Selecting patients for discussion of the ICD as primary prevention for sudden death in heart failure

This clinical perspective addresses the practical aspects of the decision to implant an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden death in patients with symptomatic heart failure and reduced left ventricular ejection fraction, based on a distillation of recent trial experience. Potentially eligible patients are selected on the basis of left ventricular ejection fraction < 30% to 35% and anticipated survival with good functional capacity beyond I year. Communication with these patients focuses on a horizon of 5 years, during which for every 100 patients receiving devices, approximately 30 patients are predicted to die with or without an ICD, while 7 to 8 lives may be saved with the ICD. These estimates are presented in the context of adverse events, including unnecessary shocks, and the possibility that circumstances may arise for which the defibrillator may be inactivated to allow natural death.