Background: Recalled St. Jude Medical Riata defibrillator leads are prone to insulation failures with externalized conductors (ECs). Longitudinal studies are needed to guide lead management.
Objective: The purpose of this study was to describe the dynamic nature of EC and the association with electrical abnormalities and lead extraction outcomes.
Methods: A nationwide cohort established in 2012 of 295 patients with recalled Riata leads with dwell time 5.1 ± 1.1 years, 34 ECs, and 19 electrical abnormalities were followed until death, lead discontinuation with fluoroscopy, or a new 2013 screening with fluoroscopy and device interrogation.
Results: Fluoroscopic follow-up of 239 patients with normal baseline fluoroscopy revealed incident overt EC in 8 leads and borderline EC in 2 leads after 1.1 ± 0.2 years, with an incidence rate of 3.7 per 100 person-years (95% confidence interval 2.0-6.9). Fluoroscopic follow-up in 27 patients with baseline EC showed an increase in EC length of 4 ± 1 mm (P <.001) after 1.1 ± 0.3 years. Electrical follow-up in 276 patients with normal baseline electrical function demonstrated 20 incident electrical abnormalities after 1.0 ± 0.3 years, with an incidence rate of 7.1 per 100 person-years (95% confidence interval 4.6-11.0). This rate was significantly higher in leads with baseline EC, with an adjusted incidence rate ratio of 4.4 (95% confidence interval 1.7-11.5, P = .002). In 15 extractions, all leads were removed, with 2 major complications.
Conclusion: The development of EC is a dynamic process despite long lead dwell time. ECs are associated with a higher risk of electrical abnormalities. Therefore, lead replacement should be considered, especially in patients with a long life expectancy.
Keywords: Advisory; Defibrillation lead; Fluoroscopy; Implantable cardioverter-defibrillator; Lead extraction; Lead failure; Recall; Riata.
Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.