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Identification, Electro-mechanical Characterisation and Ablation of Driver Regions in Persistent Atrial Fibrillation

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ClinicalTrials.gov Identifier: NCT02950844
Recruitment Status : Recruiting
First Posted : November 1, 2016
Last Update Posted : March 17, 2017
Sponsor:
Information provided by (Responsible Party):
Barts & The London NHS Trust

Brief Summary:

Atrial fibrillation (AF) is the most common sustained heart rhythm abnormality. Its incidence is increasing partly due to the ageing population and it has been referred to as a growing epidemic. AF results in irregular contractions of the heart causing unpleasant symptoms of palpitations and increasing the risk of stroke, heart failure and death. Percutaneous catheter ablation is a safe treatment option in symptomatic patients with AF. The success rate of these procedures have improved with time due to our better understanding of AF, development of new techniques and technology, and greater physician experience. However, the success rate of these procedures still only remains around 70%. This is contributed to our limited ability to find the areas that drive the AF.

STAR mapping is a novel mapping system that has been developed with a view of better identifying the sites that drive AF, through taking into account the mechanisms of AF that have already been demonstrated. Data from this study will be used to refine the identification of drivers in the fibrillation left atrium with enormous potential to simplify ablation and improve success rates and thereby reducing the need for further procedures.

To better validate this mapping system the investigators also aim to use it in participants with atrial tachycardia (AT), which is a heart rhythm abnormality of which the mechanism can be readily identified with the existing mapping systems used in clinical practice. The investigators will demonstrate that the STAR mapping algorithm can effectively map AT.

To gain further understanding of the changes that occur in the left upper chamber of the heart in the context of AF half of the participants with AF will undergo cardiac magnetic resonance imaging to assess for the presence of scar. This will enhance our understanding of how atrial remodelling promotes AF, which may point to ways of modifying this process and preventing AF.


Condition or disease Intervention/treatment Phase
Atrial Fibrillation Other: Novel mapping algorithm Phase 4

Detailed Description:

AF catheter ablation success rates are still limited to around 70% with a large proportion of patients requiring to have further procedures to remain in normal heart rhythm. The current strategies that are used in catheter ablation of AF involve targeting the pulmonary veins that enter the left sided upper chamber of the heart. The supportive evidence in targeting other areas beyond the pulmonary veins remains mixed. Thereby with the existing mapping systems other sites that potentially drive AF have not been effectively identified. Further to this, it has also been suggested that these sites are intermittent and mobile in nature making it more difficult to effectively map. With this in mind the investigators have developed STAR mapping, a novel mapping system that takes these factors into account. The purpose of this study is to use this mapping system prospectively to effectively map and ablate drivers of AF as identified by termination and/or slowing of AF during the catheter ablation.

Participants that have documented AF that has been present all the time for less than 24 months i.e. early persistent AF and that have been referred for catheter ablation for AF by an Electrophysiologist will be recruited into the study.

Participants will undergo consenting for the procedure and their involvement in the research study. The procedures will be conducted either under local anaesthetic/sedation or general anaesthetic depending on the clinical needs of the patient. During the procedure tubes will be passed into the left upper chamber of the heart through the groin. Through these tubes catheters will be used to create a geometry of the heart chamber. Following this, in half of the participants a basket catheter with 64 electrodes will be positioned in the upper chamber whilst conventional catheters will be used in the other half of the participants. This is to demonstrate that this mapping system can effectively be used with a variety of mapping catheters. The signals collected will then be used in the novel mapping system to identify sites as potential drivers of AF. These sites will then be targeted and the response to ablation will be recorded particularly looking at slowing and/or termination of the AF, which will support these sites identified as drivers.

As part of the validation phase of the study participants that have been scheduled for a catheter ablation for AT by their Electrophysiologist will be enrolled into the study. The STAR maps generated in these cases will be compared to the maps generated by the conventional system. This will enable validation of the STAR mapping system.

The mapping system used for this study will be CARTOFINDER (CARTO, Biosense Webster, Inc, CA). Analyses using this mapping system will allow a sub-study on identifying mechanisms of AT and drivers in AF using the CARTOFINDER system.


Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 60 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Identification, Electro-mechanical Characterisation and Ablation of Driver Regions in Persistent Atrial Fibrillation (STAR MAPPING)
Study Start Date : October 2016
Estimated Primary Completion Date : October 2019
Estimated Study Completion Date : October 2019

Resource links provided by the National Library of Medicine



Intervention Details:
  • Other: Novel mapping algorithm

    Mapping and ablation of atrial fibrillation drivers identified by the STAR mapping algorithm.

    In a sub-study a novel mapping system (CARTOFINDER, Biosense Webster, Inc, CA) was used in mapping drivers in AF.

    Other Name: STAR MAPPING


Primary Outcome Measures :
  1. Number of participants with AT that have STAR maps that are consistent with conventional maps. [ Time Frame: During the catheter ablation ]
    The number of participants with AT that have STAR maps acquired with multi-polar mapping catheters (basket or other) that yield consistent maps with mechanisms corresponding to those identified by conventional mapping.

  2. Number of participants with AF that have STAR maps that suggest a small number of drivers sustain AF. [ Time Frame: During the catheter ablation ]
    The number of participants with consecutive STAR maps acquired with multi-polar mapping catheters (basket or other) that demonstrate a consistent proportion of wave fronts with a given activation pattern suggesting a small number of drivers (whether consistent or intermittent) sustaining AF.

  3. Number of participants with AF and AT that have an ablation effect. [ Time Frame: During the catheter ablation ]
    The number of participants that had a response to ablation (slowing or termination of AT/AF) that is consistent with the mechanism of AT/AF identified by the STAR mapping.


Secondary Outcome Measures :
  1. The number of driver sites that correlate with sites of scar. [ Time Frame: 30 min up to 1 hour (CMR) and during study ]
    The number of driver sites identified on the STAR map that correlate to sites of late gadolinium enhancement on the cardiac magnetic resonance imaging and areas of low voltage on the voltage map.

  2. The number of sites in the left atrium with altered conduction that correlate with sites of scar. [ Time Frame: During the catheter ablation ]


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Patients able to provide informed consent
  2. Patients with AT (whether de novo or occuring post AF ablation) undergoing catheter ablation (validation phase)
  3. Patients with early persistent AF <24months undergoing their first catheter ablation (mapping phase)

Exclusion Criteria:

  1. Unwillingness to sign consent
  2. Age <18 years old
  3. Contraindications for catheter ablation procedure

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02950844


Contacts
Contact: Ross Hunter 02037658635 ross.hunter@bartshealth.nhs.uk
Contact: Richard Schilling 02037658635 richard.schilling@bartshealth.nhs.uk

Locations
United Kingdom
Barts Heart Centre Recruiting
London, United Kingdom, EC1A 7BE
Contact: Ross Hunter    02037658635    ross.hunter@bartshealth.nhs.uk   
Contact: Richard Schilling    02037658635    richard.schilling@bartshealth.nhs.uk   
Sponsors and Collaborators
Barts & The London NHS Trust

Responsible Party: Barts & The London NHS Trust
ClinicalTrials.gov Identifier: NCT02950844     History of Changes
Other Study ID Numbers: 011040
PG/16/10/32016 ( Other Grant/Funding Number: British Heart Foundation )
First Posted: November 1, 2016    Key Record Dates
Last Update Posted: March 17, 2017
Last Verified: March 2017

Keywords provided by Barts & The London NHS Trust:
Atrial fibrillation
Electrogram
Ablation
Drivers

Additional relevant MeSH terms:
Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes