Atrial FibrillationRADARNCT01187914
Effect of Structural Remodeling on Scar Formation as Assessed by DE-MRI of the Left Atrium
An observational study of Atrial Fibrillation, run by University of Utah.
Trial summary
The purpose of this study is to evaluate the impact of pre-ablation fibrosis on scar formation in the left atrium of the heart. This will be assessed by delayed enhancement magnetic resonance imaging and will be looked at in patients who have undergone successful open irrigated cooled-tipped radio-frequency ablation… Read more about this study
- Who is it for?
- Ages 18 to 89 years
- Conditions the study is for
- Atrial Fibrillation
- How many people
- 40 participants
- Where
- No sites listed yet
- Study dates
- Aug 2010to Jun 2011
- Phase
- Observational
- 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 89 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Forty patients ages 18-89 years, who have had an open irrigation cooled-tipped RF ablation procedure for PAF. Patients must participate in 3-, 6-, and 12-months follow-up post ablation. PAF is defined by >2 documented episodes of AF that terminate spontaneously within 7 days. AF has to be documented by means of electrocardiography, holter monitor, loop recorder, or echocardiography.
Who may be able to join
- > 17 years-old and < 90 years-old
- Long-term care for PAF
- Participated in regular clinical follow-ups
Who cannot join
- Patients who did not receive long-term follow-up care defined as at least 12-months post ablation.
- Women who were pregnant during the time period to be covered by this study.
About this study
Official title: RADAR: Effect of Structural Remodeling on Scar Formation as Assessed by DE-MRI of the Left Atrium Following Open-Irrigation Cooled-Tip Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation
The purpose of this study is to evaluate the impact of pre-ablation fibrosis on scar formation in the left atrium of the heart. This will be assessed by delayed enhancement magnetic resonance imaging and will be looked at in patients who have undergone successful open irrigated cooled-tipped radio-frequency ablation of paroxysmal atrial fibrillation. Follow-up after ablation will be for 12 months.
Read the detailed description
Atrial fibrillation (AF) is an electrophysiological condition characterized by disorganized electrical activity that involves the entire atria. AF manifests initially as paroxysms of arrhythmia that later progress into persistent and permanent forms. It is a progressive disease associated with structural, electrical and contractile changes in the left atrium (LA). A major determinant of the progression of AF is structural remodeling or fibrosis that occurs in the left atrium. A more extensively remodeled atrium presents the substrate needed for the arrhythmia to persist. Structural remodeling is also a major determinant for success of rhythm control strategies in AF. While catheter ablation has reproducibly been shown to be superior to anti-arrhythmic drug (AAD) therapy for rhythm control in AF, the success of this procedure is significantly affected by the extent of structural remodeling present at the time of catheter ablation.
Delayed-Enhancement Magnetic Resonance Imaging (DE-MRI) has been demonstrated to be a very effective modality in identifying fibrotic and scarred cardiac tissue with excellent correlation to electro-anatomical mapping. This is related to the characteristics of Gadolinium, an extracellular contrast agent that is very effective in identifying regions of fibrotic non-viable myocardium. DE-MRI technology can be a very powerful, non-invasive method, of identifying the extent and the distribution of structural remodeling or fibrosis associated with AF. Specific image acquisition sequences have allowed for reproducible identification of high pixel intensity regions within the 2-dimensional images of the atrial wall. 3-Dimensional reconstruction of the entire left atrium then provides a quantification of the overall volume occupied by these hyper-enhanced regions relative to the entire left atrial wall volume. Used prior to catheter ablation, DE-MRI can therefore identify regions of significant structural remodeling or fibrosis. The same technology has also been shown to be very useful in examining the amount and distribution of ablation-induced scarring.
Catheter ablation has emerged as an effective interventional therapeutic modality for AF patients. Current ablation techniques, including pulmonary vein antrum isolation (PVAI), use radiofrequency (RF) energy to induce thermal damage to the LA substrate in an attempt to electrically disconnect and isolate arrhythmogenic foci originating from the pulmonary veins (PVs). Multiple catheter technologies for RF have been developed. Catheters may be either cooled or not. Cooling allows for higher and deeper energy delivery with larger lesion formation. Open irrigation cooled-tip RF ablation of AF is associated with less impedance rise, microbubble formation, and esophageal injury when compared with traditional non-cooled ablation catheters. It is also associated with shorter RF delivery time, fluoroscopy, and procedural time.
Understanding the temporal sequence of events of LA structural remodeling (preceding AF ablation) to scar formation (following AF ablation) can prove valuable in determining whether certain patients are more susceptible to recovery of electrical conduction and recurrence of AF. DE-MRI recently has been introduced as a means to visualize this RF-induced scarring post-ablation. These scans can be reconstructed into three-dimensional (3D) recreations of the LA allowing for further analysis and quantification of the LA scar formation following RF ablation.
Objectives:
Primary Objective
- To evaluate the impact of pre-ablation structural remodeling (fibrosis) on scar formation and progression in the LA as assessed by DE-MRI in patients who have undergone successful open irrigated cooled-tipped RF ablation of paroxysmal atrial fibrillation (PAF), using observational, longitudinal data from the University of Utah Comprehensive Arrhythmia Research \& Management (CARMA) Center supported AFIB database (approved IRB #20347) over a 12-month follow up period.
Secondary Objectives
- To determine if secondary variables, such as total ablation time, number of lesions, power delivered, and impedance, may play a significant role in catheter induced scar formation.
- To promulgate future research opportunities in the field of AF, particularly with regards to possible early intervention measures that may impact its progression.
- To adapt treatments aimed at patients with AF who are diagnosed at earlier stages.
- To use DE-MRI to further the knowledge and understanding of RF ablation therapy and to better understand the benefits and longitudinal effects of using scar formation to eliminate the fibrotic tissue that conducts the impulses which leads to AF.
- Conditions
- Atrial Fibrillation
- Keywords
- Paroxysmal Atrial Fibrillation, Radio-frequency Ablation, Ablation, Open irrigation cooled-tip
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Open Irrigation | Those individuals who had an ablation using open irrigation cooled-tip RF ablation. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Left Atrial (LA) Remodeling Pre-ablation
Utah staging for fibrosis (I - <=5%, II - 5.01%-20.0%, III - 20.01%-35% and IV - >=35.01%)
Measured: Once pre-ablation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Aug 2010 (estimated)
- Study startAug 2010
- Primary completionJun 2011
- Study completionJun 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- More trials run by University of UtahThe sponsor's other registered studies.
- 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
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Utah
- Sponsor type
- University, hospital or other
- Collaborators
- Biosense Webster, Inc.
- Responsible party
- Principal investigator, Nassir F. Marrouche, MD, University of Utah
- Investigators
- Nassir F Marrouche, MD, Principal investigator, University of Utah
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01187914
- Sponsor's protocol ID
- IRB_00042859
- Acronym
- RADAR
- Status last verified
- Feb 2012
- First submitted
- 3 Aug 2010
- Last updated
- 13 Feb 2012
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Badger TJ, Oakes RS, Daccarett M, Burgon NS, Akoum N, Fish EN, Blauer JJ, Rao SN, Adjei-Poku Y, Kholmovski EG, Vijayakumar S, Di Bella EV, MacLeod RS, Marrouche NF. Temporal left atrial lesion formation after ablation of atrial fibrillation. Heart Rhythm. 2009 Feb;6(2):161-8. doi: 10.1016/j.hrthm.2008.10.042. Epub 2008 Nov 6.
PubMed 19187904McGann CJ, Kholmovski EG, Oakes RS, Blauer JJ, Daccarett M, Segerson N, Airey KJ, Akoum N, Fish E, Badger TJ, DiBella EV, Parker D, MacLeod RS, Marrouche NF. New magnetic resonance imaging-based method for defining the extent of left atrial wall injury after the ablation of atrial fibrillation. J Am Coll Cardiol. 2008 Oct 7;52(15):1263-71. doi: 10.1016/j.jacc.2008.05.062.
PubMed 18926331Marrouche NF, Guenther J, Segerson NM, Daccarett M, Rittger H, Marschang H, Schibgilla V, Schmidt M, Ritscher G, Noelker G, Brachmann J. Randomized comparison between open irrigation technology and intracardiac-echo-guided energy delivery for pulmonary vein antrum isolation: procedural parameters, outcomes, and the effect on esophageal injury. J Cardiovasc Electrophysiol. 2007 Jun;18(6):583-8. doi: 10.1111/j.1540-8167.2007.00879.x. Epub 2007 May 9.
PubMed 17490437Haissaguerre M, Jais P, Shah DC, Takahashi A, Hocini M, Quiniou G, Garrigue S, Le Mouroux A, Le Metayer P, Clementy J. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998 Sep 3;339(10):659-66. doi: 10.1056/NEJM199809033391003.
PubMed 9725923Marrouche NF, Schweikert R, Saliba W, Pavia SV, Martin DO, Dresing T, Cole C, Balaban K, Saad E, Perez-Lugones A, Bash D, Tchou P, Natale A. Use of different catheter ablation technologies for treatment of typical atrial flutter: acute results and long-term follow-up. Pacing Clin Electrophysiol. 2003 Mar;26(3):743-6. doi: 10.1046/j.1460-9592.2003.00126.x.
PubMed 12698676Oakes RS, Badger TJ, Kholmovski EG, Akoum N, Burgon NS, Fish EN, Blauer JJ, Rao SN, DiBella EV, Segerson NM, Daccarett M, Windfelder J, McGann CJ, Parker D, MacLeod RS, Marrouche NF. Detection and quantification of left atrial structural remodeling with delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation. Circulation. 2009 Apr 7;119(13):1758-67. doi: 10.1161/CIRCULATIONAHA.108.811877. Epub 2009 Mar 23.
PubMed 19307477
Study at a glance
From the registry record, last updated by the sponsor on 13 Feb 2012. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- RADAR: Effect of Structural Remodeling on Scar Formation as Assessed by DE-MRI of the Left Atrium Following Open-Irrigation Cooled-Tip Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation
- ClinicalTrials.gov ID
- NCT01187914
- Acronym / sponsor ID
- RADAR / IRB_00042859
- Conditions
- Atrial Fibrillation
- Keywords
- Paroxysmal Atrial Fibrillation, Radio-frequency Ablation, Ablation, Open irrigation cooled-tip
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- University of UtahUniversity, hospital or other
- Collaborators
- Biosense Webster, Inc.
- Study start
- Aug 2010
- Primary completion
- Jun 2011 (actual)
- Study completion
- Jun 2011 (actual)
- First posted
- 24 Aug 2010 (estimated)
- Results
- Posted 10 Jan 2012
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the impact of pre-ablation fibrosis on scar formation in the left atrium of the heart. This will be assessed by delayed enhancement magnetic resonance imaging and will be looked at in patients who have undergone successful open irrigated cooled-tipped radio-frequency ablation of paroxysmal atrial fibrillation. Follow-up after ablation will be for 12 months.
Detailed description
Atrial fibrillation (AF) is an electrophysiological condition characterized by disorganized electrical activity that involves the entire atria. AF manifests initially as paroxysms of arrhythmia that later progress into persistent and permanent forms. It is a progressive disease associated with structural, electrical and contractile changes in the left atrium (LA). A major determinant of the progression of AF is structural remodeling or fibrosis that occurs in the left atrium. A more extensively remodeled atrium presents the substrate needed for the arrhythmia to persist. Structural remodeling is also a major determinant for success of rhythm control strategies in AF. While catheter ablation has reproducibly been shown to be superior to anti-arrhythmic drug (AAD) therapy for rhythm control in AF, the success of this procedure is significantly affected by the extent of structural remodeling present at the time of catheter ablation.
Delayed-Enhancement Magnetic Resonance Imaging (DE-MRI) has been demonstrated to be a very effective modality in identifying fibrotic and scarred cardiac tissue with excellent correlation to electro-anatomical mapping. This is related to the characteristics of Gadolinium, an extracellular contrast agent that is very effective in identifying regions of fibrotic non-viable myocardium. DE-MRI technology can be a very powerful, non-invasive method, of identifying the extent and the distribution of structural remodeling or fibrosis associated with AF. Specific image acquisition sequences have allowed for reproducible identification of high pixel intensity regions within the 2-dimensional images of the atrial wall. 3-Dimensional reconstruction of the entire left atrium then provides a quantification of the overall volume occupied by these hyper-enhanced regions relative to the entire left atrial wall volume. Used prior to catheter ablation, DE-MRI can therefore identify regions of significant structural remodeling or fibrosis. The same technology has also been shown to be very useful in examining the amount and distribution of ablation-induced scarring.
Catheter ablation has emerged as an effective interventional therapeutic modality for AF patients. Current ablation techniques, including pulmonary vein antrum isolation (PVAI), use radiofrequency (RF) energy to induce thermal damage to the LA substrate in an attempt to electrically disconnect and isolate arrhythmogenic foci originating from the pulmonary veins (PVs). Multiple catheter technologies for RF have been developed. Catheters may be either cooled or not. Cooling allows for higher and deeper energy delivery with larger lesion formation. Open irrigation cooled-tip RF ablation of AF is associated with less impedance rise, microbubble formation, and esophageal injury when compared with traditional non-cooled ablation catheters. It is also associated with shorter RF delivery time, fluoroscopy, and procedural time.
Understanding the temporal sequence of events of LA structural remodeling (preceding AF ablation) to scar formation (following AF ablation) can prove valuable in determining whether certain patients are more susceptible to recovery of electrical conduction and recurrence of AF. DE-MRI recently has been introduced as a means to visualize this RF-induced scarring post-ablation. These scans can be reconstructed into three-dimensional (3D) recreations of the LA allowing for further analysis and quantification of the LA scar formation following RF ablation.
Objectives:
Primary Objective
- To evaluate the impact of pre-ablation structural remodeling (fibrosis) on scar formation and progression in the LA as assessed by DE-MRI in patients who have undergone successful open irrigated cooled-tipped RF ablation of paroxysmal atrial fibrillation (PAF), using observational, longitudinal data from the University of Utah Comprehensive Arrhythmia Research \& Management (CARMA) Center supported AFIB database (approved IRB #20347) over a 12-month follow up period.
Secondary Objectives
- To determine if secondary variables, such as total ablation time, number of lesions, power delivered, and impedance, may play a significant role in catheter induced scar formation.
- To promulgate future research opportunities in the field of AF, particularly with regards to possible early intervention measures that may impact its progression.
- To adapt treatments aimed at patients with AF who are diagnosed at earlier stages.
- To use DE-MRI to further the knowledge and understanding of RF ablation therapy and to better understand the benefits and longitudinal effects of using scar formation to eliminate the fibrotic tissue that conducts the impulses which leads to AF.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Open Irrigation | – | –Those individuals who had an ablation using open irrigation cooled-tip RF ablation. |
Who may qualify
- Ages
- 18 to 89 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Forty patients ages 18-89 years, who have had an open irrigation cooled-tipped RF ablation procedure for PAF. Patients must participate in 3-, 6-, and 12-months follow-up post ablation. PAF is defined by >2 documented episodes of AF that terminate spontaneously within 7 days. AF has to be documented by means of electrocardiography, holter monitor, loop recorder, or echocardiography.
Key inclusion criteria (3 listed)
- > 17 years-old and < 90 years-old
- Long-term care for PAF
- Participated in regular clinical follow-ups
Key exclusion criteria (2 listed)
- Patients who did not receive long-term follow-up care defined as at least 12-months post ablation.
- Women who were pregnant during the time period to be covered by this study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Left Atrial (LA) Remodeling Pre-ablation
Time frame: Once pre-ablation
Utah staging for fibrosis (I - <=5%, II - 5.01%-20.0%, III - 20.01%-35% and IV - >=35.01%)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Feb 2012.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 19187904Badger TJ, Oakes RS, Daccarett M, Burgon NS, Akoum N, Fish EN, Blauer JJ, Rao SN, Adjei-Poku Y, Kholmovski EG, Vijayakumar S, Di Bella EV, MacLeod RS, Marrouche NF. Temporal left atrial lesion formation after ablation of atrial fibrillation. Heart Rhythm. 2009 Feb;6(2):161-8. doi: 10.1016/j.hrthm.2008.10.042. Epub 2008 Nov 6.
- Background: PubMed 18926331McGann CJ, Kholmovski EG, Oakes RS, Blauer JJ, Daccarett M, Segerson N, Airey KJ, Akoum N, Fish E, Badger TJ, DiBella EV, Parker D, MacLeod RS, Marrouche NF. New magnetic resonance imaging-based method for defining the extent of left atrial wall injury after the ablation of atrial fibrillation. J Am Coll Cardiol. 2008 Oct 7;52(15):1263-71. doi: 10.1016/j.jacc.2008.05.062.
- Background: PubMed 17490437Marrouche NF, Guenther J, Segerson NM, Daccarett M, Rittger H, Marschang H, Schibgilla V, Schmidt M, Ritscher G, Noelker G, Brachmann J. Randomized comparison between open irrigation technology and intracardiac-echo-guided energy delivery for pulmonary vein antrum isolation: procedural parameters, outcomes, and the effect on esophageal injury. J Cardiovasc Electrophysiol. 2007 Jun;18(6):583-8. doi: 10.1111/j.1540-8167.2007.00879.x. Epub 2007 May 9.
- Background: PubMed 9725923Haissaguerre M, Jais P, Shah DC, Takahashi A, Hocini M, Quiniou G, Garrigue S, Le Mouroux A, Le Metayer P, Clementy J. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998 Sep 3;339(10):659-66. doi: 10.1056/NEJM199809033391003.
- Background: PubMed 12698676Marrouche NF, Schweikert R, Saliba W, Pavia SV, Martin DO, Dresing T, Cole C, Balaban K, Saad E, Perez-Lugones A, Bash D, Tchou P, Natale A. Use of different catheter ablation technologies for treatment of typical atrial flutter: acute results and long-term follow-up. Pacing Clin Electrophysiol. 2003 Mar;26(3):743-6. doi: 10.1046/j.1460-9592.2003.00126.x.
- Results publication: PubMed 19307477Oakes RS, Badger TJ, Kholmovski EG, Akoum N, Burgon NS, Fish EN, Blauer JJ, Rao SN, DiBella EV, Segerson NM, Daccarett M, Windfelder J, McGann CJ, Parker D, MacLeod RS, Marrouche NF. Detection and quantification of left atrial structural remodeling with delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation. Circulation. 2009 Apr 7;119(13):1758-67. doi: 10.1161/CIRCULATIONAHA.108.811877. Epub 2009 Mar 23.
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Atrial Fibrillation (AF)
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.
Nassir F Marrouche, MD principal investigator
University of Utah
Questions about this trial
What is this clinical trial studying?
An observational study of Atrial Fibrillation, run by University of Utah.
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 3 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: finished, as of the sponsor's last update on 13 Feb 2012. Status can change between updates, so confirm with the study contact before making plans.
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 10 Jan 2012). 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?
Left Atrial (LA) Remodeling Pre-ablation (time frame: Once pre-ablation). 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 NCT01187914, 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 13 Feb 2012.