PROPHYLACTIC TRIALS WITH IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS - MADIT AND BEYOND

Numerous studies have proven the efficacy of the ICD in prolonging lif e, both in patients with previous history of ventricular tachyarrhythm ias and in patients such as in MADIT, without such arrhythmias, but at a high risk of VT or VF. Nevertheless, this therapy has had relativel y small impact on reducing the overall problem of sudden cardiac death , simply be cause the populations treated using currently accepted ind ications make up a tiny portion of at-risk patients. There are numerou s studies aiming to further clarify which patients can benefit from IC Ds for primary prevention. One of these, CABG-Patch, has finished, wit h a neutral result. The only certain implication is that patients dest ined for CABG surgery and having no further specific arrhythmia risk m arkers should not receive ICDs. Other studies have recently begun, and it will be several years before their results are known iz. The prove n efficacy of the ICD for therapy of VT and VF has, in fact, introduce d new feasibility and ethical considerations in designing future clini cal trials. (J Interven Cardiol 1998; 11:227-233).