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

NCT ID: NCT06657170

Last Updated: 2024-12-12

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 212 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-12-31
• Study Completion Date: 2027-09-30

Brief Summary

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.

Conditions

Atrial Fibrillation

Keywords

Catheter Ablation; Re-do Procedures; Hidden Slow Conduction; Functional Substrate Ablation

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

PV reconnection + HSC ablation

Patients undergoning pulmunary veins (PV) reconnection checking and ablation plus identification and ablation of hidden sites of slow conduction (HSC)

Group Type: EXPERIMENTAL

Pulmunary veins reconnection plus hidden slow conduction ablation

Intervention Type: PROCEDURE

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).

PV reconnection ablation only

Patients undergoning PV reconnection checking and ablation only.

Group Type: ACTIVE_COMPARATOR

Pulmunary veins (PV) reconnection ablation only

Intervention Type: PROCEDURE

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).

Interventions

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).

Intervention Type: 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).

Intervention Type: PROCEDURE

Eligibility Criteria

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

• Minimum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Centro Medico Teknon

OTHER

Sponsor Role: lead

Responsible Party

Antonio Berruezo, MD, PhD

Director of Electrophysiology unit

Responsibility Role: PRINCIPAL_INVESTIGATOR

Central Contacts

Antonio Berruezo Sanchez, MD, PHD

Role: CONTACT

Phone: 3384090290

Email: antonio.berruezo@quironsalud.es

References

Pokushalov E, Romanov A, De Melis M, Artyomenko S, Baranova V, Losik D, Bairamova S, Karaskov A, Mittal S, Steinberg JS. Progression of atrial fibrillation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation: a randomized comparison of drug therapy versus reablation. Circ Arrhythm Electrophysiol. 2013 Aug;6(4):754-60. doi: 10.1161/CIRCEP.113.000495. Epub 2013 Jun 7.

Reference Type: RESULT

PMID: 23748210 (View on PubMed)

Saglietto A, Falasconi G, Soto-Iglesias D, Francia P, Penela D, Alderete J, Viveros D, Bellido AF, Franco-Ocana P, Zaraket F, Turturiello D, Marti-Almor J, Berruezo A. Assessing left atrial intramyocardial fat infiltration from computerized tomography angiography in patients with atrial fibrillation. Europace. 2023 Dec 6;25(12):euad351. doi: 10.1093/europace/euad351.

Reference Type: RESULT

PMID: 38011712 (View on PubMed)

Silva Garcia E, Lobo-Torres I, Fernandez-Armenta J, Penela D, Fernandez-Garcia M, Gomez-Lopez A, Soto-Iglesias D, Fernandez-Rivero R, Vazquez-Garcia R, Acosta J, Bisbal F, Cano-Calabria L, Berruezo A. Functional mapping to reveal slow conduction and substrate progression in atrial fibrillation. Europace. 2023 Nov 2;25(11):euad246. doi: 10.1093/europace/euad246.

Reference Type: RESULT

PMID: 37961921 (View on PubMed)

Other Identifiers

Unmask-AF

Identifier Type: -

Identifier Source: org_study_id