Catheter Versus Thoracoscopic Surgical Ablation Strategy in Persistent Atrial Fibrillation (CASA-AF)
Recruitment status was: Enrolling by invitation
Atrial fibrillation(AF)is the commonest arrhythmia worldwide and can lead to significant morbidity and mortality, posing an increasing public health burden. Restoration of sinus rhythm (SR) is the preferred strategy in symptomatic patients but outcomes with anti-arrhythmic drugs (AAD) are poor. The alternatives to AAD are two-fold.Firstly, catheter ablation (CA)- a technique that uses catheters (thin tubes) to deliver small 'heat lesions' to areas of the heart to eliminate AF. Secondly, surgical ablation, where multiple incisions are made in the atria to restore SR. Long term results from this traditional surgical approach are excellent however as it is technically difficult open-heart procedure with significant morbidity and mortality, it is seldom used.
CA is very effective in restoring SR in the early stages of AF when it is a paroxysmal (intermittent) rhythm disturbance. If not treated at this stage AF inevitably evolves into a more persistent or permanent state and becomes more difficult to treat with CA. Therefore, the optimum approach to treat patients with symptomatic long standing persistent AF has yet to be determined and remains a key area of on-going research.
New minimally invasive, thoracoscopically assisted surgical(closed-heart)approaches have recently developed which ablate a wide area around the pulmonary veins, and may offer advantages over the best current strategies in CA. There are also clear advantages for patients with greater safety and less discomfort when compared to traditional surgical open-heart procedures.
At present there is small amount of encouraging data on this thoracoscopic surgical technique but there is no data comparing these two modalities of treatment in persistent AF patients. The investigators therefore wish to prospectively investigate the safety and efficacy of this thoracoscopic surgical technique and compare with CA in this group of patients. MRI scanning will also be used to visualise the effects of ablation by analysis of scar formation.
The study hypothesises that thoracoscopics surgical ablation is a
|Persistent Atrial Fibrillation||Procedure: Thoracoscopically Assisted Surgical Ablation Procedure: Catheter Ablation|
|Study Design:||Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||A Study to Assess Catheter Ablation Versus Thoracoscopically Assisted Surgical Ablation in Persistent Atrial Fibrillation|
- Freedom from atrial tachyarrhythmias at 12 months. [ Time Frame: 12 months ]Freedom from atrial tachyarrhythmias at 12 months which will be analysed with or without anti-arrhythmic drugs (AAD). Monitoring will be undertaken with ambulatory ECG monitoring in compliance with latest international guidelines.
- Freedom from atrial tachyarrhythmias at 12 months from a single procedure on/off AAD; [ Time Frame: 12 months ]Only 1 re-do procedure is allowed in study time frame. But this outcome will look at single procedure success in both arms at 12 months.
- Change in AF symptom score [ Time Frame: Various time points 0,3,6,9,12 months ]Using recognised AF symptom score scale
- Integrity of ablation lesion after index procedure at 3 months (as assessed by MRI if in SR +/- electrophysiologically if redo procedure is undertaken for atrial arrhythmia recurrence); [ Time Frame: 3 months ]Using MRI +/- electrophysiological techniques.
- Freedom of serious adverse events (stroke, myocardial infarction, emergency surgery, death) immediately after the procedure and during follow-up. [ Time Frame: 12 months ]
- Cost analysis (procedural and hospital stay costs). [ Time Frame: 12 months ]Top down cost analysis
|Study Start Date:||April 2011|
|Estimated Study Completion Date:||October 2013|
|Estimated Primary Completion Date:||October 2013 (Final data collection date for primary outcome measure)|
Experimental: Thoracoscopically Assisted Surgical Ablation
This arm will have an index thoracoscopically assisted surgical ablation.
Procedure: Thoracoscopically Assisted Surgical Ablation
Surgical AF ablation including pulmonary vein isolation, gananglionated plexi ablation +/- LAA excision/exclusion.
Active Comparator: Catheter Ablation
This is an active comparator arm where study subjects will undergo conventional catheter ablation.
Procedure: Catheter Ablation
In this arm, study subjects will undergo conventional catheter ablation as their index procedure. This will include pulmonary vein isolation, linear and electrogram based ablation.
This will be a pilot, prospective, observational study of catheter ablation compared with thoracoscopically assisted, surgical ablation strategies using a case control design.
The study population will be patients between the ages of 18 and 80 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.
Thoracoscopically Assisted Surgical Ablation Group Patients assigned to this group will undergo minimally invasive, thoracoscopically assisted, surgical ablation to isolate the pulmonary veins (PVI) using a radiofrequency (RF) clamp device. This will include ganglionated plexi ablation +/- LAA excision/exclusion.
Catheter Ablation Group Patients will undergo pulmonary vein isolation, linear and electrogram based ablation.
Recurrences Only one redo procedure is allowed for atrial tachyarrhythmia recurrences in the 12 month follow-up period.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01385358
|Royal Brompton & Harefield NHS Foundation Trust|
|London, Greater London, United Kingdom, SW3 6NP|
|Principal Investigator:||Tom Wong, MD||Royal Brompton & Harefield NHS Foundation Trust|