Ablation TechniquesPARADISONCT07910825
Paroxysmal Atrial Fibrillation Repeat Ablation Strategies With Durably Isolated Pulmonary Veins
A study testing Tailored Strategy in people with Ablation Techniques and Atrial Fibrillation (Paroxysmal), run by Ottawa Heart Institute Research Corporation at 1 site in Canada.
Trial summary
This study looks at participants who have undergone an ablation procedure for atrial fibrillation previously, and atrial fibrillation has occurred and a second ablation procedure is needed. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Ablation Techniques, Atrial Fibrillation (Paroxysmal), Quality of Life
- What is being tested?
- Tailored Strategy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteCanada
- Study dates
- Dec 2026to Sep 2032
- 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
- Paroxysmal atrial fibrillation with durable pulmonary vein isolation (PVI)
- Age >/= 18 years
- at least one episode of atrial fibrillation documented on 12-lead ECG, Holter monitor, or loop recorder in the preceding 12 months
- ability to provide informed consent
Who cannot join
- Persistent atrial fibrillation
- documented sustained atrial tachycardia or atypical atrial flutter.
- Previous atrial ablation excluding PVI or cavotricuspid Isthmus (CTI) ablation (having undergoing more than one procedure is acceptable as long as only PVI +/- CTI ablation was preformed)
- previous left atrial surgery
- known PV stenosis or history of PV intervention
- active intracardiac thrombus
Show all 13Show fewer
- contraindication to systemic anticoagulation
- hypertrophic cardiomyopathy
- significant left-sided valve disease (moderate or severe mitral or aortic stenosis or regurgitation)
- significant congenital heart disease, including atrial septal defects or PV abnormalities (patent foramen ovale is not an exclusion)
- active pregnancy
- participation or anticipated participation in another clinical trial that could affect the results of this trial
- unwillingness or inability to adhere fully with study procedures and follow up
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site
University of Ottawa Heart Institute
Ottawa, Ontario, K1Y 4W7
Tammy Knight, 613-696-7000, tknight@ottawaheart.ca
F. Daniel Ramirez, MD
About this study
Official title: Paroxysmal Atrial Fibrillation Repeat Ablation Strategies With Durably Isolated Pulmonary Veins (PARADISO): a Vanguard Study
This study looks at participants who have undergone an ablation procedure for atrial fibrillation previously, and atrial fibrillation has occurred and a second ablation procedure is needed. The study will randomize participants to either a tailored strategy for ablation or to widening the pulmonary vein isolation procedure with or without cavotricuspid isthmus ablation. The goal is to improve freedom from recurrent atrial arrhythmias at 12 months.
Read the detailed description
This is a study of patients who have undergone an ablation procedure for AF but in whom AF recurred and who are undergoing a second ablation procedure. Specifically, the investigators are interested in the group of patients whose PVs are still "isolated" during that second procedure because doctors are unsure of how best to ablate them. It is even possible that doing any more ablation in those patients is harmful.
The study will compare (1) an ablation strategy that includes commonly done ablation steps that tackle abnormalities found during the procedure (i.e., ablating "low voltage areas", searching for and ablating other arrhythmias called supraventricular tachycardias, and in some patients ablating the "posterior wall") to (2) an ablation strategy that reinforces or extends the PVI step only. In both groups, cavotricuspid isthmus ablation is also performed, if not already successfully done previously. The vanguard study will follow participants for 1 year, with a 3 year follow up planned if feasibility is met. Participants will be required to wear a Holter monitor at various timepoints and will be asked to complete atrial fibrillation and quality of life questionnaires.
- Being tested
- Tailored Strategy, Control Strategy
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Tailored StrategyProcedure or surgery
Homogenizing left atrium/atrial (LA) low voltage areas (LVAs), ablating inducible supraventricular tachycardia (SVTs), and if no abnormality is identified, performing empiric posterior wall isolation (PWI )followed by cavotricuspid isthmus (CTI) ablation (if successful CTI ablation not performed previously).
Control StrategyProcedure or surgery
Widening wide area circumferential ablation (WACA) lines and cavotricuspid isthmus (CTI) ablation if not successfully performed previously.
| Study group | Role | What they receive |
|---|---|---|
| Tailored Strategy | Experimental | Homogenizing left atrium/atrial (LA) low voltage areas (LVAs), ablating inducible supraventricular tachycardia (SVTs), and if no abnormality is identified, performing empiric posterior wall isolation (PWI )followed by cavotricuspid isthmus (CTI) ablation (if successful CTI ablation not performed previously). Receives: Procedure: Tailored Strategy |
| Control Strategy | Other | Widening wide area circumferential ablation (WACA) lines and cavotricuspid isthmus (CTI) ablation if not successfully performed previously. Receives: Procedure: Control Strategy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Freedom from recurrent atrial arrhythmia lasting >/= 30 seconds
Atrial arrhythmias include atrial fibrillation, atrial flutter, or atrial tachycardia.
Measured: Days 57 to 365 from repeat procedure.
Secondary outcomes (5)
Procedure duration
Time, in minutes, of the repeat procedure
Measured: From beginning of vascular access to removal of all catheters
Composite of major procedure-related complications
Procedure-related complications include embolic events, pulmonary vein stenosis, cardiac perforation, major bleeding, atrioesophageal fistula, or death)
Measured: Baseline to 12 months
Emergency Room visits or re-hospitalizations
Visits and admissions related to recurrent atrial arrhythmias
Measured: Baseline to 12 months
Repeat Catheter Ablation procedure
Occurrence of additional ablation after the study index procedure.
Measured: Baseline to 12 months
Atrial Fibrillation Effect on Quality of Life
Measured by the Atrial Fibrillation Effect on Quality of Life questionnaire. Scale of 0-100, with 100 being best quality of life.
Measured: Baseline to 12 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2026
- Study startDec 2026 (estimated)
- Primary completionSep 2030 (estimated)
- Study completionSep 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ablation TechniquesStudies of the same condition, open and under way.
- More trials run by Ottawa Heart Institute Research CorporationThe 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
- Randomised
- Intervention model
- Parallel groups
- Model description
- Vanguard stage: single-centre, parallel group, two arm, randomized clinical trial. Full study: plan for multicenter
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ottawa Heart Institute Research Corporation
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- F. Daniel Ramirez, MD, Principal investigator, Ottawa Heart Institute Research Corporation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07910825
- Sponsor's protocol ID
- 20260577-01H
- Acronym
- PARADISO
- Status last verified
- May 2026
- First submitted
- 13 Oct 2026
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Paroxysmal Atrial Fibrillation Repeat Ablation Strategies With Durably Isolated Pulmonary Veins (PARADISO): a Vanguard Study
- ClinicalTrials.gov ID
- NCT07910825
- Acronym / sponsor ID
- PARADISO / 20260577-01H
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Ottawa Heart Institute Research CorporationUniversity, hospital or other
- Study start
- Dec 2026 (estimated)
- Primary completion
- Sep 2030 (estimated)
- Study completion
- Sep 2032 (estimated)
- First posted
- 2 Nov 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.
This study looks at participants who have undergone an ablation procedure for atrial fibrillation previously, and atrial fibrillation has occurred and a second ablation procedure is needed. The study will randomize participants to either a tailored strategy for ablation or to widening the pulmonary vein isolation procedure with or without cavotricuspid isthmus ablation. The goal is to improve freedom from recurrent atrial arrhythmias at 12 months.
Detailed description
This is a study of patients who have undergone an ablation procedure for AF but in whom AF recurred and who are undergoing a second ablation procedure. Specifically, the investigators are interested in the group of patients whose PVs are still "isolated" during that second procedure because doctors are unsure of how best to ablate them. It is even possible that doing any more ablation in those patients is harmful.
The study will compare (1) an ablation strategy that includes commonly done ablation steps that tackle abnormalities found during the procedure (i.e., ablating "low voltage areas", searching for and ablating other arrhythmias called supraventricular tachycardias, and in some patients ablating the "posterior wall") to (2) an ablation strategy that reinforces or extends the PVI step only. In both groups, cavotricuspid isthmus ablation is also performed, if not already successfully done previously. The vanguard study will follow participants for 1 year, with a 3 year follow up planned if feasibility is met. Participants will be required to wear a Holter monitor at various timepoints and will be asked to complete atrial fibrillation and quality of life questionnaires.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Vanguard stage: single-centre, parallel group, two arm, randomized clinical trial. Full study: plan for multicenter
| Arm | Type | Receives |
|---|---|---|
| Tailored Strategy | Experimental | Procedure: Tailored StrategyHomogenizing left atrium/atrial (LA) low voltage areas (LVAs), ablating inducible supraventricular tachycardia (SVTs), and if no abnormality is identified, performing empiric posterior wall isolation (PWI )followed by cavotricuspid isthmus (CTI) ablation (if successful CTI ablation not performed previously). |
| Control Strategy | Other | Procedure: Control StrategyWidening wide area circumferential ablation (WACA) lines and cavotricuspid isthmus (CTI) ablation if not successfully performed previously. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Paroxysmal atrial fibrillation with durable pulmonary vein isolation (PVI)
- Age >/= 18 years
- at least one episode of atrial fibrillation documented on 12-lead ECG, Holter monitor, or loop recorder in the preceding 12 months
- ability to provide informed consent
Key exclusion criteria (13 listed)
- Persistent atrial fibrillation
- documented sustained atrial tachycardia or atypical atrial flutter.
- Previous atrial ablation excluding PVI or cavotricuspid Isthmus (CTI) ablation (having undergoing more than one procedure is acceptable as long as only PVI +/- CTI ablation was preformed)
- previous left atrial surgery
- known PV stenosis or history of PV intervention
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 |
|---|---|---|
| Tailored StrategyHomogenizing left atrium/atrial (LA) low voltage areas (LVAs), ablating inducible supraventricular tachycardia (SVTs), and if no abnormality is identified, performing empiric posterior wall isolation (PWI )followed by cavotricuspid isthmus (CTI) ablation (if successful CTI ablation not performed previously). | Procedure or surgery | Tailored Strategy |
| Control StrategyWidening wide area circumferential ablation (WACA) lines and cavotricuspid isthmus (CTI) ablation if not successfully performed previously. | Procedure or surgery | Control Strategy |
Primary outcome
Freedom from recurrent atrial arrhythmia lasting >/= 30 seconds
Time frame: Days 57 to 365 from repeat procedure.
Atrial arrhythmias include atrial fibrillation, atrial flutter, or atrial tachycardia.
5 secondary outcomes
Procedure duration
Time frame: From beginning of vascular access to removal of all catheters
Composite of major procedure-related complications
Time frame: Baseline to 12 months
Emergency Room visits or re-hospitalizations
Time frame: Baseline to 12 months
Repeat Catheter Ablation procedure
Time frame: Baseline to 12 months
Atrial Fibrillation Effect on Quality of Life
Time frame: Baseline to 12 months.
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 3 Nov 2026.
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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.
F. Daniel Ramirez, MD principal investigator
Ottawa Heart Institute Research Corporation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Tailored Strategy in people with Ablation Techniques and Atrial Fibrillation (Paroxysmal), run by Ottawa Heart Institute Research Corporation at 1 site in Canada.
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 4 inclusion and 13 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 3 Nov 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 Canada. 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 Tammy Knight (613-696-7000, TKnight@ottawaheart.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Freedom from recurrent atrial arrhythmia lasting >/= 30 seconds (time frame: Days 57 to 365 from repeat procedure.). 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 3 Nov 2026.