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Comparing catheter ablation (cryo, radiofrequency, pulsed field) with medical therapy for people with atrial fibrillation and heart failure.

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

NA · University College, London · NCT06505798

This study will see if catheter ablation plus optimal heart-failure medicines helps people with atrial fibrillation and heart failure have fewer unplanned heart-failure hospital stays and lower risk of death than medicines alone.

Quick facts

PhaseNA
Study typeInterventional
Enrollment1200 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity College, London (other)
Locations24 sites (Halifax and 23 other locations)
Trial IDNCT06505798 on ClinicalTrials.gov

What this trial studies

This randomized trial will compare catheter ablation (using cryoballoon, radiofrequency, or pulsed field pulmonary vein isolation) plus guideline-directed heart-failure therapy versus guideline-directed therapy alone in people with AF and heart failure. The primary outcomes include unplanned heart-failure hospitalisations and all-cause death, with quality-of-life and ventricular function as additional measures. Ablation is performed using established PVI techniques and patients are followed for at least 12 months to capture clinical events and patient-reported outcomes. The trial aims to enroll a broad, generalizable heart-failure population rather than the narrowly selected groups of prior small studies.

Who should consider this trial

Good fit: Adults (≥18) with documented paroxysmal or persistent atrial fibrillation (paroxysmal >6 hours and <7 days; persistent >7 days but ≤3 years) who are on optimal tolerated heart-failure therapy for at least 6 weeks and can consent and attend 12 months of follow-up.

Not a fit: Patients with long-standing AF (>3 years since first documentation), those not on guideline heart-failure therapy, or those unable or unwilling to undergo catheter ablation or attend follow-up are unlikely to gain benefit from this protocol.

Why it matters

Potential benefit: If successful, ablation could reduce unplanned heart-failure hospitalisations and deaths and improve quality of life for people with AF and heart failure.

How similar studies have performed: Small prior trials, notably CASTLE-AF, suggested mortality and hospitalization benefits in highly selected patients, but overall evidence is mixed and not clearly generalizable to typical heart-failure populations.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion criteria:

1. Patients aged ≥18 years.
2. Patient is willing and able to give informed consent for participation.
3. Able and willing to comply with all study requirements, including ability to participate in study for 12 months.
4. Willing to allow their General Practitioner (GP) to be notified of participation in the study.
5. 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.
   * Persistent AF as defined by at least one episode of AF \>7 days but not \>3 years (since 1st documentation)
6. 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.
7. New York Heart Association Classification (NYHA) class II to III
8. 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.

   1. 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.
   2. For those with LVEF 41-49% and with ongoing atrial fibrillation/flutter, NTproBNP of ≥600pg/mL is required within 12 months prior randomisation.
   3. For those with LVEF ≤40%, NTproBNP is not required

Exclusion criteria:

1. Long standing (\>3 year) persistent or permanent AF.
2. Previous atrioventricular (AV) nodal ablation.
3. Previous pulmonary vein isolation (PVI) or surgical ablation.
4. 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.
5. Severe aortic or pulmonary valve disease.
6. Severe primary or secondary mitral valve regurgitation.
7. Active illness (other than HF) likely to result in death within 2 years.
8. People who are pregnant or planning to become pregnant during the trial.
9. People who are breastfeeding.
10. Known allergy to contrast.
11. Contraindication for PVI.
12. Other conditions that may prevent subjects from adhering to the trial protocol, in the opinion of the investigator.
13. Currently participating in another randomised controlled trial of another drug or medical device.

Where this trial is running

Halifax and 23 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Atrial Fibrillation, AF

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.