Prospective Nationwide Fluoroscopic and Electrical Longitudinal Follow-up of Recalled Riata Defibrillator Leads in Denmark

BACKGROUND: Recalled St Jude Medical Riata defibrillator leads are prone to insulation failures with externalized conductors (EC). Longitudinal studies are needed to guide lead management.

OBJECTIVE: 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 EC, 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 eight and borderline EC in two leads after 1.1 ± 0.2 years, incidence rate 3.7 per 100 person-years, 95% CI (2.0 - 6.9). Fluoroscopic follow-up in 27 patients with baseline EC showed an increase in EC length of 4 ± 1 mm (P < 0.001) 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, incidence rate 7.1 per 100 person-years, 95% CI (4.6-11.0). This rate was significantly higher in leads with baseline EC, adjusted incidence rate ratio 4.4, 95% CI (1.7-11.5), P = 0.002. In 15 extractions, all leads were removed with two major complications.

CONCLUSIONS: The development of EC is a dynamic process despite long lead dwell time. EC are associated with a higher risk of electrical abnormalities. Therefore, lead replacement should be considered, especially in patients with long life expectancy.