Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

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

Trial website

Contact information



Primary contact

Dr Farkas Vánky


Contact details

Dept of Cardiothoracic and Vascular Surgery
University Hospital Linköping
581 85

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Myocardial 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 hypothesis

1. 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

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

Study design

Single-centre, prospective randomized interventional study, also including a non-randomized arm for comparison.

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in English. Existing information is written in Swedish.


Patients with pre-existing atrial fibrillation scheduled for elective mitral valve surgery.


1. 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 type



Drug names

Primary outcome measure

1. 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 measures

1. 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 trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. 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

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. 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

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University Hospital Linköping
Dept of Cardiothoracic and Vascular Surgery
581 85

Sponsor information


University of Linköping, Dept. of Clinical Health and Science

Sponsor details

c/o Dr Farkas Vánky
Dept of Cardiothoracic and Vascular Surgery
University Hospital in Linköping
581 85
+46 10 103 00 00

Sponsor type

Hospital/treatment centre



Funder type


Funder name

County Council of Östergötland - ALF funding (Sweden)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

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)