Hidden Slow Conduction Ablation for Recurrent Atrial Fibrillation: Unmasking the Arrhythmogenic Substrate (Unmask-AF)

December 8, 2024 updated by: Antonio Berruezo, MD, PhD, Centro Medico Teknon

Hidden Slow Conduction Ablation for Recurrent Atrial Fibrillation: Unmasking the Arrhythmogenic Substrate

Over recent years, pulmonary vein isolation (PVI) procedures have demonstrated progressively enhanced efficacy and safety, resulting in a substantial increase in the number of atrial fibrillation ablations, not only as a first-line treatment but also for repeat procedures. However, there is still a notable lack of randomized evidence in this area, which limits guidance and decision-making in clinical practice. Recently, the investigators found that employing short-coupled atrial extrastimuli revealed highly fragmented or double atrial evoked electrograms (EGMs) in AF patients, termed as hidden slow conduction (HSC). Identifying HSC sites may provide insight into the early identification of the arrhythmogenic substrate, offering a potential target for ablation This multi-center, prospective, randomized, controlled trial will include two arms: one investigational (PV reconnection + HSC) and one control (PV reconnection). All the subjects will be followed for 12 months after the ablation procedure.

The aim of our study is to investigate the impact of ablating HSC sites on arrhythmia recurrence in repeat ablation procedures. The hypothesis is that the additional ablation of HSC zones may improve the freedom from atrial arrhythmia recurrence after repeat ablation procedure.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

212

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Recurrent paroxysmal AF (continuous AF episode lasting longer than 30 s but terminating spontaneously or with intervention within 7 days of onset), recurrent persistent AF (continuous AF episode lasting longer than 7 days but < 1 year) and recurrent long standing persistent AF (continuous AF ≥1 year in duration, in patients where rhythm control management is being pursued)
  • Previous PVI procedure
  • Age > 40 years
  • Willing and capable of providing consent
  • Able and willing to comply with all follow-up testing and requirements

Exclusion Criteria:

  • Additional left atrial ablations during the previous procedures (es. posterior wall isolation, anterior line, roof line, CFAE and others)
  • Acute illness, active systemic infection, or sepsis
  • Presence of intracardiac thrombus, myxoma, tumor, interatrial baffle or patch or other abnormality that precludes catheter introduction or manipulation.
  • Severe mitral regurgitation
  • Women who are pregnant, lactating, or who are planning to become pregnant during the course of the clinical investigation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PV reconnection + HSC ablation
Patients undergoning pulmunary veins (PV) reconnection checking and ablation plus identification and ablation of hidden sites of slow conduction (HSC)
Procedure: Pulmunary veins reconnection plus hidden slow conduction ablation

Ablation of pulmonary veins reconnections plus the search and ablation of hidden slow conductions sites (HSC) in the left atrium.

HSC sites are defined as EGMs showing highly fragmented or double electrograms in response atrial triple extrastimulus, presenting normal or fractionated electrogram in the sinus rhythm.

After checking for PV's conduction breakthroughs, point-by point ablation targeting HSC-EGMs will be performed.

The end point for HSC+ ablation will be reached with loss of local capture at a given lesion, pacing from the ablation catheter at high output (10V·2ms).
Active Comparator: PV reconnection ablation only
Patients undergoning PV reconnection checking and ablation only.
Procedure: Pulmunary veins (PV) reconnection ablation only
Each vein will be re-assessed by observing PV potentials along the PV ostia and by pacing from the distal bipole of the ablation catheter (10mA at 2ms) within the lesion set with failed capture of the left atrium. In case of PVs reconnection touch-up applications will be performed at the earliest potential site, identified by comparing far-field atrial EGM to near-field local EGM timing, until isolation will be achieved (entrance and exit block).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Atrial arrhythmias recurrence
Time Frame: up to 12 moths
The primary endpoint of the study aims to establish the impact of targeting HSC sites alongside PV gaps in repeat ablation procedures for patients with recurrent AF. Specifically evaluating the freedom from atrial tachyarrhythmia recurrence (documented AF/AT/AFL lasting at least 30s).
up to 12 moths

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Burden of atrial arrhythmias
Time Frame: up to 12 moths
Arrhythmic burden (average percentage of time in AF/AT in 24h Holter)
up to 12 moths
incidence of periprocedural complications (pericardial effusion)
Time Frame: up to 12 months
incidence of periprocedural complications such as pericardial effusion
up to 12 months
Use of antiarrhythmic drugs
Time Frame: up to 12 months
Use of antiarrhythmic drugs after the blanking period of 60 days.
up to 12 months
incidence of periprocedural complications (peripheral complication)
Time Frame: up to 12 moths
incidence of periprocedural complications such as peripheral complication
up to 12 moths
incidence of periprocedural complications (transient ischemic attack or stroke)
Time Frame: up to 12 months
incidence of periprocedural complications such as transient ischemic attack or stroke
up to 12 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Procedure features
Time Frame: up to 12 months
procedure time
up to 12 months
procedure features
Time Frame: up to 12 months
fluoroscopy time
up to 12 months
procedure features
Time Frame: up to 12 months
fluoroscopy dose
up to 12 months
procedure features
Time Frame: up to 12 months
number of radiofrequency (RF) applications
up to 12 months
procedure times
Time Frame: up to 12 months
radiofrequency (RF) total delivery time
up to 12 months
Concentration of intramyocardial fat (inFAT) into the HSC points
Time Frame: up to 12 months
Concentration of intramyocardial fat (inFAT) into the atrial area where we found the HSC points
up to 12 months
Atrial arrhythmias first recurrence
Time Frame: up to 12 months
Evaluation of the atrial arrhythmias recurrence in patients with isolated PVs underwent HSC sites ablation
up to 12 months
Left atrial wall thickness (LAWT) measurement into the HSC points
Time Frame: up to 12 months
Left atrial wall thickness (LAWT) measurement into the atrial areas where we found the HSC points
up to 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centro Medico Teknon

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2024

Primary Completion (Estimated)

September 1, 2026

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

August 22, 2024

First Submitted That Met QC Criteria

October 22, 2024

First Posted (Actual)

October 24, 2024

Study Record Updates

Last Update Posted (Estimated)

December 12, 2024

Last Update Submitted That Met QC Criteria

December 8, 2024

Last Verified

December 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Unmask-AF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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