[ICD therapy as secondary prevention]

Patients who survive out-of-hospital cardiac arrest or symptomatic ventricular tachyarrhythmias are at considerable risk of recurrence of these events and ultimately death. The implantation of an implantable cardioverter defibrillator (ICD) in patients with previous sustained ventricular tachyarrhythmias (VT) is considered secondary prevention of sudden cardiac death. The purpose of this review is to summarize the most important trials on secondary prevention with an ICD. The results from a meta-analysis showed a relative-risk reduction of 28% in overall mortality. Compared with amiodarone, an ICD provided maximal benefit for those patients with an ejection fraction between 20% and 35%. The results of the ICD trial demonstrate that there is clear evidence for the effectiveness of an ICD in patients with unstable VT; however, for patients with stable VT the results are less clear. Data on older patients are scant, and whether the survival benefit observed in the middle aged and younger-old also extend to older elderly patients with a more limited life span is less clear. Therefore, as the population becomes older, it is important to evaluate the safety, effectiveness, and the cost effectiveness of ICD implantation in this population. Guidelines are important and helpful to guide clinical decisions, but the indication for an ICD still remains an individual decision after evaluation of the risks and benefits for the individual patient. However, the patient needs to be involved, which emphasizes the importance of dialogue between the patient and physician.