What physicians do in case of a failure of the pace-sense part of a defibrillation lead : Survey in Germany, Austria and Switzerland.

BACKGROUND: The possible treatment strategies for defects of the pace-sense (P/S) part of a defibrillation lead are either implantation of a new high-voltage (HV)-P/S lead, with or without extraction of the malfunctioning lead, or implantation of a P/S lead. METHODS: We conducted a Web-based survey across cardiac implantable electronic device (CIED) centers to investigate their procedural practice and decision-making process in cases of failure of the P/S portion of defibrillation leads. In particular, we focused on the question of whether the integrity of the HV circuit is confirmed by a test shock before decision-making. The questionnaire included 14 questions and was sent to 951 German, 341 Austrian, and 120 Swiss centers. RESULTS: The survey was completed by 183 of the 1412 centers surveyed (12.7% response rate). Most centers (90.2%) do not conduct a test shock to confirm the integrity of the HV circuit before decision-making. Procedural practice in lead management varies depending on the presentation of lead failure and whether the center applies a test shock. In centers that do not conduct a test shock, the majority (69.9%) implant a new HV-P/S lead. Most centers (61.7%) that test the integrity of the HV system implant a P/S lead. The majority of centers favor DF-4 connectors (74.1%) over DF-1 connectors (25.9%) at first CIED implantation. CONCLUSION: Either implanting a new HV-P/S lead or placing an additional P/S lead are selected strategies if the implantable cardioverter-defibrillator lead failure is localized to the P/S portion. However, conducting a test shock to confirm the integrity of the HV component is rarely performed.

Externalized conductors and electrical dysfunction in transvenous ventricular leads: Results of the Cardiac Lead Assessment Study.

Background: The Cardiac Lead Assessment Study (CLAS) was a large prospective, multicenter, international postmarket surveillance study conducted at 45 sites. Objective: The purpose of CLAS was to examine the prevalence and incidence of externalized conductors and electrical dysfunction in subjects with selected St. Jude Medical defibrillator and left ventricular leads. Methods: Cinefluoroscopy was used to determine the presence of externalized conductors at enrollment and at 12-, 24-, and 36-month follow-up visits. Lead electrical measurements were collected systematically. Results: The study enrolled 2216 subjects with a total of 2847 study leads. The prevalence of externalized conductors through 36 months for Riata leads was 30.9%, Riata ST leads 12.6%, Durata leads 0.5%, and QuickSite/QuickFlex leads 4.7%. The prevalence of electrical dysfunction through 36 months for Riata was 4.0%, Riata ST 3.3%, Durata 2.4%, and QuickSite/QuickFlex 0.3%. In Riata and Riata ST leads with externalized conductors, there was a low risk of electrical dysfunction. None of the Durata or QuickSite/QuickFlex leads with externalized conductors developed electrical dysfunction. There was no evidence of an electrical short in a high-voltage shocking circuit leading to failed shock. Conclusion: A high prevalence of externalized conductors was found in Riata and Riata ST defibrillator leads, with a higher risk of externalization for 8F Riata leads than for 7F Riata ST leads. The 98% reduction in prevalence of externalized conductors in Durata leads compared to Riata/Riata ST leads confirms that the design improvements culminating in Durata leads significantly improved abrasion resistance and durability.

Prevalence of externalized conductors in Riata and Riata ST silicone leads: results from the prospective, multicenter Riata Lead Evaluation Study.

BACKGROUND/OBJECTIVE: Following a class I recall of St. Jude Medical Riata/Riata ST silicone implantable cardioverter-defibrillator leads, we report on the phase I results of the Riata Lead Evaluation Study, a prospective, multicenter investigation to assess the prevalence of externalized conductors (ECs) and the electrical dysfunction in these leads. METHODS: We enrolled patients previously implanted with Riata/Riata ST leads and performed cinefluoroscopy using multiple views. A physician panel adjudicated the images for the presence of EC. The prevalence of EC was stratified and compared by lead model and patient characteristics. Upon occurrence of a lead revision, another physician panel determined whether electrical dysfunction had occurred based on predefined criteria. RESULTS: Seven hundred seventy six patients with Riata/Riata ST silicone leads (8Fr/7Fr = 66.6%/33.4%; single-/dual-coil = 12.9%/87.1%) across 23 centers were analyzed. Implant duration was 4.8 ± 0.9 years for 7Fr and 6.5 ± 1.6 years for 8Fr leads (P <.001). The prevalence of EC was significantly lower in 7Fr compared with 8Fr leads for the entire study population (9.3% vs 24.2%, P < .001) and for leads implanted ≤6 years (9.4% vs 18.8%, P = .006). Other than lead size, there were no significant differences in lead, patient, or electrical characteristics between leads with and without EC. Over a period of 9.8 ± 2.0 months, the overall prevalence of electrical dysfunction was 1.3% (confidence interval 0.49%-2.1%), with only 3 of 10 cases occurring in leads with EC. CONCLUSION: Larger-diameter Riata leads were more prone to EC than smaller-diameter Riata ST leads. The prevalence of electrical dysfunction was not associated with EC.