Gutman SJ, et al. - Given that left ventricular (LV) scar identified by cardiac magnetic resonance (CMR) imaging is associated with a high risk of malignant arrhythmia in non-ischemic cardiomyopathy (NICM), researchers investigated how LV scar influences the mortality benefit from a primary prevention implantable cardioverter-defibrillator (ICD) in NICM. From a state-wide CMR service, recruitment of 452 consecutive heart failure patients (New York Heart Association Class II/III) with NICM and LV ejection fraction ≤35% was carried out. The analysis of these patients revealed that primary prevention ICD implantation was only related to attenuated mortality in patients with LV scar.