Leyva F, et al. - Authors wanted to quantify clinical outcomes after primary prevention of cardiac resynchronization therapy-defibrillation (CRT-D) and CRT-pacing (CRT-P) and determine if these were different according to the etiology of cardiomyopathy. CRT-D correlated with a lower total mortality, total mortality or HF hospitalization and total mortality or hospitalization for MACE in patients with ischemic cardiomyopathy when stratified according to etiology. In this study, CRT-D was superior to CRT-P in terms of total mortality and composite endpoints, independent of known confounders. Findings revealed that the benefit of CRT-D was evident in ischemic cardiomyopathy but not in non-ischemic cardiomyopathy.