Incidence of Defibrillator Shocks After Elective Generator Exchange Following Uneventful First Battery Life

• Type of Material: Article
• Authors: Faisal Merchant, Emory University; Paul Jones, Boston Scientific Corporation; Scott Wehrenberg, Boston Scientific Corporation; Michael Lloyd, Emory University; Leslie A. Saxon, University of Southern California
• Language: English
• Date: 2014-12-01
• Publisher: Wiley Open Access: Creative Commons Attribution Non-Commercial
• Publication Version: Final Published Version
• Copyright Statement: © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1161/JAHA.114.001289
• Title of Journal or Parent Work: Journal of the American Heart Association
• ISSN: 2047-9980
• Volume: 3
• Issue: 6
• Start Page: e001289
• End Page: e001289
• Keywords: CARDIAC RESYNCHRONIZATION THERAPY; Life Sciences & Biomedicine; CARDIOMYOPATHY; HEART-FAILURE; RECIPIENTS; sudden death; TIME; MORTALITY; Science & Technology; IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR; Cardiovascular System & Cardiology; defibrillation; SURVIVAL; Cardiac & Cardiovascular Systems; electrophysiology; LONGEVITY; ICD REPLACEMENT
• Research Categories: Health Sciences, General; Health Sciences, Medicine and Surgery

Abstract

Background: A significant number of implantable cardioverter-defibrillator (ICD) patients do not experience shocks after ICD implant. Elective generator exchange (GE) has been associated with increased risk of infection and ICD lead failure. There is a paucity of contemporary data reporting on shock incidence with replacement devices. Methods and Results: Patients undergoing elective GE (n=24 203) who transmit data remotely via a remote monitoring system were analyzed to determine the incidence of ICD shocks after GE. A total of 16 230 patients (67%) did not experience a shock with the first ICD (group A), and 7973 (33%) received at least 1 shock (group B). Patients in group A were older (71.3 versus 68.8 years, P<0.001) and more often female (71% versus 77% male, P<0.001). Over an average follow-up of 1.9±1.2 years after GE, the proportion of patients with shocks and risk of ICD shocks was lower for those who did not receive a shock during the first battery life (group A: 9.9% versus 27.7%, hazard ratio 0.36, 95% CI 0.34 to 0.38, P<0.001). The cumulative rate of ICD shocks at 5 years after GE was 25.7% in group A and 51.1% in group B. Conclusions: In this large cohort of ICD patients implanted across the United States, two thirds did not receive ICD shock therapy prior to GE. The occurrence of ICD shocks prior to GE is an important predictor of shocks after GE; however, even among those without shocks during first battery life, the incidence of shocks at 5 years following GE is >25%. These data should support informed decision making for patients and physicians at the time of ICD generator end of service.