Ventricular TachycardiaPhase 4AVATARNCT02114528
Anti-arrhythmic Therapy vs Catheter Ablation as First Line Treatment for AICD Shock Prevention
A Phase 4 study testing Antiarrhythmic Drug Therapy and Catheter ablation in people with Ventricular Tachycardia and Ventricular Arrhythmia, run by Ottawa Heart Institute Research Corporation at 1 site in Canada.
Trial summary
The purpose of this study is to determine whether catheter based ablation is better than conventional anti-arrhythmic drug (AAD) therapy for reducing recurrent shocks in patients with an implantable cardioverter defibrillator (ICD). Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Ventricular Tachycardia, Ventricular Arrhythmia
- What is being tested?
- Antiarrhythmic Drug Therapy and Catheter ablation
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 3 participants
- Where
- 1 siteCanada
- Study dates
- Oct 2014to Nov 2015
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- ≥ 18 and ≤ 85 years old
- Able to provide informed consent
- AICD implanted for primary prophylaxis against sudden cardiac death
- AICD implanted for secondary prophylaxis against spontaneous or inducible sustained VT without any reversible causes
- CAD with prior myocardial infarction (>60 days prior to enrollment)
- AICD or ECG documentation of ventricular arrhythmia responsible for appropriate AICD therapy (> 3 ATP or ≥ 1 appropriate Shock)
Who cannot join
- Contraindication or allergy to contrast media, routine procedural medications or catheter materials
- Contraindication to an interventional procedure
- Current or previous (within 3 months) antiarrhythmic therapy
- Absolute contraindication to amiodarone or other AAD
- New York Heart Association (NYHA) functional class IV
- Stroke within the past 90 days
Show all 18Show fewer
- Unstable angina
- Hypertrophic cardiomyopathy, Non-ischemic dilated cardiomyopathy, Arrhythmogenic Right Ventricular Dysplasia, Brugada Syndrome, Catecholamine sensitive polymorphic VT or long QT syndrome
- Subjects with active ischemia that are eligible for revascularization
- Life expectancy less than 6 months
- Incessant or multiple episodes of VT requiring immediate therapy with medications or ablation
- Untreated hypothyroidism or hyperthyroidism. Subjects who are euthyroid on thyroid hormone replacement therapy are acceptable.
- Current enrollment in another investigational drug or device study.
- Presence of any other condition that the investigator feels would be problematic or would restrict or limit the participation of the Subject for the entire study period.
- Absolute contra-indication to the use of heparin and or warfarin.
- Documented intra-atrial thrombus, ventricular thrombus (< 6 months after detection of thrombus), tumor, or another abnormality, which precludes catheter introduction.
- Previous VT ablation
- Are pregnant.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Antiarrhythmic Therapy Versus Catheter Ablation as First Line Treatment for AICD Shock Prevention: A Randomized Vanguard Pilot Trial
The purpose of this study is to determine whether catheter based ablation is better than conventional anti-arrhythmic drug (AAD) therapy for reducing recurrent shocks in patients with an implantable cardioverter defibrillator (ICD). The second purpose of the study is to determine the safety of catheter-based ablation and the effect on quality of life of patients.
The study hypothesis is that catheter ablation is superior to AAD therapy in preventing recurrent ventricular arrhythmia in such subjects. This is a pilot trial which will provide data regarding recruitment potential and the feasibility of conducting a larger trial.
Read the detailed description
AAD and catheter ablation have been shown to reduce the incidence of recurrent AICD shocks. The disadvantages of AAD include side effects from medications and the lack of compliance during long-term therapy. Previous trials have demonstrated the feasibility, safety and efficacy of catheter ablation as "first-line" treatment for reducing recurrent ventricular arrhythmia and AICD shocks in this subject population. However, these catheter ablation trials did not systematically compare the efficacy of catheter ablation with AAD therapy. While both treatment strategies have been shown to be effective in this setting it is unclear how they compare with each other in preventing AICD shocks.
This is a single centre, parallel group, two-arm, unblinded randomized vanguard pilot trial comparing catheter ablation with AAD therapy for preventing recurrent AICD shocks.
Eligible and consenting subjects will be equally randomized to receive either AAD therapy or a catheter ablation procedure.
A 30-day treatment period will be provided to allow for adequate time to implement the two treatments.
Subjects randomized to the antiarrhythmic therapy arm will receive clinically effective loading doses of either sotalol, mexiletine, procainamide or amiodarone (oral or IV) alone or in combination, as chosen by the study investigator.
Subjects randomized to the catheter ablation arm will undergo the procedure within the 30 treatment period. Concomitant antiarrhythmic therapy with amiodarone or other AAD will be avoided if possible in the ablation group. However, AAD may be used to suppress ventricular arrhythmia resulting in AICD shocks or anti-tachycardia pacing (ATP) while waiting for the catheter ablation procedure.
Subjects will be seen for a baseline randomization visit, then at 3, 6, 9 and 12 months after enrollment and every 3 months thereafter until the end of the study. Subjects will be followed up for a minimum of 12 months and a maximum of 24 months.
Quality of life questionnaires will be done at each visit. Standard of care blood work, chest x-ray, and ECG will be done in the AAD arm depending on the AAD chosen as treatment. ICD programming will be standardized for all subjects.
- Conditions
- Ventricular Tachycardia, Ventricular Arrhythmia
- Being tested
- Antiarrhythmic Drug Therapy, Catheter ablation
- Keywords
- Ventricular Tachycardia, Ventricular Arrhythmia, Anti-arrhythmic drugs, Catheter Ablation, ICD Shocks
- Medical subject headings
- Tachycardia, Ventricular
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Antiarrhythmic Drug TherapyDrug
Also called Betapace (sotalol), Mexitil (mexiletine), Pronestyl (procainamide), Cordarone (amiodarone)
Either one or more of the following antiarrhythmic drugs: sotalol, mexiletine, procainamide, or amiodarone.
Catheter ablationProcedure or surgery
Ventricular tachycardia catheter ablation.
| Study group | Role | What they receive |
|---|---|---|
| Anti-arrhythmic drug therapy | Active comparator | Oral and/or intravenous loading doses of Sotalol, mexiletine, procainamide or amiodarone as first line therapy. Drug chosen is preference of the treating physician. May use single or combination of AAD. Loading doses as per standard dosing guidelines for VT. Subjects on amiodarone should receive oral maintenance dose of at least 200 mg/day. Receives: Drug: Antiarrhythmic Drug Therapy |
| Catheter ablation | Active comparator | Ventricular tachycardia (VT) Catheter ablation, using a standardized VT ablation procedure protocol. Receives: Procedure: Catheter ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Appropriate ICD therapy
Appropriate AICD therapy after the 30 day treatment period; defined as ≥ 1 appropriate Shock or ATP that needs further intervention in the form of catheter ablation or AAD therapy.
Measured: After 30 day treatment period
Secondary outcomes (1)
Composite Safety Endpoint
- Catheter ablation arm- procedure related complications, need for concomitant use of AAD (sotalol, mexiletine, propafenone or amiodarone) and/or death.
- Antiarrhythmic arm- medication side effects, discontinuation of AAD and death, inappropriate shocks from AICD.
- Slow VT below AICD tachyarrhythmia detection threshold that leads to hospitalization or necessitates catheter ablation
- Mortality
- Quality of life score in each treatment arm using the EQ-5D questionnaire
- Health care resource utilization
Measured: Up to 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Apr 2014 (estimated)
- Study startOct 2014
- Primary completionNov 2015
- Study completionNov 2015
Why it stopped: Low recruitment. Pilot trial.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ventricular TachycardiaStudies 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 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Enrolment
- 3 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ottawa Heart Institute Research Corporation
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Girish Nair, MD, Principal investigator, Ottawa Heart Institute Research Corporation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02114528
- Sponsor's protocol ID
- 20130425
- Acronym
- AVATAR
- Status last verified
- Nov 2015
- First submitted
- 4 Apr 2014
- Last updated
- 4 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 4 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Antiarrhythmic Therapy Versus Catheter Ablation as First Line Treatment for AICD Shock Prevention: A Randomized Vanguard Pilot Trial
- ClinicalTrials.gov ID
- NCT02114528
- Acronym / sponsor ID
- AVATAR / 20130425
- Conditions
- Ventricular Tachycardia, Ventricular Arrhythmia
- Keywords
- Ventricular Tachycardia, Ventricular Arrhythmia, Anti-arrhythmic drugs, Catheter Ablation, ICD Shocks
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Low recruitment. Pilot trial.
- Enrolment
- 3 participants (actual)
- Lead sponsor
- Ottawa Heart Institute Research CorporationUniversity, hospital or other
- Study start
- Oct 2014
- Primary completion
- Nov 2015 (actual)
- Study completion
- Nov 2015 (actual)
- First posted
- 15 Apr 2014 (estimated)
- 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.
The purpose of this study is to determine whether catheter based ablation is better than conventional anti-arrhythmic drug (AAD) therapy for reducing recurrent shocks in patients with an implantable cardioverter defibrillator (ICD). The second purpose of the study is to determine the safety of catheter-based ablation and the effect on quality of life of patients.
The study hypothesis is that catheter ablation is superior to AAD therapy in preventing recurrent ventricular arrhythmia in such subjects. This is a pilot trial which will provide data regarding recruitment potential and the feasibility of conducting a larger trial.
Detailed description
AAD and catheter ablation have been shown to reduce the incidence of recurrent AICD shocks. The disadvantages of AAD include side effects from medications and the lack of compliance during long-term therapy. Previous trials have demonstrated the feasibility, safety and efficacy of catheter ablation as "first-line" treatment for reducing recurrent ventricular arrhythmia and AICD shocks in this subject population. However, these catheter ablation trials did not systematically compare the efficacy of catheter ablation with AAD therapy. While both treatment strategies have been shown to be effective in this setting it is unclear how they compare with each other in preventing AICD shocks.
This is a single centre, parallel group, two-arm, unblinded randomized vanguard pilot trial comparing catheter ablation with AAD therapy for preventing recurrent AICD shocks.
Eligible and consenting subjects will be equally randomized to receive either AAD therapy or a catheter ablation procedure.
A 30-day treatment period will be provided to allow for adequate time to implement the two treatments.
Subjects randomized to the antiarrhythmic therapy arm will receive clinically effective loading doses of either sotalol, mexiletine, procainamide or amiodarone (oral or IV) alone or in combination, as chosen by the study investigator.
Subjects randomized to the catheter ablation arm will undergo the procedure within the 30 treatment period. Concomitant antiarrhythmic therapy with amiodarone or other AAD will be avoided if possible in the ablation group. However, AAD may be used to suppress ventricular arrhythmia resulting in AICD shocks or anti-tachycardia pacing (ATP) while waiting for the catheter ablation procedure.
Subjects will be seen for a baseline randomization visit, then at 3, 6, 9 and 12 months after enrollment and every 3 months thereafter until the end of the study. Subjects will be followed up for a minimum of 12 months and a maximum of 24 months.
Quality of life questionnaires will be done at each visit. Standard of care blood work, chest x-ray, and ECG will be done in the AAD arm depending on the AAD chosen as treatment. ICD programming will be standardized for all subjects.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Anti-arrhythmic drug therapy | Active comparator | Drug: Antiarrhythmic Drug TherapyOral and/or intravenous loading doses of Sotalol, mexiletine, procainamide or amiodarone as first line therapy. Drug chosen is preference of the treating physician. May use single or combination of AAD. Loading doses as per standard dosing guidelines for VT. Subjects on amiodarone should receive oral maintenance dose of at least 200 mg/day. |
| Catheter ablation | Active comparator | Procedure: Catheter ablationVentricular tachycardia (VT) Catheter ablation, using a standardized VT ablation procedure protocol. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- ≥ 18 and ≤ 85 years old
- Able to provide informed consent
- AICD implanted for primary prophylaxis against sudden cardiac death
- AICD implanted for secondary prophylaxis against spontaneous or inducible sustained VT without any reversible causes
- CAD with prior myocardial infarction (>60 days prior to enrollment)
Key exclusion criteria (18 listed)
- Contraindication or allergy to contrast media, routine procedural medications or catheter materials
- Contraindication to an interventional procedure
- Current or previous (within 3 months) antiarrhythmic therapy
- Absolute contraindication to amiodarone or other AAD
- New York Heart Association (NYHA) functional class IV
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 |
|---|---|---|
| Antiarrhythmic Drug TherapyAlso: Betapace (sotalol), Mexitil (mexiletine), Pronestyl (procainamide), Cordarone (amiodarone)Either one or more of the following antiarrhythmic drugs: sotalol, mexiletine, procainamide, or amiodarone. | Drug | Anti-arrhythmic drug therapy |
| Catheter ablationVentricular tachycardia catheter ablation. | Procedure or surgery | Catheter ablation |
Primary outcome
Appropriate ICD therapy
Time frame: After 30 day treatment period
Appropriate AICD therapy after the 30 day treatment period; defined as ≥ 1 appropriate Shock or ATP that needs further intervention in the form of catheter ablation or AAD therapy.
1 secondary outcome
Composite Safety Endpoint
Time frame: Up to 24 months
Results and safety
The study was stopped early (reason given: Low recruitment. Pilot trial.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 May 2026.
Related trials for Ventricular Tachycardia
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VINTAGE (Ventricular Intramyocardial Navigation for Tachycardia Ablation Guided by Electrograms) Using Commercial Off-The-Shelf (COTS) Catheters
Ventricular Arrhythmia
Active, not recruiting
Assessment of Combined CCM and ICD Device in HFrEF
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A Study Assessing Arrhythmia Mapping With a Multi-Electrode Mapping Catheter
Scar-related Atrial Tachycardia, Persistent Atrial Fibrillation
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Genetic Markers of Cardiovascular Disease in Epilepsy
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Cardiac RADIoablation Versus Repeat Catheter Ablation: a Pivotal Randomized Clinical Trial Evaluating Safety and Efficacy for Patients With High-risk Refractory Ventricular Tachycardia (RADIATE-VT)
Tachycardia, Ventricular
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. This study is not recruiting at the moment.
Girish Nair, 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 Phase 4 study testing Antiarrhythmic Drug Therapy and Catheter ablation in people with Ventricular Tachycardia and Ventricular Arrhythmia, 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 6 inclusion and 18 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: stopped early, as of the sponsor's last update on 4 May 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: Low recruitment. Pilot trial.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Appropriate ICD therapy (time frame: After 30 day treatment period). 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 4 May 2026.