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Atrial Fibrillation (AF)VARIACENCT07363278

A Prospective Observational Study Evaluating the Incidence of Silent Cerebral Lesions and Procedural Safety Following Atrial Fibrillation Ablation Using the VARIPULSE™ Pulsed Field Ablation System

An observational study of Atrial Fibrillation (AF), run by Seoul National University Hospital at 1 site in South Korea.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Study Type: Observational Study Goal: The goal of this study is to evaluate the incidence and burden of silent cerebral lesions (SCLs) detected on brain magnetic resonance imaging (MRI) after pulsed field ablation (PFA) for atrial fibrillation (AF). Read more about this study

Who is it for?
Ages 19 years and older
Conditions the study is for
Atrial Fibrillation (AF)
How many people
40 participants
Where
1 siteSouth Korea
Study dates
26 Dec 2025to 31 Dec 2027
How long will I take part?
3 Months
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 19 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: This study is designed as a registry to evaluate safety without a control group. The target sample size was determined with reference to previous studies that assessed the incidence of silent cerebral lesions (SCLs) using post-procedural MRI, in which approximately 30 to 40 patients were typically included.

Who may be able to join

  • 1) Patients undergoing atrial fibrillation ablation using the Varipulse™ catheter

Who cannot join

  • Individuals under 19 years of age
  • Patients who undergo concomitant radiofrequency ablation of the left atrium during the procedure
  • Patients with a history of stroke or transient ischemic attack (TIA)
  • Patients who have previously undergone ablation or surgery for atrial fibrillation
  • Patients with intracardiac thrombus or embolic events within the past 90 days
  • Patients who have experienced cardiac surgery or acute coronary syndrome within the past 90 days
Show all 11Show fewer
  • Patients with contraindications to oral anticoagulant therapy, or those who require temporary discontinuation of anticoagulation due to procedural complications (e.g., cardiac tamponade)
  • Patients with a left ventricular ejection fraction (LVEF) of less than 35%
  • Women who are currently pregnant or planning to become pregnant during the study period
  • Patients with a life expectancy of less than one year
  • Patients at increased risk during MRI scanning (e.g., those with pacemakers or other metallic implants affected by MRI, or those with severe claustrophobia)

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Eue-Keun Choi, MD, PhD contact

82-2-2072-0688

choiek417@gmail.com

South Korea1 site, 1 recruiting

  • Seoul National Universtiy Hospital, Seoul

    Seoul, Jongro-ku, 03080

    Eue-Keun Choi, MD, PhD, 82-2-2072-0688, choiek417@gmail.com

    Recruiting

Other trials in South Korea

About this study

Study Type: Observational Study

Goal:

The goal of this study is to evaluate the incidence and burden of silent cerebral lesions (SCLs) detected on brain magnetic resonance imaging (MRI) after pulsed field ablation (PFA) for atrial fibrillation (AF). PFA is a new non-thermal ablation technique that selectively targets cardiac tissue while minimizing damage to surrounding structures. The study focuses on adult patients with paroxysmal or persistent AF who undergo left-atrial ablation using the VARIPULSE PFA system.

Read the detailed description

Main Questions the Study Aims to Answer:

What percentage of patients develop silent cerebral lesions after PFA using the VARIPULSE system?

What are the lesion characteristics (number, size, and location) and total lesion burden on MRI?

Are there any early neurological or cognitive changes related to these MRI findings?

Comparison:

This is an observational, single-arm study with no active control group. However, the findings will be compared with historical data from previous studies of thermal ablation (radiofrequency and cryoballoon) to explore potential differences in neurological safety.

Participant Activities:

Participants in this study will:

Undergo brain MRI (DWI and FLAIR sequences) within 1-3 days after PFA to detect any silent cerebral lesions.

Complete neurological and cognitive assessments (for example, tests of memory, language, and attention) to identify subtle functional changes.

Receive routine clinical follow-up for AF management according to institutional standard of care.

Background:

Silent cerebral lesions are small ischemic brain injuries seen on MRI that cause no immediate symptoms but have been linked to later cognitive decline and increased risk of clinical stroke. They are known to occur in 10-40 % of patients after conventional AF ablation using radiofrequency or cryoballoon energy. Because PFA employs electrical pulses rather than heat, its effects on cerebral safety may differ. The VARIPULSE system integrates a variable-loop, multipolar PFA catheter with a three-dimensional electro-anatomical mapping system to improve procedural precision and reduce risk.

Significance:

As PFA use expands in clinical practice, understanding its neurological safety is crucial. This study will provide quantitative MRI data and standardized neurological evaluations to define the cerebral safety profile of PFA. The results are expected to inform procedural optimization and help establish evidence-based strategies for safer AF ablation.

Keywords
atrial fibrillation, catheter ablation, silent cerebral lesions, pulsed field ablation
Medical subject headings
Atrial Fibrillation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of silent cerebral lesions (SCLs)

    The proportion of patients in whom silent cerebral lesions (SCLs) are detected on brain MRI performed within 72 hours after atrial fibrillation ablation using the VARIPULSE PFA catheter.

    Definition of SCL:

    A lesion that shows positive findings on both diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) sequences.

    Measured: From enrollment to the end of treatment at 3 months

Secondary outcomes (5)

  1. Number and total volume (mm³) of silent cerebral lesions (SCLs) in patients with positive SCL findings after the procedure.

    Number and total volume (mm³) of silent cerebral lesions (SCLs) in patients with positive SCL findings after the procedure.

    Measured: From enrollment to the end of treatment at 3 months

  2. Neurological complications

    Incidence of newly developed neurological symptoms or signs (e.g., motor weakness, speech impairment, cognitive changes) after the procedure.

    Measured: From enrollment to the end of treatment at 3 months

  3. Cognitive function

    Change in Montreal Cognitive Assessment (MoCA) score from baseline (pre-procedure) to 3 months after the procedure.

    Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA; range: 0-30; higher scores indicate better cognitive performance). A score of 26 or higher is generally considered to represent normal cognitive function.

    Measured: From enrollment to the end of treatment at 3 months

  4. Quality of Life (QoL)

    Patient-reported quality of life was assessed using the Atrial Fibrillation Effect on QualiTy of Life (AFEQT) questionnaire. The AFEQT overall summary score ranges from 0 to 100, where a score of 0 represents the most severe symptoms and functional limitation, and a score of 100 indicates the best possible quality of life (higher scores indicate better clinical outcomes).

    Measured: From enrollment to the end of treatment at 3 months

  5. General health status

    General health status was measured using the EuroQol 5-Dimension (EQ-5D) index. The index scores typically range from less than 0 (representing a state 'worse than death') to 1 (representing 'full health'), where higher scores indicate a better overall health state.

    Measured: From enrollment to the end of treatment at 3 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Jan 2026
  2. Study start26 Dec 2025
  3. Primary completion31 Dec 2027 (estimated)
  4. Study completion31 Dec 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case only
Time perspective
Prospective
Enrolment
40 participants (estimated)
Target duration
3 Months
IDs, dates and publications
ClinicalTrials.gov ID
NCT07363278
Sponsor's protocol ID
VARIACE study
Acronym
VARIACE
Status last verified
Oct 2025
First submitted
29 Dec 2025
Last updated
23 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

An observational study of Atrial Fibrillation (AF), run by Seoul National University Hospital at 1 site in South Korea.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 23 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Eue-Keun Choi, MD, PhD (82-2-2072-0688, choiek417@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of silent cerebral lesions (SCLs) (time frame: From enrollment to the end of treatment at 3 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07363278.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jan 2026.

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