Knowledge of major adverse clinical events (MACE) associated with ICD and pacemaker (PM) pulse generator (PG) and lead performance may be important for managing patients who have these devices. The aim of our study was to assess MACE in our Multicenter Registry. Participating centers prospectively reported ICD and PM PG and lead failures, and PG replaced for normal battery depletion (NBD). Data included dates of implant and removal, failure signs including the elective replacement indicator (ERI), clinical consequences, and reason for removal. MACE were death, inappropriate shocks (IAS), syncope, heart failure, ischemia, sustained tachyarrhythmias, and replacement of a normally functioning PG or lead due to a manufacturers recall. Since 1998, 6,291 ICD and PM PG and leads were removed from service. Of 5,212 ICD and PM PGs, 4,562 (88%) were removed for NBD, 346 (7%) for a recall, and 304 (5%) for component defects. MACE are shown in the Table
. The deaths (n=2) were due to component defects causing an ICD PG to short-circuit and a PM PG to deliver high rate pacing. Thus, of the 304 component defects in our database, 2 resulted in death (0.7%). No deaths were associated with ICD or PM lead failure, but 2 deaths occurred following PM lead extraction. The ERI, signifying NBD, resulted in 48 MACE, primarily syncope (67%). Most MACE are due to replacement of normally functioning recalled devices. However, our experience suggests that death due to ICD and PM PG component or lead failure is rare; this finding may be important for managing patients who have recalled devices. Overall, MACE may be substantially reduced by improving high voltage lead reliability, and by providing physiologic ERIs.
In situ
damage assessment using synchrotron X-rays in materials loaded by a Hopkinson bar