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Not yet recruitingNCT07889440COSMICUpdated Oct 22, 2026

Conduction Breakthrough in the Coronary Sinus Post Endocardial Mitral Isthmus Ablation

An observational study in Atrial Fibrillation (AF), Atrial Tachycardia and Paroxysmal AF, sponsored by Sebastien Knecht. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-22.

Sponsored by Sebastien Knecht · Observational

Updated Oct 22, 2026Newly registeredGo to Updates ↓
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
50
Ages
18 Years and older
Sex
All
01

Study summary

The goal of this observational study is to learn more about how doctors can create a complete electrical block in the heart during catheter ablation procedures used to treat certain abnormal heart rhythms. The main questions it aims to answer are:

  • How often do electrical signals continue to travel through a blood vessel around the heart after ablation?
  • Which ablation applications are most important for achieving a successful electrical block?
  • How do different procedural factors affect the success of the treatment?

Participants who undergo a catheter ablation procedure as part of their normal medical care may take part in this study. No additional tests, visits, or procedures will be required. Researchers will collect information that is routinely recorded during the procedure to better understand how electrical signals travel in the heart and how ablation procedures can be improved.

02

Conditions studied

  • Atrial Fibrillation (AF)
  • Atrial Tachycardia
  • Paroxysmal AF
  • Persisent Atrial Fibrillation

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Keywords

  • Catheter Ablation
  • Mitral Isthmus Ablation
  • Coronary Sinus Conduction
  • Paroxysmal Atrial Fibrillation
  • Persisent Atrial Fibrillation
  • Perimitral Atrial Tachycardia
03

In context

Atrial Fibrillation

3,957 studies on the registry are indexed under Atrial Fibrillation; 933 are open to participants now.

This study's planned enrollment of 50 is below the median of 300 across 1,390 observational studies indexed under Atrial Fibrillation.

Browse Atrial Fibrillation studies →

Lead sponsor

Sebastien Knecht is the lead sponsor of 3 studies on the registry; 3 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

The study population comprises adult patients (≥18 years) with symptomatic AF (paroxysmal, persistent) or perimitral atrial tachycardia (PMAT) undergoing left atrial catheter ablation with a planned first-time mitral isthmus line. Both sexes are eligible without restriction on body weight, BMI, or ethnicity. Patients must have sufficient procedural documentation to allow complete lesion-level data extraction.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Age ≥18 years at the time of the ablation procedure.
  • Diagnosis of paroxysmal AF, persistent AF, or perimitral atrial tachycardia.
  • Catheter ablation with a planned and performed first-time MI line (lateral mitral annulus to left inferior pulmonary vein) during the index procedure.
  • Procedure performed at AZ Sint-Jan Brugge AV.
  • Complete and interpretable procedural documentation (electrophysiology system data, fluoroscopy, procedural report).
  • For prospective patients: written informed consent obtained prior to the procedure.

Exclusion criteria

Exclusion Criteria:

  • Subjects meeting any of the following criteria will be excluded:
  • Age \<18 years.
  • No attempted MI line during the index procedure.
  • Prior MI line ablation (redo MI line procedures).
  • Incomplete or non-interpretable procedural documentation precluding lesion-level analysis.
  • Absence of written informed consent (prospective cohort only).
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
50 participants (estimated)
Target follow-up
1 Day
Patient registry
Yes
06

What researchers measure

Primary outcomes

  1. Anatomical Zone of the Effective Coronary Sinus RF Application

    Anatomical location of the first epicardial radiofrequency (RF) application within the coronary sinus that is temporally associated with achievement of bidirectional mitral isthmus conduction block. Unit: categorical variable (Superior, Anterior, Inferior, or Posterior zone).

    Time frame: During the index ablation procedure

  2. RF Power of the Effective Coronary Sinus RF Application

    RF power delivered during the first epicardial coronary sinus RF application that is temporally associated with achievement of bidirectional mitral isthmus conduction block. Unit: Watts (W).

    Time frame: During the index ablation procedure

  3. Duration of the Effective Coronary Sinus RF Application

    Duration of the first epicardial coronary sinus RF application that is temporally associated with achievement of bidirectional mitral isthmus conduction block. Unit: seconds (s).

    Time frame: During the index ablation procedure

  4. Contact Force of the Effective Coronary Sinus RF Application

    Mean contact force recorded during the first epicardial coronary sinus RF application that is temporally associated with achievement of bidirectional mitral isthmus conduction block. Unit: grams (g).

    Time frame: During the index ablation procedure

  5. Ablation Index of the Effective Coronary Sinus RF Application

    Ablation Index value of the first epicardial coronary sinus RF application that is temporally associated with achievement of bidirectional mitral isthmus conduction block.

    Time frame: During the index ablation procedure

  6. Cumulative Epicardial RF Time to Mitral Isthmus Block

    Total cumulative duration of epicardial coronary sinus RF applications delivered up to and including the first application associated with achievement of bidirectional mitral isthmus conduction block. Unit: seconds (s).

    Time frame: During the index ablation procedure

  7. Relative Order of the Effective Coronary Sinus RF Application

    Sequence number of the first epicardial coronary sinus RF application that is temporally associated with achievement of bidirectional mitral isthmus conduction block. Unit: lesion number (n).

    Time frame: During the index ablation procedure

Secondary outcomes

  1. Number of Epicardial Coronary Sinus RF Applications

    Total number of epicardial radiofrequency (RF) applications delivered within the coronary sinus during the ablation procedure. Unit: number of RF applications (n).

    Time frame: During the index ablation procedure

  2. Distribution of Epicardial Coronary Sinus RF Applications

    Number of epicardial RF applications delivered within each of the 8 predefined anatomical coronary sinus zones. Unit: number of RF applications per anatomical zone (n).

    Time frame: During the index ablation procedure

  3. Cumulative Epicardial Coronary Sinus RF Time

    Total cumulative duration of all epicardial RF applications delivered within the coronary sinus. Unit: seconds (s).

    Time frame: During the index ablation procedure

  4. Total Procedure RF Time

    Total duration of radiofrequency energy delivery during the entire ablation procedure. Unit: seconds (s).

    Time frame: During the index ablation procedure

  5. Total Fluoroscopy Time

    Total fluoroscopy time during the ablation procedure. Unit: minutes (min).

    Time frame: During the index ablation procedure

  6. Total Procedure Duration

    Total duration of the ablation procedure. Unit: minutes (min).

    Time frame: During the index ablation procedure

  7. Achievement of Bidirectional Mitral Isthmus Block Without Epicardial Coronary Sinus Ablation

    Proportion of procedures in which bidirectional mitral isthmus (MI) conduction block is achieved without delivery of epicardial RF applications within the coronary sinus. Unit: percentage of procedures (%).

    Time frame: During the index ablation procedure

  8. Number of Coronary Sinus RF Applications According to VOM-EI Success

    Difference in the total number of epicardial coronary sinus RF applications between procedures with successful Vein of Marshall ethanol infusion (VOM-EI) and procedures with failed or absent VOM-EI. Unit: number of RF applications (n).

    Time frame: During the index ablation procedure

  9. Distribution of Coronary Sinus RF Applications According to VOM-EI Success

    Difference in the distribution of epicardial coronary sinus RF applications across the 8 predefined anatomical zones between procedures with successful VOM-EI and procedures with failed or absent VOM-EI. Unit: number of RF applications per anatomical zone (n).

    Time frame: During the index ablation procedure

  10. Cumulative Epicardial RF Time According to VOM-EI Success

    Difference in cumulative epicardial coronary sinus RF time between procedures with successful VOM-EI and procedures with failed or absent VOM-EI. Unit: seconds (s).

    Time frame: During the index ablation procedure

  11. Time to Mitral Isthmus Block According to VOM-EI Success

    Difference in time to achievement of bidirectional mitral isthmus conduction block between procedures with successful VOM-EI and procedures with failed or absent VOM-EI. Unit: seconds (s).

    Time frame: During the index ablation procedure

  12. Incidence of Periprocedural Complications

    Incidence of periprocedural complications related to mitral isthmus ablation, epicardial coronary sinus RF ablation, or Vein of Marshall ethanol infusion (VOM-EI), including pericardial effusion or cardiac tamponade, coronary sinus dissection or perforation, coronary artery injury or spasm, stroke or transient ischemic attack (TIA), phrenic nerve palsy, steam pop, and complications specifically related to VOM-EI. Unit: percentage of participants with at least one periprocedural complication (%).

    Time frame: During the index ablation procedure

07

Study locations

No study locations are listed for this record.

08

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Start is estimated for Oct 2026; primary completion for Dec 2027, 14 months later.

Of 536 non-industry observational studies under Atrial Fibrillation, half reached primary completion within 46 months of starting (the median), counting those still running; a quarter within 24 and three quarters within 85. This study's planned 14 months is below that.

Counting every sponsor, half of 685 studies reached it within 38 months; a quarter within 22 and three quarters within 75.

How these figures are worked out, and which studies are left out of them.

Registered
Oct 16, 2026
First posted
Oct 22, 2026
StartEst.
Oct 2026
Primary completionEst.
Dec 2027
CompletionEst.
Dec 2027
Last update
Oct 22, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Registered
First appeared on the registry. No changes since
Oct 22, 2026
Show all 1 update
  1. Oct 22, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

09

Registry details

Key details

Study ID
NCT07889440
Lead sponsor
Sebastien Knecht
Responsible party
Sebastien Knecht (Coordinating investigator, AZ Sint-Jan AV) — Sponsor-investigator
First posted
Oct 22, 2026
Start date
Oct 2026 (estimated)
Primary completion
Dec 2027 (estimated)
Completion
Dec 2027 (estimated)
Last update
Oct 22, 2026

Study contacts

Emma Christiaen
Contact
SM-SJ-Cardiologie-Studies@azsintjan.be
+3250453293

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.

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