[Implantable defibrillators and prevention of sudden death: clinical and economic implications in the light of the MADIT II study]. FT Defibrillatori impiantabili e prevenzione della morte improvvisa: implicazioni cliniche ed economiche alla luce dello studio MADIT II.

The cardioverter-defibrillator is the most effective strategy to prevent sudden death in patients with previous episodes of ventricular tachyarrhythmia (secondary prevention of sudden death). In recent years the possibility of primary prevention of sudden death in selected groups of high risk patients has raised great interest. The MADIT II study highlighted the possibility of preventing sudden death in patients with coronary artery disease. According to this trial, identification of such patients can be performed by means of few clinical data and without expensive screenings (i.e. electrophysiological study). Indeed, patients with a previous myocardial infarction and low left ventricular ejection fraction (< 30%) may benefit from the implant of a cardioverter-defibrillator, with a reduction of the mortality risk by about 31% in the following two years. In the light of these data, implant of a cardioverter-defibrillator should be proposed in such patients, even if the problem of limited economic resources to meet the cost of the devices has to be considered even in the richest country of the world. Despite the positive scientific result, MADIT II has raised the problem of the effective possibility of adopting this therapeutic strategy in clinical practice and this question is still open. Strategies to reduce the theoretically high costs implicated by the MADIT II study include a reduction in the cost of defibrillators through dynamic market forces, the identification of subgroups at higher risk of sudden death, and the use of cheap defibrillators with limited diagnostic and therapeutic options. A long-term evaluation of the cost-effectiveness for western countries of these strategies is necessary to identify in which patient subgroups implant of a cardioverter-defibrillator is acceptable, i.e. cost-effective, in terms of primary prevention.