Sprint Fidelis Lead Fractures in Patients With Cardiac Resynchronization Therapy Devices: Insight From the Resynchronization/Defibrillation for Ambulatory Heart Failure (RAFT) Study

Study Questions:

Are Fidelis lead fractures more common in patients with an implantable cardioverter-defibrillator/cardiac resynchronization therapy device (ICD-CRT) than in patients with an ICD?


This was a post-hoc analysis of data from a randomized comparison of ICDs and ICD-CRTs in patients with heart failure and a QRS duration ≥120 ms. A total of 818 patients (45.8%) in the trial received a Fidelis lead (n = 405 in the ICD group, n = 413 in the ICD-CRT group). The median follow-up was 39 months.


The composite outcome of mortality or heart failure hospitalization did not differ significantly between patients with (37.9%) and without (34.4%) a Fidelis lead. The prevalence of lead fracture was significantly higher in the Fidelis group (5.5%) than in the non-Fidelis group (0.2%). Among the patients with a Fidelis lead, a lead fracture occurred significantly more often in the ICD-CRT group (7.8%) than in the ICD group (3.2%).


The risk of a Fidelis lead fracture is approximately 2.5 times higher in patients with an ICD-CRT than in patients with an ICD.


The reason that CRT predisposes to Fidelis lead fractures is unclear. Possible explanations include: 1) a larger number of leads in the subclavian vein, 2) an improvement in ejection fraction due to CRT, or 3) a higher likelihood of detecting lead fractures in CRT patients because of a high proportion of ventricular pacing. Regardless of the mechanism, the clinical implication of this study is that the threshold for replacing a Fidelis lead should be lower in patients with an ICD-CRT than in patients with an ICD.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Acute Heart Failure

Keywords: Heart Diseases, Cardiac Resynchronization Therapy Devices, Cardiac Pacing, Artificial, Electric Countershock, Heart Failure, Pacemaker, Artificial, Hospitalization, Defibrillators, Implantable, Subclavian Vein, Cardiac Resynchronization Therapy

< Back to Listings