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NCT Number: NCT03401099

Cryoballoon Ablation as First Line Treatment of Atrial Flutter

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').

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Key information

Conditions

Atrial Flutter Typical

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University Hospital Basel, Basel, Switzerland

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About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

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

Treatment and study plan

Radiofrequency ablation of CTI

Procedure

Delivery of radiofrequency energy to the cavotricuspid isthmus (region of right atrial tissue between the tricuspid annulus and the inferior vena cava) until bidirectional block is achieved

Other names: CTI ablation

Cryoballoon PVI

Procedure

Cryoballoon application to the pulmonary veins aiming for Pulmonary Vein Isolation

Other names: Cryoablation Pulmonary Vein Isolation

Primary outcomes

  1. 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

    Time frame: 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 outcomes

  1. Time to first symptomatic or asymptomatic Atrial Fibrillation lasting ≥2 min

    Time frame: 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

  2. Total Burden of Atrial fibrillation over 12 months

    Time frame: 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

  3. Time to first symptomatic or asymptomatic atrial flutter/atrial tachycardia

    Time frame: 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

  4. Incidence of any significant arrhythmia

    Time frame: 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

  5. Total burden of abnormal heart rhythm measured by the implantable loop recorder

    Time frame: 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.

  6. Incidence of repeat electrophysiological interventional procedure (repeat catheter ablation, or DCCV) over the follow-up period.

    Time frame: After 4 weeks of ablation treatment (blanking period) up to 12 months of follow up

    Occurrence of repeat ablations/cardioversion

  7. Incidence of procedural complications

    Time frame: 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

  8. Incidence of all-cause hospitalisations

    Time frame: After first ablation procedure, through study completion, an average of 12 months

    Any hospital admission post-ablation

  9. Quality of Life questionnaire

    Time frame: 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.

  10. Procedural duration

    Time frame: Only during the first ablation procedure

    Duration of ablation measured in minutes for either treatment

  11. Total Fluoroscopy times

    Time frame: 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

Sponsors and collaborators

Lead sponsor

Liverpool Heart and Chest Hospital NHS Foundation Trust

Other

Collaborators

  • Medtronic International Trading Sarl

Registry information

Official study title

Cryoballoon Pulmonary Vein Isolation as First Line Treatment for Typical Atrial Flutter

Acronym: CRAFT

Important dates

Study start
2018
Primary completion
2021
Study completion
2023
First posted
Jan 17, 2018
Registry last updated
Nov 13, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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