Cryoballoon Ablation as First Line Treatment of Atrial Flutter

Not Applicable

Completed

• Conditions: Atrial Flutter Typical
• Interventions: Procedure: Radiofrequency ablation of CTI; Procedure: Cryoballoon PVI

• Registration Number: NCT03401099
• Lead Sponsor: Liverpool Heart and Chest Hospital NHS Foundation Trust

Brief Summary

Current guidelines recommend radiofrequency catheter ablation of the cavotricuspid isthmus as treatment for symptomatic/drug-refractory atrial flutter, in spite of the fact that recurrences of flutter and incidence of post-ablation atrial fibrillation are common.

In this study, the investigators assess the hypothesis that the use of cryoballoon Pulmonary Vein Isolation ('novel' treatment) to achieve the electrical disconnection between the pulmonary veins and the heart will lead to higher rates of freedom from abnormal heart rhythms (atrial flutter, atrial fibrillation, or atrial tachycardia) and more improved quality of life than treatment using heat energy (radiofrequency ablation) directed at the cavotricuspid isthmus ('conventional treatment').

Detailed Description

Atrial flutter and atrial fibrillation are believed to share the same initiating triggers in the form of pulmonary vein ectopy. Cavo-tricuspid isthmus-dependent atrial flutter almost always results from short bursts of antecedent atrial fibrillation. Radiofrequency (RF) ablation of the cavo-tricuspid isthmus (CTI) is the current accepted first-line treatment for atrial flutter, although post-ablation atrial fibrillation commonly occurs, even in the absence of pre-existing atrial fibrillation.

Cryoballoon Pulmonary Vein Isolation (PVI) has become an established treatment for atrial fibrillation. In patients with both atrial flutter and fibrillation, PVI alone has been shown to control both types of atrial arrhythmia, with no benefit derived from supplemental RF CTI ablation.

This study aims to demonstrate that standalone cryoballoon PVI for typical atrial flutter without RF CTI ablation will lead to a significant difference in preventing recurrence of atrial arrhythmia compared to radiofrequency ablation of the CTI, and should be offered as first-line therapy.

Study Timeline

• Study First Submitted: 2017-12-14
• Study First Submitted QC: 2018-01-09
• Study First Posted: 2018-01-17
• Study Start: 2018-08-17
• Primary Completion: 2021-12-01
• Status Verified: 2023-11
• Study Completion: 2023-11-01
• Last Update Submitted: 2023-11-10
• Last Update Posted: 2023-11-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 113

Inclusion Criteria

• 1. Age 18-80 years
• 2. Patients referred for catheter ablation for typical atrial flutter. The atrial flutter may be either persistent or paroxysmal, with at least one episode having been documented on 12-lead ECG. In the view of the treating physician, the ECG morphology should be compatible with a CTI-dependent circuit, either counterclockwise or clockwise.

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Exclusion Criteria

• 1. Any evidence of previously documented atrial fibrillation
• 2. Previous cavo-tricuspid isthmus ablation or atrial fibrillation ablation
• 3. Atrial flutter documented solely on Ambulatory monitoring
• 4. Atrial flutter morphology on ECG suggestive of a left atrial flutter
• 5. History of atrial flutter with 1:1 atrioventricular conduction and haemodynamic compromise
• 6. Indwelling atrial-septal defect occluder device, or any anatomical reason that precludes left atrial access
• 7. Left atrial diameter (PLAX M-mode) >5.5 cm
• 8. Severe left ventricular dysfunction (LV ejection fraction < 30% on Echocardiography)
• 9. Recent stroke/transient ischaemic attack within 3 months
• 10. Inability or unwillingness to take oral anticoagulant treatment
• 11. Morbid obesity (Body Mass Index ≥40)
• 12. Extreme frailty (A score of 7,8 or worse on the Clinical Frailty Scale)
• 13. Implanted metal prosthetic valve(s) in mitral position
• 14. Indwelling cardiac resynchronisation therapy device, pacemaker or implantable cardioverter defibrillator
• 15. Advanced Renal dysfunction (eGFR<30 ml/min)
• 16. Pregnancy
• 17. Severe valvular heart disease of any kind as assessed by the investigator
• 18. Previous valve replacement surgery or other prosthetic heart valve

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Radiofrequency ablation of CTI	Radiofrequency ablation of CTI	Radiofrequency ablation of CTI (cavo-tricuspid isthmus), which is the 'conventional' treatment of atrial flutter
Cryoballoon PVI	Cryoballoon PVI	Cryoballoon PVI (Pulmonary Vein Isolation), which is the 'novel treatment'

Primary Outcome Measures

Name	Time	Method
Time to first recurrence of sustained, symptomatic supraventricular arrhythmia (Atrial Fibrillation, Atrial Flutter or Atrial Tachycardia) following a blanking period of 4 weeks after a single ablation procedure	After 4 weeks of ablation treatment (blanking period) up to 12 months of follow up	'Sustained' is defined as lasting \>30 seconds. 'Symptomatic' is defined as acute onset awareness of palpitations, breathlessness, dizziness, fatigue or chest pain associated with patient activation of the loop recorder.

Secondary Outcome Measures

Name	Time	Method
Total burden of abnormal heart rhythm measured by the implantable loop recorder	After first ablation procedure through study completion or time of intervention, whichever comes first, assessed up to 12 months	Total arrhythmic burden up to end of follow up or up to time of intervention (either cardioversion or ablation), whichever comes first.
Quality of Life questionnaire	At baseline and at 12 months	Quality of life as assessed by the standard EuroQol Group's 5-dimensional questionnaire. This comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and the visual analogue scale. The single digits for the five dimensions will be combined into a 5-digit number that describes the patient's health state.
Total Fluoroscopy times	Only during the first ablation procedure	The total time in minutes during which patient will be exposed to radiation under each of the two treatment techniques
Time to first symptomatic or asymptomatic Atrial Fibrillation lasting ≥2 min	After 4 weeks of ablation treatment (blanking period) up to 12 months of follow up	How long it takes until first occurrence of atrial fibrillation (associated with symptoms or no symptoms) lasting 2 or more minutes after blanking period. Two minutes is the minimum duration detectable by the loop recorder
Total Burden of Atrial fibrillation over 12 months	After 4 weeks of ablation treatment (blanking period) up to 12 months of follow up	The total occurrence of atrial fibrillation recorded by the loop recorder (symptomatic or asymptomatic) during the follow-up period
Time to first symptomatic or asymptomatic atrial flutter/atrial tachycardia	After 4 weeks of ablation treatment (blanking period) up to 12 months of follow up	Occurrence of atrial flutter/atrial tachycardia with/without symptoms following the blanking period
Incidence of any significant arrhythmia	After first ablation procedure, through study completion, an average of 12 months	Incidence of any arrhythmia requiring medical visit to primary or secondary care, or hospitalisation, or leading to death
Incidence of repeat electrophysiological interventional procedure (repeat catheter ablation, or DCCV) over the follow-up period.	After 4 weeks of ablation treatment (blanking period) up to 12 months of follow up	Occurrence of repeat ablations/cardioversion
Incidence of procedural complications	During and after ablation procedure, through study completion, an average of 12 months	Composite of cardiac tamponade requiring drainage, persistent phrenic nerve palsy lasting \>24 hours, serious vascular complications requiring intervention or delaying discharge, stroke/transient ischaemic attack, requirement for a permanent pacemaker, atrio-esophageal fistula, or death
Incidence of all-cause hospitalisations	After first ablation procedure, through study completion, an average of 12 months	Any hospital admission post-ablation
Procedural duration	Only during the first ablation procedure	Duration of ablation measured in minutes for either treatment

Trial Locations

Locations (10)

University Hospital Basel; 🇨🇭 Basel, Switzerland

University Hospital Inselspital Bern; 🇨🇭 Bern, Switzerland

Royal Papworth Hospital NHS Foundation Trust; 🇬🇧 Papworth Everard, Cambridge, United Kingdom

University Hospitals Plymouth NHS Trust; 🇬🇧 Plymouth, United Kingdom

Manchester University NHS Foundation Trust, Wythenshawe Hospital; 🇬🇧 Manchester, United Kingdom

Leeds Teaching Hospitals NHS Trust; 🇬🇧 Leeds, United Kingdom

Liverpool Heart and Chest Hospital NHS Foundation Trust; 🇬🇧 Liverpool, United Kingdom

South Tees Hospitals NHS Foundation Trust, James Cook University Hospital; 🇬🇧 Middlesbrough, United Kingdom

The Newcastle Upon Tyne Hospital NHS Foundation Trust, Freeman Hospital; 🇬🇧 Newcastle Upon Tyne, United Kingdom

Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital; 🇬🇧 Oxford, United Kingdom