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Atrial Fibrillation (AF)CRAAFT-HFNCT06505798

Cryoballoon/Radiofrequency/Pulsed Field Ablation of Atrial Fibrillation Versus Medical Treatment for Heart

A study testing Catheter Ablation in people with Atrial Fibrillation (AF), run by University College, London at 24 sites in 2 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

Atrial fibrillation (AF) is a common heart rhythm disorder that causes an irregular heart beat and is a cause of heart failure (HF). Treatments include drugs to slow the heart rate, anti-arrhythmic drugs or ablation of the heart to help preserve normal rhythm. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Atrial Fibrillation (AF)
What is being tested?
Catheter Ablation
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
1,200 participants
Where
24 sitesin 2 countries
Study dates
21 Nov 2024to 15 Dec 2031
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

  • Patients aged ≥18 years.
  • Patient is willing and able to give informed consent for participation.
  • Able and willing to comply with all study requirements, including ability to participate in study for 12 months.
  • Willing to allow their General Practitioner (GP) to be notified of participation in the study.
  • Patient with one of the following AF categories and at least one episode of AF documented (by any means eg ECG, Holter, Cardiac Implantable Electronic Device (CIED) interrogation or any other means):
  • Paroxysmal AF defined as spontaneous self-terminating AF lasted > 6 hours and <7 days.
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  • Persistent AF as defined by at least one episode of AF >7 days but not >3 years (since 1st documentation)
  • Optimal tolerated medical therapy for HF (including ACE-I (or ARB or ARNi), beta-blocker, SGLT2 inhibitor and mineralocorticoid receptor antagonist (MRA) and cardiac resynchronisation therapy (CRT) where indicated \& tolerated) for at least 6 weeks (according to the most contemporary European Society of Cardiology (ESC) HF guidelines). Maximal doses of these drugs are not mandated.
  • New York Heart Association Classification (NYHA) class II to III
  • LVEF <50% (Cardiac imaging report of LVEF<50% within 1 year (by echocardiography, cardiac magnetic resonance imaging or nuclear cardiology assessment)) AND after optimisation of medical therapy (see previous definition). Note - a LVEF of <50% must be documented by any cardiac imaging performed after optimisation of medical therapy. Documentation of other baseline echocardiographic parameters (eg LA volume, E/E' etc can be obtained from any echocardiogram within 2.5 years). This allows a handheld or echocardiogram focused on LVEF assessment.
  • For those with LVEF 41-49% and without ongoing atrial fibrillation/flutter, N-terminal pro B-type natriuretic peptide (NT-proBNP) of ≥300pg/mL is required within 12 months prior to randomisation.
  • For those with LVEF 41-49% and with ongoing atrial fibrillation/flutter, NTproBNP of ≥600pg/mL is required within 12 months prior randomisation.
  • For those with LVEF ≤40%, NTproBNP is not required

Who cannot join

  • Long standing (>3 year) persistent or permanent AF.
  • Previous atrioventricular (AV) nodal ablation.
  • Previous pulmonary vein isolation (PVI) or surgical ablation.
  • Recent (<90 days) (type 1 spontaneous) myocardial infarction (type 2 myocardial infarctions are not an exclusion criterion), percutaneous coronary intervention, coronary artery bypass grafting, cardiac resynchronisation therapy or stroke.
  • Severe aortic or pulmonary valve disease.
  • Severe primary or secondary mitral valve regurgitation.
Show all 13Show fewer
  • Active illness (other than HF) likely to result in death within 2 years.
  • People who are pregnant or planning to become pregnant during the trial.
  • People who are breastfeeding.
  • Known allergy to contrast.
  • Contraindication for PVI.
  • Other conditions that may prevent subjects from adhering to the trial protocol, in the opinion of the investigator.
  • Currently participating in another randomised controlled trial of another drug or medical device.

Trial locations and contacts

24 sites in 2 countries. Contact the study team or a site near you to ask about taking part.

Pier Lambiase contact

07977217787

p.lambiase@ucl.ac.uk

CRAAFT-HF Team @ Barts CVCTU contact

craaft-hf-cvctu@qmul.ac.uk

24 sites in 2 countries

United Kingdom23 sites, 23 recruiting
  • Mid and South Essex NHS Foundation Trust

    Basildon

    Sophie Harris, 01268 524900 ext. 6712, sophie.harris56@nhs.net

    Neil Srinivasan

    Recruiting
  • Queen Elizabeth Hospital

    Birmingham

    Annette Nilsson, Annette.Nilsson@uhb.nhs.uk

    Manish Kalla

    Recruiting
  • Blackpool Victoria Hospital

    Blackpool

    Natalie Irvine, natalie.irvine3@nhs.net

    Alison Seed

    Recruiting
  • University Hospitals Dorset NHS Foundation Trust

    Bournemouth

    Becky Troke, 0300 0194514, becky.troke@uhd.nhs.uk

    Richard Balasubramaniam

    Recruiting
  • Royal Papworth Hospital NHS Foundation Trust

    Cambridge, CB2 0AY

    Niina Ala-Krekola, 01223 639042, niina.ala-krekola@nhs.net

    Claire Martin

    Recruiting
  • University Hospitals Coventry and Warwickshire NHS Trust

    Coventry

    Abeesh Sadasiva Panicker, 024 7696 7668 ext. 27668, abeeshsadasiva.panicker@uhcw.nhs.uk

    Tarv Dhanjal

    Recruiting
  • Golden Jubilee National Hospital

    Glasgow, G81 4DY

    Linda Cassidy, 0141 951 5490, linda.cassidy@gjnh.scot.nhs.uk

    Roy Gardner

    Recruiting
  • Hull University Teaching Hospitals NHS Trust

    Hull

    Jeanne Bulemfu, 07800726002, jeanne.bulemfu@nhs.net

    Andrew Clark

    Recruiting
  • Leeds Teaching Hospitals NHS Trust

    Leeds

    Lucy Leese, 0113 3923131, l.leese@nhs.net

    Muzahir Tayebjee

    Recruiting
  • Glenfield Hospital

    Leicester

    Judith Fisher, Judith.fisher6@nhs.net

    Louise Clayton

    Recruiting
  • Liverpool Heart and Chest Hospital NHS Foundation Trust

    Liverpool

    Rajiv Sankaranarayanan

    Recruiting
  • Royal Brompton and Harefields Hospitals

    London, UB9 6JH

    Myra Brigoli, 01895 823 737, myra.brigoli1@nhs.net

    Shouvik Haldar

    Recruiting
  • Barts Health NHS Trust

    London

    Flavia Pereira, 0, flavia.pereira1@nhs.net

    Shohreh Honarbakhsh

    Recruiting
  • Imperial College Healthcare NHS Trust

    London

    Aisha Abdi, 0, aisha.abdi4@nhs.net

    Prapa Kanagaratnam

    Recruiting
  • St George's University Hospitals NHS Foundation Trust

    London

    Zainab Ahmed, 020 8725 1029, zahmed@sgul.ac.uk

    Mark Gallagher

    Recruiting
  • St Thomas' hospital

    London

    Olivia Fox, olivia.fox2@nhs.net

    Aldo Rinaldi

    Recruiting
  • James Cook University Hosptial

    Middlesbrough

    Ben Ward, ben.ward8@nhs.net

    Andrew Thornley

    Recruiting
  • Freeman Hospital, Royal Victoria Infirmary

    Newcastle

    Claire McMillan, claire.mcmillan4@nhs.net

    Moloy Das

    Recruiting
  • Nottingham University Hospital NHS Trust

    Nottingham

    Jane Quinn, 0115 9691169 ext. 77460, Jane.Quinn7@nhs.net

    Shahnaz Jamil-Copley

    Recruiting
  • University Hospitals Plymouth NHS Trust

    Plymouth

    Lorraine Madziva, 0, lorraine.madziva1@nhs.net

    Sharon Man

    Recruiting
  • Queen Alexandra Hospital

    Portsmouth

    Serene Howe, Serena.howe1@nhs.net

    Senthil Kirubakaran

    Recruiting
  • Southampton General

    Southampton

    Elizabeth Greenwood, elizabeth.greenwood@uhs.nhs.uk

    John Paisey

    Recruiting
  • Swansea Bay University Health Board

    Swansea

    Debbie Williams, debbie.williams8@wales.nhs.uk

    Dewi M Thomas

    Recruiting

Other trials in United Kingdom

Canada1 site, 1 recruiting
  • Halifax Infirmary

    Halifax

    Stephanie Hobbs, stephanie.hobbs@nshealth.ca

    Aileen Davis, aileen.davis@nshealth.ca

    Recruiting

Other trials in Canada

About this study

Atrial fibrillation (AF) is a common heart rhythm disorder that causes an irregular heart beat and is a cause of heart failure (HF). Treatments include drugs to slow the heart rate, anti-arrhythmic drugs or ablation of the heart to help preserve normal rhythm. A number of trials have suggested that ablation may be superior to drug treatment to reduce hospitalisations or prevent early death. However, these studies have been small and the results not applicable to the general population with AF and heart failure in the UK. This international study will compare catheter ablation and optimal medical therapy versus optimal medical therapy alone to see if catheter ablation reduces unplanned heart failure hospitalisations and death rates and improves quality of life.

Read the detailed description

Atrial fibrillation (AF) increases the severity of, and death from, heart failure (HF). Several small studies have demonstrated that restoration of sinus rhythm by catheter ablation in patients with HF improves left ventricular (LV) function and exercise tolerance. What is unknown is whether or not AF ablation reduces all-cause death and urgent CV hospitalisations in populations with HF. The current trial will answer this outstanding question, which is faced by HF clinicians and electrophysiologists on a daily basis. AF ablation can be performed very effectively and efficiently using a cryo-balloon or radio-frequency ablation PVI technique. These techniques have evolved slowly and are unlikely to change substantially over the course of this trial. One small trial (n=363) in implantable cardioverter-defibrillator and CRT defibrillator recipients (CASTLE-AF) reported a death benefit of AF ablation but the patients were highly selected and the death reduction was far higher than real world expected differences. Recent studies have noted that the population randomised in CASTLE-AF was not representative of the general HF population with only 7% of patients in the "real world" setting meeting the trial entry criteria. CASTLE-AF is therefore provocative but inconclusive; it has made little change to clinical practice. As no studies have investigated the death benefit in a general HF population, the proposed trial is necessary and warranted. This study is designed as a randomised, open label multicentre clinical trial in which catheter ablation and medical therapy is compared to medical therapy alone in patients with HF with reduced ejection fraction (<50%) and paroxysmal or persistent AF to determine if this reduces all-cause death and urgent CV hospitalisations as well as improving QoL. By utilising the clinical and research networks of the British Heart Failure Society and British Heart Rhythm Society (BHRS) we will recruit 1200 patients. The current trial will be almost three times the size of the only previous inconclusive trial which was reported in the New England Journal of Medicine.

Being tested
Catheter Ablation
Keywords
AF
Medical subject headings
Atrial Fibrillation

What participants receive

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

  • Catheter AblationProcedure or surgery

    Participants randomised to the catheter ablation arm will undergo Pulmonary Vein Isolation (PVI) which is the essential ablation intervention. The technique used will be at the discretion of the treating physician but may include Cryoballoon (Medtronic/Boston Scientific), Radiofrequency: CARTO (Biosense), pulsed field radiofrequency ablation, or Precision (Abbott Medical) electro-anatomical mapping systems. Additional ablation lesions may be delivered as preferred by the operator and will be documented. Electro-anatomical voltage maps will be collected (in SR/AF) and stored for later analysis.

Study groups in NCT06505798
Study groupRoleWhat they receive
The optimal medical therapy as per standard of careNo interventionParticipants randomised to the optimal medical therapy arm will receive optimal medical therapy according to the most contemporary ESC HF guidelines.
The catheter ablationOtherCatheter ablation is an established therapeutic strategy in patients without HF that aims to convert AF to sinus rhythm in symptomatic, drug-refractory AF in patients.
Receives: Procedure: Catheter Ablation

What is being measured

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

  1. Time to first all-cause death and urgent CV hospitalisation

    The primary outcome (time to first all-cause death and urgent CV hospitalisation) will be summarised by randomised group and analysed using a Cox proportional hazards regression model for time to first event, adjusting for factors used to balance the randomisation.

    Measured: 2 years minimum (range: 2-5.5 years)

Secondary outcomes (5)
  1. Total (first and recurrent) all-cause death and urgent cardiovascular hospitalisations.

    Total (first and recurrent) number of all-cause deaths and urgent cardiovascular-related hospitalisations. Joint frailty models will be used to analyse time to death and recurrent urgent CV hospitalisations simultaneously. Additionally, negative binomial regression will be used to analyse the number of recurrent urgent CV hospitalisations.

    Measured: 2 years minimum (range: 2-5.5 years)

  2. QoL at 6 and 12 months assessed using the KCCQ-CSS.

    Quality of Life (QoL) at 6 and 12 months assessed using the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS). Linear mixed effects regression models will be used to analyse repeated measurements of QoL. Scored from 0- 100, with a higher score indicating better health.

    Measured: 12 months

  3. Time to all-cause death

    Time to all-cause death will be analysed using Cox proportional hazards regression model for time to event, matching the primary outcome.

    Measured: 2 years minimum (range: 2-5.5 years)

  4. Total (first and recurrent) all-cause death and urgent HF hospitalisations

    Total (first and recurrent) number of all-cause deaths and urgent heart failure-related hospitalisations. Joint frailty models will be used to analyse time to death and recurrent urgent HF hospitalisations simultaneously. Additionally, negative binomial regression will be used to analyse the number of recurrent urgent HF hospitalisations.

    Measured: 2 years minimum (range: 2-5.5 years)

  5. Cardiovascular death

    Total number of cardiovascular-related deaths. Cox proportional hazards regression model for time to event, matching the primary outcome.

    Measured: 2 years minimum (range: 2-5.5 years)

Timeline

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

  1. First posted17 Jul 2024
  2. Study start21 Nov 2024
  3. Primary completion15 Dec 2031 (estimated)
  4. Study completion15 Dec 2031 (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
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
This is a randomised, adaptive open label multicentre clinical trial which compares optimal medical therapy (as per standard of care) with catheter ablation plus optimal medical therapy alone in participants with HfrEF (LVEF\<50%) and paroxysmal or persistent atrial fibrillation. This design is adaptive in that the required sample size is reviewed in an interim analysis at 80% recruitment. This interim analysis aims to ensure that sufficient patients are recruited to maintain the conditional power of the study at 80% or higher. Options which can be deployed at the interim analysis include increasing patient numbers and increasing duration of follow up.
Masking
None (open label)
Enrolment
1,200 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06505798
Sponsor's protocol ID
136905
Other IDs
CS/F/21/190034 CRAAFT-HF, 281142, 24/LO/0301
Acronym
CRAAFT-HF
Status last verified
Mar 2026
First submitted
1 Jul 2024
Last updated
4 May 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Catheter Ablation in people with Atrial Fibrillation (AF), run by University College, London at 24 sites in 2 countries.

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 13 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: looking for participants now, as of the sponsor's last update on 4 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 24 sites in United Kingdom, Canada. 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?

Contact Pier Lambiase (07977217787, p.lambiase@ucl.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Time to first all-cause death and urgent CV hospitalisation (time frame: 2 years minimum (range: 2-5.5 years)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 4 May 2026.

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