Atrial FibrillationNCT05993104
Shape vs Substrate in AF
An observational study of Atrial Fibrillation and Atrial Fibrillation, Persistent, run by Oxford University Hospitals NHS Trust at 1 site in United Kingdom.
Trial summary
Atrial fibrillation (AF) is an abnormal heart rhythm which originates from the top two chambers (atria) of the heart. It can cause significant symptoms and have severe consequences such as stroke. Catheter ablation is a treatment for AF. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Fibrillation, Atrial Fibrillation, Persistent
- What is being tested?
- Intrachamber ultrasound and Statistical shape analysis
- How many people
- 0 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Jan 2024to Sep 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
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
Study population: Participants with atrial fibrillation referred to a tertiary hospital (John Radcliffe, Oxford) for ablation.
Who may be able to join
- Retrospective component:
- Participant gave consent for anonymised data being utilised for clinical research at time of procedure.
- Male or Female, aged 18 years or above.
- Previous AcQMap guided ablation for paroxysmal or persistent atrial fibrillation.
- Prospective component:
- Participant is willing and able to give informed consent for participation in the study.
- Male or Female, aged 18 years or above.
- Diagnosed with paroxysmal or persistent atrial fibrillation and planned for an AcQMap guided catheter ablation procedure.
Who cannot join
- Congenital cardiac abnormality.
- Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participant at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
John Radcliffe Hospital
Oxford, Oxfordshire, OX3 9DU
About this study
Official title: Investigating the Interplay of Left Atrial Geometry With Abnormal Propagation Patterns in Atrial Fibrillation
Atrial fibrillation (AF) is an abnormal heart rhythm which originates from the top two chambers (atria) of the heart. It can cause significant symptoms and have severe consequences such as stroke.
Catheter ablation is a treatment for AF. It is minimally invasive, involving thin tubes known as catheters, being inserted through a blood vessel in the groin and passed to the heart under X-ray guidance. Once in the heart, regions of tissue believed responsible for the abnormal heart rhythm can be identified, and hot or cold energy used to create scar at these areas, preventing the abnormal rhythm.
Read more
Identifying these regions is a key challenge in making the treatment as effective as possible. The investigators believe that there may be a change in the shape of a participant's atria in these regions and as such identifying and treating areas of abnormal shape may be beneficial.
To investigate this, the study team propose three phases. The first, uses previously collected data to make a model of what is average atrial geometry in AF. Investigators will then compare individual participants' atrial geometries to this average shape to identify areas of geometric abnormality and see how these correspond to areas of abnormal electrical activity. In the second phase, investigators will collect new data on how much atrial geometry changes during catheter ablation procedures. Finally, in the third phase, investigators will investigate whether including geometric assessment in the catheter ablation procedure is feasible from a work flow perspective.
Read the detailed description
This study will utilise the AcQMap system (Acutus Medical). This is a combined multi-electrode and imaging mapping system, with intra chamber ultrasound used to create a surface mesh of a participant's atrial anatomy. Noncontact charge-density mapping using AcQMap is novel, in that it allows whole chamber conduction to be analysed during AF. This is a distinct advantage over traditional contact mapping techniques, which are unable to globally map the inherently unstable and changing activation patterns occurring in AF. The system's AcQTrack software identifies patterns of localised propagation which may represent AF drivers and displays these on the surface mesh. They are classified as one of three phenomena (localised irregular activation [LIA], localised rotational activity [LRA], focal firing [FF]). AcQMap is the ideal tool for our investigation, given its ability to capture both global AF maps and geometric data. It is utilised routinely in clinical practice and there is an existing rich local dataset of previous cases.
Study Phases:
- A retrospective observational phase recruiting >50 participants, utilising data already collected as part of standard clinical care. Investigators will use statistical shape analysis methods to create a left atrial shape model for perAF and see how individuals' left atrial geometries differ from this model. Investigators will then assess whether areas of abnormal geometry correlate with areas of abnormal electrical propagation in AF.
- A prospective single-arm phase recruiting 20 participants undergoing AcQMap guided ablation. As previously mentioned, temporal stability is a defining characteristic of suitable ablation targets. Atrial geometry is dynamic, being related to phase of ventricular contraction and is also affected by an individual's volume status. To investigate variation in geometry, individuals in this substudy will have additional ultrasound geometries collected during their ablation procedure.
- A feasibility study in 10 participants will assess our ability to include shape analysis as part of the procedural workflow for AF ablation utilising the AcQMap system.
- Being tested
- Intrachamber ultrasound, Statistical shape analysis
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intrachamber ultrasoundDiagnostic test
Ultrasound left atrial geometry collecting using AcQMap.
Statistical shape analysisOther
Statistical shape analysis tools used to investigate left atrial geometry
| Study group | Role | What they receive |
|---|---|---|
| Retrospective observational | Retrospective observational arm recruiting >50 participants, utilising data already collected as part of standard clinical care. Receives: Other: Statistical shape analysis | |
| Prospective single-arm | Prospective single-arm recruiting 20 participants undergoing AcQMap guided ablation. Receives: Diagnostic Test: Intrachamber ultrasound | |
| Feasibility study | Feasibility study recruiting 10 participants. Receives: Other: Statistical shape analysis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Regional deformation between participant left atrial geometry and SSM (study phase 1).
Left atria will be partitioned into 6 segments: anterior, posterior, inferior, roof, septal and lateral. Regional deformation is defined by the mean proximity of these segments from their respective closest locations on the SSM.
Measured: 1 year.
Location of AF drivers defined by AcQTrack (study phase 1).
Location defined using 6 segment model as described above (outcome 1).
Measured: 1 year.
Frequency of AF drivers defined by AcQTrack (study phase 1).
Frequency of AcQTrack phenomena reported as #/s.
Measured: 1 year.
Regional change in AcQMap left atrial geometry during ablation procedure (study phase 2).
Regional change defined using 6 segments as per outcome 1. Calculated as mean proximity of these segments during repeated geometry collection from their respective closest locations during initial geometry collection.
Measured: 2 years.
Completion of additional shape analysis (study phase 3).
Measured: 3 years.
Additional procedure time (study phase 3).
Measured: 3 years.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Aug 2023
- Study startJan 2024 (estimated)
- Primary completionSep 2026 (estimated)
- Study completionSep 2026 (estimated)
Why it stopped: Funder no longer operating so the study team is unable to deliver the study.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Other
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- Oxford University Hospitals NHS Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tim Betts MD MBChB FRCP, Oxford University Hospitals NHS Trust
- Investigators
- Tim Betts, MD MBChB FRCP, Principal investigator, Oxford University Hospitals NHS Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05993104
- Sponsor's protocol ID
- 16749
- Status last verified
- Feb 2024
- First submitted
- 5 Jul 2023
- Last updated
- 21 Feb 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Feb 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigating the Interplay of Left Atrial Geometry With Abnormal Propagation Patterns in Atrial Fibrillation
- ClinicalTrials.gov ID
- NCT05993104
- Acronym / sponsor ID
- 16749
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: Funder no longer operating so the study team is unable to deliver the study.
- Enrolment
- 0 participants (actual)
- Lead sponsor
- Oxford University Hospitals NHS TrustUniversity, hospital or other
- Study start
- Jan 2024 (estimated)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Sep 2026 (estimated)
- First posted
- 15 Aug 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Atrial fibrillation (AF) is an abnormal heart rhythm which originates from the top two chambers (atria) of the heart. It can cause significant symptoms and have severe consequences such as stroke.
Catheter ablation is a treatment for AF. It is minimally invasive, involving thin tubes known as catheters, being inserted through a blood vessel in the groin and passed to the heart under X-ray guidance. Once in the heart, regions of tissue believed responsible for the abnormal heart rhythm can be identified, and hot or cold energy used to create scar at these areas, preventing the abnormal rhythm.
Identifying these regions is a key challenge in making the treatment as effective as possible. The investigators believe that there may be a change in the shape of a participant's atria in these regions and as such identifying and treating areas of abnormal shape may be beneficial.
To investigate this, the study team propose three phases. The first, uses previously collected data to make a model of what is average atrial geometry in AF. Investigators will then compare individual participants' atrial geometries to this average shape to identify areas of geometric abnormality and see how these correspond to areas of abnormal electrical activity. In the second phase, investigators will collect new data on how much atrial geometry changes during catheter ablation procedures. Finally, in the third phase, investigators will investigate whether including geometric assessment in the catheter ablation procedure is feasible from a work flow perspective.
Detailed description
This study will utilise the AcQMap system (Acutus Medical). This is a combined multi-electrode and imaging mapping system, with intra chamber ultrasound used to create a surface mesh of a participant's atrial anatomy. Noncontact charge-density mapping using AcQMap is novel, in that it allows whole chamber conduction to be analysed during AF. This is a distinct advantage over traditional contact mapping techniques, which are unable to globally map the inherently unstable and changing activation patterns occurring in AF. The system's AcQTrack software identifies patterns of localised propagation which may represent AF drivers and displays these on the surface mesh. They are classified as one of three phenomena (localised irregular activation [LIA], localised rotational activity [LRA], focal firing [FF]). AcQMap is the ideal tool for our investigation, given its ability to capture both global AF maps and geometric data. It is utilised routinely in clinical practice and there is an existing rich local dataset of previous cases.
Study Phases:
- A retrospective observational phase recruiting >50 participants, utilising data already collected as part of standard clinical care. Investigators will use statistical shape analysis methods to create a left atrial shape model for perAF and see how individuals' left atrial geometries differ from this model. Investigators will then assess whether areas of abnormal geometry correlate with areas of abnormal electrical propagation in AF.
- A prospective single-arm phase recruiting 20 participants undergoing AcQMap guided ablation. As previously mentioned, temporal stability is a defining characteristic of suitable ablation targets. Atrial geometry is dynamic, being related to phase of ventricular contraction and is also affected by an individual's volume status. To investigate variation in geometry, individuals in this substudy will have additional ultrasound geometries collected during their ablation procedure.
- A feasibility study in 10 participants will assess our ability to include shape analysis as part of the procedural workflow for AF ablation utilising the AcQMap system.
Study design
- Observational model
- Case only
- Time perspective
- Other
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Retrospective observational | – | Other: Statistical shape analysisRetrospective observational arm recruiting >50 participants, utilising data already collected as part of standard clinical care. |
| Prospective single-arm | – | Diagnostic Test: Intrachamber ultrasoundProspective single-arm recruiting 20 participants undergoing AcQMap guided ablation. |
| Feasibility study | – | Other: Statistical shape analysisFeasibility study recruiting 10 participants. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Participants with atrial fibrillation referred to a tertiary hospital (John Radcliffe, Oxford) for ablation.
Key inclusion criteria (8 listed)
- Participant gave consent for anonymised data being utilised for clinical research at time of procedure.
- Male or Female, aged 18 years or above.
- Previous AcQMap guided ablation for paroxysmal or persistent atrial fibrillation.
- Participant is willing and able to give informed consent for participation in the study.
- Male or Female, aged 18 years or above.
Key exclusion criteria (2 listed)
- Congenital cardiac abnormality.
- Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participant at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intrachamber ultrasoundUltrasound left atrial geometry collecting using AcQMap. | Diagnostic test | Prospective single-arm |
| Statistical shape analysisStatistical shape analysis tools used to investigate left atrial geometry | Other | Feasibility study, Retrospective observational |
Primary outcome
Regional deformation between participant left atrial geometry and SSM (study phase 1).
Time frame: 1 year.
Left atria will be partitioned into 6 segments: anterior, posterior, inferior, roof, septal and lateral. Regional deformation is defined by the mean proximity of these segments from their respective closest locations on the SSM.
Location of AF drivers defined by AcQTrack (study phase 1).
Time frame: 1 year.
Location defined using 6 segment model as described above (outcome 1).
Frequency of AF drivers defined by AcQTrack (study phase 1).
Time frame: 1 year.
Frequency of AcQTrack phenomena reported as #/s.
Regional change in AcQMap left atrial geometry during ablation procedure (study phase 2).
Time frame: 2 years.
Regional change defined using 6 segments as per outcome 1. Calculated as mean proximity of these segments during repeated geometry collection from their respective closest locations during initial geometry collection.
Completion of additional shape analysis (study phase 3).
Time frame: 3 years.
Additional procedure time (study phase 3).
Time frame: 3 years.
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Feb 2024.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tim Betts, MD MBChB FRCP principal investigator
Oxford University Hospitals NHS Trust
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Atrial Fibrillation and Atrial Fibrillation, Persistent, run by Oxford University Hospitals 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?
The sponsor lists 8 inclusion and 2 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: withdrawn, as of the sponsor's last update on 21 Feb 2024. 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?
The study was withdrawn before enrolling participants, so there are no results.
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?
Regional deformation between participant left atrial geometry and SSM (study phase 1). (time frame: 1 year.). The study lists 6 primary outcomes in all. 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 21 Feb 2024.