Award Title: Long-term Outcomes in Long Standing Persistent Atrial Fibrillation Comparing Catheter Ablation and Thoracoscopic Surgical Ablation
Funder: Department of Health and Social Care

Abstract: Background   Atrial fibrillation (AF) is the most common arrhythmia worldwide and causes detrimental effects on quality of life, morbidity (stroke and heart failure) and mortality. The most challenging type of AF to treat is long-standing persistent AF (LSPAF), which is in part due to atrial substrate undergoing extensive electro-anatomical remodelling. Anti-arrhythmic drugs have proven to be less effective to restore sinus rhythm in symptomatic patients when compared to catheter ablation. At present, catheter ablation is the main interventional treatment for symptomatic LSPAF patients. The alternative option to catheter ablation is thoracoscopic surgical ablation, currently being investigated by our group in a randomised control trial (CASA-AF RCT, NIHR EME 12/127/127) with a follow-up period of 12 months. The longer terms effects of thoracoscopic surgical ablation in this cohort is not known.       Research question   Is thoracoscopic surgical ablation superior to catheter ablation at maintaining arrhythmia-free survival in the long-term (36-months) after a single procedure using implantable loop recorder monitoring?       Aims and objectives    This study aims to explore the long-term effectiveness of thoracoscopic surgical ablation when compared to catheter ablation at 36-month follow-up using implantable loop recorder, which monitors the heart rhythm. Additionally, further objectives include the comparison of arrhythmia burden reduction between the two groups, cost-effectiveness, biomarkers to predict outcomes and quality of life for patient-centric outcomes.       Methods   As part of the CASA-AF study, patients have been recruited and randomised to have either thoracoscopic surgical ablation or catheter ablation.  During the procedure, the patients have had an implantable loop recorder inserted, which monitors their rhythm. The patients in the study have consented to keep their implantable loop recorders at the end of the CASA-AF trial. All the patients in the trial will be contacted, and if they agree to participate in the new study, we will obtain written consent to continue to monitor their implantable loop recorder and analyse the data. These implantable loop recorders have an expected battery life for at least 3 years. The study will begin at 12 months after their index procedure date until the end of the battery life. The loop recorded data will be reviewed monthly, in addition patients will attend clinical follow-up at 24 months and 36 months. This clinical review will consist of clinical examination, questionnaires, collecting blood and ECG.       Timelines for delivery   The trial will begin on 1st January 2020 and will require 20 months to complete patient follow-up. We will need another 4 months to complete data analysis and to publish the results to a peer-reviewed journal.       Anticipated impact and dissemination   Long term efficacy results of catheter ablation and thoracoscopic surgical ablation will potentially allow clinicians to offer an alternative procedure to patients with symptomatic LSPAF. These results will provide invaluable evidence to inform guidelines, which as it stands is devoid of robust randomised controlled trial data in this arena.  This data will be highly relevant to inform the best patient care.

Lay Abstract: Background     Atrial fibrillation (AF) is a heart rhythm problem, which causes an irregular heartbeat.  It is the most common rhythm disturbance worldwide. AF can lead to significant symptoms and distressing health problems (stroke and heart failure). As people live longer, more people will need services for AF, putting financial pressure on the NHS.     The longer a person has AF, the more difficult it is to go back into a normal heart rhythm. Those who have continuous AF for longer than a year are described as having longstanding persistent AF (LSPAF). This is the most challenging type of AF to treat and makes up a large proportion of all AF patients. The drugs that are used to treat AF do not work well in LSPAF.     Currently, patients with LSPAF may be offered a procedure to help improve their symptoms. It involves putting a flexible thin tube (catheter) into a blood vessel in the groin and up into the heart. This procedure has modest success rates in improving symptoms in the long term. Recently, keyhole surgery has been used for these patients and evidence shows that it is better than the catheter procedure. However, we do not know how well people are doing beyond one year.     Feedback from a patient focus group reported that they would like to understand the long-term results of the procedures to make an informed decision.  Purpose     To investigate this further, we plan to monitor patients from a previous research study who have already had both procedures. They have a small device implanted under the skin to monitor their heartbeat. This heartbeat monitor has a battery life of around 3 years, and the previous research study followed up patients for only 1 year. We will ask this group of patients if they would like to participate in this new study and obtain written consent. We will aim to make use of the remaining 2 years of monitoring on the device to identify whether they have had a recurrence of the abnormal rhythm.     This project will have two stages. The first stage will involve downloading information from the implanted device that monitors their heartbeat on a monthly basis. The second stage of the study will include two clinic visits to collect blood and answer questionnaires; one at 2-years and another at 3-years from the procedure. We will assess the costs incurred over the 3 years for both procedures. Furthermore, in combination with quality of life scores from questionnaires, we will analyse the cost-benefit for patients and the NHS.     The results may help to inform clinical guidelines (UK and international) on whether surgery has better outcomes for patients in the long term compared to the catheter procedure.

Research Activity Codes: 6.4 SURGERY
Health Categories: CARDIOVASCULAR