Author + information
- Received July 22, 2012
- Revision received March 20, 2013
- Accepted April 23, 2013
- Published online October 29, 2013.
- Brian D. Powell, MD∗∗ (, )
- Leslie A. Saxon, MD†,
- John P. Boehmer, MD‡,
- John D. Day, MD§,
- F. Roosevelt Gilliam III, MD‖,
- Paul A. Heidenreich, MD, MS¶,
- Paul W. Jones, MS#,
- Matthew J. Rousseau, MS# and
- David L. Hayes, MD∗∗
- ∗Division of Cardiovascular Disease, Sanger Heart & Vascular Institute, Charlotte, North Carolina
- †Division of Cardiovascular Disease, University of Southern California, Los Angeles, California
- ‡Division of Cardiovascular Disease, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania
- §Division of Cardiovascular Disease, Intermountain Medical Center, Salt Lake City, Utah
- ‖Division of Cardiovascular Disease, Cardiology Associates of Northeast Arkansas, Jonesboro, Arkansas
- ¶Division of Cardiovascular Disease, VA Palo Alto Health Care System, Palo Alto, California
- #Biostatistics, Boston Scientific, St. Paul, Minnesota
- ∗∗Division of Cardiovascular Disease, Mayo Clinic, Rochester, Minnesota
- ↵∗Reprint requests and correspondence:
Dr. Brian D. Powell, Cardiovascular Division, Sanger Heart & Vascular Institute, 1001 Blythe Boulevard, Suite 300, Charlotte, North Carolina 28203.
Objectives This study sought to determine if the risk of mortality associated with inappropriate implantable cardioverter-defibrillator (ICD) shocks is due to the underlying arrhythmia or the shock itself.
Background Shocks delivered from ICDs are associated with an increased risk of mortality. It is unknown if all patients who experience inappropriate ICD shocks have an increased risk of death.
Methods We evaluated survival outcomes in patients with an ICD and a cardiac resynchronization therapy defibrillator enrolled in the LATITUDE remote monitoring system (Boston Scientific Corp., Natick, Massachusetts) through January 1, 2010. First shock episode rhythms from 3,809 patients who acutely survived the initial shock were adjudicated by 7 electrophysiologists. Patients with a shock were matched to patients without a shock (n = 3,630) by age at implant, implant year, sex, and device type.
Results The mean age of the study group was 64 ± 13 years, and 78% were male. Compared with no shock, there was an increased rate of mortality in those who received their first shock for monomorphic ventricular tachycardia (hazard ratio [HR]: 1.65, p < 0.0001), ventricular fibrillation/polymorphic ventricular tachycardia (HR: 2.10, p < 0.0001), and atrial fibrillation/flutter (HR: 1.61, p = 0.003). In contrast, mortality after first shocks due to sinus tachycardia and supraventricular tachycardia (HR: 0.97, p = 0.86) and noise/artifact/oversensing (HR: 0.91, p = 0.76) was comparable to that in patients without a shock.
Conclusions Compared with no shock, those who received their first shock for ventricular rhythms and atrial fibrillation had an increased risk of death. There was no significant difference in survival after inappropriate shocks for sinus tachycardia or noise/artifact/oversensing. In this study, the adverse prognosis after first shock appears to be more related to the underlying arrhythmia than to an adverse effect from the shock itself.
- atrial fibrillation
- cardiac resynchronization therapy
- implantable cardioverter defibrillators
- ventricular tachycardia
The ALTITUDE Study Group activities are financially supported by Boston Scientific (St. Paul, Minnesota).
Dr. Powell has received consulting fees from Boston Scientific. Dr. Saxon has received consulting fees from Boston Scientific and St. Jude Medical; and institutional grant support from Boston Scientific, Medtronic, Inc., and St. Jude Medical. Dr. Boehmer has received consulting fees and institutional grant support from Boston Scientific. Dr. Gilliam has received consulting fees from Boston Scientific, Medtronic, Inc., Philips Medical, and St. Jude Medical. Mr. Jones and Mr. Rousseau are employees of Boston Scientific. Dr. Hayes is an advisory board member for Boston Scientific and Medtronic, Inc.; is a steering committee member for St. Jude Medical; has received royalties from Wiley Publishing; and has received honoraria from Boston Scientific, Medtronic, Inc., St. Jude Medical, Biotronik, Inc., and Sorin Medical. All other authors have reported that they have no relationships relevant to the content of this paper to disclose.
- Received July 22, 2012.
- Revision received March 20, 2013.
- Accepted April 23, 2013.
- 2013 American College of Cardiology Foundation