None listed
Conditions
Brief summary
Atrial fibrillation is the commonest heart rhythm disturbance in humans. It is associated with an increased risk of death and serious illnesses like stroke and heart failure. Drug therapy alone has limited effectiveness in some patients who remain in atrial fibrillation and they may be highly symptomatic despite maximal treatment. Recently, it has been possible to cure atrial fibrillation in many patients by creating ablation lesions in the heart using flexible plastic coated wire catheters to deliver electrical energy. This is done by passing these catheters via veins in the leg into the left upper chamber of the heart, the left atrium. This is a rapidly evolving technique and it is not clear what pattern of ablation lesions is most effective. Moreover, it is a time consuming procedure with significant serious complications and a small risk of death and this has limited its application. The aim of this project is to compare two different patterns of ablation in terms of safety and efficacy. The patients in this study will be randomly assigned to one of two groups. One group of patients will undergo circumvenous ablation consists of a single ring that encircles all the pulmonary veins which carry blood from the lungs back to the left atrium. The other group will have their veins isolated in pairs on each side. Patients in each group will also be randomised to receive ablation of the mitral isthmus. Both groups will then be followed up for a year to determine if either pattern is superior in terms of recurrence rates, complication rates, exercise capacity and quality of life. Both procedures will also be compared in terms of procedure time and radiation exposure. Atrial fibrillation is responsible for a considerable burden of illness and death on the community and any improvements in ablation techniques for its treatment can have a major impact on the quality of life for a significant number of people.
Interventions
The two procedures being compared in this trial, namely circumvenous pulmonary vein isolation and conventional pulmonary vein isolation (which is the control group) are largely similar except for the pattern of ablation lesions deployed in the left atrium. Circumvenous ablation lesions will be deployed as a large ring that encircles all four pulmonary veins, whereas conventional ablation will be as two rings that encircle ipsilateral pulmonary veins. These procedures will be performed under gene
The two procedures being compared in this trial, namely circumvenous pulmonary vein isolation and conventional pulmonary vein isolation (which is the control group) are largely similar except for the pattern of ablation lesions deployed in the left atrium. Circumvenous ablation lesions will be deployed as a large ring that encircles all four pulmonary veins, whereas conventional ablation will be as two rings that encircle ipsilateral pulmonary veins. These procedures will be performed under general anaesthesia or intravenous sedation with midazolam and fentanyl. Three long sheaths will be inserted via the right femoral vein. An SL3 Daig sheath (St Jude Medical, St Paul, MN) will be used to place a decapolar catheter in the coronary sinus. The other two sheaths (Preface, Cordis-Webster, Diamond Bar, CA and Agilis Steerable Introducer (St Jude Medical, St Paul, MN) will be passed into the left atrium via transeptal punctures and used to introduce a circular decapolar catheter (Lasso, Cordis-Webster, Diamond Bar, CA) and an open irrigated 5mm tip ablation catheter (Thermocool, Cordis-Webster, Diamond Bar, CA) respectively. Fluoroscopy and an electroanatomical mapping system (CARTO, Biosense Webster, Diamond Bar, CA) will be used to guide the manipulation of the ablation catheter. After the pulmonary veins have been identified using contrast cineradiography and by observing the movement of the catheters in the left atrium, patients will be randomized to have one of the two patterns of lesions made using radiofrequency ablation. The endpoint for both techniques will be electrical isolation of all the pulmonary veins. Patients will also be randomised to receive linear ablations across the left mitral isthmus. A tricuspid annulus- inferior vena cava isthmus ablation will be performed on all patients. Both types of ablation procedure will usually take between three to five hours to complete. Patients will then be followed up for one year post procedure.
Sponsors
Stuart P Thomas
Study design
Allocation
Randomised controlled trial
Intervention model
Factorial
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Symptomatic atrial fibrillation refractory to medical therapy2. Ability to provide informed consent.
Exclusion criteria
1. Previous percutaneous or operative procedure for atrial fibrillation involving linear or encircling lesions.
Outcome results
None listed