Thirty seven cardiac deaths (12.2%) occurred in 301 pts with third generation implantable cardioverter-defibrillators (ICD) during a mean followup of 26±15 months. There were 17 (5.6%) heart failure deaths (HFD) and 20 (6.6%) sudden cardiac deaths (SCD). Baseline variables including age, gender, cardiac diagnosis, index or induced arrhythmia, and left ventricular ejection fraction were similar for HFD and SCD; mean NYHA class at ICD implant was lower in the SCD group (p=0.001). Kaplan-Meier survival rates for each group were not different(Figure, p=0.22).Time-dependent multivariate analysis revealed ejection fraction and NYHA class were the only variables independently related to time until death:Independent variableTime-dependent variablep-valueEjection fractionTotal cardiac death0.01Heart failure death008Sudden cardiac death0.04NYHA heart failure classTotal cardiac death0.10Sudden cardiac death0.10Sudden death and heart failure death occur at similar rates in ICD pts. Ejection fraction and NYHA heart failure class are the most important baseline determinants of time to death regardless of mechanism.