ICD therapy in survivors of sudden cardiac death awaiting heart transplantation.

The impact of implantable cardioverter defibrillator (ICD) therapy on survival of heart transplant candidates is of major socioeconomic and ethical interest. However, efficacy is even uncertain for patients at highest risk of tachyarrhythmic death on the waiting list. We studied 60 selected heart transplant candidates (mean age, 55.8 years; mean left ventricular ejection fraction, 0.15; functional class III and IV) with a history of successful resuscitation by external electric defibrillation for spontaneous, syncopal ventricular tachyarrhythmia during the study period from March 1992 through September 1994. At the time of registration for transplantation, 30 patients had ICD devices implanted, whereas 30 patients lacked ICD therapy for various nonmedical reasons. Both therapy groups were comparable in clinical and hemodynamic characteristics as well as in intention to transplant (median waiting time to transplantation, 5.7 and 6 months, respectively; not significant by log-rank method). Survival on the waiting list was significantly improved by ICD therapy; only 1 of the 30 ICD patients (19 transplanted) but 7 of the 30 non-ICD patients (14 transplanted) died on the waiting list (p < 0.05 by log-rank method). Implantable cardioverter defibrillator therapy did not affect survival after transplantation as compared with non-ICD patients (not significant by log-rank method). During the waiting time, 26 of the ICD patients (87%) experienced adequate ICD discharges, and 12 of the non-ICD patients were treated successfully by external electric defibrillation (40%).(ABSTRACT TRUNCATED AT 250 WORDS)