Scar channels in cardiac magnetic resonance to predict appropriate therapies in primary prevention.

Abstract: Background Scar characteristics analysed by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related with ventricular arrhythmias. Current guidelines are based only on the left ventricle ejection fraction (LVEF) to recommend an implantable cardioverter defibrillator (ICD) in primary prevention. Objectives Our study aims to analyse the role of imaging to stratify arrhythmogenic risk in patients with ICD for primary prevention Methods Since 2006 to 2017, we included 200 patients with LGE-CMR prior ICD implantation in primary prevention. The scar, border zone (BZ), core and conducting channels (CC) were automatically measured by a dedicated software. Results Mean age was 60.9±10.9 years, 81.5% male, 52% with ischemic cardiomyopathy. Mean LVEF was 29±10.1%. After a follow-up of 4.6±2 years, 46 patients (22%) reached the primary endpoint (appropriate ICD therapy). Scar mass (36.2±19g vs. 21.7±10 g;p 10 grams (25,31% vs 5,26%;HR 4.74,p=0.034) and the presence of CC (34,75% vs 8,93%;HR 4.07,p=0.003) were also strongly associated with the primary endpoint. However, patients without channels and with scar mass Conclusions Scar characteristics analysed by LGE-CMR are strong predictors of appropriate therapies in patients with an ICD in primary prevention. Absence of channels and scar mass