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 (BRITISH)

Sudden arrhythmic death is an important cause of death in patients with non-ischaemic cardiomyopathy (NICM). Current guidelines recommend prophylactic implantation of a defibrillator (ICD) if left ventricular ejection fraction (LVEF) is ≤35%. A recent substantial trial found no overall benefit from an ICD in this population. Selection criteria for an ICD in NICM are blunt; most patients receiving an ICD will never benefit from it. Strategies to improve stratification of NICM patients who would benefit from an ICD would have important clinical and economic impacts. The presence of CMR-identified scar indicates an increased risk of sudden death and these patients have potential to benefit from ICD therapy. The aim of BRITISH is to determine, in a randomised trial of 1252 patients at 35 UK centres, whether the presence of CMR-detected scar used as the arbiter of ICD therapy results in a lower all-cause mortality. A registry will allow observation of event rates in scar negative patients. Feasibility will be tested in a Vanguard phase, aiming to recruit 256 randomised patients over 12 months (following set up) with clear stop/go criteria. The results of this trial will inform international guidelines and have the potential to improve patient care and save money.