Use of myocardial scar characterization to predict ventricular arrhythmia in cardiac resynchronization therapy

Aims There is insufficient evidence to implant a combined cardiac resynchronization therapy (CRT) device with defibrillation capabilities (CRT-D) in all CRT candidates. The aim of the study was to assess myocardial scar size and its heterogeneity as predictors of sudden cardiac death (SCD) in CRT candidates. Methods and results A cohort of 78 consecutive patients with dilated cardiomyopathy and class I indication for CRT-D were prospectively enrolled. Before CRT-D implantation, a contrast-enhanced cardiac magnetic resonance (ce-CMR) was performed. The core and border zone (BZ) of the myocardial scar were characterized and quantified with a customized post-processing software. The first appropriate implantable cardioverter defibrillator (ICD) therapy was considered as a surrogate of SCD. During a mean follow-up of 25 months (25–75th percentiles, 15–34), appropriate ICD therapy occurred in 11.5% of patients. In a multivariate Cox proportional hazards regression model for clinical and ce-CMR variables, the scar mass percentage [hazards ratio (HR) per 1% increase 1.1 (1.06–1.15), P < 0.01], the BZ mass [HR per 1 g increase 1.06 (1.04–1.09), P < 0.01], and the BZ percentage of the scar [HR per 1% increase 1.06 (1.02–1.11), P < 0.01], were the only independent predictors of appropriate ICD therapy. Receiver-operating characteristic curve analysis showed that a scar mass