Sprint Fidelis lead fractures in patients with cardiac resynchronization therapy devices: insight from the Resynchronization/Defibrillation for Ambulatory Heart Failure (RAFT) study.

Background: Using data from the Resynchronization/Defibrillation for Ambulatory Heart Failure (RAFT) study, we examined whether Fidelis lead failure was more common in patients with implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (ICD-CRT) than in patients with an ICD only.

Methods And Results: All cases of patients who had a right ventricular defibrillation lead revision in the RAFT study were adjudicated for the presence of lead fracture. Criteria for fracture were at least 2 of the following: (1) Impedance rise (>50% or >500 Ω in 1 week), (2) short interval count >10 times per day or 300 times per month, or (3) inappropriate shock caused by noise, verified by stored electrogram. A total of 1798 patients were enrolled into the RAFT study, with a mean follow-up of 40±20 months. There were 818 patients (45.5%) who received a Fidelis lead at the original implantation, 405 with an ICD only and 413 with an ICD-CRT. There were 47 confirmed defibrillation lead fractures; 45 were Fidelis leads (5.5% of Fidelis leads). The overall rate of fracture in the ICD group was 3.2% compared with 7.8% in the ICD-CRT group (P=0.006; hazard ratio, 2.42; 95% confidence interval, 1.27-4.61). Significant correlates of lead fracture in this population were undergoing an ICD-CRT implantation and having ≥2 leads.

Conclusions: In this analysis of the RAFT study, patients with an ICD-CRT were found to have a significantly higher fracture rate than patients with an ICD. This finding needs to be considered when these patients are assessed for possible lead revision at the time of an elective generator replacement.