[ICD: to replace or not to replace, this is the question. the ICD-downgrade + telemetry-upgrade-trial]

Implantable defibrillators (ICDs) have to be replaced after 4-6 years due to battery depletion. Therefore, 195-267 ICDs may be necessary for 100 ICD patients, if device longevity is 6 and 4 years, respectively. In Germany, 35% of all ICDs were replacements in 2003. The percentage of replacements will probably increase to > 50% in the next years. With fixed budgets, a de novo implantation may therefore compete with an exchange ICD in the future. The explantation of an ICD is currently only possible under special circumstances, even in patients without adequate therapies during recent years, since data on the risk of a sudden cardiac death after an explantation are rare and contradictory. However, a downgrading of the ICD in patients without any therapies in recent years may be feasible, i. e., the ICD may be programmed to a shock-only device with a therapy delay of 15 s. This may even result in an increased longevity of the devices. This concept will be prospectively tested in the randomized ICD-Downgrade + Telemetry-Upgrade study.