Hybrid Ablation of Atrial Fibrillation in Heart Failure (HALT AF)

November 23, 2025 updated by: Riyaz Kaba, St. George's Hospital, London

A Randomised Controlled Trial Comparing Convergent Hybrid Ablation to Catheter Ablation in Patients With Persistent Atrial Fibrillation and Heart Failure

A randomised controlled trial to assess the efficacy of staged hybrid ablation when compared with standard catheter ablation in patients with non-paroxysmal atrial fibrillation (AF) and Heart Failure

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The objective of this randomized study is to evaluate the safety and efficacy of Convergent hybrid ablation when compared to standard catheter ablation in patients with non-paroxysmal AF and heart failure.

Patients will be randomised in a 1:1 ratio. The primary efficacy endpoint will be freedom from persistent atrial arrhythmia (measured from the end of a 3-month blanking period up to 24 months (12 and 24 months).

Study Type

Interventional

Enrollment (Estimated)

120

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 Contact Backup

Study Locations

  • United Kingdom
      • Chertsey, United Kingdom
        • Recruiting
        • Ashford & St Peters Hospital NHS Trust
        • Contact:
      • Epsom, United Kingdom
        • Recruiting
        • Epsom General Hospital
        • Contact:
      • London, United Kingdom
      • London, United Kingdom
        • Active, not recruiting
        • Cromwell Hospital
      • London, United Kingdom
        • Active, not recruiting
        • St Anthonys Hospital
      • London, United Kingdom
        • Recruiting
        • St Georges at Kingston Hospital
        • Contact:
      • London, United Kingdom

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Persistent or Long-standing Persistent AF
  • Dilated left atrium (at least moderately dilated)
  • Suitable for either procedure
  • LVEF < 50%

Exclusion Criteria:

  • Not yet optimised from a medical or lifestyle perspective for AF or heart failure
  • Unable to provide written consent
  • Previous open-heart surgery
  • Active infection, oesophageal ulcer stricture or oesophageal varices
  • Prior catheter ablation of atrial fibrillation (prior ablation for atrial flutter / supraventricular tachycardia or ventricular arrhythmia acceptable)
  • Contraindication to anticoagulation, or active thrombus in the left atrium despite therapeutic anticoagulation
  • Severe valvular heart disease
  • Unstable coronary artery disease
  • Uncontrolled ventricular arrhythmia
  • Heart attack or stroke within the last 90 days
  • Pregnant, breastfeeding, or women of childbearing age who plan to get pregnant within six months
  • Severe concomitant condition or presence of an implanted device that would preclude the patient from undergoing trial procedures

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Standard Endocardial Catheter Ablation
Standard endocardial catheter ablation
Device: Endocardial Catheter Ablation
Standard percutaneous endocardial catheter ablation of atrial fibrillation
Other Names:
  • Percutaneous Catheter Ablation
Experimental: Convergent Hybrid Ablation +/- Left Atrial Appendage Exclusion

Staged Convergent Hybrid Ablation Procedure

Stage 1 - Minimally-Invasive Surgical Epicardial Ablation Procedure +/- concomitant LAA exclusion.

Stage 2 - Endocardial Catheter Ablation
Device: Endocardial Catheter Ablation
Standard percutaneous endocardial catheter ablation of atrial fibrillation
Other Names:
  • Percutaneous Catheter Ablation
Device: AtriCure EPi-Sense-AF Guided Coagulation System +/- Atriclip
Minimally-invasive epicardial ablation +/- left atrial appendage exclusion using an epicardial clip, combined with endocardial radiofrequency catheter ablation
Other Names:
  • Convergent Hybrid Epicardial Endocardial Ablation plus/minus left atrial appendage exclusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Freedom from persistent atrial arrhythmia after a single procedure (either the completed hybrid ablation or catheter ablation) off Class I or III medications
Time Frame: Measured from the end of a 3-month blanking period at 12 and 24 months
Recurrence of persistent atrial arrhythmia during follow-up months).
Measured from the end of a 3-month blanking period at 12 and 24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Safety Endpoint
Time Frame: Measured as early (within 30- days) and late (> 30 days) after each procedure or part of procedure
Safety endpoint of severe and non-severe complications as defined in the protocol
Measured as early (within 30- days) and late (> 30 days) after each procedure or part of procedure
Freedom from any atrial arrhythmia lasting > 30 seconds after a single completed procedure on class I/III medications
Time Frame: Measured from the end of a 3- month blanking period at 12 and 24 months
Recurrence of any atrial arrhythmia > 30 seconds on or off class I / III medications, considering any repeat ablation procedures
Measured from the end of a 3- month blanking period at 12 and 24 months
Freedom from atrial arrhythmias after any redo procedures (on or off class I or III medications)
Time Frame: Measured from the end of a 3- month blanking period at 12 and 24 months
Recurrence of any atrial arrhythmia > 30 seconds on or off class I / III medications, considering any repeat ablation procedures
Measured from the end of a 3- month blanking period at 12 and 24 months
To assess left ventricular structural remodelling and change in ventricular function in response to either procedure
Time Frame: Pre-procedure and at 12 and 24 months post-procedure
Left ventricular ejection fraction as recorded on transthoracic echocardiography (TTE)
Pre-procedure and at 12 and 24 months post-procedure
To evaluate the effects of the interventions on the patient's symptoms and quality of life (EHRA Score)
Time Frame: Pre-procedure and at 12 and 24 months post-procedure
Change in European Heart Rhythm Association (EHRA) AF Symptom score
Pre-procedure and at 12 and 24 months post-procedure
To evaluate the effects of the interventions on the patient's symptoms and quality of life (NYHA Class).
Time Frame: Pre-procedure and at 12 and 24 months post-procedure
Change in New York Heart Association (NYHA) class
Pre-procedure and at 12 and 24 months post-procedure
To evaluate the effects of the interventions on the patient's quality of life (EQ5D)
Time Frame: Pre-procedure and at 12 and 24 months post-procedure
Change in EuroQol Quality of life Score (EQ5D)
Pre-procedure and at 12 and 24 months post-procedure
To evaluate the effects of the interventions on the patient's quality of life (AFEQT)
Time Frame: Pre-procedure and at 12 and 24 months post-procedure
Change in Atrial Fibrillation Effect on Quality of Life Score (AFEQT)
Pre-procedure and at 12 and 24 months post-procedure
To assess left atrial remodelling in response to either technique.
Time Frame: Pre-procedure and up to 12 and 24 months post-procedure
Left atrial dimensions/function on Echocardiography
Pre-procedure and up to 12 and 24 months post-procedure

Collaborators and Investigators

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

Sponsor

St. George's Hospital, London

Investigators

  • Principal Investigator: Riyaz A Kaba, St Georges Hospital NHS Trust
  • Principal Investigator: Omar Ahmed, St Georges Hospital NHS Trust

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)

June 25, 2022

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

October 1, 2027

Study Registration Dates

First Submitted

May 20, 2022

First Submitted That Met QC Criteria

June 6, 2022

First Posted (Actual)

June 9, 2022

Study Record Updates

Last Update Posted (Actual)

November 28, 2025

Last Update Submitted That Met QC Criteria

November 23, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2021.0137

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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