A randomised controlled trial comparing high frequency jet ventilation and conventional ventilation used in catheter ablation to establish whether using a breathing method that gives very small, rapid breaths during general anaesthetic, makes atrial fibrillation ablation more successful than the standard breathing machine currently used in most UK hospitals

INTERVENTION: This multicentre randomised controlled trial will compare high‐frequency jet ventilation (HFJV) with conventional intermittent positive‐pressure ventilation (IPPV) during general anaesthesia for first‐time point‐by‐point catheter ablation in adults with symptomatic paroxysmal or early persistent atrial fibrillation. A total of 316 participants will be recruited from an expected 11 UK tertiary arrhythmia centres and allocated in a 1:1 ratio to one of the two ventilation strategies. Participants and outcome assessors will be blinded to treatment allocation. All participants will undertake remote wearable heart‐rhythm monitoring before ablation and for 12 months after the procedure. ‐HFJV is a ventilation strategy delivering sub‐dead‐space tidal volumes at high respiratory frequencies during general anaesthesia. It will be used during catheter ablation with the aim of reducing respiratory movement during lesion delivery. ‐IPPV, also known as conventional mechanical ventilation, is the standard ventilation strategy used during general anaesthesia, involving delivery of physiological tidal volumes at conventional respiratory frequencies. All participants will use a wrist‐worn monitoring system that continuously assesses heart rate and rhythm using photoplethysmography and permits confirmatory single‐lead electrocardiogram recordings. Participants will complete a daily recording, symptom‐triggered recordings and device‐prompted recordings. Monitoring will begin up to three months before ablation and continue for 12 months after the procedure. Randomisation will be completed using the study database, REDCap. Randomisation will occur as close as practicable to the participant’s ablation procedure, normally on the day of the procedure or up to three days beforehand where required for staffing and equipment arrangements. The allocated ventilation strategy will be started only after induction of general anaesthesia, thereby helping to preserve participant blinding. CONDITION: Atrial fibrillation, paroxysmal atrial fibrillation, early persistent atrial fibrillation, general anaesthesia ; Circulatory System PRIMARY OUTCOME: Proportion of participants with no episode of atrial fibrillation, atrial flutter or atrial tachycardia lasting more than 30 seconds measured using remote wearable rhythm monitoring at the post‐ablation blanking period (8 weeks) through 12 months after ablation Quality of life measured using Atrial Fibrillation Effect on Quality‐of‐Life (AFEQT) questionnaire at baseline and 12 months after ablation INCLUSION CRITERIA: 1. Symptomatic paroxysmal atrial fibrillation or early persistent atrial fibrillation. Early persistent atrial fibrillation is defined as persistent atrial fibrillation of less than si Xmonths’ duration, or maintenance of sinus rhythm for more than three months while receiving antiarrhythmic medication 2. Scheduled for first atrial fibrillation ablation using a point‐by‐point approach 3. Aged 18 or older 4. Able to provide informed consent SECONDARY OUTCOME: Atrial arrhythmia burden measured using percentage of analysable monitoring time spent in atrial fibrillation, atrial flutter or atrial tachycardia. Calculated as the total cumulative duration of atrial arrhythmia divided by total analysable monitoring time. Total episode count and cumulative episode duration will also be reported at ablation through 12 months after ablation Patient satisfaction with anaesthesia measured using the Bauer anaesthesia satisfaction questionnaire at the ablation procedure and before hospital discharge, generally day 0 or day 1 Proportion of participants experiencing a composite of all‐cause death, non‐fatal ischaemic or haemorrhagic stroke, transient ischaemic attack, systemic arterial embolism, resuscitated or aborted cardiac arrest, incident heart failure, myocardial infarction, or hospitalisation for any cardiac cause measured using patient records at baseline through 12 months Proportion of participants listed for a further atrial fibrillation ablation procedure measured using clinical record review, participant report and follow‐up clinician assessment at baseline through 12 months Proportion of participants who restart antiarrhythmic medication measured using clinical record review, participant report and follow‐up clinician assessment at baseline through 12 months Proportion of participants with no episode of atrial fibrillation, atrial flutter or atrial tachycardia lasting more than one hour measured using remote wearable rhythm monitoring at the post‐ablation blanking period through 12 months after ablation Within‐trial cost‐effectiveness measured using incremental NHS costs and quality‐adjusted life years associated with high‐frequency jet ventilation compared with conventional ventilation. Quality‐adjusted life years will be derived from EQ‐5D‐5L assessments. Results will include incremental cost, incremental quality‐adjusted life years and incremental cost per quality‐adjusted life year gained at baseline through 12 months