Microfidelity (MIFI) Ablation Technology Versus Standard Ablation Catheter for Atrioventricular Nodal Ablation

Microfidelity (MIFI) Ablation Technology Versus Standard Ablation Catheter for Atrioventricular Nodal Ablation A Comparative Pilot Study of Time to Success

The aim of our study is to investigate the comparative efficacy of high fidelity multi electrode ablation catheters vs the standard bipolar configuration in success of AV nodal ablation This study will provide insights on the use of new technology where application may increase efficacy, promote patient and physician safety and decrease costs.

Study Overview

• Status: Completed
• Conditions: Atrial Fibrillation
• Intervention / Treatment: Device: Standard Ablation Catheter; Device: MIFI Catheter

Detailed Description

Introduction In some elderly patients with atrial fibrillation (AF), especially in combination with heart failure, a rate control strategy may be preferred. When pharmacological therapy is ineffective or not tolerated, it is reasonable to perform atrioventricular (AV) node ablation with ventricular pacing as a class IIA indication per current guidelines.

Usually, the procedure is simple and straightforward and complete heart block can be achieved without any difficulty. However, this "simple" procedure can sometimes prove to be a most difficult case. The most common reason for failure to achieve complete heart block is the inability to localize the compact AV node using the His signal with standard intracardiac electrograms. As these patients come to the laboratory in AF, the His signal may be obscured by AF waves. In some patients with a deeper intramyocardial location of the His bundle and compact AV node it becomes necessary to produce deeper ablation lesions using an irrigated catheter to achieve block.

In patients with AF, the target of ablation for the "ablate and pace" approach is the compact AV node, located at the apex of the triangle of Koch. Ideally, ablation is performed at the most proximal penetrating part of the His bundle in order to maintain a proximal automatic junctional rhythm and avoid pacemaker dependence.

Para Hisian pacing is most commonly used to reveal the presence of a septal accessory pathway.

The His bundle is a deep insulated structure and it is difficult to capture it at usual energy outputs. Using a high- output pacing (usually 20 mA at 2 msec) it is possible to directly capture the deeply situated His bundle, which is confirmed by a narrower QRS complex on the paced electrograms. Thus, high-output pacing can be utilized to map the His bundle area in difficult situations.

By applying this electrophysiologic principle of differential tissue capture to help identify the location of the compact AV node, which is in close proximity to the His bundle. Ventricular pacing was performed initially at high output to capture both the basal right ventricular myocardium and the His bundle and the output was gradually lowered to lose His bundle capture. The QRS duration is relatively narrow with high output pacing and increases when the pacing output is lowered, representing ventricular myocardial capture alone. Finally, loss of ventricular capture is seen with further reduction of pacing output. This maneuver has been shown to aid in determining the proximity of the ablation catheter to compact AV node as was validated by successful ablation at this site. Parahisian pacing in conjunction with av nodal ablation has recently been described in the literature.

A novel catheter with three mini electrodes within the ablation tip (IntellaTip MiFi, Boston Scientific, Boston, MA) may enhance the available data for such a signal dependent technique. In this catheter, bipolar signals can be recorded between the three 0.8-mm-wide electrodes that are arranged radially 1.3 mm from the end of the catheter alongside the standard distal and proximal bipolar recordings. Animal studies have already demonstrated that the mini electrodes in this novel catheter are more accurate in identifying conducting gaps in linear ablations than conventional electrode recordings.

Study Aims:

The aim of our study is to investigate the comparative efficacy of high fidelity multi electrode ablation catheters vs the standard bipolar configuration in success of AV nodal ablation This study will provide insights on the use of new technology where application may increase efficacy, promote patient and physician safety and decrease costs.

Primary and secondary objectives Primary endpoints

1. Acute success of ablation identified by a junctional rhythm or complete heart block
2. Time from application of radiofrequency energy to acute success

Secondary endpoints include

1. Procedure time
2. Radiation time
3. Frequency of ablation application
4. Duration of ablation application

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Jacksonville, Florida, United States, 32209
      • University of Florida

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 95 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Patients with a diagnosis of persistent or permanent atrial fibrillation documented on electrocardiography
2. Patients must meet American College of Cardiology and Heart Rhythm Society "ACC/HRS" guidelines for atrioventricular nodal ablation procedure
3. Patients must be available for at least 1 month post procedure
4. Patients must be greater than or equal to 18 years old.

Exclusion Criteria:

1. Patients who do not meet ACC/HRS indications for av nodal ablation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Bipolar Ablation Catheter; Subjects will be randomized by random computer programming to receive standard ablation catheter for their procedure.	Device: Standard Ablation Catheter; Standard of care for patients with certain cardiac arrhythmias.
Experimental: MIFI Ablation Catheter; Subjects will be randomized by random computer programming to receive an ablation with MIFI technology. MIFI Catheter contains tightly spaced multielectrode pattern	Device: MIFI Catheter; Multielectrode Catheter: standard ablation catheter that has the ability to record low and high frequency signals with high fidelity

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Time Differences Between the 2 Arms for Acute Success of Ablation Identified by a Junctional Rhythm or Complete Heart Block	Identified by a junctional rhythm or complete heart block. Time zero is when the ablation procedure begins and the successful outcomes are either complete heart block or junctional rhythm.	60 seconds

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time From Application of Radio-frequency Energy to Acute Success	The target will be where the HIS electrogram amplitude is greatest and where the QRS complex from pacing is narrowest.	up to 3000 seconds

Collaborators and Investigators

• Sponsor: University of Florida
• Investigators: Principal Investigator: John N Catanzaro, MD, University of Florida

Study record dates

Study Major Dates

• Study Start (Actual): May 23, 2017
• Primary Completion (Actual): September 26, 2019
• Study Completion (Actual): November 9, 2019

Study Registration Dates

• First Submitted: March 21, 2017
• First Submitted That Met QC Criteria: April 10, 2017
• First Posted (Actual): April 14, 2017

Study Record Updates

• Last Update Posted (Actual): September 22, 2021
• Last Update Submitted That Met QC Criteria: August 31, 2021
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Keywords: ablation; atrioventricular node; microfidelity
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Atrial Fibrillation
• Other Study ID Numbers: ir-iis02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No