Why Are Implantable Cardioverter-Defibrillators and Pacemakers Being Revised Today?

Implantation of pacemakers (PM) and implantable cardioverter defibrillators (ICDs) has dramatically increased in recent years.  An estimated 300,000 patients in the US were implanted with a pacemaker or an ICD in 2007. Despite the growing use of ICDs and PMs, there are few studies in the literature that report of the rates of explantation for these devices. The purpose of this study was to characterize the reasons for revision of PMs and ICDs in a teaching hospital program. In a 10-month period, a consecutive series of 90 devices (54 ICDs and 36 PMs) were collected as part of an IRB-approved device retrieval program. During that same time period, 397 device-related procedures were performed.  Among the 54 explanted ICDs , 43 (79.6%) were removed for elective replacement (ERI) for battery life, 6 (11.1%) were upgraded to biventricular devices, 3 were removed for infection, 1 was removed for lead malfunction, and 1 was removed for erosion of skin near the generator. Among the 36 revised PMs, 28 (77.8%) were removed for ERI, 4 were upgraded to biventricular devices, 3 were removed for infection and 1 was removed for erosion of the skin near the generator. ICD average implantation time was 4.9±2.0 y (range: 0.10 -10.3). PM average implantation time was 6.5±2.9 y (0.1-11.1). Implantation time for devices removed for ERI were higher than all other removal reasons (ICD 5.5±1.5, PM 7.7±1.6). Devices removed for upgrading or infection were associated with lower implantation times. The results of this study provide insight into the revision reasons and durations for contemporary pacemakers and ICDs based on a high-volume academic research center, where device removal accounted for > one-fifth of all device related procedures. Further expansion of this study is underway to include additional centers and battery testing to characterize remaining battery life on explanted devices.