Fluoroscopic, Contact Force and Local Impedance With Ultra-high Density Mapping Guided Radiofrequency Ablation Comparison for cavoTricuspid Isthmus dependenT Atrial fluttER: the FLUTTER Study

Typical Atrial Flutter Clinical Trial

— FLUTTER  

Official title:

Fluoroscopic, Contact Force and Local Impedance With Ultra-high Density Mapping Guided Radiofrequency Ablation Comparison for cavoTricuspid Isthmus dependenT Atrial fluttER: the FLUTTER Study

Clinical Trial Details — Status: Withdrawn

Administrative data

• NCT number: NCT04434599
• Other study ID #: 281105
• Status: Withdrawn
• Phase: N/A
• Start date: October 30, 2022
• Est. completion date: January 1, 2024

Study information

• Verified date: October 2023
• Source: University of Manchester
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Catheter ablation is a first-line treatment for patients with cavotricuspid isthmus (CTI) dependent atrial flutter (AFL; also known as typical AFL), a common arrhythmia. This is done using radiofrequency (RF) catheters and single-procedure success is approximately 95%. Ablation is often done using one of three methods:

1. fluoroscopically, using X-rays to guide the operator to visualise catheter position within the heart. This method involves the most radiation exposure to patient and operator. Ablation is generally performed for a set time-period (eg. 30-60secs) to ensure each ablation lesion is successful.

2. using a 3-dimensional mapping system which allows the catheters to be magnetically located and visualised on a monitor without X-rays, and using "contact force" (CF) sensing catheters. This requires minimal X-ray use, and by ensuring a minimum degree of force between catheter tip and the heart before applying RF for a set time-period (eg. 30 seconds), operators can be more confident of successful lesions.

3. using an ultra-high density mapping system which uses magnetic tracking as above, but allows higher resolution visualisation of the cardiac electrical system with potential for improving procedure success; this has not yet been formally evaluated for AFL. Catheters using this method use "local impedance" (LI) instead of CF. This is a direct measure of heart tissue impedance with real-time changes during ablation. A minimum drop or plateau in the LI value during ablation allows confidence of lesion success, without the need to ablate for a pre-defined time-period. This could potentially reduce ablation time and subsequent complications, but has also not yet been formally compared to the above for this indication.

This prospective randomised study aims to compare these three standard of care procedures to determine if differences in ablation metrics, efficacy and safety exist.

Recruitment information / eligibility

• Status: Withdrawn
• Enrollment: 0
• Est. completion date: January 1, 2024
• Est. primary completion date: September 1, 2023
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Patients under the care of the NHS

• Aged 18-80 years

• Symptoms and 12-lead ECG suggestive of typical (cavotricuspid isthmus dependent) atrial flutter

• Due to undergo first-time cavotricuspid isthmus ablation (including as part of a combined ablation if also having pulmonary vein isolation for atrial fibrillation) on clinical grounds

Exclusion Criteria:

Pre-procedure:

• Inability to given informed consent / lack of mental capacity

• Obesity (BMI >40)

• Congenital heart disease or tricuspid valve abnormalities likely to prolong procedure time, including Ebstein anomaly, atrial septal defects, tricuspid valve repair or replacement, severe tricuspid valve regurgitation

• Inability or unwillingness to receive oral anticoagulation with a vitamin K antagonist (VKA) or non-VKA oral anticoagulant (NOAC)

• Previous cavotricuspid isthmus ablation procedure

• Known infiltrative cardiomyopathy

• Pregnancy

• Age < 18 or >80

• Inability to speak adequate English/need for an interpreter for study consent process

Post procedure:

• arrhythmia mechanism found not to be cavotricuspid isthmus dependent atrial flutter

Related Conditions & MeSH terms

• Atrial Flutter
• Typical Atrial Flutter

Intervention

Device:
• Fluoroscopically guided ablation
Catheter ablation of the cavotricuspid isthmus using ablation catheters guided by fluoroscopy
• Contact force guided ablation
Catheter ablation of the cavotricuspid isthmus using ablation catheters guided by contact force measurement and 3D electroanatomic mapping
• Local impedance guide ablation
Catheter ablation of the cavotricuspid isthmus using ablation catheters guided by local impedance measurement and ultra-high density 3D electroanatomic mapping

Locations

Country	Name	City	State
n/a

Sponsors (2)

Lead Sponsor	Collaborator
University of Manchester	Manchester University NHS Foundation Trust

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time from first application of radiofrequency energy to confirmation of bidirectional cavotricuspid isthmus block	Time from first application of radiofrequency energy to confirmation of bidirectional cavotricuspid isthmus block	At time of procedure
Secondary	Mean total ablation time to achieve bidirectional cavotricuspid isthmus block	Mean total ablation time to achieve bidirectional cavotricuspid isthmus block	At time of procedure
Secondary	Mean total radiation exposure	Mean total radiation exposure	At time of procedure
Secondary	Mean total number of ablation lesions required to achieve bidirectional cavotricuspid isthmus block	Mean total number of ablation lesions required to achieve bidirectional cavotricuspid isthmus block	At time of procedure
Secondary	Number of cases where bidirectional cavotricuspid isthmus block was not achieved after the first pass of ablation	Number of cases where bidirectional cavotricuspid isthmus block was not achieved after the first pass of ablation	At time of procedure
Secondary	Mean time taken for second pass ablation (with or without the use of 3D mapping) to achieve bidirectional cavotricuspid isthmus block	Mean time taken for second pass ablation (with or without the use of 3D mapping) to achieve bidirectional cavotricuspid isthmus block	At time of procedure
Secondary	Locations of breakthrough across the initial ablation line	Locations of breakthrough across the initial ablation line	At time of procedure
Secondary	Frequency of procedural complications	Frequency of procedural complications	At time of and immediately following procedure
Secondary	Acute and medium-term success rates	Acute and medium-term success rates	12 months