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RecruitingNCT06096246ORBICA-AFUpdated Sep 22, 2026

Investigation of Cardioversion Versus Therapeutic Ablation for Persistent AF (ORBICA-AF)

An interventional study of Pulmonary vein isolation and DC Cardioversion in Persistent Atrial Fibrillation, Cardiac Arrhythmia and Catheter Ablation, sponsored by Barts & The London NHS Trust. Recruiting at 1 site in United Kingdom. Open to participants aged 18 Years to 85 Years. Per ClinicalTrials.gov, last updated 2026-09-22.

Sponsored by Barts & The London NHS Trust · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Started Jul 2024; still recruiting 2 years 3 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
208
Allocation
Randomized
Ages
18 Years to 85 Years
Sex
All
01

Study summary

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

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 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 have not been tested. Investigators 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 of 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 in persistent AF. The investigators of this trial have achieved successful recruitment and concluded the pilot phase (ORBITA AF trial; ClinicalTrials.gov Identifier: NCT03907982) with the goal of assessing feasibility and optimizing the study protocol prior to conducting a larger trial. The positive outcomes of the pilot phase have paved the way for this larger follow-on trial.

02

Conditions studied

  • Persistent Atrial Fibrillation
  • Cardiac Arrhythmia
  • Catheter Ablation
03

In context

Atrial Fibrillation

4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.

This study's planned enrollment of 208 is above the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.

Browse Atrial Fibrillation studies →

Lead sponsor

Barts & The London NHS Trust is the lead sponsor of 151 studies on the registry; 21 are open to participants now.

Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 85 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Ability to give
  • Age 18-85 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

Exclusion Criteria:

  • () \< 30mls/min
  • or unable to take anticoagulation
  • Uncontrolled hypertension
  • Contraindication for catheter ablation
  • > 40
  • Patients in Persistent AF who have had more than one previous cardioversion.
  • Established diagnosis of Hypertrophic cardiomyopathy
Terms in these criteria, in plain language(5)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
208 participants (estimated)

Study arms

  • Active comparator
    Experimental: DCCV + PVI

    An implantable loop recorder will be inserted in the pre pectoral area with local anaesthetic at least one week before the randomisation. Two femoral sheaths will be inserted at the groin area in all patients on the day of the procedure prior randomisation. This will be utilised as the access route for cardiac catheter insertion for ablation and for phrenic nerve pacing during the procedure. DC cardioversion (DCCV) plus Pulmonary Vein Isolation - At the end of pulmonary vein isolation, DCCV is performed (if the patient is still in AF).

    Procedure: Pulmonary vein isolation · Procedure: DC Cardioversion · Device: Implantable loop recorder · Procedure: Femoral sheath insertion

  • Sham comparator
    DC cardioversion (DCCV) + Sham procedure

    An implantable loop recorder will be inserted in the pre-pectoral area with local anaesthetic at least one week before the randomisation. Two femoral sheaths will be inserted at the groin area in all patients on the day of the procedure prior randomisation. This will be utilised as the access route for cardiac catheter insertion for intermittent phrenic nerve pacing during the procedure. DC Cardioversion and Sham procedure will be performed after randomisation. Intermittent phrenic nerve pacing will be employed for the sham group through the femoral venous sheath using a quadripolar catheter.

    Procedure: DC Cardioversion · Device: Implantable loop recorder · Procedure: Femoral sheath insertion

Interventions

  • ProcedurePulmonary vein isolation

    The catheter ablation (with a CE \[Conformité Européenne\] marked device) 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 ablation around the pulmonary veins to electrically isolate the vein, thus preventing pulmonary vein ectopy from triggering AF.

    Also known as: Catheter ablation

  • ProcedureDC Cardioversion

    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.

  • DeviceImplantable loop recorder

    The Reveal device is inserted in the pre-pectoral position under the skin. This is performed with local anaesthetic and sedation at least a week before the randomisation. The device will provide a continuous recording of the heart rhythm and rate, and will be able to download duration of AF episodes via a home monitoring system to establish the primary endpoint of the study .

    Also known as: Reveal LINQ

  • ProcedureFemoral sheath insertion

    Two femoral sheaths (7Fr) will be inserted using ultrasound guidance under local anaesthetic.

06

What researchers measure

Primary outcomes

  1. Recurrence of Persistent AF (AF episode lasting > 7 days) or left atrial ablation/ DC Cardioversion for atrial arrhythmia after 6 weeks of blanking period.

    Rates of recurrence of arrhythmia and data on episodes of Atrial Fibrillation (rate, duration) will be provided by the loop recorder, and downloaded via a home monitoring system \[ rhythm on ILR ECG\]

    Time frame: Within 12 months following the procedure

  2. A change in the burden of AF, as measured by continuous monitoring through ILR (Implantable loop recorder) at 3 months

    Percentage time the patient is in AF as measured by the ILR device (in percentage) compared to pre-randomisation

    Time frame: 3 months post randomisation

Secondary outcomes

  1. Death

    Death of the patient

    Time frame: Within 12 months of study index procedure.

  2. Rates of Subject Hospital re-admission

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

    Time frame: Within 12 months of study index procedure.

  3. Procedural complications

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

    Time frame: Up to 7 days post procedure

  4. Bleeding events

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

    Time frame: Within 7 days of the index procedure

  5. Rates of Repeat procedures

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

    Time frame: within 12 months following the procedure

  6. Cardiac function

    Measurement of change in ejection fraction by echocardiogram

    Time frame: between baseline and 12 months following the procedure

  7. Percentage of 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.

    Time frame: Within 12 months following the index procedure

  8. Change in quality of life score using in 12 item Short Form health survey (SF12)

    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. 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. Scores range from 0 to 100, with higher scores indicating better physical and mental health functioning.

    Time frame: Between baseline and 3, 6 and 12 months after procedure

  9. Change in quality of life measures using Atrial Fibrillation Effect on QualiTy-of-life(AFEQT) questionnaire

    Assessment of AF specific symptoms to assess the impact of AF on the subject's quality of life. The responses on the 20-item AFEQT are scored on a 1 to 7 Likert scale. Overall and subscale scores range from 0 to 100. A score of 0 corresponds to complete disability, while a score of 100 describes the highest level of QoL

    Time frame: Between baseline and 3, 6 and 12 months after procedure

  10. Measuring Blinding index

    Assessing the maintenance of blinding measured by Blinding index in both study participant and blinded medical staff.

    Time frame: Day 0 (within 24 hours post randomisation) and 3 months

  11. Measuring AF Burden

    Percentage time the patient is in AF as measured by the ILR (Implantable loop recorder) device compared to pre-randomisation

    Time frame: At 3, 6 and 12 months follow up

  12. The occurrence of atrial tachyarrhythmias

    Assessment of the occurence of other atrial tachyarrhythmia (Atrial flutter or Atrial tachycardia) in the continuous monitoring

    Time frame: Within 12 months following the index procedure

  13. Symptomatic Atrial fibrillation/Atrial tachycardia episodes

    Number of symptomatic AF/AT triggered/reported by patients correlating to true episodes in the continuous monitoring.

    Time frame: At 3, 6, 12 months follow up

  14. Antiarrhythmic drug use

    Assessment of the use of antiarrhythmic drugs (combined data collected on duration , dose and frequency of drug use) prior to and after the DCCV +/- PVI procedure

    Time frame: Between baseline and 12months after procedure

  15. Composite adverse events

    Assessment of rates of adverse events during follow up

    Time frame: 12 months

07

Study locations

1 of 1 sites recruiting
08

References and documents

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 ↗
  • Bang H, Ni L, Davis CE. Assessment of blinding in clinical trials. Control Clin Trials. 2004 Apr;25(2):143-56. doi: 10.1016/j.cct.2003.10.016. PubMed 15020033 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 22, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06096246
Responsible party
Sponsor
First posted
Oct 23, 2023
Start date
Jul 26, 2024
Primary completion
Jul 26, 2027 (estimated)
Completion
Dec 5, 2027 (estimated)
Last update
Sep 22, 2026

Study contacts

Malcolm Finlay, FRCP PhD
Contact
malcolm.finlay1@nhs.net
02037658635
Vijayabharathy Kanthasamy, MRCP
Contact
vijayabharathy.kanthasamy@nhs.net
02037658635
Richard Schilling, FRCP MD
study chair · Barts & The London NHS Trust
Malcolm Finlay
principal investigator · Barts & The London NHS Trust

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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