Atrial FlutterCASTAFNCT01604369
Cryoablation as Standard Treatment of Atrial Flutter
A study testing Medtronic Freezor Max Cardiac Cryoablation Catheter in people with Atrial Flutter, run by Karolinska University Hospital at 1 site in Sweden.
Trial summary
The hypothesis of the present study is to evaluate cryoablation(cooling of the tissue) as standard therapy of common atrial flutter,focusing on efficacy, feasibility, procedure time, and patient content. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Flutter
- What is being tested?
- Medtronic Freezor Max Cardiac Cryoablation Catheter
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 193 participants
- Where
- 1 siteSweden
- Study dates
- Jun 2012to Jun 2016
- Phase
- Interventional
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Consecutive patients referred to our institution for ablation therapy of ECG-documented, typical CTI dependent AFL.
- Patients above the age of 18 having symptomatic CTI-dependent AFL documented on a 12-lead ECG with typical ECG appearance of negative saw tooth waves in the inferior limb leads and positive deflections in V1 or positive saw tooth waves in the inferior limb leads and negative deflections in V1.
- Patients with a history of atrial fibrillation will only be included if they have predominant atrial flutter under chronic treatment with class I or III antiarrhythmic agents.
Who cannot join
- prior ablation for AFL;
- atrial flutter related to recently undergone surgery, hyperthyroidism or other severe disease;
- inability to adhere with the study protocol;
- pregnancy;
- predominant atrial fibrillation; and
- for patients with persistent atrial flutter contraindication to warfarin
Trial locations and contacts
1 site in 1 country.
Sweden1 site
Karolinska University Hospital
Stockholm, Stockholm County, SE-14186
About this study
Official title: Cryoablation as Standard Treatment of Atrial Flutter - Long Term Efficacy and Patient Content
The hypothesis of the present study is to evaluate cryoablation(cooling of the tissue) as standard therapy of common atrial flutter,focusing on efficacy, feasibility, procedure time, and patient content.
The purpose of this study is to determine whether cryoablation, performed only by operators experienced in cryothermic ablation is effective and safe in the treatment of atrial flutter.
Read the detailed description
Atrial flutter (AFL), a common atrial tachyarrhythmia may cause significant symptoms and serious adverse effects including embolic stroke, myocardial ischemia and congestive heart failure. Currently, radiofrequency (RF) catheter ablation of the cavotricuspid isthmus (CTI) is considered first-line therapy for treatment of CTI-dependent AFL. However, RF ablation of the CTI is associated with significant pain during lesion delivery. Furthermore, RF ablation can potentially injure cardiac structures adjacent to the CTI such as the AV node, tricuspid valve and right coronary artery. RF ablation can also lead to steam pops, cardiac tamponade and fatal complications have also been reported in association with CTI-ablation. Ablation using cryothermal energy (Cryo) has several potential advantages over RF ablation including greater catheter stability due to adherence to myocardial tissue during applications, reduced risk of thrombus formation, systemic embolization, and lower risk of myocardial perforation due to preservation of tissue architecture.
The investigators have in a prospective randomized, single centre study (CRAFT) investigated efficacy and safety of RF versus Cryo for atrial flutter, and showed that cryoablation is as effective as RF ablation in the short and long term. The patients perceived significantly less pain and required significantly lower doses of analgesia and sedation during cryoablation compared to RF ablation. The study was powered for non-inferiority with 75 patients in each group.
The objective of the present study is to expand the findings from the CRAFT study in a larger cohort of patients, letting only operators experienced in cryothermic CTI ablation use Cryo as standard therapy focusing on efficacy, feasibility, procedure time, and patient content.
To perform an ablation within the study, the electrophysiologist must have a previous experience of a minimum of 25 cryoablations of atrial flutter.
- Conditions
- Atrial Flutter
- Being tested
- Medtronic Freezor Max Cardiac Cryoablation Catheter
- Keywords
- Atrial flutter, Cryoablation, Cavotricuspid isthmus, Visual analogue scale
- Medical subject headings
- Atrial Flutter
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Medtronic Freezor Max Cardiac Cryoablation CatheterProcedure or surgery
Also called Cryoablation, CTI ablation
Cryoablation is performed using a sequential application technique point-by-point from the tricuspid annulus to the inferior vena cava. Ablation is performed at a target temperature of -80 ºC. Each application will last for 240 seconds.
| Study group | Role | What they receive |
|---|---|---|
| Cryoablation | Experimental | Not described Receives: Procedure: Medtronic Freezor Max Cardiac Cryoablation Catheter |
What is being measured
The primary outcome is the main question the study is designed to answer.
Efficacy
Clinical success defined as the freedom from atrial flutter evaluated at the 12-month follow-up.
Measured: One year after intervention
Secondary outcomes (1)
Safety
The secondary endpoints will be acute ablation success defined as bidirectional CTI-block, safety assessed by the rate of periprocedural complications, procedure and fluoroscopy times and the level of pain experienced by the patient during the ablation procedure.
Measured: During and up to one year after intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 May 2012 (estimated)
- Study startJun 2012
- Primary completionJun 2016
- Study completionJun 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial FlutterStudies of the same condition, open and under way.
- More trials run by Karolinska University HospitalThe 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
- 193 participants (actual)
Sponsor and investigators
- Lead sponsor
- Karolinska University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mats Jensen-Urstad, Karolinska University Hospital
- Investigators
- Mats Jensen-Urstad, Professor, Principal investigator, Karolinska University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01604369
- Sponsor's protocol ID
- KS1
- Acronym
- CASTAF
- Status last verified
- Oct 2016
- First submitted
- 21 May 2012
- Last updated
- 6 Oct 2016
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cryoablation as Standard Treatment of Atrial Flutter - Long Term Efficacy and Patient Content
- ClinicalTrials.gov ID
- NCT01604369
- Acronym / sponsor ID
- CASTAF / KS1
- Conditions
- Atrial Flutter
- Keywords
- Atrial flutter, Cryoablation, Cavotricuspid isthmus, Visual analogue scale
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 193 participants (actual)
- Lead sponsor
- Karolinska University HospitalUniversity, hospital or other
- Study start
- Jun 2012
- Primary completion
- Jun 2016 (actual)
- Study completion
- Jun 2016 (actual)
- First posted
- 23 May 2012 (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 hypothesis of the present study is to evaluate cryoablation(cooling of the tissue) as standard therapy of common atrial flutter,focusing on efficacy, feasibility, procedure time, and patient content.
The purpose of this study is to determine whether cryoablation, performed only by operators experienced in cryothermic ablation is effective and safe in the treatment of atrial flutter.
Detailed description
Atrial flutter (AFL), a common atrial tachyarrhythmia may cause significant symptoms and serious adverse effects including embolic stroke, myocardial ischemia and congestive heart failure. Currently, radiofrequency (RF) catheter ablation of the cavotricuspid isthmus (CTI) is considered first-line therapy for treatment of CTI-dependent AFL. However, RF ablation of the CTI is associated with significant pain during lesion delivery. Furthermore, RF ablation can potentially injure cardiac structures adjacent to the CTI such as the AV node, tricuspid valve and right coronary artery. RF ablation can also lead to steam pops, cardiac tamponade and fatal complications have also been reported in association with CTI-ablation. Ablation using cryothermal energy (Cryo) has several potential advantages over RF ablation including greater catheter stability due to adherence to myocardial tissue during applications, reduced risk of thrombus formation, systemic embolization, and lower risk of myocardial perforation due to preservation of tissue architecture.
The investigators have in a prospective randomized, single centre study (CRAFT) investigated efficacy and safety of RF versus Cryo for atrial flutter, and showed that cryoablation is as effective as RF ablation in the short and long term. The patients perceived significantly less pain and required significantly lower doses of analgesia and sedation during cryoablation compared to RF ablation. The study was powered for non-inferiority with 75 patients in each group.
The objective of the present study is to expand the findings from the CRAFT study in a larger cohort of patients, letting only operators experienced in cryothermic CTI ablation use Cryo as standard therapy focusing on efficacy, feasibility, procedure time, and patient content.
To perform an ablation within the study, the electrophysiologist must have a previous experience of a minimum of 25 cryoablations of atrial flutter.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Cryoablation | Experimental | Procedure: Medtronic Freezor Max Cardiac Cryoablation Catheter |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Consecutive patients referred to our institution for ablation therapy of ECG-documented, typical CTI dependent AFL.
- Patients above the age of 18 having symptomatic CTI-dependent AFL documented on a 12-lead ECG with typical ECG appearance of negative saw tooth waves in the inferior limb leads and positive deflections in V1 or positive saw tooth waves in the inferior limb leads and negative deflections in V1.
- Patients with a history of atrial fibrillation will only be included if they have predominant atrial flutter under chronic treatment with class I or III antiarrhythmic agents.
Key exclusion criteria (6 listed)
- prior ablation for AFL;
- atrial flutter related to recently undergone surgery, hyperthyroidism or other severe disease;
- inability to adhere with the study protocol;
- pregnancy;
- predominant atrial fibrillation; and
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 |
|---|---|---|
| Medtronic Freezor Max Cardiac Cryoablation CatheterAlso: Cryoablation, CTI ablationCryoablation is performed using a sequential application technique point-by-point from the tricuspid annulus to the inferior vena cava. Ablation is performed at a target temperature of -80 ºC. Each application will last for 240 seconds. | Procedure or surgery | Cryoablation |
Primary outcome
Efficacy
Time frame: One year after intervention
Clinical success defined as the freedom from atrial flutter evaluated at the 12-month follow-up.
1 secondary outcome
Safety
Time frame: During and up to one year after intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Oct 2016.
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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. This study is not recruiting at the moment.
Mats Jensen-Urstad, Professor principal investigator
Karolinska University Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Medtronic Freezor Max Cardiac Cryoablation Catheter in people with Atrial Flutter, run by Karolinska University Hospital at 1 site in Sweden.
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 3 inclusion and 6 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: finished, as of the sponsor's last update on 6 Oct 2016. 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 Sweden. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Efficacy (time frame: One year after intervention). 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 6 Oct 2016; AzTrials last refreshed its copy on 7 Nov 2026.