An interventional study of Active group ablation and Control group ablation in Atrial Fibrillation (AF), Ablation Treatment and TerFib_Hyerarchy, sponsored by Hospital San Carlos, Madrid. Recruiting at 1 site in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-20.
Sponsored by Hospital San Carlos, Madrid · Not applicable, Interventional, and Treatment
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).
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.
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 78 is below the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Hospital San Carlos, Madrid is the lead sponsor of 74 studies on the registry; 17 are open to participants now.
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-Patients over 18 years of age with recurrent VF/VT and poor control with conventional pharmacological measures.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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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
Procedure: Control group ablation
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
Procedure: Active group ablation
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.
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.
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 3, 6 and 12 months follow-up visits
Plan to share: Undecided
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Started Jan 2025 (actual). Primary completion is estimated for Dec 2026, 23 months after the start.
Of 796 non-industry interventional studies with no phase under Atrial Fibrillation, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 59. This study's planned 23 months is below that.
Counting every sponsor, half of 1,051 studies reached it within 33 months; a quarter within 18 and three quarters within 54.
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Hospital San Carlos, Madrid