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Persistent Atrial FibrillationORBITA-AFNCT03907982

Investigation of Therapeutic Ablation Versus Cardioversion for AF

A study testing DC Cardioversion, Pulmonary vein isolation and Implantable loop recorder in people with Persistent Atrial Fibrillation and Cardiac Arrhythmia, run by Barts & The London NHS Trust at 1 site in United Kingdom.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The main aim of the research is to investigate whether patients undergoing pulmonary vein isolation with cryoablation for atrial fibrillation (AF) will have lower rates of AF recurrence than those treated by DC cardioversion without an ablation procedure. Read more about this study

Who is it for?
Ages 18 to 80 years
What is being tested?
DC Cardioversion, Pulmonary vein isolation and Implantable loop recorder
Could I receive a placebo?
No, everyone receives an active treatment
How many people
20 participants
Where
1 siteUnited Kingdom
Study dates
1 Oct 2021to 26 Apr 2023
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Inclusion Criteria: Patients who meet the following inclusion criteria will be eligible for the study;

  • Ability to give informed consent
  • Age 18-80 years
  • Persistent AF (atrial fibrillation lasting > 7days) of total continuous duration <2 years as documented in medical notes.
  • Patients being considered for cardioversion.

Exclusion Criteria: Patients who meet the following exclusion criteria will be ineligible for study participation;

  • Creatinine clearance (eGFR) < 30mls/min
  • Contraindication or unable to take anticoagulation
  • Known contraindication to or unable to tolerate amiodarone
  • Uncontrolled hypertension
  • Contraindication to catheter ablation
  • BMI > 35

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site

  • Barts Health NHS Trust - St Bartholomew's Hospital and Whipps Cross Hospital

    London, EC1 6BQ

Other trials in United Kingdom

About this study

Official title: Objective Randomised Blinded Investigation of Therapeutic Ablation Versus Cardioversion for Persistent Atrial Fibrillation

The main aim of the research is to investigate whether patients undergoing pulmonary vein isolation with cryoablation for atrial fibrillation (AF) will have lower rates of AF recurrence than those treated by DC cardioversion without an ablation procedure. The objectives of the Pilot Study are to validate the key study logistics with a view to optimising methods to be used in the main study.

Read the detailed description

After adequate stroke prevention (e.g. anticoagulation) and rate control, the optimum strategy for patients who continue to be symptomatic with persistent AF has not been established. Cardioversion with antiarrhythmic medication is commonly used as a first-line rhythm control strategy despite very high recurrence rates of the index arrhythmia and high serious complications associated with this strategy. Further treatment options, such as catheter ablation or implantation of a pacemaker and ablation of the atrioventricular (AV) node, are considered once AF recurs. The benefits of first-line ablation in patients presenting with persistent AF has not been tested. We seek to perform a blinded, randomised trial comparing an electrical cardioversion-led strategy with a pulmonary-vein isolation strategy for the treatment of persistent atrial fibrillation.

No blinded randomised controlled trial comparing early-ablation strategies to cardioversion-led strategies has been performed. The rationale for blinding where possible in clinical trials is well established. The recently published ORBITA trial performed a blinded, multicentre randomised trial of percutaneous coronary intervention (PCI) in stable angina compared to a placebo procedure. This trial demonstrated that the efficacy of invasive procedures can be assessed with a placebo procedure and that this type of trial remains necessary. Knowledge of treatment assignment influences physician behaviour, drug recommendations and encourages bias in outcome reporting. The treatment effect size and the effects of confounding factors will be exaggerated and thus limit the interpretation of the true patient experienced outcomes either strategy. In a comparison of surgical procedures, a sham-control arm represents the gold standard of blinding. A systematic review of placebo-controlled surgical trials found no evidence of harm to participants assigned to the placebo group. For a procedure whose primary purpose is to give sustained symptomatic relief, definitive quantification of the true placebo-controlled effect size of AF ablation is necessary. There is a need to clarify the relationship between patient reported symptoms and the arrhythmia itself. Patient reported symptoms may not always be related to the severity of the arrhythmia or quality of life. No bias-resistant blinded, randomised, trial has yet been performed seeking to measure the benefits of AF ablation.

Being tested
DC Cardioversion, Pulmonary vein isolation, Implantable loop recorder
Keywords
Cardiac ablation, Cardioversion, pacemaker, implantable cardioverter-defibrillator
Medical subject headings
Atrial Fibrillation, Arrhythmias, Cardiac

What participants receive

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

  • DC CardioversionProcedure or surgery

    DC cardioversion (DCCV) is used to treat irregular heart rhythms (commonly atrial fibrillation). The procedure involves sedation or anaesthetic and placement of electrodes on the chest. An electrical impulse is passed across the electrodes to return the heart rhythm to normal.

  • Pulmonary vein isolationProcedure or surgery

    The cryoballoon (CE marked) is the key specified technique for performing pulmonary vein isolation in the ablation arm in this trial. This allows the physician electrophysiologist to perform a circumferential freeze around the pulmonary veins to electrically isolate the vein, thus preventing pulmonary vein ectopy from triggering AF.

  • Implantable loop recorderDevice

    Also called LINQ

    The Reveal device is inserted in the pre-pectoral position under the skin. This is performed with local anaesthetic and sedation at the end of the procedure clinic by the electrophysiologist performing the procedure. The device will provide a continuous recording of the heart rhythm and rate, and will be able to down load duration of AF episodes via a home monitoring system to establish the primary endpoint of the study.

Study groups in NCT03907982
Study groupRoleWhat they receive
DCCV + PVIExperimentalDC cardioversion (DCCV) plus Pulmonary Vein Isolation (Cryoablation) At end of pulmonary vein isolation, DCCV performed (if patient still in AF). An implantable loop recorder will be inserted in the prepectoral area with local anaesthetic at the end of the procedure.
Receives: Procedure: DC Cardioversion; Procedure: Pulmonary vein isolation; Device: Implantable loop recorder
DC cardioversion (DCCV)Active comparatorAcute treatment of heart rhythm by cardioversion. An implantable loop recorder will be inserted in the prepectoral area with local anaesthetic at the end of the procedure.
Receives: Procedure: DC Cardioversion; Device: Implantable loop recorder

What is being measured

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

  1. Recurrence of Persistent AF (of AF Episode Lasting > 7 Days).

    Data on epsiodes of Atrial Fibrillation (rate, duration) will be provided by the loop recorder, and downloaded via a home monitoring system

    Measured: Within 12 months following the procedure

Secondary outcomes (8)

  1. Death

    Death of the patient

    Measured: Within 12 months of study recruitment

  2. Rates of Subject Hospital Re-admission

    Rates of admission of the subject back to hospital following the initial treatment for AF

    Measured: Within 12 months following the procedure

  3. Procedural Complications

    Assessment of rates of events that are considered procedural complications during the DCCV +/- Pulmonary Vein isolation (PVI) procedure

    Measured: At the time of the procedure

  4. Bleeding Events

    Rates of bleeding in subjects following the study DCCV +/- pulmonary vein isolation (PVI) procedures

    Measured: Within 7 days of the procedure

  5. Rates of Repeat Procedures

    Requirement for repeat procedures following the initial DCCV +/- pulmonary vein isolation (PVI) procedure for the study

    Measured: within 12 months following the procedure

  6. Clinical Success of Procedure

    Clinical procedural success as defined by 75% or greater reduction in the number of AF episodes as measured by the insertable cardiac monitoring system (LINQ) device.

    Measured: Within 12 months following the procedure

  7. Change in Quality of Life Measures (Using Short Form-12 Survey)

    Assessment of quality of life measures using Short Form Health Survey (SF12) questionnaire, which is a multipurpose short form survey with 12 questions, all selected from the SF-36 Health Survey (Ware, Kosinski, and Keller, 1996). The questions are combined, scored, and weighted to create two scales that provide glimpses into mental and physical functioning and overall health-related-quality of life. Scale range from 0 to 100, with higher scores indicating better quality of life.

    Measured: Between baseline and 12 months after procedure

  8. Change in Quality of Life Measures (AF-PROMS)

    Assessment of Patient Reported Outcome Measures (PROMS) specific for Atrial Fibrillation (AF) in a series of 28 questions to assess the impact of AF on the subject's quality of life. Atrial Fibrillation Severity Scale (AFSS) uses a scale ranging from 0 to 35, where a higher score indicates more severe symptoms.

    Measured: between baseline and 12 months after procedure

Timeline

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

  1. First posted9 Apr 2019
  2. Study start1 Oct 2021
  3. Primary completion26 Apr 2023
  4. Study completion26 Apr 2023

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
Internal Pilot as part of a future study, Randomised, blinded, controlled trial with 2 arms.
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
20 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03907982
Sponsor's protocol ID
ORBITA-AF Pilot study
Acronym
ORBITA-AF
Status last verified
Jun 2025
First submitted
22 Mar 2019
Last updated
26 Jun 2025
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Wartolowska K, Judge A, Hopewell S, Collins GS, Dean BJ, Rombach I, Brindley D, Savulescu J, Beard DJ, Carr AJ. Use of placebo controls in the evaluation of surgery: systematic review. BMJ. 2014 May 21;348:g3253. doi: 10.1136/bmj.g3253.

    PubMed 24850821

  • Redberg RF. Sham controls in medical device trials. N Engl J Med. 2014 Sep 4;371(10):892-3. doi: 10.1056/NEJMp1406388. No abstract available.

    PubMed 25184861

  • Miller FG, Kaptchuk TJ. Sham procedures and the ethics of clinical trials. J R Soc Med. 2004 Dec;97(12):576-8. doi: 10.1177/014107680409701205. No abstract available.

    PubMed 15574854

  • Jones C, Pollit V, Fitzmaurice D, Cowan C; Guideline Development Group. The management of atrial fibrillation: summary of updated NICE guidance. BMJ. 2014 Jun 19;348:g3655. doi: 10.1136/bmj.g3655. No abstract available.

    PubMed 24948694

  • Brim RL, Miller FG. The potential benefit of the placebo effect in sham-controlled trials: implications for risk-benefit assessments and informed consent. J Med Ethics. 2013 Nov;39(11):703-7. doi: 10.1136/medethics-2012-101045. Epub 2012 Dec 13.

    PubMed 23239742

  • Al-Lamee R, Thompson D, Dehbi HM, Sen S, Tang K, Davies J, Keeble T, Mielewczik M, Kaprielian R, Malik IS, Nijjer SS, Petraco R, Cook C, Ahmad Y, Howard J, Baker C, Sharp A, Gerber R, Talwar S, Assomull R, Mayet J, Wensel R, Collier D, Shun-Shin M, Thom SA, Davies JE, Francis DP; ORBITA investigators. Percutaneous coronary intervention in stable angina (ORBITA): a double-blind, randomised controlled trial. Lancet. 2018 Jan 6;391(10115):31-40. doi: 10.1016/S0140-6736(17)32714-9. Epub 2017 Nov 2.

    PubMed 29103656

Questions about this trial

What is this clinical trial studying?

A study testing DC Cardioversion, Pulmonary vein isolation and Implantable loop recorder in people with Persistent Atrial Fibrillation and Cardiac Arrhythmia, run by Barts & The London NHS Trust at 1 site in United Kingdom.

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

Who may be eligible to take part?

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: finished, as of the sponsor's last update on 26 Jun 2025. 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 United Kingdom. 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?

Yes. Results are posted in the registry (first posted 26 Jun 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Recurrence of Persistent AF (of AF Episode Lasting > 7 Days). (time frame: Within 12 months following the 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 NCT03907982, which also lists 6 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 26 Jun 2025.

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