Rationale and study protocol for the BRITISH randomised trial (Using cardiovascular magnetic resonance identified scar as the Benchmark Risk Indication Tool for Implantable cardioverter defibrillators in patients with Non-Ischaemic Cardiomyopathy and Severe systolic Heart failure)

• Published in: The American heart journal 2023-12, Vol.266, p.149-158
• Main Authors: Flett, Andrew, Cebula, Anna, Nicholas, Zoe, Adam, Robert, Ewings, Sean, Prasad, Sanjay, Cleland, John GF, Eminton, Zina, Curzen, Nicholas
• Format: Article
• Language: English
• Subjects: Benchmarking; Cardiac magnetic resonance imaging; Cardiology; Cardiomyopathies - complications; Cardiomyopathies - diagnosis; Cardiomyopathies - therapy; Cardiomyopathy; Cicatrix - complications; Clinical medicine; Clinical trials; Complications; Congestive heart failure; Consent; Death; Death, Sudden, Cardiac - etiology; Death, Sudden, Cardiac - prevention & control; Defibrillators; Defibrillators, Implantable; Heart failure; Heart Failure, Systolic; Humans; Hypotheses; implantable cardiac defibrillator; left ventricular systolic dysfunction; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Mortality; Multicenter Studies as Topic; non-ischaemic cardiomyopathy; Patients; Prevention; Prospective Studies; Randomized Controlled Trials as Topic; Research ethics; Risk; Risk Factors; Stroke Volume; Subgroups; sudden cardiac death; Transplants & implants; Ventricle; Ventricular Function, Left
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2023.09.008

For patients with non-ischaemic cardiomyopathy (NICM), current guidelines recommend implantable cardioverter defibrillators (ICD) when left ventricular ejection fraction (LVEF) is ≤35%, but the DANISH trial failed to confirm that ICDs reduced all-cause mortality for such patients. Circumstantial evidence suggests that scar on CMR is predictive of sudden and arrhythmic death in this population. The presence of myocardial scar identified by cardiac magnetic resonance imaging (CMR) in patients with NICM and an LVEF ≤35% might identify patients at higher risk of sudden arrhythmic death, for whom an ICD is more likely to reduce all-cause mortality. The BRITISH trial is a prospective, multicentre, randomised controlled trial aiming to enrol 1252 patients with NICM and an LVEF ≤35%. Patients with non-ischaemic scar on CMR will be randomised to either: (A) ICD, with or without cardiac resynchronisation (CRT-D) or (b) implantable loop recorder (ILR) or cardiac resynchronisation (CRT-P). Patients who are screened for the trial but are found not to be eligible, predominantly due to an absence of scar, or those who decline to be randomised will be enrolled in an observational registry. The primary endpoint is all-cause mortality, which we plan to assess at 3 years after last participant is randomised. Secondary endpoints include clinical outcomes, appropriate and inappropriate device therapies, symptom severity and wellbeing, device-related complications, and analysis of the primary endpoint by subgroups with other risk markers. www.Clinicaltrials.gov: identifier NCT05568069. The BRITISH trial will assess whether use of CMR-defined scar to direct ICD implantation in patients with NICM and an LVEF ≤35% is associated with a reduction in mortality.