Thoracoscopic Versus Catheter Ablation in Persistent Atrial Fibrillation With Enlarged Left Atrium

August 19, 2026 updated by: Young Keun On, Samsung Medical Center

Endocardial Catheter Ablation Versus Thoracoscopic Ablation in De Novo Persistent Atrial Fibrillation Patients With Enlarged Left Atrium: A Randomized Controlled Trial

This is a prospective, single-center, open-label, randomized controlled trial comparing thoracoscopic surgical ablation with percutaneous endocardial catheter ablation as the first rhythm-control procedure in patients with persistent atrial fibrillation and an enlarged left atrium (LA diameter ≥50 mm or LA volume index ≥45 mL/m²).

A total of 194 patients who have never undergone an ablation procedure for atrial fibrillation will be randomly assigned 1:1 to thoracoscopic ablation or percutaneous catheter ablation, stratified by duration of atrial fibrillation. The primary endpoint is recurrence of atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) after a 3-month blanking period. The investigators hypothesize that thoracoscopic ablation will significantly reduce recurrence compared with catheter ablation in this population.

A secondary hypothesis is that 14-day patch monitoring detects recurrent atrial tachyarrhythmia more sensitively than conventional 24-hour Holter monitoring.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Pulmonary vein isolation is an established rhythm-control therapy for symptomatic atrial fibrillation refractory to antiarrhythmic drugs. Its efficacy is lower in persistent than in paroxysmal atrial fibrillation, and additional substrate modification of the left atrium is frequently required.

Percutaneous catheter ablation (radiofrequency, cryoballoon or PFA) and thoracoscopic surgical ablation are both used in current practice. Thoracoscopic ablation additionally allows epicardial pulmonary vein isolation, ganglionated plexi ablation, dissection of the ligament of Marshall, and left atrial appendage exclusion, at the cost of a longer hospital stay and a higher incidence of post-procedural pericarditis. Recent trials have shown broadly comparable efficacy and safety between the two approaches, so both are used interchangeably in practice.

In a retrospective analysis of the institutional ablation registry at the study site, overall outcomes of the two strategies were comparable, but among patients with an enlarged left atrium thoracoscopic ablation was associated with significantly lower recurrence of atrial tachyarrhythmia. Because that finding came from a subgroup of a retrospective cohort, it could not support a firm conclusion.

This trial therefore prospectively tests, in patients with persistent atrial fibrillation and an enlarged left atrium undergoing a first rhythm-control procedure, whether thoracoscopic ablation is superior to percutaneous catheter ablation.

Post-procedural management is identical in both arms: a 3-month blanking period, discontinuation of antiarrhythmic drugs at 3 months (up to 6 months) if sinus rhythm is maintained, and anticoagulation for at least 3 months with subsequent decisions based on recurrence, prior stroke, and CHA2DS2-VASc score. Follow-up visits occur at 3, 6, and 12 months and every 6 months thereafter until 1 year after the last patient is enrolled. Rhythm monitoring uses 12-lead ECG, 24-hour Holter (3, 6, 12 months), and 14-day patch monitoring; echocardiography and NT-proBNP are obtained at baseline, 12 months, and annually thereafter.

Study Type

Interventional

Enrollment (Estimated)

194

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Young Keun On, MD, PhD
  • Phone Number: +82-2-3410-2578
  • Email: yk.on@samsung.com

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 19 years or older
  • Persistent atrial fibrillation refractory to antiarrhythmic drug therapy, or in whom antiarrhythmic drug therapy cannot be maintained
  • European Heart Rhythm Association (EHRA) symptom score ≥ 2
  • Considered suitable for rhythm-control therapy by either percutaneous catheter ablation or thoracoscopic ablation, at the investigator's medical discretion
  • Enlarged left atrium, defined as left atrial diameter ≥ 50 mm or left atrial volume index ≥ 45 mL/m²

Exclusion Criteria:

  • Previous percutaneous catheter ablation or thoracoscopic ablation for atrial fibrillation
  • Previous thoracic or cardiac surgery
  • Absolute contraindication to anticoagulation therapy
  • Life expectancy less than 1 year due to non-cardiac disease, or anticipated poor adherence to treatment, at the investigator's medical discretion
  • Refusal to participate in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Thoracoscopic ablation
Thoracoscopic surgical ablation is performed according to the standard technique. Pulmonary vein isolation and left atrial appendage exclusion are mandatory. Additional lesions are at the operator's discretion.
Procedure: Thoracoscopic ablation
Thoracoscopic surgical ablation is performed according to the standard technique. Pulmonary vein isolation and left atrial appendage exclusion are mandatory. Additional lesions are at the operator's discretion.
Active Comparator: Percutaneous catheter ablation
Percutaneous endocardial catheter ablation is performed using radiofrequency, cryoballoon, or pulsed field energy. Pulmonary vein isolation is mandatory. Additional lesions are at the operator's discretion.
Procedure: Percutaneous catheter ablation
Percutaneous endocardial catheter ablation is performed using radiofrequency, cryoballoon, or pulsed field energy. Pulmonary vein isolation is mandatory. Additional lesions are at the operator's discretion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Recurrence of atrial tachyarrhythmia
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
Recurrence of atrial fibrillation, atrial flutter, or atrial tachycardia, defined as an episode documented on 12-lead ECG or sustained for at least 30 seconds on continuous monitoring (14-day patch monitor or 24-hour Holter). Recurrences during the 3-month blanking period are not counted as events.
From 3 months after the index procedure until 1 year after enrollment of the last patient

Secondary Outcome Measures

Outcome Measure
Time Frame
Recurrence of atrial fibrillation
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
Recurrence of atrial flutter
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
Recurrence of atrial tachycardia
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
All-cause death
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
Cardiac death
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
Stroke
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
Hospitalization for heart failure
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient
Procedure-related complications
Time Frame: From 3 months after the index procedure until 1 year after enrollment of the last patient
From 3 months after the index procedure until 1 year after enrollment of the last patient

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Samsung Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 1, 2024

Primary Completion (Estimated)

May 1, 2028

Study Completion (Estimated)

May 1, 2029

Study Registration Dates

First Submitted

August 19, 2026

First Submitted That Met QC Criteria

August 19, 2026

First Posted (Actual)

August 25, 2026

Study Record Updates

Last Update Posted (Actual)

August 25, 2026

Last Update Submitted That Met QC Criteria

August 19, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SMC 2023-06-103
  • KCT0009360 (Other Identifier: Korea National Institute of Health)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe