An interventional study of CTI ablation in Cavotricuspid Isthmus Dependent Atrial Flutter, sponsored by Chinese University of Hong Kong. Not yet recruiting at 1 site in Hong Kong. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2025-06-10.
Sponsored by Chinese University of Hong Kong · Not applicable, Interventional, and Treatment
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.
223 studies on the registry are indexed under Atrial Flutter; 51 are open to participants now.
This study's planned enrollment of 30 is below the median of 150 across 155 interventional studies indexed under Atrial Flutter.
Browse Atrial Flutter studies →Chinese University of Hong Kong is the lead sponsor of 1,454 studies on the registry; 474 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
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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.
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The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Device: CTI ablation
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.
Rate of residual conduction
Evaluate rate of residual conduction across CTI in 3-month remapping
Time frame: In 3 months follow up
Rate of coronary artery damage
Evaluate rate of coronary artery damage in 3-month repeat coronary angiogram
Time frame: 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)
Time frame: In 3 months follow up
Rate of clinical recurrence of atrial arrhythmia
Evaluate rate of clinical recurrence of atrial arrhythmia at 3 months
Time frame: In 3 months follow up
Number of PFA applications
Evaluate number of PFA applications required to achieve CTI block
Time frame: In ablation procedure
Rate of successful acute conduction block by PFA alone
Evaluate 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)
Evaluate 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
Evaluate number of mapping points in right atrium in electroanatomic system
Time frame: In mapping procedure
Start is estimated for Jun 2025; primary completion for Mar 2026, 9 months later.
Of 55 interventional studies with no phase under Atrial Flutter, half reached primary completion within 31 months of starting (the median), counting those still running; a quarter within 14 and three quarters within 63. This study's planned 9 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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Chinese University of Hong Kong →