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Brighton & Sussex Medical School

Current studies

CHILLY-AF

A randomised comparison of cardioversion and catheter cryoablation in patients with persistent atrial fibrillation

Trial acronym: CHILLY-AF

Description

Persistent atrial fibrillation (AF) is the most common sustained heart rhythm disorder and is associated with a variety of symptoms including lethargy and breathlessness. This can be treated with cardioversion with long-term medication, or a more definitive treatment with ablation. The usual first line treatment for persistent AF is cardioversion but recurrence rates following this are up to 90%. The aim of this study is to determine whether cryoablation is more effective than cardioversion at preventing recurrence of persistent AF.

Patients aged over 18 with persistent AF who are suitable for cryo catheter ablation are eligible to be included in the study. Participants are randomly allocated to one of two groups. 

Group 1 undergo AF ablation with pulmonary vein isolation using cryoablation.  Cryoablation is a minimally invasive procedure and has a success rate of between 57-69% in treating persistent AF. The procedure involves passing two tubes into a vein from the groin. After crossing to the left chamber of the heart (atrium), a balloon is used to engage the pulmonary veins which are then frozen. The procedure lasts around 90 minutes. 

Group 2 undergo cardioversion, which involves a controlled electric shock to the chest wall under general anaesthesia or heavy sedation. This is usually performed as a day case procedure. 

Participants are followed up with three clinic visits 3, 6 and 12 months later, along with a 24-hour Holter monitor to assess symptoms and medication review as well as a telephone interview at 9 months. All patients are provided with and trained to use a home monitor to send weekly ECGs and further ECGs at times of symptoms. Patients are also asked to complete questionnaire forms at the beginning and end of the study.

Study design: Randomised Controlled Trial

Multicentres: 
1. University Hospitals Sussex NHS Foundation Trust (UK)
2. Portsmouth Hospitals NHS Trust (UK)
3. University Hospital Southampton NHS Foundation Trust (UK)
4. East Sussex Healthcare NHS Trust (UK)
5. Leeds Teaching Hospitals NHS Trust (UK).

Trial status: Closed

Chief Investigator: Dr James McCready, University Hospitals Sussex NHS Foundation Trust (UK).

Start date: August 2017

End date: February 2020

Recruitment target: 150

Summary of study results: n/a 

For further information contact:

E: bsctu@bsms.ac.uk