Cavotricuspid Isthmus Dependent Atrial FlutterNCT07012460
Pulsed Field Ablation for Cavotricuspid Isthmus Dependent Atrial Flutter Cohort Study
A study testing CTI ablation in people with Cavotricuspid Isthmus Dependent Atrial Flutter, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
Pulsed field ablation (PFA) has been demonstrated to be safe and effective in achieving pulmonary vein isolation in patients with atrial fibrillation (AF). Coexisting atrial flutter is common in patients with AF. It is therefore appealing to treat the atrial futters with PFA. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Cavotricuspid Isthmus Dependent Atrial Flutter
- What is being tested?
- CTI ablation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteHong Kong
- Study dates
- Jun 2025to Jun 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 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 1. Patients with atrial fibrillation who are clinically planned to undergo AF ablation and atrial flutter ablation per guideline recommendations
Who cannot join
- >80 years old or <18 years old
- Known severe coronary artery disease
- Prior history of atrial flutter or atrial fibrillation ablation
- Refusal for remapping or coronary angiogram
- Contraindication for coronary angiogram
- Pregnancy
- Expected life expectancy <1 year
- Inability to provide informed consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site
Prince of Wales Hospital
Hong Kong
Tammy Yeung, 852 35051750, tammyooyeung@cuhk.edu.hk
About this study
Pulsed field ablation (PFA) has been demonstrated to be safe and effective in achieving pulmonary vein isolation in patients with atrial fibrillation (AF). Coexisting atrial flutter is common in patients with AF. It is therefore appealing to treat the atrial futters with PFA. The use of PFA for extra-pulmonary ablation, such as linear ablation at the mitral or cavo-tricuspid isthmus (CTI) has been investigated. When PFA is applied near a coronary vessel, acute coronary spasm is a common observation, which has been reported to be reversible and largely mitigated by pre-emptive intravenous or intracoronary nitroglycerine (TNG) injection. A recent clinical study based on qualitative coronary angiogram reported no apparent coronary stenosis 6 months after PFA. However, quantitative measurements were not provided. While acute conduction block is easy to create with pulsed field ablation catheters, the long-term lesion durability is unknown. The circular array pulsed field ablation catheter was shown to be safe and effective in achieving pulmonary vein isolation. This study aims to evaluate the safety and efficacy of pulsed-field ablation for CTI flutters.
This study will be a multicenter prospective cohort study involving 30 patients undergoing ablation for atrial fibrillation and CTI flutter. The decision for ablation will be a clinical decision based on existing class I and II guideline recommendations.
Read more
The atrial fibrillation ablation procedure will be performed as per routine clinical practice. Procedure will be performed with a 3-D electro-anatomical system guidance. Pulmonary vein isolation (PVI) will be performed with pulsed field ablation with a circular array catheter (Pulse Select system, Medtronic). After confirming PVI, extrapulmonary ablation will be performed per clinically need. CTI ablation will be performed with PFA as planned.
Patient will be managed by usual clinical care after ablation. They will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage. A multipolar catheter will be inserted via right femoral vein to check for conduction block across CTI. If there is ongoing conduction, a repeat ablation will be performed with radiofrequency ablation.
- Being tested
- CTI ablation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CTI ablationDevice
CTI ablation will be performed with PFA. Before ablation, The RA geometry will be created with a multipolar catheter. Coronary angiogram will be performed at baseline in LAO 45 degree before and after each set of ablations. After ablation, a 15-minute waiting period will be mandated. The CTI block will be rechecked with 3D mapping system and multipolar catheter. If there is persistent CTI conduction, ablation will be repeated until CTI block is achieved. This will be followed by another 15 minutes of waiting period before rechecking the block across CTI, and so on. TNG will be prepared. It will be given via intracoronary route in 100-200mcg bolus if severe spasm is observed. If CTI block cannot be achieved with repeated PFA ablation, ablation with radiofrequency will be allowed to achieve block. Patient will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage.
| Study group | Role | What they receive |
|---|---|---|
| CTI ablation | Other | CTI ablation will be performed with PFA. Coronary angiogram will be performed at baseline in LAO 45 degree before and after each set of ablations. The CTI block will be rechecked with 3D mapping system and multipolar catheter. If there is persistent CTI conduction, ablation will be repeated until CTI block is achieved. If CTI block cannot be achieved with repeated PFA ablation, ablation with radiofrequency will be allowed to achieve block. Patient will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage. Receives: Device: CTI ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of residual conduction
Evaluate rate of residual conduction across CTI in 3-month remapping
Measured: In 3 months follow up
Rate of coronary artery damage
Evaluate rate of coronary artery damage in 3-month repeat coronary angiogram
Measured: In 3 months follow up
Rate of acute severe coronary spasm
Evaluate rate of acute severe coronary spasm induced by PFA (>70% diameter reduction or ST change)
Measured: In 3 months follow up
Secondary outcomes (5)
Rate of clinical recurrence of atrial arrhythmia
Evaluate rate of clinical recurrence of atrial arrhythmia at 3 months
Measured: In 3 months follow up
Number of PFA applications
Evaluate number of PFA applications required to achieve CTI block
Measured: In ablation procedure
Rate of successful acute conduction block by PFA alone
Evaluate rate of successful acute conduction block by PFA alone
Measured: In ablation procedure
Rate of successful acute conduction block in all patients (with PFA or PFA + RFA)
Evaluate rate of successful acute conduction block in all patients (with PFA or PFA + RFA)
Measured: In ablation procedure
Number of mapping points in right atrium in electroanatomic system
Evaluate number of mapping points in right atrium in electroanatomic system
Measured: In mapping procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jun 2025
- Study startJun 2025 (estimated)
- Primary completionMar 2026 (estimated)
- Study completionJun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cavotricuspid Isthmus Dependent Atrial FlutterStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tam Tsz Kin, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07012460
- Sponsor's protocol ID
- Pulse CTI study
- Status last verified
- May 2025
- First submitted
- 2 Jun 2025
- Last updated
- 10 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pulsed Field Ablation for Cavotricuspid Isthmus Dependent Atrial Flutter Cohort Study
- ClinicalTrials.gov ID
- NCT07012460
- Acronym / sponsor ID
- Pulse CTI study
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- Jun 2025 (estimated)
- Primary completion
- Mar 2026 (estimated)
- Study completion
- Jun 2026 (estimated)
- First posted
- 10 Jun 2025 (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.
Pulsed field ablation (PFA) has been demonstrated to be safe and effective in achieving pulmonary vein isolation in patients with atrial fibrillation (AF). Coexisting atrial flutter is common in patients with AF. It is therefore appealing to treat the atrial futters with PFA. The use of PFA for extra-pulmonary ablation, such as linear ablation at the mitral or cavo-tricuspid isthmus (CTI) has been investigated. When PFA is applied near a coronary vessel, acute coronary spasm is a common observation, which has been reported to be reversible and largely mitigated by pre-emptive intravenous or intracoronary nitroglycerine (TNG) injection. A recent clinical study based on qualitative coronary angiogram reported no apparent coronary stenosis 6 months after PFA. However, quantitative measurements were not provided. While acute conduction block is easy to create with pulsed field ablation catheters, the long-term lesion durability is unknown. The circular array pulsed field ablation catheter was shown to be safe and effective in achieving pulmonary vein isolation. This study aims to evaluate the safety and efficacy of pulsed-field ablation for CTI flutters.
This study will be a multicenter prospective cohort study involving 30 patients undergoing ablation for atrial fibrillation and CTI flutter. The decision for ablation will be a clinical decision based on existing class I and II guideline recommendations.
The atrial fibrillation ablation procedure will be performed as per routine clinical practice. Procedure will be performed with a 3-D electro-anatomical system guidance. Pulmonary vein isolation (PVI) will be performed with pulsed field ablation with a circular array catheter (Pulse Select system, Medtronic). After confirming PVI, extrapulmonary ablation will be performed per clinically need. CTI ablation will be performed with PFA as planned.
Patient will be managed by usual clinical care after ablation. They will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage. A multipolar catheter will be inserted via right femoral vein to check for conduction block across CTI. If there is ongoing conduction, a repeat ablation will be performed with radiofrequency ablation.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| CTI ablation | Other | Device: CTI ablationCTI ablation will be performed with PFA. Coronary angiogram will be performed at baseline in LAO 45 degree before and after each set of ablations. The CTI block will be rechecked with 3D mapping system and multipolar catheter. If there is persistent CTI conduction, ablation will be repeated until CTI block is achieved. If CTI block cannot be achieved with repeated PFA ablation, ablation with radiofrequency will be allowed to achieve block. Patient will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- 1. Patients with atrial fibrillation who are clinically planned to undergo AF ablation and atrial flutter ablation per guideline recommendations
Key exclusion criteria (8 listed)
- >80 years old or <18 years old
- Known severe coronary artery disease
- Prior history of atrial flutter or atrial fibrillation ablation
- Refusal for remapping or coronary angiogram
- Contraindication for coronary angiogram
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 |
|---|---|---|
| CTI ablationCTI ablation will be performed with PFA. Before ablation, The RA geometry will be created with a multipolar catheter. Coronary angiogram will be performed at baseline in LAO 45 degree before and after each set of ablations. After ablation, a 15-minute waiting period will be mandated. The CTI block will be rechecked with 3D mapping system and multipolar catheter. If there is persistent CTI conduction, ablation will be repeated until CTI block is achieved. This will be followed by another 15 minutes of waiting period before rechecking the block across CTI, and so on. TNG will be prepared. It will be given via intracoronary route in 100-200mcg bolus if severe spasm is observed. If CTI block cannot be achieved with repeated PFA ablation, ablation with radiofrequency will be allowed to achieve block. Patient will come back for follow up at 3 months for a remapping procedure. During the remapping procedure, a RCA coronary angiogram will be performed to exclude late coronary damage. | Device | CTI ablation |
Primary outcome
Rate of residual conduction
Time frame: In 3 months follow up
Evaluate rate of residual conduction across CTI in 3-month remapping
Rate of coronary artery damage
Time frame: In 3 months follow up
Evaluate rate of coronary artery damage in 3-month repeat coronary angiogram
Rate of acute severe coronary spasm
Time frame: In 3 months follow up
Evaluate rate of acute severe coronary spasm induced by PFA (>70% diameter reduction or ST change)
5 secondary outcomes
Rate of clinical recurrence of atrial arrhythmia
Time frame: In 3 months follow up
Number of PFA applications
Time frame: In ablation procedure
Rate of successful acute conduction block by PFA alone
Time frame: In ablation procedure
Rate of successful acute conduction block in all patients (with PFA or PFA + RFA)
Time frame: In ablation procedure
Number of mapping points in right atrium in electroanatomic system
Time frame: In mapping procedure
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 10 Jun 2025.
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 CTI ablation in people with Cavotricuspid Isthmus Dependent Atrial Flutter, run by Chinese University of Hong Kong at 1 site in Hong Kong.
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 8 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: opening soon, as of the sponsor's last update on 10 Jun 2025. 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 Hong Kong. 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 Tsz Kin Mark Tam (852 35051750, marktam@cuhk.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of residual conduction (time frame: In 3 months follow up). The study lists 3 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 10 Jun 2025.