A randomised controlled trial to investigate the biochemical and myocardial effects of ablation for atrial fibrillation at concomitant elective cardiac surgery with two different methods, freezing versus heating.

ISRCTN ISRCTN14454361
DOI https://doi.org/10.1186/ISRCTN14454361
Secondary identifying numbers N/A
Submission date
16/11/2014
Registration date
05/01/2015
Last edited
07/05/2021
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Surgery
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Atrial fibrillation (AF) is a heart condition which results in an irregular and often abnormally fast heart rate. Symptoms can include feeling dizzy, being short of breath and palpitations. Having the condition increases the risk of a stroke or, in extreme cases, heart failure. This is because AF can lead to blood clots forming in the heart, which may then be pumped into the general blood circulation and eventually block arteries in the brain. Treatment can include medicines called anti-arrhythmics which help restore a regular heart beat and antithrombotic treatment to stop blood clots from forming. Surgical ablation is a procedure where the diseased area of the heart is destroyed, causing electrically isolating scar lines. The abnormal electrical circuits caused by the diseased area then stops and a normal heartbeat restored. About 5-10% of patients scheduled for cardiac (heart) surgery have AF and surgical ablation is often done at the same time. There are a number of different methods/devices that can be used to destroy the diseased tissue, including freezing (cryo) or heating (using radio frequencies or microwaves) the area. Both these methods have proved to be effective treatments for AF. We want to compare the amount of myocardial (heart muscle) injury, degree of systemic inflammatory response and levels of biochemical markers for cell death in patients when they (a) undergo AF ablation with a cryo-device along with their cardiac surgery (b) undergo AF ablation with a radio frequency (RF) device along with their cardiac surgery and (c) undergo only their cardiac surgery. The atrial function and the heart rhythm will be compared between the groups one year after surgery.

Who can participate?
Adults who are at least 18, about to have elective mitral valve surgery and a history of atrial fibrillation.

What does the study involve?
For each participant, the decision on whether they should have treatment for their AF is made at a meeting involving cardiologists and cardiac surgeons and it is based on general recommendations. Those participants that are recommended for AF ablation are then randomly assigned to receive either the cryo or RF ablation procedure. The study involves taking blood samples at various points throughout the study, taking myocardial biopsies during the surgery, echocardiography examinations and monitoring the heartbeat.

What are the possible benefits and risks of participating?
There are no benefits for the participants in this study. There might be a slightly increased risk for postoperative bleeding from the myocardial biopsies and the blood samples taken for the study result in some additional blood loss.

Where is the study run from?
Dept. of Cardiothoracic and Vascular Surgery, University Hospital Linköping (Sweden)

When is the study starting and how long is it expected to run for?
September 2013 to December 2018

Who is funding the study?
ALF funding (Sweden)

Who is the main contact?
Dr Farkas Vánky
farkas.vanky@lio.se

Contact information

Dr Farkas Vánky
Scientific

Dept of Cardiothoracic and Vascular Surgery
University Hospital Linköping
Linköping
581 85
Sweden

ORCiD logoORCID ID 0000-0003-1005-091X
Email farkas.vanky@lio.se

Study information

Study designSingle-centre, prospective randomized interventional study, also including a non-randomized arm for comparison.
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in English. Existing information is written in Swedish.
Scientific titleMyocardial and systemic response in patient undergoing mitral valve surgery with and without concomitant maze ablation for atrial fibrillation. Patients scheduled for maze treatment are randomized to ablation with cryo or radio frequency (RF) device.
Study acronymRAFT-MSR
Study objectives1. Atrial fibrillation (AF) treatment with maze procedure concomitant to mitral valve surgery results in higher levels of markers for myocardial injury, higher systemic inflammatory response, and elevated levels of markers for apoptosis.
2. Patients treated with concomitant cryo ablation and RF ablation have different levels of markers for myocardial injury, systemic inflammatory response, and levels of markers for apoptosis.
3. Concomitant AF treatment results in better atrial contractile function at one year follow up.

Added 20/10/2016:
4. Concomitant AF treatment with RF ablation results in better atrial contractile function than concomitant cryo ablation.
Ethics approval(s)Regional Ethical Review Board in Linköping, Sweden, 12/12/2012, ref. 2012/371-31

Added 20/10/2018:
refs: 2013/173-32, 2014/451-32, 2015/400-32
Health condition(s) or problem(s) studiedPatients with pre-existing atrial fibrillation scheduled for elective mitral valve surgery.
Intervention1. Non intervention: Mitral valve surgery with or without other cardiac procedures.
2. Intervention 1: Mitral valve surgery with or without other cardiac procedures and concomitant cryo-maze ablation device. Ablation lines according to Cox-Maze IV procedure.
3. Intervention 2: Mitral valve surgery with or without other cardiac procedures and concomitant radio frequency (RF)-maze ablation device. Ablation lines according to Cox-Maze IV procedure.
Intervention typeDevice
Pharmaceutical study type(s)
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measure1. Markers for myocardial injury: troponin T, creatinine kinase-MB, matrix metalloproteinase-2, tissue inhibitor of matrix metalloproteinase-2, myeloperoxidase (preoperatively, at skin closure, and 3 and 20 hrs postoperatively)
2. Markers for inflammatory response: high sensitive C reactive protein, interleukins, tumour necrosis factors, tumour growth factors (preoperatively, at skin closure, and 3 and 20 hrs postoperatively)
Secondary outcome measures1. Markers for heart failure and renal function: N-terminal pro brain natriuretic peptide (Nt-proBNP), Creatinine, Cystatin-C (preoperatively, 20 hrs postoperatively, 3 days postoperatively, and Nt-proBNP also at 1 year follow up)
2. Atrial size and contractile function: measured with echocardiography on the preoperative day and at 1 year follow up

Rate of stable sinus rhythm at 1 year follow up: measured with 48 hrs electrocardiogram monitors.
Overall study start date01/11/2012
Completion date31/12/2018

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants150
Total final enrolment41
Key inclusion criteria1. Males and females, age over 18
2. Patients will have been accepted for elective mitral valve surgery (with or without additional cardiac procedures)
3. Patients will have a history of atrial fibrillation (chronic, persistent or paroxysmal), documented before decision on mitral valve surgery was made
4. All patients will provide written informed consent to participation
Key exclusion criteria1. Patients having mitral surgery planned through minimal invasive access
2. Patients with active endocarditis
3. Patients having emergency or salvage cardiac operations
4. Patients who are unlikely to be available for follow-up over a two-year period
5. Patients who are deemed not competent to provide consent
Date of first enrolment01/09/2013
Date of final enrolment01/01/2018

Locations

Countries of recruitment

  • Sweden

Study participating centre

University Hospital Linköping
Dept of Cardiothoracic and Vascular Surgery
Linköping
581 85
Sweden

Sponsor information

University of Linköping, Dept. of Clinical Health and Science
Hospital/treatment centre

c/o Dr Farkas Vánky
Dept of Cardiothoracic and Vascular Surgery
University Hospital in Linköping
Linköping
581 85
Sweden

Phone +46 10 103 00 00
Email farkas.vanky@lio.se
ROR logo "ROR" https://ror.org/05ynxx418

Funders

Funder type

Government

County Council of Östergötland - ALF funding (Sweden)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 13/07/2020 07/05/2021 Yes No

Editorial Notes

07/05/2021: The following changes have been made:
1. Publication reference added.
2. The final enrolment number has been added from the reference.
20/10/2016: Changed overall trial end date from 01/11/2016 to 31/12/2018. Changed recruitment end date from 01/09/2015 to 01/01/2018. Changed number of participants from 60 to 150. Amended study hypothesis and ethics sections (date stamped in field)