ACE and nonischemic cardiomyopathy: After stratifying into Ischemic and Non Ischemic Cardiomyopathy, a Cox regression analysis was performed using Backward stepwise Ward rule for the occurrence of VT/VF with covariates—Age, Sex, type of intervention (ICD or CRT-D), Use of Amiodarone, Beta blocker, ACE inhibitor, NYHA Class and mean EF at the time of device implant and presence of CKD.