Characterization of Arrhythmia Substrate to Ablate Persistent Atrial Fibrillation (COAST-AF RCT)

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).

Study Overview

• Status: Active, not recruiting
• Conditions: Atrial Fibrillation
• Intervention / Treatment: Procedure: Catheter ablation

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:

i. 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 Type: Interventional
• Enrollment (Estimated): 502
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada
      • Libin Cardiovascular Institute
  • British Columbia
    • Vancouver, British Columbia, Canada
      • Vancouver General Hospital
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3H 1V7
      • QEII Health Sciences Centre, Nova Scotia Health Authority
  • Ontario
    • Hamilton, Ontario, Canada
      • Hamilton General Hospital
    • London, Ontario, Canada
      • London Health Sciences Centre
    • Newmarket, Ontario, Canada, L3Y 2P9
      • Southlake Regional Health Centre
    • Ottawa, Ontario, Canada, K1Y 4W7
      • University of Ottawa Heart Institute
    • Toronto, Ontario, Canada, M5B 1W8
      • St. Michael's Hospital
    • Toronto, Ontario, Canada
      • Rouge Valley Regional Heart Centre
  • Quebec
    • Montreal, Quebec, Canada
      • McGill University Health Centre
    • Montreal, Quebec, Canada
      • Montreal Heart Institute
    • Montreal, Quebec, Canada, H2W 1T8
      • Centre hospitalier de l'Université de Montréal (CHUM)
    • Québec, Quebec, Canada, G1V 4G5
      • Institute Universitaire de Cardiologie et Pneumologie du Quebec (IUCPQ)
    • Sherbrooke, Quebec, Canada, J1H 5N4
      • CIUSSS de L'Estrie-CHUS-Hopital Fleurimont

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age ≥18 years;
2. Subjects with symptomatic persistent AF AND clinically indicated catheter ablation for AF;
3. Persistent AF defined as a sustained episode beyond 3 months in duration;
4. 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;
5. Modified DR-FLASH score >=3

4. Subjects must be able to provide informed consent.

Exclusion Criteria:

1. History of previous catheter ablation for AF or left atrial flutter;
2. History of previous surgical ablation for AF;
3. Known intracardiac thrombus;
4. Contraindication to systemic oral anticoagulation therapy;
5. Reversible causes of AF;
6. Hypertrophic cardiomyopathy;
7. Severe valvular disease (mitral/aortic stenosis or regurgitation);
8. Subjects that are pregnant or breastfeeding;
9. Comorbid condition with life expectancy < 1 year

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Pulmonary Vein Isolation; Wide area circumferential catheter ablation for pulmonary vein isolation	Procedure: Catheter ablation; Wide area circumferential catheter ablation for pulmonary vein isolation of persistent atrial fibrillation; Other Names: Atrial Fibrillation Ablation
Experimental: Pulmonary Vein Isolation and atrial low voltage area ablation; Wide area circumferential catheter ablation for pulmonary vein isolation and atrial low voltage area ablation	Procedure: Catheter ablation; Wide area circumferential catheter ablation for pulmonary vein isolation of persistent atrial fibrillation; Other Names: Atrial Fibrillation Ablation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	day 91 post ablation to 18 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Need for repeat ablation procedure for AF, AFl or AT	Documented by ECG, holter or ECG loop recorder	Up to 18 months
Need for emergency room visits or hospitalization	Hospital admission for > 24 hours and emergency room admission	Up to 18 months
Total ablation delivery time	RF ablation time	Day of ablation procedure
Total procedure duration	Start of ablation to end of ablation	Day of ablation procedure
Quality of life analyses	Using EQ-5D general quality of life score, and AF severity scale (symptoms and functionality)	18 months
Composite safety endpoints	Procedure related complications at any time (stroke, PV stenosis, pericarditis, cardiac perforation, major bleeding) and/or death	Up to 18 months
AF burden	Documented assessment of AF burden	At 12 months and 18 months
Quality of Life assessment with EQ5D	Assess the participants quality of life	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	18 months
Effect of Atrial Fibrillation on Quality of Life using AFEQT	Assess the participants quality of life due to atrial fibrillation	Baseline to 18months

Collaborators and Investigators

• Sponsor: Ottawa Heart Institute Research Corporation
• Collaborators: Heart and Stroke Foundation of Canada
• Investigators: Principal Investigator: Pablo Nery, MD, Ottawa Heart Institute Research Corporation

Study record dates

Study Major Dates

• Study Start (Actual): August 24, 2018
• Primary Completion (Actual): April 23, 2026
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: November 15, 2017
• First Submitted That Met QC Criteria: November 16, 2017
• First Posted (Actual): November 20, 2017

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Pulmonary vein isolation; AF ablation; Atrial scar ablation
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation; Therapeutics; Surgical Procedures, Operative; Ablation Techniques; Radiofrequency Ablation; Radiofrequency Therapy; Catheter Ablation
• Other Study ID Numbers: 20170

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No