The Pacemaker and Implantable Defibrillator Leads Survival Study (“PAIDLESS”): Causes of Defibrillator Lead Failure

Aims: Previously, PAIDLESS demonstrated a correlation between lead failure, the number of recalled leads, and mortality. It also showed outcome differences between high and low-volume operators, as well as age and gender. The objective of this sub-study of PAIDLESS was to evaluate the causes of lead failure across three major implantable defibrillator lead manufactures (St. Jude Medical, Boston Scientific, Medtronic); between two recalled lead families (Medtronic Sprint Fidelis and St. Jude Medical Riata/Riata ST); and between recalled and non-recalled lead groups.

Methods and Results: This is a non-randomized, retrospective single-center study of 3,802 patients with 4,078 defibrillator leads implanted between 2/1/1996 and 12/31/2011. The causes of lead failure were categorized as insulation defect, lead fracture, or unclear etiology. A total of 153 leads (3.8%) failed during the study. The majority of failed Medtronic and St. Jude Medical leads failed by lead fracture (75.8% and 52.8%, respectively). 44.4% of failed Boston Scientific leads were from fractures as well. The mechanism of failure amongst failed recalled leads (Medtronic Sprint Fidelis and St. Jude Medical Riata/Riata ST) was also predominantly fracture (89.3% and 65.0%, respectively). Furthermore, patients with lead failures due to insulation defect or unclear mechanisms had decreased time to mortality after lead failure compared to patients with at least one lead fracture (p=0.007 and p=0.019, respectively).

Conclusions: The predominant cause of defibrillator lead failure was lead fracture regardless of the manufacturer or recalled lead status. Patients with lead failure due to insulation defect or an unclear etiology had a decreased time to mortality relative to those with lead fracture failures.