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

Overview

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.

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.

Interventions

• 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 conf
• 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 t

Primary outcome measures

• Recurrence of atrial tachyarrhythmia [Time frame: From 3 months to 12 months after the index procedure]

Secondary outcome measures (12)

• Atrial fibrillation burden [Time frame: From 3 months to 12 months after the index procedure]
• Repeat ablation [Time frame: From index procedure to 12 months]
• Use of antiarrhythmic drug therapy [Time frame: 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]
• Stroke [Time frame: From index procedure to 12 months]
• Cardiovascular hospitalization [Time frame: From index procedure to 12 months]
• Bleeding event [Time frame: From index procedure to 12 months]
• All-cause mortality [Time frame: From index procedure to 12 months]
• Procedure-related complications [Time frame: From index procedure to 30days]
• Procedure time [Time frame: at the index procedure]
• Radiation time [Time frame: at the index procedure]
• Left atrial reservoir strain [Time frame: From index procedure to 12 months]

Eligibility criteria

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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

South Korea · 2 centers

• Samsung Medical Center — Seoul
• Samsung Medical Center — Seoul

Publications

• Al-Aidarous S, Horrach CV, Roney C, Butcher C, Hunter RJ, Honarbakhsh S. Peak frequency can be effectively used to characterize scar in atrial fibrillation. Heart Rhythm O2. 2025 Jan 9;6(4):434-443. doi: 10.1016/j.hroo.2024.12.011. eCollection 2025 Apr. PMID 40321733
• Honarbakhsh S, Horrach CV, Lambiase PD, Roney C, Hunter RJ. The effect of fixed and functional remodelling on conduction velocity, wavefront propagation, and rotational activity formation in atrial fibrillation. Europace. 2024 Oct 3;26(10):euae239. doi: 10.1093/europace/euae239. PMID 39283961
• Verma A, Jiang CY, Betts TR, Chen J, Deisenhofer I, Mantovan R, Macle L, Morillo CA, Haverkamp W, Weerasooriya R, Albenque JP, Nardi S, Menardi E, Novak P, Sanders P; STAR AF II Investigators. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med. 2015 May 7;372(19):1812-22. doi: 10.1056/NEJMoa1408288. PMID 25946280
• Yang G, Zheng L, Jiang C, Fan J, Liu X, Zhan X, Li J, Wang L, Yang H, Zhu W, Du H, Ma G, Ma W, Kojodjojo P, Chen M; STABLE-SR-II Investigators. Circumferential Pulmonary Vein Isolation Plus Low-Voltage Area Modification in Persistent Atrial Fibrillation: The STABLE-SR-II Trial. JACC Clin Electrophysiol. 2022 Jul;8(7):882-891. doi: 10.1016/j.jacep.2022.03.012. Epub 2022 Apr 27. PMID 35863814
• Huo Y, Gaspar T, Schonbauer R, Wojcik M, Fiedler L, Roithinger FX, Martinek M, Purerfellner H, Kirstein B, Richter U, Ulbrich S, Mayer J, Krahnefeld O, Agdirlioglu T, Zedda A, Piorkowski J, Piorkowski C. Low-Voltage Myocardium-Guided Ablation Trial of Persistent Atrial Fibrillation. NEJM Evid. 2022 Nov;1(11):EVIDoa2200141. doi: 10.1056/EVIDoa2200141. Epub 2022 Oct 19. PMID 38319851
• Reddy VY, Gerstenfeld EP, Schmidt B, Nair D, Natale A, Saliba W, Verma A, Sommer P, Metzner A, Turagam M, Weiner S, Champagne J, Garcio-Bolao I, Calkins H, Olson J, Issa Z, Winner M, Su W, Tomassoni G, Kim J, Hook B, Delurgio DB, Gibson DN, Daccarett M, Patel C, Bhalla K, Shehata M, Harding JD, Cheung JW, Raybuck JD, Roelke S, Schwartz T, Sutton BS, Mansour M; ADVANTAGE-AF Investigators. Pulsed Fi PMID 40306839
• Casula M, Scajola LV, Quilico F, Pasotti B, Cesarano E, Sanzo A, Savastano S, Rordorf R. Posterior left atrial wall isolation for treatment of persistent atrial fibrillation during first-time catheter ablation: An updated systematic review and meta-analysis. Int J Cardiol. 2025 Mar 1;422:132987. doi: 10.1016/j.ijcard.2025.132987. Epub 2025 Jan 12. PMID 39809414
• Ibrahim AA, Elaraby A, Almaadawy O, Abuelazm M, Hassan AR, Bakr A, Husain MA, Elsayed H, Abdelazeem B. Adjunctive left atrial posterior wall isolation for atrial fibrillation: An updated systematic review and meta-analysis. Pacing Clin Electrophysiol. 2024 Aug;47(8):1108-1123. doi: 10.1111/pace.15035. Epub 2024 Jul 5. PMID 38967398

Identifiers

NCT: NCT07726901 · SMC 2026-02-103 · KCT0011829

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗