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

Overview

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.

This study is a randomized controlled trial evaluating two different catheter ablation strategies for patients with paroxysmal atrial fibrillation (AF). Participants are randomly assigned in a 1:1 ratio to either the control arm or the experimental arm prior to undergoing their ablation procedure. In the control arm, patients receive a pulmonary vein isolation (PVI)-only strategy using pulsed field ablation (PFA). This approach targets only the pulmonary veins, which are the most common source of AF triggers, and does not include additional ablation beyond isolating these veins. In contrast, the experimental arm uses a more comprehensive PVI-PLUS strategy with radiofrequency ablation (RFA). In addition to standard pulmonary vein isolation, this strategy includes patient-specific ablation of non-pulmonary vein triggers and abnormal atrial substrate, such as low-voltage areas identified during electrophysiologic testing. This individualized approach aims to reduce arrhythmia recurrence by addressing additional sources of AF beyond the pulmonary veins. All participants undergo their assigned catheter ablation procedure as part of routine clinical care, with procedural details tailored according to the randomized strategy. Following the ablation, patients receive an implantable loop recorder (ILR), which is a small device placed under the skin that continuously monitors heart rhythm. The ILR allows for continuous, long-term detection of atrial arrhythmias, including both symptomatic and asymptomatic episodes, ensuring accurate assessment of treatment outcomes throughout the study period. Participants are followed closely for a total of 24 months after the ablation procedure. During this follow-up period, patients attend scheduled visits at 2, 6, 12, 18, and 24 months, where ILR data are reviewed and clinical assessments are performed. The continuous monitoring provided by the ILR is central to evaluating the study's primary and secondary outcomes, including recurrence of atrial fibrillation, atrial flutter, or atrial tachycardia. In addition to rhythm monitoring, patients complete quality-of-life questionnaires at baseline and at 24 months, and any repeat procedures, hospital visits, or complications are recorded. This structured follow-up ensures comprehensive evaluation of both the effectiveness and safety of the two ablation strategies over time.