Randomized Controlled Trial- Ablation Strategy for Paroxysmal Atrial Fibrillation - Trigger and Substrate Guided Wide Area Radiofrequency Ablation Compared to Pulsed Field Ablation Pulmonary Vein Isolation
Recruiting now NCT04823299
Run by Ottawa Heart Institute Research Corporation · for 18 and older · All sexes
What this study is about
Atrial fibrillation (AF) is a common heart rhythm disorder affecting over a million people in North America and is associated with serious complications including stroke, heart failure, reduced quality of life, and premature death. Catheter ablation has been shown to be more effective than medications for controlling symptoms and reducing the risk of these complications; however, recurrence of AF after ablation remains a significant challenge, often due to incomplete or ineffective initial procedures. This clinical trial aims to determine whether a novel, patient-tailored ablation strategy can improve outcomes compared to the current standard-of-care approach. Participants will be randomly assigned to undergo either standard pulmonary vein isolation or a more individualized ablation procedure that identifies and targets patient-specific sources of AF. All participants will undergo the ablation procedure, receive continuous heart rhythm monitoring, and be followed over time to assess recurrence and safety outcomes.
Who can join (things the study team will check)
✅ You may be able to join if…
- Age ≥18 years on the date of consent for the trial.
- Subjects must have paroxysmal AF with at least one episode of AF over the past 12 months (patients on antiarrhythmic medications do not need to satisfy this criterion). At least one episode of AF documented on 12-lead ECG, Holter monitor, Trans-telephonic monitor (TTM) or Loop Recorder.
- Subjects must be able to provide informed consent.
🚫 You may not be able to join if…
- Persistent and permanent AF.
- History of previous catheter or surgical ablation for AF, AFl, AT, Atrioventricular Nodal Reentrant Tachycardia (AVNRT), Atrioventricular Reentrant Tachycardia (AVRT).
- Documented AVNRT, AVRT, AT or Atrial Flutter prior to enrolment in the trial.
- Previous left atrial (LA) ablation or LA surgery.
- Previous pulmonary vein stenosis or pulmonary vein stent.
- Pre-existing hemi-diaphragmatic paralysis.
- Active intracardiac thrombus.
- Contraindication to systemic oral anticoagulation therapy
- Current immunosuppressant therapy (corticosteroids, biologic immunomodulators; such patients may be considered if they can safely discontinue immunosuppressants for three months prior to and for three months following catheter ablation).
- Reversible causes of AF (e.g., uncontrolled hyperthyroidism, within six months of cardiac surgery).
- Left ventricular ejection fraction <35%.
- NYHA Class 4 heart failure.
- Hypertrophic cardiomyopathy
- Significant valve disease (moderate or severe mitral/aortic stenosis or regurgitation).
- Patients with mechanical mitral prosthetic valves
- Known adverse reaction to adenosine.
- Chronic Kidney Disease ≥ Stage 4.
- Significant congenital heart disease (including atrial septal defects or pulmonary vein abnormalities; however, subjects with patent foramen ovale will not be excluded).
- Pregnant subjects.
- Cerebral ischemic event (stroke or transient ischemic attack) in the six months prior to consenting for the trial.
+ 8 more criteria — see the full checklist in the app.
Where this trial is running
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada
- McGill University Health Center, Montreal, Quebec, Canada
Who to contact
Girish Nair, MD · 613-696-7272 · GNair@ottawaheart.ca
It's completely normal to call and ask questions before deciding anything. Mention the study ID: NCT04823299.
Verify everything on the official ClinicalTrials.gov record. Page updated July 2026.