Correlation of the Arrhythmia Mechanism and Substrate to Ablate Persistent Atrial Fibrillation Study (COAST-AF)

Correlation of Arrhythmia Mechanism and Substrate to Ablate Persistent Atrial Fibrillation:A Pilot Study

This is a pilot study to assess the usefulness of ECG mapping, and enhanced MRI and PET scan imaging in identifying atrial fibrosis and arrhythmia circuits involved in persistent atrial fibrillation and in guiding an innovative AF catheter ablation strategy.

It is hypothesized that identifying these critical arrhythmia circuits and atrial fibrosis with enhanced imaging and performing an individualized innovative AF catheter ablation will result in higher procedural success rates.

Study Overview

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

Detailed Description

Pulmonary vein isolation catheter ablation for the treatment of persistent AF (PeAF)or longstanding persistent AF is associated with success rates of 40-50% at one year. Experimental models have shown that AF results in progressive structural changes due to electrical atrial remodeling, where AF burden correlates with atrial fibrosis. The optimal ablation strategy for patients with PeAF is not yet known. There is limited understanding of the critical mechanisms responsible for maintenance of AF in these patients.

In this study ECG body mapping (ECGI) will be used to look for distinct electrical rotors in the atria. Delayed gadolinium enhanced magnetic resonance imaging (DE-MRI) will be used to assess the extent of left atrial fibrosis. In addition to PVI catheter ablation procedure, an ablation strategy guided by the results of the ECGI mapping and DE-MRI will be performed.A C-metahydroxyepherdrine (HED) PET scan will also be done pre-ablation to evaluate left atrial sympathetic denervation and any relationship to the initiation and/or maintenance of AF.

Subjects will be seen at 3 and 6 months after ablation, with 12 lead ECG and 2-week loop monitoring done at each visit.

• Study Type: Interventional
• Enrollment (Actual): 52
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Ottawa, Ontario, Canada, K1Y 4W7
      • University of Ottawa Heart Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥18 years and ≤ 80 years;
• Symptomatic persistent AF AND clinically indicated for AF catheter ablation
• At least one episode of AF lasting more than 7 days, documented on 12-lead ECG, Holter monitor, 2-week loop monitor or trans-telephonic monitor (TTM) within 12 months of enrollment in the study
• Able to provide informed consent.

Exclusion Criteria:

• History of previous catheter or surgical ablation for AF
• Presence of intracardiac thrombus
• contraindication to systemic oral anticoagulation therapy
• Subjects with reversible causes of AF
• Antero-posterior left atrial dimension > 60 mm on echocardiography
• Severe valvular disease (mitral/aortic stenosis or regurgitation);
• Subjects that are pregnant or breastfeeding;
• Chronic kidney disease and creatinine clearance <50ml/min.
• Contraindication to MRI Imaging (e.g. permanent pacemaker, metallic implants, etc)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Atrial Fibrillation (AF) Termination	AF termination resulting in restoration of sinus rhythm during ablation.	During catheter ablation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radio frequency (RF) ablation time		During catheter ablation
Procedure Duration	Total procedure duration	During catheter ablation
Freedom from AF		6 months

Collaborators and Investigators

• Sponsor: Ottawa Heart Institute Research Corporation
• Investigators: Principal Investigator: Pablo B Nery, MD, Ottawa Heart Institute Research Corporation; Principal Investigator: Robert deKemp, PhD, Ottawa Heart Institute Research Corporation; Principal Investigator: Elena Pena, MD, The Ottawa Hospital; Principal Investigator: David H Birnie, MD, Ottawa Heart Institute Research Corporation

Study record dates

Study Major Dates

• Study Start (Actual): September 14, 2015
• Primary Completion (Actual): August 23, 2018
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: July 2, 2014
• First Submitted That Met QC Criteria: July 2, 2014
• First Posted (Estimated): July 8, 2014

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Atrial fibrillation; Catheter ablation; Atrial Fibrosis; Delayed gadolinium enhanced MRI; C-metahydroxyepherdrine (HED) PET scan; ECGI mapping; Atrial sympathetic denervation
• 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: 20140623