Performance of Lead Integrity Alert to Assist in the Clinical Diagnosis of Implantable Cardioverter Defibrillator Lead Failures

Abstract

Background— The Lead Integrity Alert (LIA) was developed for Medtronic implantable cardioverter defibrillators to reduce inappropriate shocks for rapid oversensing caused by conductor fractures and reported for Medtronic Fidelis conductor fractures. The goal of this study was to compare the performance of LIA with conventional impedance monitoring for identifying lead system events (LSEs) and lead failures (LFs) in lead families that differ from Fidelis. Methods and Results— We analyzed data from 12 793 LIA enabled implantable cardioverter-defibrillator and lead combinations including 6123 St. Jude Riata or Durata, 5114 Boston Scientific Endotak, and 1556 Fidelis combinations followed in the CareLink remote monitoring network for LSEs and LFs. Each alert was adjudicated based on implantable cardioverter-defibrillator stored electrograms/diagnostics and clinical data as an LSE or non–lead system event by 2 physicians after reviewing the electrograms and clinical data. During 13 562 patient-years of LIA follow-up, there were 179 adjudicated alerts, of which 84 were LSEs (including 65 LFs) and 95 were non–lead system events. LIA identified >66% more LSE and >67% more LF compared with conventional impedance monitoring and did not differ by lead family for LSE ( P =0.573) or LF ( P =0.332). Isolated spikes on electrogram were associated more often with LF in St. Jude leads (71%) compared with Endotak (9%; P <0.001) and Fidelis leads (11%; P <0.001). The non–lead system event detection rate was different among lead families ( P <0.001) ranging from 1 in every 78.5 years (Endotak), 228.9 years (St. Jude leads), and 627.6 years (Fidelis). Conclusions— LIA markedly increased the detection rate of LSE compared with conventional impedance monitoring.