Incidence of adequate and inadequate therapies in patients with an implantable Cardioverter Defibrillator for primary prevention

We evaluated the number of adequate and inappropriate therapies for ventricular tachyarrhythmia and trigger mechanisms in 55 MADIT II (MII) and 86 SCD-HeFT (SH) like patients. Results 399 adequate episodes could be analysed from 31 patients implanted according to the MII trial, while 502 adequate episodes were registered in 47 patients matching the SIT inclusion criteria (mean follow-up in both collectives 33 +/- 19 months). The results of the present study regarding inappropriate therapies illustrate that patients from the MII cohort had 39 inadequately treated episodes (9% of all included episodes). Patients from the SH group were treated inadequately 76 times (15% of all included episodes). 18% of the MII group (10 patients) and even 22% of the SH collective (19 patients) were treated inadequately at least once. Discussion Our data of > 500 malignant ventricular arrhythmias substantiate the use of an ICD in a collective of primary prevention patients. Therefore, the findings of our study encourage the need of an ICD in these patients. On the other hand, despite skilled ICD programming and an optimal medical treatment, a relevant rate of inadequate therapies could be demonstrated. Conclusion Although a noteworthy proportion of inadequate ICD interventions was observed, our study supports the indication of an ICD implant in a collective of patients who are in danger of sudden cardiac death.