Empirical Anatomy-Based Ablation vs Emphasize Map-Guided Substrate Ablation in Persistent Atrial Fibrillation : (COMPASS-AF) (COMPASS-AF)

July 21, 2026 updated by: Ju Youn Kim, Samsung Medical Center

This study is aimed to compare the clinical efficacy of two different catheter ablation strategies in patients with persistent atrial fibrillation.

Participants will be randomized 1:1 into either the Anatomy-based group or the Emphasize map-guided group

  • Anatomy-based group : Pulmonary vein isolation (PVI) using pulsed-field ablation (PFA) with a single-shot multielectrode catheter.
  • Emphasize map-guided group : PVI using radiofrequency (RF) ablation followed by additional EnSite X-guided pathologic substrate modification.

Participants will be followed for 1 year to compare the incidence of any atrial tachyarrhythmia and other clinical parameters between the two groups.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Pulsed-field ablation (PFA) is increasingly being adopted in clinical practice due to its advantages in shortening procedure times and reducing the incidence of complications. While the majority of PFA-related research has focused on PVI-centric strategies, recent studies have reported that posterior wall isolation (PWI) using PFA can also be performed safely. However, sufficient clinical evidence regarding the efficacy of additional ablation strategies beyond PVI in patients with persistent atrial fibrillation (AF) has yet to be established.

The Emphasize mapping system, a software feature within the EnSite X platform, is designed to simultaneously visualize Voltage maps, Peak frequency, and CFAE-related information. Unlike the individual analysis of each parameter, this integrated approach allows for a more precise identification of electrophysiologically significant pathologic substrates by evaluating the complex characteristics of electrical signals holistically. Currently, however, Emphasize-guided ablation is technically limited to the use of radiofrequency (RF) energy.

Persistent AF is characterized by complex and heterogeneous mechanisms, meaning a single, uniform ablation strategy may not yield consistent clinical outcomes across all patients. Consequently, it is hypothesized that an individualized substrate ablation strategy guided by functional mapping may be more effective than a conventional, empirical anatomy-based approach.

Therefore, this study aims to compare the clinical efficacy and safety of an empirical anatomy-based ablation strategy using PFA versus an individualized Emphasize map-guided substrate ablation strategy in patients with persistent AF.

Study Type

Interventional

Enrollment (Estimated)

360

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

Study Locations

  • South Korea
    • Seoul
      • Seoul, Seoul, South Korea, 06351
        • Recruiting
        • Samsung Medical Center
        • Contact:
      • Seoul, Seoul, South Korea, 06351
        • Not yet recruiting
        • Samsung Medical Center
        • Contact:

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:

  • Adults aged 19 years or older who have voluntarily provided written informed consent to participate in the study
  • Patients diagnosed with persistent atrial fibrillation (AF) who are scheduled to undergo catheter ablation for AF.

Exclusion Criteria:

  • History of prior catheter ablation or MAZE surgery for atrial fibrillation.
  • Left atrial (LA) diameter exceeding 60 mm.
  • Patients with end-stage renal disease (ESRD).
  • History of prior open-heart surgery.
  • Women who are pregnant, lactating, or of childbearing potential.
  • Heart failure corresponding to New York Heart Association (NYHA) functional class IV.
  • Acute coronary syndrome (ACS) experienced within the past 3 months.
  • Patients with terminal illness and a life expectancy of less than one year.
  • Any other condition that the investigator deems inappropriate for participation 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
Active Comparator: Anatomy-based group
Procedure: Anatomy-based ablation
In the empirical anatomy-based ablation strategy group, pulmonary vein isolation (PVI) will be performed using pulsed-field ablation (PFA) with a single-shot multielectrode catheter. For each pulmonary vein, approximately 4-10 pulse applications will be delivered depending on the catheter position, with each application consisting of several seconds of pulse delivery. The catheter will be positioned around the PV ostia, and electrical isolation will be achieved by utilizing various catheter configurations as necessary. The energy settings and application methods for PFA in this study will follow the manufacturer's recommended protocols and established methods from prior clinical studies. Additionally, the creation of supplementary lesion sets is permitted at the operator's discretion.
Experimental: Emphasize map-guided group
Procedure: Emphasize map-guided ablation
In the Emphasize map-guided substrate ablation group, ablation will be performed using a contact force-sensing irrigated radiofrequency (RF) catheter. Following pulmonary vein isolation (PVI), an Emphasize map will be acquired during atrial fibrillation (AF) using the EnSite X mapping system. Based on this map, electrophysiologically significant pathologic substrates will be evaluated, and additional substrate ablation will be performed. Subsequently, electrical cardioversion will be conducted to restore sinus rhythm. If sinus rhythm is not maintained or if AF is re-induced, an additional Emphasize map may be acquired in the right atrium (RA), and RA substrate ablation can be performed if necessary.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Recurrence of atrial tachyarrhythmia
Time Frame: From 3 months to 12 months after the index procedure

Any documented atrial tachyarrhythmias excluding the initial 3-month blanking period. Documented atrial tachyarrhythmias (atrial fibrillation, atrial flutter, atrial tachycardia) were defined as follows:

  • Atrial tachyarrhythmias documented in 12 lead ECG
  • Atrial tachyarrhythmias of more than 30 seconds in Holter monitoring Recorded as a binary outcome (presence or absence of recurrence)
From 3 months to 12 months after the index procedure

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Atrial fibrillation burden
Time Frame: From 3 months to 12 months after the index procedure
The proportion of time spent in atrial fibrillation or atrial flutter during rhythm monitoring .The burden will be assessed as percent(%) using Holter monitoring.
From 3 months to 12 months after the index procedure
Repeat ablation
Time Frame: From index procedure to 12 months
Any additional catheter ablation procedure performed after the index procedure for documented recurrent atrial tachyarrhythmia during the follow-up period.
From index procedure to 12 months
Use of antiarrhythmic drug therapy
Time Frame: From 3 months to 12 months after the index procedure
Percentage of patients prescribed any Class I or Class III antiarrhythmic Temporary use during the blanking period (first 3 months) will not be counted.
From 3 months to 12 months after the index procedure
Atrial Fibrillation Effect on Quality-of-life (AFEQT) questionnaire score
Time Frame: From index procedure to 12 months
The AFEQT is outcome instrument designed to measure the impact of AF on a patient's health-related quality of life. Scores range from 0 to 100, with higher scores indicating a better health-related quality of life
From index procedure to 12 months
Stroke
Time Frame: From index procedure to 12 months
Proportion of participants experiencing a new focal or global neurological deficit lasting ≥24 hours with imaging evidence of ischemic or hemorrhagic stroke. Transient ischemic attack will not be included.
From index procedure to 12 months
Cardiovascular hospitalization
Time Frame: From index procedure to 12 months

Proportion of participants experiencing hospitalization primarily due to a cardiovascular cause, including:

  • Atrial tachyarrhythmia recurrence
  • Heart failure exacerbation
  • Acute coronary syndrome
  • Cardiovascular procedural complications
From index procedure to 12 months
Bleeding event
Time Frame: From index procedure to 12 months

Proportion of participants experiencing bleeding events.

Bleeding event will be classified according to the International Society on Thrombosis and Haemostasis(ISTH) criteria:

  • Major bleeding
  • Clinically relevant non-major bleeding
From index procedure to 12 months
All-cause mortality
Time Frame: From index procedure to 12 months
Death due to any cause occurring during the follow-up period.
From index procedure to 12 months
Procedure-related complications
Time Frame: From index procedure to 30days

Proportion of participants experiencing any complication occurring during or within 30 days after the index procedure, including:

  • Cardiac tamponade
  • Vascular access complication
  • Pulmonary vein stenosis
  • Esophageal injury
  • Phrenic nerve injury
  • Major bleeding.
From index procedure to 30days
Procedure time
Time Frame: at the index procedure
Total procedure time measured in minutes from vascular access puncture to removal of all catheters at the end of the procedure.
at the index procedure
Radiation time
Time Frame: at the index procedure
Total fluoroscopy exposure time measured in minutes.
at the index procedure
Left atrial reservoir strain
Time Frame: From index procedure to 12 months
Measured as percentage by echocardiography
From index procedure to 12 months

Collaborators and Investigators

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

Sponsor

Samsung Medical Center

Collaborators

Asan Medical Center
Korea University Anam Hospital
Keimyung University Dongsan Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 19, 2026

Primary Completion (Estimated)

December 31, 2030

Study Completion (Estimated)

December 31, 2030

Study Registration Dates

First Submitted

July 21, 2026

First Submitted That Met QC Criteria

July 21, 2026

First Posted (Actual)

July 24, 2026

Study Record Updates

Last Update Posted (Actual)

July 24, 2026

Last Update Submitted That Met QC Criteria

July 21, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SMC 2026-02-103
  • KCT0011829 (Other Identifier: Korea National Institute of Health)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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.

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