time
Measured: Day of ablation procedure
Total procedure duration
Start of ablation to end of ablation
Measured: Day of ablation procedure
Quality of life analyses
Using EQ-5D general quality of life score, and AF severity scale (symptoms and functionality)
Measured: 18 months
Effect of Atrial Fibrillation on Quality of Life using AFEQT
Assess the participants quality of life due to atrial fibrillation
Measured: Baseline to 18months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Nov 2017
- Study start24 Aug 2018
- Primary completion23 Apr 2026
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Prospective, parallel arm randomized clinical trial
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 510 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ottawa Heart Institute Research Corporation
- Sponsor type
- University, hospital or other
- Collaborators
- Heart and Stroke Foundation of Canada
- Responsible party
- Sponsor
- Investigators
- Pablo Nery, MD, Principal investigator, Ottawa Heart Institute Research Corporation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03347227
- Sponsor's protocol ID
- 20170
- Acronym
- COAST-AF RCT
- Status last verified
- Apr 2026
- First submitted
- 15 Nov 2017
- Last updated
- 15 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of Arrhythmia Substrate to Ablate Persistent Atrial Fibrillation (Coast-AF) Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT03347227
- Acronym / sponsor ID
- COAST-AF RCT / 20170
- Conditions
- Atrial Fibrillation
- Keywords
- AF ablation, Pulmonary vein isolation, Atrial scar ablation
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 510 participants (estimated)
- Lead sponsor
- Ottawa Heart Institute Research CorporationUniversity, hospital or other
- Collaborators
- Heart and Stroke Foundation of Canada
- Study start
- 24 Aug 2018 (actual)
- Primary completion
- 23 Apr 2026 (actual)
- Study completion
- Dec 2027 (estimated)
- First posted
- 20 Nov 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A multicentre, parallel group, two arm, single-blinded randomized clinical trial, assessing the efficacy of a patient-tailored catheter ablation (CA) strategy guided by atrial low voltage area mapping in addition to pulmonary vein isolation (PVI) when compared to PVI alone in patients with persistent atrial fibrillation (AF).
Detailed description
The optimal CA strategy for persistent AF remains unknown. Current data highlight the need for a better understanding of the substrate and mechanisms of arrhythmia maintenance in this population. Atrial low voltage area (LVA)-based catheter ablation has recently emerged as a promising strategy for ablation of AF. However, the available data has limitations that preclude definitive conclusions regarding the utility of this strategy (no data from multicenter, randomized studies available). Further research is needed to assess the role of LVA-based ablation for persistent AF.
The Investigators hypothesize that catheter ablation of persistent AF (PeAF) tailored to abolish abnormal atrial substrate identified by intracardiac atrial (LVA) mapping in addition to pulmonary vein isolation (PVI) will result in higher procedural success rates when compared to PVI alone.
The study will recruit 502 patients with PeAF (251 per treatment arm) who are candidates for CA ablation of AF according to the treating physician (and in agreement with current practice guidelines). Subjects will be recruited over a 42-month period. The total duration of the study is 60 months.
Prior to undergoing catheter ablation subjects will be seen by the investigator/ research assistant and the following data will be collected:
- Age and sex ii. Structural heart disease if present iii. CHADS2VASc score iv. DR-FLASH score v. NYHA class vi. Current medications vii. Duration of uninterrupted AF viii. Height and weight ix. Echocardiogram and other cardiac imaging results (within previous 24 months, including assessment of left ventricular ejection fraction, left atrial volume and valve function) x. ECG, Holter or loop monitor recording (within past 36 months) documenting AF.
Subjects will be randomly assigned in a 1:1 ratio to undergo wide area circumferential ablation for pulmonary vein isolation (PVI- control arm) or wide area circumferential ablation PVI and atrial LVA ablation (experimental arm). Randomization will be stratified by centre and by sex. Subjects will be randomized prior to the procedure.
Enrolled subjects will have a clinical follow-up visit at 3, 6, 12, 18, 24 and 36 months after the ablation procedure, defined as Holter monitoring with equipment capable of recording 14 days of continuous ambulatory ECG. Patients will be followed for 36 months or until the last recruited patient completes the mandatory 18-month follow-up visit. The results of monitoring will be interpreted at a centralized core lab, and the results will be adjudicated by an arrhythmia specialist blinded to treatment group. A total of three questionnaires will be administered throughout the study, each at a specific time point. The Quality of Life (EQ-5D), CCS-Severity of AF scale, and Atrial Fibrillation Effect on Quality of life (AFEQT) will be completed at baseline, and at the 12-month and 18-month visit.
Concomitant medical therapy will be selected according to the treating physician. All subjects will be maintained on systemic oral anticoagulation for at least 2 months following catheter ablation.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Prospective, parallel arm randomized clinical trial
| Arm | Type | Receives |
|---|---|---|
| Pulmonary Vein Isolation | Active comparator | Procedure: Catheter ablationWide area circumferential catheter ablation for pulmonary vein isolation |
| Pulmonary Vein Isolation and atrial low voltage area ablation | Experimental | Procedure: Catheter ablationWide area circumferential catheter ablation for pulmonary vein isolation and atrial low voltage area ablation |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥18 years;
- Subjects with symptomatic persistent AF AND clinically indicated catheter ablation for AF;
- Persistent AF defined as a sustained episode beyond 3 months in duration;
- At least one episode of AF must have been documented on 12-lead ECG, Holter monitor, loop monitor or trans-telephonic monitor (TTM) within 36 months of enrollment in the study;
- Modified DR-FLASH score >=3
Key exclusion criteria (9 listed)
- History of previous catheter ablation for AF or left atrial flutter;
- History of previous surgical ablation for AF;
- Known intracardiac thrombus;
- Contraindication to systemic oral anticoagulation therapy;
- Reversible causes of AF;
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 |
|---|---|---|
| Catheter ablationAlso: Atrial Fibrillation AblationWide area circumferential catheter ablation for pulmonary vein isolation of persistent atrial fibrillation | Procedure or surgery | Pulmonary Vein Isolation, Pulmonary Vein Isolation and atrial low voltage area ablation |
Primary outcome
Rate of documented (>30s) AF, atrial flutter or atrial tachycardia occuring from day 91 to 18 months post ablation
Time frame: day 91 post ablation to 18 months
Documented AF, Aflutter or AT by ECG, holter or external loop monitoring and has a duration of at least 30 seconds
10 secondary outcomes
Composite safety endpoints
Time frame: Up to 18 months
AF burden
Time frame: At 12 months and 18 months
Need for repeat ablation procedure for AF, AFl or AT
Time frame: Up to 18 months
Need for emergency room visits or hospitalization
Time frame: Up to 18 months
Quality of Life assessment with EQ5D
Time frame: Baseline to 18months
Time to first recurrence at 18 months according to sex and atrial low voltage area extent
Time frame: 18 months
Total ablation delivery time
Time frame: Day of ablation procedure
Total procedure duration
Time frame: Day of ablation procedure
Quality of life analyses
Time frame: 18 months
Effect of Atrial Fibrillation on Quality of Life using AFEQT
Time frame: Baseline to 18months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jun 2026.
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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.
Pablo Nery, MD principal investigator
Ottawa Heart Institute Research Corporation
14 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Catheter ablation in people with Atrial Fibrillation, run by Ottawa Heart Institute Research Corporation at 14 sites in Canada.
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 9 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: under way, not looking for participants, as of the sponsor's last update on 15 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 14 sites in Canada. 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
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?
Rate of documented (>30s) AF, atrial flutter or atrial tachycardia occuring from day 91 to 18 months post ablation (time frame: day 91 post ablation to 18 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 15 Jun 2026; AzTrials last refreshed its copy on 31 Oct 2026.