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Atrial FibrillationIDEAL-AFNCT04377594

Ablation of Fibrotic Areas in Patients With Persistent Atrial Fibrillation.

A study testing Radio frequency ablation in people with Atrial Fibrillation, run by Karolinska University Hospital at 1 site in Sweden.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Brief summary: The objective of this study is to compare two different ablation strategies in participants with persistent atrial fibrillation and fibrotic areas in the left atrium. The participant will be randomized to pulmonary vein isolation or pulmonary vein isolation plus ablation of fibrotic areas. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Atrial Fibrillation
What is being tested?
Radio frequency ablation
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
200 participants
Where
1 siteSweden
Study dates
20 May 2020to 11 Apr 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • ECG-documented persistent or long-standing persistent atrial fibrillation according to European Society of Cardiology (ESC) definition
  • Symptoms e. g. palpitations, dyspnea, tiredness that is due to the atrial fibrillation.
  • Suitable candidate for catheter ablation.
  • Tried one or more antiarrhythmic drugs or unwilling to try antiarrhythmic drugs
  • Age ≥18 years.

Who cannot join

  • LA dimension >55 mm as determined by an echocardiography within the previous year
  • Acute coronary syndrome or coronary artery bypass surgery within 12 weeks
  • Severe aortic or mitral valvular heart disease using the ESC guidelines
  • Congenital heart disease
  • Prior surgical or percutaneous AF ablation procedure or atrioventricular-nodal ablation
  • Medical condition likely to limit survival to < 1 year
Show all 13Show fewer
  • New York Heart Association (NYHA) class IV heart failure symptoms
  • Contraindication to oral anticoagulation
  • Renal failure requiring dialysis
  • AF due to reversible cause
  • Pregnant and fertile women without anticonception
  • History of non-compliance to medical therapy
  • Unable or unwilling to provide informed consent

Trial locations and contacts

1 site in 1 country.

Sweden1 site

  • Karolinska University Hospital

    Stockholm, Stockholm County, SE-14186

Other trials in Sweden

About this study

Official title: Individually DEsigned Ablation of Low Voltage Areas in Patients With Persistent Atrial Fibrillation, a Randomized Controlled Multicenter Trial

Brief summary: The objective of this study is to compare two different ablation strategies in participants with persistent atrial fibrillation and fibrotic areas in the left atrium. The participant will be randomized to pulmonary vein isolation or pulmonary vein isolation plus ablation of fibrotic areas.

Read the detailed description

Background:

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice with a prevalence of 2-3 percent in the population. Catheter ablation performing pulmonary vein isolation (PVI) is an established treatment, which aim to eliminate triggers from the pulmonary veins. This treatment is successful in most patients with paroxysmal AF. In many patients, especially the patients with persistent AF, this treatment is not sufficiently to achieve freedom from arrhythmia and symptoms.

There are several studies showing that fibrosis in the left atrium (LA) is an independent factor to relapse in AF after PVI. The fibrotic areas can be detected by measuring the voltage in the left atrium and creating a voltage map. There are non-randomized studies that suggest better results regarding reduction of arrhythmia burden after ablating the low voltage areas (LVAs). This ablation strategy is commonly used in clinical praxis although there are no randomized studies in this field.

Aim:

The objective of this study is to compare two different ablation strategies in participants with persistent atrial fibrillation and fibrotic areas in the left atrium. The participant will be randomized to PVI versus PVI plus ablation of LVAs.

The primary endpoint is freedom of atrial arrhythmias after 1 to 2 ablation procedures within 6 months measured at 12 months after the first ablation procedure without antiarrhythmic drugs. Secondary endpoints will be atrial arrhythmia burden, health related quality of life measured by AFEQT score, and RAND 36 and periprocedural complications; death, stroke/ TIA, tamponade, atrio-esophageal fistula, and atrioventricular block.

Study design:

Randomized controlled multicenter trial. The study will be single blinded. All the participants will undergo PVI and the substrate map will be collected during atrial pacing. The patients with LVA will be randomized in a 1:1 fashion to; PVI plus ablation of LVA or PVI alone. Follow up visits will be at 3, 6, 12, 18 and 24 months. Before ablation and at every follow up visit the participants will fill in arrhythmia symptom specific questionnaires (AFEQT and ASTA) and questionnaire about quality of life (RAND 36). The participants will register arrhythmia with a heart monitoring system if symptoms of arrhythmia and two times daily during two weeks before every follow up visit.

Being tested
Radio frequency ablation
Keywords
Catheter ablation, Low voltage
Medical subject headings
Atrial Fibrillation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Radio frequency ablationProcedure or surgery

    Two different radio frequency ablation procedures

Study groups in NCT04377594
Study groupRoleWhat they receive
Pulmonary vein isolation plus substrate modificationExperimentalPulmonary vein isolation plus ablation of low voltage areas in the left atrium
Receives: Procedure: Radio frequency ablation
Pulmonary vein isolationActive comparatorPulmonary vein isolation
Receives: Procedure: Radio frequency ablation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants with Freedom from Atrial Arrhythmia

    Freedom from documented atrial arrhythmias >30 seconds at 12 months after 1 or 2 ablation procedures within 6 months without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 12 months after the first ablation procedure

Secondary outcomes (16)

  1. Number of Participants with Freedom from Atrial Arrhythmia after 1 Ablation Procedure without Antiarrhythmic Drugs (AAD)

    Freedom from documented atrial arrhythmias >30 seconds at 12 months after 1 ablation procedure without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 12 months after the first ablation procedure

  2. Number of Participants with Freedom from Atrial Arrhythmia after 1 Ablation Procedure with/ without AAD

    Freedom from documented atrial arrhythmias >30 seconds at 12 months after 1 ablation procedure with or without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 12 months after the first ablation procedure

  3. Number of Participants with Freedom from Atrial Arrhythmia after 1 or 2 Ablation Procedures with/ without AAD

    Freedom from documented atrial arrhythmias >30 seconds at 12 months after 1 or 2 ablation procedures with or without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 12 months after the first ablation procedure

  4. Number of Participants with Freedom from Atrial Fibrillation

    Freedom from documented atrial fibrillation >30 seconds at 12 months after 1 or 2 ablation procedures without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 12 months after the first ablation procedure

  5. Number of Participants with Freedom from Symptomatic Atrial Arrhythmias

    Freedom from documented symptomatic atrial arrhythmias >30 seconds at 12 months after 1 or 2 ablation procedures with or without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 12 months after the first ablation procedure

  6. Number of Participants with Freedom from Atrial Arrhythmias without AAD

    Freedom from documented atrial arrhythmias >30 seconds at 24 months after 1 or several ablation procedures without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 24 months after the first ablation procedure

  7. Number of Participants with Freedom from Atrial Arrhythmias with or without AAD

    Freedom from documented symptomatic atrial arrhythmias >30 seconds at 24 months after 1 or several ablation procedures with or without antiarrhythmic drugs

    Measured: From 3 months (blanking period) to 24 months after the first ablation procedure

  8. Arrhythmia Burden

    Number of Registrations with Remote Heart Monitor / Number of Registrations with Atrial Arrhythmia with Remote Heart Monitor

    Measured: From 3 months (blanking period) to 12 months and 24 months after the first ablation procedure

  9. Time to First Recurrens

    Time from first ablation procedure to first documented recurrens of atrial arrhythmias

    Measured: From first ablation procedure to 24 months

  10. Number of Repeat Procedures

    Number of repeat procedures

    Measured: 12 and 24 months after the first ablation procedure

  11. Changes in Quality of Life Measures: Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) Overall Score and Subscale Scores

    AFEQT is a 21 questions atrial fibrillation specific health related quality of life questionnaire. Overall Score (calculated from 18 of the questions) and subscale scores in three domains: symptoms, daily activities, and treatment concern. Score ranges from 0 to 100 points. Higher scores mean a better outcome.

    Measured: Baseline, 12 and 24 months after the first ablation procedure

  12. Changes in Quality of Life Measures: RAND 36 (Research ANd Development) 36 All Domains

    RAND 36 (developed by RAND corporation) is a 36 questions health related quality of life questionnaire. The RAND 36 is divided into 8 domains: Physical functioning, role physical, role emotional, bodily pain, vitality, general health, social functioning and mental health. Score range from 0 to 100 points. Higher scores mean a better outcome.

    Measured: Baseline,12 and 24 months after the first ablation procedure

  13. Number of Participants with Adverse Events/ Complications

    Complications related to the ablation procedure: Cardiac perforation, stroke, transitory ischemic attack (TIA), systemic embolic events, atrio-esophageal fistula, major bleeding, atrioventricular block, groin hematoma requiring vascular surgery or extended hospitalization.

    Measured: 12 and 24 months after the first ablation procedure

  14. Number of Participants With All-cause Mortality

    Number of Participants With All-cause Mortality

    Measured: 12 and 24 months after the first ablation procedure

  15. Procedure time

    Time from start of groin punction to withdrawal of the catheters

    Measured: Immediately after the procedure

  16. Fluoroscopy time

    Total fluoroscopy time during the procedure

    Measured: Immediately after the procedure

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 May 2020
  2. Study start20 May 2020
  3. Primary completion10 Apr 2026
  4. Study completion11 Apr 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Randomization 1:1
Masking
Single blind
Who is masked
Participant
Enrolment
200 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04377594
Sponsor's protocol ID
200212IDEALAF
Acronym
IDEAL-AF
Status last verified
Dec 2025
First submitted
23 Apr 2020
Last updated
3 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Lloyd-Jones DM, Wang TJ, Leip EP, Larson MG, Levy D, Vasan RS, D'Agostino RB, Massaro JM, Beiser A, Wolf PA, Benjamin EJ. Lifetime risk for development of atrial fibrillation: the Framingham Heart Study. Circulation. 2004 Aug 31;110(9):1042-6. doi: 10.1161/01.CIR.0000140263.20897.42. Epub 2004 Aug 16.

    PubMed 15313941

  • Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, Castella M, Diener HC, Heidbuchel H, Hendriks J, Hindricks G, Manolis AS, Oldgren J, Popescu BA, Schotten U, Van Putte B, Vardas P; ESC Scientific Document Group. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016 Oct 7;37(38):2893-2962. doi: 10.1093/eurheartj/ehw210. Epub 2016 Aug 27. No abstract available.

    PubMed 27567408

  • Calkins H, Hindricks G, Cappato R, Kim YH, Saad EB, Aguinaga L, Akar JG, Badhwar V, Brugada J, Camm J, Chen PS, Chen SA, Chung MK, Cosedis Nielsen J, Curtis AB, Davies DW, Day JD, d'Avila A, Natasja de Groot NMS, Di Biase L, Duytschaever M, Edgerton JR, Ellenbogen KA, Ellinor PT, Ernst S, Fenelon G, Gerstenfeld EP, Haines DE, Haissaguerre M, Helm RH, Hylek E, Jackman WM, Jalife J, Kalman JM, Kautzner J, Kottkamp H, Kuck KH, Kumagai K, Lee R, Lewalter T, Lindsay BD, Macle L, Mansour M, Marchlinski FE, Michaud GF, Nakagawa H, Natale A, Nattel S, Okumura K, Packer D, Pokushalov E, Reynolds MR, Sanders P, Scanavacca M, Schilling R, Tondo C, Tsao HM, Verma A, Wilber DJ, Yamane T; Document Reviewers:. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation. Europace. 2018 Jan 1;20(1):e1-e160. doi: 10.1093/europace/eux274. No abstract available.

    PubMed 29016840

  • Tilz RR, Rillig A, Thum AM, Arya A, Wohlmuth P, Metzner A, Mathew S, Yoshiga Y, Wissner E, Kuck KH, Ouyang F. Catheter ablation of long-standing persistent atrial fibrillation: 5-year outcomes of the Hamburg Sequential Ablation Strategy. J Am Coll Cardiol. 2012 Nov 6;60(19):1921-9. doi: 10.1016/j.jacc.2012.04.060. Epub 2012 Oct 10.

    PubMed 23062545

  • Scherr D, Khairy P, Miyazaki S, Aurillac-Lavignolle V, Pascale P, Wilton SB, Ramoul K, Komatsu Y, Roten L, Jadidi A, Linton N, Pedersen M, Daly M, O'Neill M, Knecht S, Weerasooriya R, Rostock T, Manninger M, Cochet H, Shah AJ, Yeim S, Denis A, Derval N, Hocini M, Sacher F, Haissaguerre M, Jais P. Five-year outcome of catheter ablation of persistent atrial fibrillation using termination of atrial fibrillation as a procedural endpoint. Circ Arrhythm Electrophysiol. 2015 Feb;8(1):18-24. doi: 10.1161/CIRCEP.114.001943. Epub 2014 Dec 20.

    PubMed 25528745

  • Verma A, Wazni OM, Marrouche NF, Martin DO, Kilicaslan F, Minor S, Schweikert RA, Saliba W, Cummings J, Burkhardt JD, Bhargava M, Belden WA, Abdul-Karim A, Natale A. Pre-existent left atrial scarring in patients undergoing pulmonary vein antrum isolation: an independent predictor of procedural failure. J Am Coll Cardiol. 2005 Jan 18;45(2):285-92. doi: 10.1016/j.jacc.2004.10.035.

    PubMed 15653029

  • Oakes RS, Badger TJ, Kholmovski EG, Akoum N, Burgon NS, Fish EN, Blauer JJ, Rao SN, DiBella EV, Segerson NM, Daccarett M, Windfelder J, McGann CJ, Parker D, MacLeod RS, Marrouche NF. Detection and quantification of left atrial structural remodeling with delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation. Circulation. 2009 Apr 7;119(13):1758-67. doi: 10.1161/CIRCULATIONAHA.108.811877. Epub 2009 Mar 23.

    PubMed 19307477

  • Rolf S, Kircher S, Arya A, Eitel C, Sommer P, Richter S, Gaspar T, Bollmann A, Altmann D, Piedra C, Hindricks G, Piorkowski C. Tailored atrial substrate modification based on low-voltage areas in catheter ablation of atrial fibrillation. Circ Arrhythm Electrophysiol. 2014 Oct;7(5):825-33. doi: 10.1161/CIRCEP.113.001251. Epub 2014 Aug 23.

    PubMed 25151631

  • Yagishita A, Sparano D, Cakulev I, Gimbel JR, Phelan T, Mustafa H, De Oliveira S, Mackall J, Arruda M. Identification and electrophysiological characterization of early left atrial structural remodeling as a predictor for atrial fibrillation recurrence after pulmonary vein isolation. J Cardiovasc Electrophysiol. 2017 Jun;28(6):642-650. doi: 10.1111/jce.13211. Epub 2017 May 29.

    PubMed 28387462

  • Schreiber D, Rieger A, Moser F, Kottkamp H. Catheter ablation of atrial fibrillation with box isolation of fibrotic areas: Lessons on fibrosis distribution and extent, clinical characteristics, and their impact on long-term outcome. J Cardiovasc Electrophysiol. 2017 Sep;28(9):971-983. doi: 10.1111/jce.13278. Epub 2017 Jul 5.

    PubMed 28635186

  • Kottkamp H, Bender R, Berg J. Catheter ablation of atrial fibrillation: how to modify the substrate? J Am Coll Cardiol. 2015 Jan 20;65(2):196-206. doi: 10.1016/j.jacc.2014.10.034.

    PubMed 25593061

  • Phlips T, Taghji P, El Haddad M, Wolf M, Knecht S, Vandekerckhove Y, Tavernier R, Duytschaever M. Improving procedural and one-year outcome after contact force-guided pulmonary vein isolation: the role of interlesion distance, ablation index, and contact force variability in the 'CLOSE'-protocol. Europace. 2018 Nov 1;20(FI_3):f419-f427. doi: 10.1093/europace/eux376.

    PubMed 29315411

  • El Haddad M, Taghji P, Phlips T, Wolf M, Demolder A, Choudhury R, Knecht S, Vandekerckhove Y, Tavernier R, Nakagawa H, Duytschaever M. Determinants of Acute and Late Pulmonary Vein Reconnection in Contact Force-Guided Pulmonary Vein Isolation: Identifying the Weakest Link in the Ablation Chain. Circ Arrhythm Electrophysiol. 2017 Apr;10(4):e004867. doi: 10.1161/CIRCEP.116.004867.

    PubMed 28381417

  • Paul Nordin A, Charitakis E, Carnlof C, Akerstrom F, Saluveer O, Almroth H, Karlsson LO, Hassel Jonsson A, Herczku C, Tapanainen J, Hoglund N, Svennberg E, Braunschweig F, Bourke T, Schwieler J, Bastani H, Saygi S, Asaad F, Turkmen Y, Jensen-Urstad M, Drca N. Low-Voltage Ablation in Persistent Atrial Fibrillation: The IDEAL-AF Randomized Clinical Trial. JAMA. 2026 Aug 30. doi: 10.1001/jama.2026.17274. Online ahead of print.

    PubMed 42669133

Questions about this trial

What is this clinical trial studying?

A study testing Radio frequency ablation in people with Atrial Fibrillation, run by Karolinska University Hospital at 1 site in Sweden.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 3 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants with Freedom from Atrial Arrhythmia (time frame: From 3 months (blanking period) to 12 months after the first ablation procedure). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04377594, which also lists 14 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Sep 2026.

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