Ground-breaking clinical trial aims to reduce sudden cardiac deaths

A landmark clinical trial which aims to reduce deaths from sudden cardiac arrests has opened to patients in Southampton.

The BRITISH study is now recruiting at University Hospital Southampton, with sites in Portsmouth and Aberdeen also due to open soon.

The aim of the trial, which is funded by £1.8m from the British Heart Foundation, is to work out which patients may benefit from having a defibrillator fitted under the skin in their chest which can shock the heart if it goes into cardiac arrest.

The study is being led by consultant cardiologists Dr Andrew Flett and Professor Nick Curzen from University Hospital Southampton and is co-ordinated by the NIHR Southampton Clinical Trials Unit.

A world-first trial

Sudden cardiac arrests are a major cause of death in patients with non-ischemic cardiomyopathy (NICM), a common type of heart failure which can lead to abnormal heart rhythms.

Implantable cardioverter defibrillators (ICDs) are small devices fitted in a patient’s chest that can stop abnormal rhythms and treat cardiac arrest by delivering an electric shock to the heart.

The current guidelines look at how well the heart is pumping to decide which patients should get an implant. But for many patients who go through the procedure of having an ICD fitted, they will never actually see the device triggered and may not need it.

“As with any surgical procedure, there is a risk of complications from having an ICD fitted,” says Dr Andrew Flett, Chief Investigator of the BRITISH trial. “We therefore want to find a better way to assess which patients will truly benefit from one of these devices before it is fitted.”

“There is evidence that scar tissue in the heart muscle may be the cause of dangerous heart rhythms for patients with NICM. This will be the first ever trial to look at whether the presence of scar tissue can predict who should be fitted with an ICD.”

First patients

The first patients are now being enrolled to the BRITISH trial at University Hospital Southampton, which is also sponsoring the trial.

Over the next three years, researchers at 35 UK hospitals will aim recruit over 2,500 patients with non-ischaemic cardiomyopathy (NICM).

An MRI scan will be used to detect the presence of scar tissue in the heart and those patients will then be invited into the trial. Trial participants will be randomly allocated to one of two trial arms, with half being fitted with an implantable defibrillator. The others will be fitted with an implantable loop recorder (ILR), a device which monitors heart activity so that the team can review any abnormal rhythms, but which does not shock the heart.

“The trial will also involve a registry of patients who do not have scar tissue and are therefore treated according to current guidelines,” says Anna Cebula, Trial Manager at the Southampton Clinical Trials Unit. “This means we will be able to review data from all three groups and compare patient outcomes to establish whether scar tissue is an indicator of who should be fitted with an ICD”.

Dr Flett concludes, “The ultimate goal of any research is to improve treatment for our patients. The BRITISH trial will inform UK and international guidelines for the treatment of NICM heart failure. Depending on the outcome of the study, it could identify a group of patients who we know will benefit from ICDs and reduce unnecessary procedures for patients who don’t need them ensuring cost effective use of our health service in the future.”