Cryoablation of atrial flutter
| ISRCTN | ISRCTN46168176 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN46168176 |
| Protocol serial number | N/A |
| Sponsor | Karolinska University Hospital (Sweden) |
| Funders | Stockholm County Council (Sweden), Karolinska Institute (Sweden) |
- Submission date
- 23/03/2012
- Registration date
- 03/04/2012
- Last edited
- 18/09/2014
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Atrial flutter is an abnormality in the beating of the heart, also known as arrhythmias. This arrhythmia can be the cause of stroke, heart failure and eventually death. This heart condition is successfully treatable today with catheter ablation, which destroys a small area of heart tissue that is causing rapid and irregular heartbeats. The aim of this study was to compare two commonly used catheter ablation technologies, namely radiofrequency (burning of the tissue), which is the standard treatment, and cryoablation (freezing of the tissue), which is the alternative treatment.
Who can participate?
All patients regardless of age and gender with clear atrial flutter symptoms can participate in this study.
What does the study involve?
In order to evaluate heart function, patients undergo a clinical examination, ECG recording and echocardiography. Patients will then be randomly allocated to be treated with either radiofrequency or cryoablation. Six months after treatment all patients will be followed up with an out-patient visit and an ECG recording.
What are the possible benefits and risks of participating?
The possible benefits of participating are that cryoablation is practically painless and equally effective to standard treatment (radiofrequency). No risks have been shown in the clinical studies published so far.
Where is the study run from?
The study is run from Karolinska University Hospital, Stockholm, Sweden.
When is the study starting and how long is it expected to run for?
The study ran from January 2007 to November 2010.
Who is funding the study?
Financial support was provided through the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and the Karolinska Institute (Sweden).
Who is the main contact?
Dr Hamid Bastani
Karolinska University Hospital, Stockholm, Sweden
Contact information
Scientific
Department of Cardiology
Karolinska Institute
Karolinska University Hospital
Stockholm
14186
Sweden
| mats.jensen-urstad@karolinska.se |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Prospective single-blinded randomized controlled single-centre trial |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | Cryothermal versus Radiofrequency Ablation as atrial Flutter Therapy: a randomized comparison |
| Study acronym | CRAFT |
| Study objectives | Catheter ablation with cryothermal energy is non-inferior to ablation with radiofrequency energy for the treatment of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) |
| Ethics approval(s) | Regional Ethical Review Board, Stockholm, 2006, ref: 1006-31 |
| Health condition(s) or problem(s) studied | Atrial flutter |
| Intervention | Cryo group: Cryo was delivered with the use of a steerable 9F, 8-mm-tip catheter (Freezor MAX, CryoCath, Quebec, Canada), which was positioned on the TV annulus. Cryoablation was then performed using a sequential application technique point-by-point from the TV annulus to the inferior vena cava (IVC). RF group: RF was performed using a 7F 3.5-mm open-irrigated-tip catheter (Biosense-Webster Inc., Diamond Bar, CA. USA) to create an ablation line between the tricuspid valve and the IVC. |
| Intervention type | Other |
| Primary outcome measure(s) |
Clinical success defined as the freedom from atrial flutter evaluated at the 6-month follow-up. |
| Key secondary outcome measure(s) |
1. 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 |
| Completion date | 30/11/2010 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | All |
| Target sample size at registration | 150 |
| Key inclusion criteria | 1. Consecutive patients referred to our institution for ablation therapy of ECG-documented typical CTI-dependent AFL 2. Patients above the age of 18 with 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 3. Patients with a history of atrial fibrillation included if they had predominant atrial flutter under chronic treatment with class I or III antiarrhythmic agents |
| Key exclusion criteria | 1. Prior ablation for AFL 2. Atrial flutter related to recently undergone surgery, hyperthyroidism or other severe disease 3. Inability to adhere to the study protocol 4. Pregnancy 5. Predominant atrial fibrillation 6. Contraindication to warfarin |
| Date of first enrolment | 01/01/2007 |
| Date of final enrolment | 30/11/2010 |
Locations
Countries of recruitment
- Sweden
Study participating centre
14186
Sweden
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not provided at time of registration |
| IPD sharing plan |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
