Abstract 12713: The Impact of Inappropriate Shocks from Implantable Cardiac Defibrillator Lead Failure on Cardiovascular Morbidity and Mortality
Background: The impact of inappropriate implantable cardiac defibrillators (ICD) shocks on mortality is controversial. Inappropriate shocks are commonly caused by arrhythmias which are themselves associated with worsening cardiac status and increased mortality. This relationship between worsening non-lethal arrhythmias and worsening clinical status makes determining the true effect of the ICD shocks on a patient’s outcome difficult. In 2007 Medtronic recalled its Sprint Fidelis ICD lead because of high failure rates. Many of the lead failures were associated with inappropriate ICD shocks due to lead noise. The purpose of this study was to compare the clinical outcome of patients with inappropriate shocks to those without shocks who underwent an extraction because of a Fidelis lead failure.
Methods: We retrospectively identified 148 patients who underwent Fidelis lead extraction in our institution between 5/2007-8/2012. The patients were separated into those with (Group 1) and without (Group 2) inappropriate shocks due to lead noise. Pertinent data (patient demographics, heart disease, co-morbidities, medications, procedural techniques, length of stay (LOS), and follow-up) were obtained from chart review.
Results: There were 57 (39%) group1 and 91 (61%) group 2 patients. The mean ± SD number of inappropriate shocks in group 1 was =16 ± 22. There was no difference in age, gender, hypertension, diabetes, coronary artery disease, non-ischemic related myopathy or pre-procedural arrhythmia burden between the groups. Aside from higher beta blocker use in group 1 (p=0.02), there was no difference in medications between the two groups. There were no extraction related deaths and there was no difference in the rate of peri-procedural complications between the groups (3 vs 6 in group 1 vs 2 respectively). The mean post procedure LOS (1.1 days) was the same between the groups. Follow-up information over 1 month (mean = 18 months) was available for 96 patients (46 and 50 in groups 1 and 2 respectively). For these patients there was no difference in cardiac readmission rate and mortality (7 vs 7 and 3 vs 6 in group 1 vs 2 respectively).
Conclusions: Inappropriate shocks due to lead noise do not seem to predispose to a worse clinical outcome after ICD lead extraction.
- © 2013 by American Heart Association, Inc.