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Catheter Ablation Versus Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation (CASA-AF) (CASA-AF)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02755688
Recruitment Status : Unknown
Verified September 2019 by Royal Brompton & Harefield NHS Foundation Trust.
Recruitment status was:  Active, not recruiting
First Posted : April 29, 2016
Last Update Posted : September 12, 2019
National Institute for Health Research, United Kingdom
Liverpool Heart and Chest Hospital NHS Foundation Trust
Information provided by (Responsible Party):
Royal Brompton & Harefield NHS Foundation Trust

Brief Summary:
Atrial fibrillation (AF) is the most common heart arrhythmia. Many people do not have symptoms and are not aware they have AF. Others may feel dizzy, short of breath, feel very tired and become aware of a fast and irregular heart beat (palpitations). The main complication of AF is an increased risk of stroke and incidence of heart failure. There are two key aspects of treatment for AF. The first is protection from stroke, treated with oral anticoagulants. Treatment of AF is either by controlling the rate (frequency of contraction) or controlling the rhythm (restoring regular contraction). Rate-control is generally employed first with an intent to reduce the rate at which the lower pumping chambers contract and improve their efficiency. Appropriate medication is used and with this treatment strategy it is accepted that AF will be present as the long term heart rhythm. If symptoms persist despite medication the preferred strategy is to restore sinus rhythm (SR) and regular contraction in all pumping chambers of the heart. This can be done with electric shock treatment (DC cardioversion) together with long-term tablet medication, or by a more definitive 'cauterisation' therapy (catheter or thoracoscopic surgical ablation). In this study the investigators will study patients with symptomatic long standing persistent AF (continuous AF for more than 1 year) who have tried and failed drug and/or electrical therapy. At present the investigators do not know what the best ablation technique is for treating symptomatic, long-standing persistent AF (LSPAF). Catheter ablation (CA) is the most widely available invasive treatment available for AF. Thoracoscopic surgical ablation (SA) is not widely available but our hospitals have the expertise to conduct this procedure. CA has been shown to achieve modest degrees of success in restoring normal SR with the caveat that most patients do require 'multiple' procedures (usually two or three). SA offers patients an alternative choice of therapy with a keyhole surgical thoracoscopic) approach. It may have a higher single procedure success rate although there is the potential for greater complication rates. The investigators aim to examine this in detail to help us understand which approach might be better for managing LSPAF.

Condition or disease Intervention/treatment Phase
Persistent Atrial Fibrillation Procedure: Thoracoscopic Surgical ablation Procedure: Catheter ablation Not Applicable

Detailed Description:

This is a multi-center randomised controlled study of catheter ablation compared with totally thoracoscopic surgical ablation.

The study population will be patients above the age of 18 with symptomatic long-standing persistent atrial fibrillation (≥1≤5 years) and good left ventricular function where at least one anti-arrhythmic drug (AAD) has failed, or where such drugs are contraindicated or not tolerated.

Subjects randomised to thoracoscopic Surgical Ablation will undergo minimally invasive, thoracoscopically assisted, surgical ablation to isolate the pulmonary veins (PVI) using a radiofrequency (RF) clamp device. Posterior wall will be isolated in a box fashion with cool rail bipolar RF device. This will include ganglionated plexi ablation +/- LAA excision/exclusion.

Catheter Ablation Group Patients will undergo pulmonary vein isolation and linear ablations in the left and right atrium.

There will be a 3 month blanking period and symptomatic atrial arrhythmia may have catheter ablation during the period of 12 month follow up. The primary end point of the study will be assessed by continuous cardiac recording through an internal loop recorder that will be inserted at the end of the index procedure. The analysis and reporting of the recordings will be performed by a blinded core lab.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Catheter Ablation Versus Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation (CASA-AF)
Study Start Date : June 2015
Estimated Primary Completion Date : October 30, 2019
Estimated Study Completion Date : March 31, 2020

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Thoracoscopic surgical ablation
Pulmonary vein isolation, ganglionic plexi ablation, left atrial appendage exclusion
Procedure: Thoracoscopic Surgical ablation
Thoracoscopic approach to isolate pulmonary veins, ganglionic plexi ablation and left atrial appendage exclusion

Active Comparator: Catheter ablation
Pulmonary vein isolation, linear lines
Procedure: Catheter ablation
Ablation using contact force technology to isolate pulmonary veins and create linear lesions.

Primary Outcome Measures :
  1. Freedom from atrial arrhythmias (>30 seconds) after a single procedure without anti-arrhythmic drugs (AADs) within 12 months measured by internal loop recorder [ Time Frame: 12 months ]
    All patients will have internal loop recorder inserted after the completion of the procedure and the data will be analysed by a blinded core lab. 3 months of the blanking period will not be counted as accepted by EHRA / HRS committee. The definition of atrial arrhythmias is equal to or greater than 30 seconds of atrial tachycardia or atrial fibrillation as mentioned in EHRA / HRS consensus statement 2012.

Secondary Outcome Measures :
  1. Intervention-related major complication rate defined as permanent injury or death, requires unplanned intervention for treatment, or prolongs or requires unplanned hospitalization for more than 48 hours [ Time Frame: 12 months ]
  2. Clinical success from the arrhythmia interventions - defined as a 75% or greater reduction of AF burden with or without AADs. [ Time Frame: 12 months ]
  3. Freedom from atrial arrhythmia, after multiple procedures without AADs [ Time Frame: 12 months ]
    Measured by internal loop recorder and analysed by blinded core lab.

  4. Changes in atrial anatomy and function following ablation as assessed by echocardiography using tissue Doppler and strain [ Time Frame: 12 months ]
  5. Changes in atrial anatomy and atrial fibrosis following ablation as assessed by cardiac MRI [ Time Frame: 12 months ]
  6. Effects of the arrhythmia interventions on the patients' symptoms by Change in AF symptom score (EHRA score) [ Time Frame: 12 months ]
  7. Effects of the arrhythmia interventions on the quality of life as assessed by change in quality of life assessments (EQ5D) [ Time Frame: 12 months ]
  8. Effects of the arrhythmia interventions on the quality of life as assessed by change in quality of life assessments (AFEQT) [ Time Frame: 12 months ]
  9. Quality Adjusted Life Years (QALYs) accrued during follow up [ Time Frame: 12 months ]
  10. Cost-effectiveness (Incremental Cost per QALY gained) for surgical ablation compared with CA estimated [ Time Frame: 12 months ]

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

Inclusion Criteria:

  1. Age≥ 18 yrs.
  2. LSPAF (> 12 months' duration)
  3. EHRA>2
  4. Left ventricular ejection fraction ≥ 40%
  5. Suitable for either ablation procedure

Exclusion Criteria:

  1. Left sided valvular heart disease with severity greater than mild
  2. Contraindication to anticoagulation
  3. Thrombus in the left atrium despite anticoagulation in therapeutic range
  4. Cerebrovascular accident within the previous 6 months
  5. Previous thoracic or cardiac surgery (including surgical interventions for AF)
  6. Prior left atrial catheter ablation for AF
  7. Unable to provide informed written consent
  8. Active malignancy, another severe concomitant condition or presence of implanted intracardiac devices that would preclude patient undergoing study specific procedures
  9. Pregnant or breast-feeding, or women of childbearing age not using a reliable contraceptive method.
  10. Implanted non MRI compatible cardiac devices

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 identifier (NCT number): NCT02755688

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United Kingdom
Brighton and Sussex University Hospitals NHS Trust
Brighton, United Kingdom, BN2 5BE
Liverpool Heart and Chest Hospital
Liverpool, United Kingdom
Royal Brompton and Harefield Hospital NHS Trusts
London, United Kingdom, SW36NP
Sponsors and Collaborators
Royal Brompton & Harefield NHS Foundation Trust
National Institute for Health Research, United Kingdom
Liverpool Heart and Chest Hospital NHS Foundation Trust
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Principal Investigator: Tom Wong Royal Brompton & Harefield NHS Foundation Trust
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Royal Brompton & Harefield NHS Foundation Trust Identifier: NCT02755688    
Other Study ID Numbers: 2014CI005B
First Posted: April 29, 2016    Key Record Dates
Last Update Posted: September 12, 2019
Last Verified: September 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Royal Brompton & Harefield NHS Foundation Trust:
atrial fibrillation
catheter ablation
thoracoscopic surgical ablation
long standing persistent atrial fibrillation
Additional relevant MeSH terms:
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Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes