Inhaled Hydrogen Therapy's Effect on Early Recurrences of Atrial Fibrillation Post-ablation. (H2-FA)

November 3, 2026 updated by: University Hospital, Grenoble

Inhaled Hydrogen Therapy's Effect on Early Recurrences of Atrial Fibrillation Post-ablation. Phase II, Multicenter, Randomized, Controlled, Open-label Clinical Trial

The goal of this clinical trial is to testing the perioperative inhaled hydrogen (H2) administration's effects during atrial fibrillation ablations (AF) to reduce both early and late recurrences associated with this procedure.

Researchers will compare H2 inhalation to the standard of care to see if we observe a reduction in AF recurrence after ablation but also a reduction in rehospitalizations or emergency visits for cardioversion, and consequently an improvement in quality of life.

Participants will:

  • have an AF ablation associated to an hydrogen therapy or standard of care
  • complete quality of life questionnaires
  • record ECG on KardiaMobile©
  • Keep a diary of their symptoms
  • have a blood test
  • have 2 follow-up visits (after 3 and 12 months) and 2 phone calls (after 6 and 9 months)

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
124

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

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

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • France
    • Isère
      • Grenoble, Isère, France, 38000
        • Chu Grenoble Alpes
        • Principal Investigator:
          • Pascal DEFAYE, Pr
        • Contact:
        • Contact:
        • Sub-Investigator:
          • Sandrine VENIER, Dr
        • Sub-Investigator:
          • Peggy JACON, Dr
        • Sub-Investigator:
          • Adrien CARABELLI, Dr
    • Rhone
      • Bron, Rhone, France, 69500
        • Hopital Louis Pradel
        • Contact:
        • Contact:
        • Principal Investigator:
          • Philippe CHEVALIER, Pr
        • Sub-Investigator:
          • Kevin GARDEY, Dr

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Be over 18 years old
  2. Present with paroxysmal or persistent Atrial Fibrilation (AF) of less than 6 months with symptoms
  3. Be a candidate for a first-time AF ablation (cryoablation and electroporation)
  4. Understand and agree to comply with the study procedures
  5. Patient must have a smartphone
  6. Be enrolled in a social security scheme, or have equivalent rights
  7. Have signed the study consent form

Exclusion Criteria:

  1. Being over 80 years old
  2. Having a left atrial diameter ≥ 50mm on transthoracic echocardiography
  3. Radiofrequency ablation
  4. Having a history of AF ablation
  5. Patient on long-term anti-inflammatory treatment
  6. Patient with gas administration equipment (CPAP, NIV…)
  7. Woman of childbearing potential*
  8. Non-cooperative patient
  9. In the exclusion period for another study
  10. Persons covered by Articles L1121-5 to L1121-8 of the Public Health Code and Articles 31 to 35 of Regulation 536/2014 (corresponding to all protected persons: pregnant women, women in labor, breastfeeding mothers, persons deprived of liberty by judicial or administrative decision, persons receiving psychiatric care under Articles L. 3212-1 and L. 3213-1 who are not covered by the provisions of Article L. 1121-8, persons admitted to a healthcare or social facility for purposes other than research, minors, persons subject to legal protection measures or unable to give their consent).
  11. Staff with a hierarchical relationship with the principal investigator

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Standard of care

patients treated with usual care (Standard of Care)
Experimental: H2

patient treated with inhaled hydrogen therapy during the perioperative period
Drug: Hydrogen Gas (H2)

Patients treated with inhaled hydrogen therapy in the perioperative period (initiation of inhaled hydrogen therapy from hospital admission until discharge, except in the operating room) (dosage : H2/N2 3.6%/96.4%, 1 L/min 24 hours a day)

Other Names:
  • inhaled hydrogen therapy

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Effectiveness of inhaled hydrogen therapy on early recurrences of atrial fibrillation post-ablation and on the improvement of quality of life at 3 months
Time Frame: From baseline (before ablation) to 3 months after ablation

Composite binary endpoint, reported as the number of participants meeting both criteria: (1) no early recurrence during the blanking period (first 3 months after ablation), where recurrence is defined as any episode of atrial fibrillation, atrial flutter or atrial tachycardia lasting at least 30 seconds; AND (2) improvement in quality of life, defined as an improvement in quality of life, defined as an increase of at least 5 points in the AFEQT overall score (range 0-100; higher scores indicate better quality of life) between baseline and 3 months.
From baseline (before ablation) to 3 months after ablation

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of hospitalizations or electrical cardioversions or pharmacological cardioversions during the blanking period (3 months)
Time Frame: From ablation to 3 months after ablation

Total number of hospitalizations or electrical cardioversions or pharmacological cardioversions occurring during the blanking period, i.e. the first 3 months after ablation. The three event types are summed into a single count per participant.
From ablation to 3 months after ablation
Incidence of Late Atrial Fibrillation, Atrial Flutter or Atrial Tachycardia Recurrence Between 3 and 12 Months After Ablation
Time Frame: From 3 months to 12 months after ablation

Number of participants with late recurrence, defined as any episode of atrial fibrillation, atrial flutter or atrial tachycardia lasting at least 30 seconds on Holter or Kardia recording, or recorded on a 12-lead electrocardiogram, occurring more than 3 months and up to 12 months after ablation.
From 3 months to 12 months after ablation
Change in White Blood Cell Count (WBC) from before ablation to 24 and 48 hours after ablation
Time Frame: 24 hours before ablation, 24 hours after ablation, and 48 hours after ablation

Change in blood white blood cell (WBC) count, measured in 10^9 cells/L, between 24 hours before ablation and 24 hours and 48 hours after ablation.
24 hours before ablation, 24 hours after ablation, and 48 hours after ablation
Change in High-Sensitivity C-Reactive Protein (CRP) from before ablation to 24 and 48 hours after Ablation
Time Frame: 24 hours before ablation, 24 hours after ablation, and 48 hours after ablation

Change in blood high-sensitivity C-reactive protein (hs-CRP) concentration, measured in mg/L, between 24 hours before ablation and 24 hours and 48 hours after ablation.
24 hours before ablation, 24 hours after ablation, and 48 hours after ablation
Change in Interleukin-6 from before ablation to 24 and 48 hours after Ablation
Time Frame: 24 hours before ablation, 24 hours after ablation, and 48 hours after ablation

Change in blood interleukin-6 (IL-6) concentration, measured in pg/mL, between 24 hours before ablation and 24 hours and 48 hours after ablation.
24 hours before ablation, 24 hours after ablation, and 48 hours after ablation
Incidence of Adverse Events Graded by NCI-CTCAE Version 5.0 (Safety and Tolerability)
Time Frame: From the start of inhaled hydrogen therapy to 12 months after ablation

Number of participants with adverse events, described and graded using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 5.0. Grades range from 1 (mild) to 5 (death related to adverse event); higher grades indicate more severe events.
From the start of inhaled hydrogen therapy to 12 months after ablation
Evaluate the acceptability of hydrogen therapy treatment by healthcare providers
Time Frame: Day 2 after ablation

Custom hetero-questionnaire on the acceptability of hydrogen therapy treatment by healthcare providers
Day 2 after ablation

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Grenoble

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University Grenoble Alps

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Pascal DEFAYE, Pr, CHU Grenoble Alpes

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2027

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 2, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 3, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 10, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 3, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 38RC22.0404
  • 2024-520131-33-00 (Ctis)

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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