Atrial Fibrillation (AF)TerFibNCT07390175
Ablation of Human Cardiac Fibrillation Based on Models of Hierarchical Organization of Tissue Excitation
A study testing Active group ablation in people with Atrial Fibrillation (AF) and Ablation Treatment, run by Hospital San Carlos, Madrid at 1 site in Spain.
Trial summary
The mechanisms that maintain persistent atrial fibrillation (AF) in humans remain unknown. In the research project PI18/01268 funded in the previous call for Strategic Action in Health, the group has demonstrated that the hierarchical organization of (i) rotational domains, (ii) frequency domains and (iii)… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Fibrillation (AF), Ablation Treatment, TerFib_Hyerarchy
- What is being tested?
- Active group ablation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 78 participants
- Where
- 1 siteSpain
- Study dates
- 20 Jan 2025to 31 Dec 2026
- Phase
- Interventional
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients over 18 years of age with persistent AF lasting more than 6 months at the time of the experimental protocol (uninterrupted persistent AF) and clinical indication for an AF ablation procedure.
- or
- -Patients over 18 years of age with recurrent VF/VT and poor control with conventional pharmacological measures.
Who cannot join
- Lack of patient consent to participate in the study.
- In patients with persistent AF, contraindication for the use of adenosine.
- AF/VF/VPT secondary to endocrine-metabolic disorders and/or severe systemic disease (thyrotoxicosis, sepsis, pulmonary thromboembolism, etc.).
- Contraindications for cardiac catheterization (e.g., intracardiac thrombus).
- Impossibility of remote monitoring using an implantable Holter monitor or implantable defibrillator.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Spain1 site, 1 recruiting
- Recruiting
Hospital Clínico San Carlos
Madrid, Madrid, 28040
David Calvo Cuervo, 917044491, dcalvo307@secardiologia.es
About this study
Official title: Ablación de la fibrilación Cardiaca Humana Basada en Modelos de organización jerárquica de la excitación Tisular.
The mechanisms that maintain persistent atrial fibrillation (AF) in humans remain unknown. In the research project PI18/01268 funded in the previous call for Strategic Action in Health, the group has demonstrated that the hierarchical organization of (i) rotational domains, (ii) frequency domains and (iii) physiological responses to pharmacological provocation with adenosine, allow the identification of domains of high-frequency reentrant activity (hereinafter "DFASI domains") maintainers of AF. As a result, the investigators have developed non-invasive technological models and quantitative indices for the efficient localization of these domains, whose therapeutic approach through ablation has allowed to improve the clinical results of the patients studied, safely without increase in complications (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Likewise, and in response to the objectives of the PI18/01268 project, the investigators have identified hierarchical organization patterns in human ventricular fibrillation (VF) that indicate the existence of universal fibrillatory mechanisms, opening the door to new therapeutic opportunities (Europace 2022;24[11]:1788-1799).
Read the detailed description
The present research project proposes to characterize the physiology of persistent human AF after therapeutic interaction (ablation) with the "DFASI domains", exploring its impact on the dynamics and maintenance of AF in patients. The investigators propose to reveal the physiological mechanisms by which this interaction improves the clinical outcomes of our patients (Objective 1), which will allow the development of more efficient ablation strategies (Objective 2). Likewise, preclinical models developed by our group in collaboration with the National Center for Cardiovascular Research support the translation of our technological developments to the field of human VF. Therefore, in the present research project the investigators propose to explore the physiological significance of "DFSI domains" in patients with recurrent VF and the eventual development of efficient ablative therapies (Objective 3). With the proposed objectives, the project addresses the challenges posed in the diagnosis and treatment of cardiovascular diseases within the National Health System, in the context of a prevalent pathology (cardiac fibrillation) with high morbidity and mortality.
- Being tested
- Active group ablation, Control group ablation
- Keywords
- Hierarchical organization of tissue excitation, Atrial Fibrillation (AF), Ablation, TerFib_Hyerarchy
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Active group ablationProcedure or surgery
In patients in the active group, changes in fibrillation dynamics induced by CPVI and ablation of DFASI domains will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which, after CPVI, each DFASI domain will be addressed sequentially. The following will be determined: a) changes in hierarchical organization levels, b) the formation of new DFASI domains; c) if AF ends after ablation, the termination mechanisms will be described. Once all ablation sets on the identified DFASI reentrant domains have been completed, noninvasive maps will be acquired under the effect of adenosine in order to compare fibrillatory dynamics under basal adenosine vs. post-ablation.
Control group ablationProcedure or surgery
Therefore, an experimental protocol will be carried out in which, once the CPVI has been completed, a new acquisition of non-invasive maps will be performed to characterize the basal fibrillation dynamics and those under adenosine.
| Study group | Role | What they receive |
|---|---|---|
| Control group (CPVI only) | Active comparator | Modifications in fibrillation dynamics induced by CPVI will be evaluated. Therefore, an experimental protocol will be carried out in which, once CPVI has been completed, a new acquisition of non-invasive maps will be performed to characterize basal fibrillation dynamics and those under adenosine Receives: Procedure: Control group ablation |
| Active group (CPVI plus extrapulmonary ablation of DFASI domains) | Experimental | Modifications in fibrillation dynamics induced by ablation distributed along the points of singularity of the maintaining reentries (or their inclusion in the CPVI if applicable) will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which each DFASI reentrant domain will be addressed sequentially. After each ablation set, a new evaluation of noninvasive hierarchical organization patterns will be performed by acquiring new non-invasive maps in AF Receives: Procedure: Active group ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mapping for the identification of stable reentrant domains with high activation frequency in persistent AF.
After performing cardiac CT, non-invasive mapping will be performed using ECGi non-invasive map system. The signals will be analyzed for real-time inverse solution calculations using proprietary spectral fingerprint identification algorithms (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). In particular, non-invasive mapping will provide the fibrillation signal from both atria for the implementation of the calculations necessary for the spectral fingerprint study. The instantaneous phase will be computed by two methods: (i) by Hilbert transformation of the signal; and (ii) by phase calculation on the discrete frequencies identified in the power spectrogram. On the other hand, invasive mapping will be used to process bipolar and unipolar cardiac signals in order to analyze hierarchically organized patterns.
Measured: During procedure
Effects of ablation of DFSAI > 0.8 domains on fibrillation dynamics and sustainability
- In patients in the active group, changes in fibrillation dynamics induced by CPVI and ablation of DFASI domains will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which, after CPVI, each DFASI domain will be addressed sequentially. The following will be determined: a) changes in hierarchical organization levels, b) the formation of new DFASI domains; c) if AF ends after ablation, the termination mechanisms will be described. Once all ablation sets on the identified DFASI reentrant domains have been completed, noninvasive maps will be acquired under the effect of adenosine in order to compare fibrillatory dynamics under basal adenosine vs. post-ablation.
- In patients in the control group, once CPVI is completed new noninvasive maps will be acquired to characterize basal and adenosine-induced fibrillatory dynamics.
Measured: During procedure
Effects of ablation of reentrat domains of human ventricular fibrillation on arrhythmia inducibility.
Adapt the model to patients with ventricular arrhythmias such as polymorphic ventricular tachycardia and/or VF. After performing a cardiac CT scan, non-invasive mapping will be performed using ECGi non-invasive map system. The signals will be analyzed for real-time inverse solution calculations using algorithms for identifying reentrant domains and their correlation with hierarchical organization patterns (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). To this end, VF will be induced by programmed stimulation on two occasions in order to identify the hierarchical organization of the stability of rotational activity in terms of frequency. Ablation will follow and inducibility tested as measurement of efficacy.
Measured: Procedure
Arrhythmia burden during Follow-up
A subcutaneous Holter monitor will be implanted one month prior to the ablation procedure to mesure arrhythmia burden (Atrial fibrillation; number of recurrences and hours per day). Patients will be monitored continuously after the ablation procedure using remote subcutaneous Holter monitoring platforms and in person at cardiology consultations at 3, 6, and 12 months, at a minimum.
Patients with VF ablation will be followed up after the ablation procedure on an ongoing basis using implantable defibrillator remote monitoring platforms and in person at cardiology consultations at least 3, 6, and 12 months after the procedure. The arrhythmia burden will be measure as a function of number of recurrences per follow-up time.
Measured: 3, 6 and 12 months follow-up visits
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2026
- Study start20 Jan 2025
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial Fibrillation (AF)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 78 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospital San Carlos, Madrid
- Sponsor type
- University, hospital or other
- Collaborators
- Instituto de Salud Carlos III
- Responsible party
- Principal investigator, Daivd Calvo Cuervo, Hospital San Carlos, Madrid
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07390175
- Sponsor's protocol ID
- TerFib_Hyerarchy
- Other IDs
- 80/18
- Acronym
- TerFib
- Status last verified
- Feb 2026
- First submitted
- 16 Jan 2026
- Last updated
- 20 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 20 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ablación de la fibrilación Cardiaca Humana Basada en Modelos de organización jerárquica de la excitación Tisular.
- ClinicalTrials.gov ID
- NCT07390175
- Acronym / sponsor ID
- TerFib / TerFib_Hyerarchy
- Keywords
- Hierarchical organization of tissue excitation, Atrial Fibrillation (AF), Ablation, TerFib_Hyerarchy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 78 participants (estimated)
- Lead sponsor
- Hospital San Carlos, MadridUniversity, hospital or other
- Collaborators
- Instituto de Salud Carlos III
- Study start
- 20 Jan 2025 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 5 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The mechanisms that maintain persistent atrial fibrillation (AF) in humans remain unknown. In the research project PI18/01268 funded in the previous call for Strategic Action in Health, the group has demonstrated that the hierarchical organization of (i) rotational domains, (ii) frequency domains and (iii) physiological responses to pharmacological provocation with adenosine, allow the identification of domains of high-frequency reentrant activity (hereinafter "DFASI domains") maintainers of AF. As a result, the investigators have developed non-invasive technological models and quantitative indices for the efficient localization of these domains, whose therapeutic approach through ablation has allowed to improve the clinical results of the patients studied, safely without increase in complications (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Likewise, and in response to the objectives of the PI18/01268 project, the investigators have identified hierarchical organization patterns in human ventricular fibrillation (VF) that indicate the existence of universal fibrillatory mechanisms, opening the door to new therapeutic opportunities (Europace 2022;24[11]:1788-1799).
Detailed description
The present research project proposes to characterize the physiology of persistent human AF after therapeutic interaction (ablation) with the "DFASI domains", exploring its impact on the dynamics and maintenance of AF in patients. The investigators propose to reveal the physiological mechanisms by which this interaction improves the clinical outcomes of our patients (Objective 1), which will allow the development of more efficient ablation strategies (Objective 2). Likewise, preclinical models developed by our group in collaboration with the National Center for Cardiovascular Research support the translation of our technological developments to the field of human VF. Therefore, in the present research project the investigators propose to explore the physiological significance of "DFSI domains" in patients with recurrent VF and the eventual development of efficient ablative therapies (Objective 3). With the proposed objectives, the project addresses the challenges posed in the diagnosis and treatment of cardiovascular diseases within the National Health System, in the context of a prevalent pathology (cardiac fibrillation) with high morbidity and mortality.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control group (CPVI only) | Active comparator | Procedure: Control group ablationModifications in fibrillation dynamics induced by CPVI will be evaluated. Therefore, an experimental protocol will be carried out in which, once CPVI has been completed, a new acquisition of non-invasive maps will be performed to characterize basal fibrillation dynamics and those under adenosine |
| Active group (CPVI plus extrapulmonary ablation of DFASI domains) | Experimental | Procedure: Active group ablationModifications in fibrillation dynamics induced by ablation distributed along the points of singularity of the maintaining reentries (or their inclusion in the CPVI if applicable) will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which each DFASI reentrant domain will be addressed sequentially. After each ablation set, a new evaluation of noninvasive hierarchical organization patterns will be performed by acquiring new non-invasive maps in AF |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients over 18 years of age with persistent AF lasting more than 6 months at the time of the experimental protocol (uninterrupted persistent AF) and clinical indication for an AF ablation procedure.
- or
- -Patients over 18 years of age with recurrent VF/VT and poor control with conventional pharmacological measures.
Key exclusion criteria (5 listed)
- Lack of patient consent to participate in the study.
- In patients with persistent AF, contraindication for the use of adenosine.
- AF/VF/VPT secondary to endocrine-metabolic disorders and/or severe systemic disease (thyrotoxicosis, sepsis, pulmonary thromboembolism, etc.).
- Contraindications for cardiac catheterization (e.g., intracardiac thrombus).
- Impossibility of remote monitoring using an implantable Holter monitor or implantable defibrillator.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Active group ablationIn patients in the active group, changes in fibrillation dynamics induced by CPVI and ablation of DFASI domains will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which, after CPVI, each DFASI domain will be addressed sequentially. The following will be determined: a) changes in hierarchical organization levels, b) the formation of new DFASI domains; c) if AF ends after ablation, the termination mechanisms will be described. Once all ablation sets on the identified DFASI reentrant domains have been completed, noninvasive maps will be acquired under the effect of adenosine in order to compare fibrillatory dynamics under basal adenosine vs. post-ablation. | Procedure or surgery | Active group (CPVI plus extrapulmonary ablation of DFASI domains) |
| Control group ablationTherefore, an experimental protocol will be carried out in which, once the CPVI has been completed, a new acquisition of non-invasive maps will be performed to characterize the basal fibrillation dynamics and those under adenosine. | Procedure or surgery | Control group (CPVI only) |
Primary outcome
Mapping for the identification of stable reentrant domains with high activation frequency in persistent AF.
Time frame: During procedure
After performing cardiac CT, non-invasive mapping will be performed using ECGi non-invasive map system. The signals will be analyzed for real-time inverse solution calculations using proprietary spectral fingerprint identification algorithms (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). In particular, non-invasive mapping will provide the fibrillation signal from both atria for the implementation of the calculations necessary for the spectral fingerprint study. The instantaneous phase will be computed by two methods: (i) by Hilbert transformation of the signal; and (ii) by phase calculation on the discrete frequencies identified in the power spectrogram. On the other hand, invasive mapping will be used to process bipolar and unipolar cardiac signals in order to analyze hierarchically organized patterns.
Effects of ablation of DFSAI > 0.8 domains on fibrillation dynamics and sustainability
Time frame: During procedure
* In patients in the active group, changes in fibrillation dynamics induced by CPVI and ablation of DFASI domains will be evaluated, as suggested by our preliminary results (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). Therefore, an experimental protocol will be carried out in which, after CPVI, each DFASI domain will be addressed sequentially. The following will be determined: a) changes in hierarchical organization levels, b) the formation of new DFASI domains; c) if AF ends after ablation, the termination mechanisms will be described. Once all ablation sets on the identified DFASI reentrant domains have been completed, noninvasive maps will be acquired under the effect of adenosine in order to compare fibrillatory dynamics under basal adenosine vs. post-ablation. * In patients in the control group, once CPVI is completed new noninvasive maps will be acquired to characterize basal and adenosine-induced fibrillatory dynamics.
Effects of ablation of reentrat domains of human ventricular fibrillation on arrhythmia inducibility.
Time frame: Procedure
Adapt the model to patients with ventricular arrhythmias such as polymorphic ventricular tachycardia and/or VF. After performing a cardiac CT scan, non-invasive mapping will be performed using ECGi non-invasive map system. The signals will be analyzed for real-time inverse solution calculations using algorithms for identifying reentrant domains and their correlation with hierarchical organization patterns (Calvo D et al. Sci Rep. 2025 Dec 16;15(1):43892). To this end, VF will be induced by programmed stimulation on two occasions in order to identify the hierarchical organization of the stability of rotational activity in terms of frequency. Ablation will follow and inducibility tested as measurement of efficacy.
Arrhythmia burden during Follow-up
Time frame: 3, 6 and 12 months follow-up visits
A subcutaneous Holter monitor will be implanted one month prior to the ablation procedure to mesure arrhythmia burden (Atrial fibrillation; number of recurrences and hours per day). Patients will be monitored continuously after the ablation procedure using remote subcutaneous Holter monitoring platforms and in person at cardiology consultations at 3, 6, and 12 months, at a minimum. Patients with VF ablation will be followed up after the ablation procedure on an ongoing basis using implantable defibrillator remote monitoring platforms and in person at cardiology consultations at least 3, 6, and 12 months after the procedure. The arrhythmia burden will be measure as a function of number of recurrences per follow-up time.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Feb 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Active group ablation in people with Atrial Fibrillation (AF) and Ablation Treatment, run by Hospital San Carlos, Madrid at 1 site in Spain.
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 3 inclusion and 5 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 20 Feb 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 Spain. 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?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mapping for the identification of stable reentrant domains with high activation frequency in persistent AF. (time frame: During procedure). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 20 Feb 2026.