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

Abstract

Original ArticleBackground-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 cardioverterdefibrillator 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. 1561, 1570, 1571, 1572, 1580, 1581, 1582, 1590, 1591, 1592, 1940, 7000, 7001, 7002, 7010, 7020, 7021, 7022, 7040, 7041, 7042, 7052, 7070, 7071, 7120, 7121, 7122, 7130) or a Boston Scientific Endotak ICD lead (0061, 0064, 0072, 0074, 0075, 0095, 0115, 0125, 0127, 0128, 0134, 0135, 0137, 0138, 0144, 0145, 0147, 0148, 0149, 0154, 0155, 0157, 0158, 0159, 0171, 0174, 0175, 0180, 0181, 0182, 0184, 0185, 0186, 0187) with a CareLink remote monitoring transmission between August 28, 2008, and October 4, 2011, were included in the analysis. Patients with Fidelis leads (models 6930, 6931, 6948, 6949) from a separate prospectively defined cohort were included as controls. Device diagnostic data associated with LIA triggers or any pace-sense impedances that triggered conventional impedance alerts (>2000 or <200 ohms) were reviewed. Follow-up time was calculated in years from the date the LIA algorithm was programmed on to the date of the last LIA enabled transmission. Lead Integrity AlertThe present LIA requires 2 of 3 of components to be satisfied within 60 days: abrupt pace-sense impedance change, frequent extremely short R-R intervals, and rapid nonsustained ventricular tachycardia episodes. 7,11 The abrupt impedance change requires an increase >75% or decrease to <50% of th...

2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing

“…Approaches to minimizing Twave oversensing include reprogramming ventricular sensitivity, altering sensing bandwidth, and changing the sensing bipole [109,123,145]. One manufacturer provides an algorithm that withholds therapy after rate and duration criteria for VT/VF are fulfilled if a specific pattern of T-wave oversensing is identified [146].…”

“…Oversensed signals caused by pace-sense lead failure have specific interval patterns and EGM characteristics [145,147,148]. Present algorithms identify three features: (1) intervals can be too short to represent successive ventricular activations; (2) such short intervals are often transient and can be repetitive; and (3) in true bipolar leads, oversensed signals are absent on the shock EGM.…”

“…These algorithms might not be appropriate for detecting failures in other leads [144]. There is a high false-positive rate when using these algorithms, and caregivers must carefully review the device data that caused the alert to ensure the lead experienced a true failure [145].…”

“…Alerts that combine both oversensing and abrupt changes in impedance trends provide earlier warning of lead failure than a fixed impedance threshold [144,145,149]. Such alerts can be delivered via wireless remote monitoring and/or by notifying the patient via vibration or an audible tone.…”

Implantable Cardioverter-Defibrillator Leads

“…Electrograms associated with clinically diagnosed failures of Riata leads often showed characteristic spikes on both sensing and shock channels that may represent interactions between conductors in the lead ( Figure 4B). 29 Simultaneous nonphysiological signals on the shock and sensing electrograms have been reported in inside-out abrasion of the ring electrode cable against the RV shock coil ( Figure 4C). 21 When cyclical, they may be confused with physiological T waves.…”