Author + information
- Received October 3, 2017
- Revision received November 27, 2017
- Accepted November 30, 2017
- Published online May 21, 2018.
- David S. Frankel, MDa,∗ (, )
- Martin C. Burke, DOb,
- David J. Callans, MDa,
- Timothy M. Stivland, MBAc,
- Elizabeth Duffy, MSc and
- Andrew E. Epstein, MDa
- aElectrophysiology Section, Cardiovascular Division, Perelman School of Medicine at the University of Pennsylvania, Philadelphia
- bHeart Rhythm Center, CorVita Science Foundation, Chicago, Illinois
- cBoston Scientific Corporation, St. Paul, Minnesota
- ↵∗Address for correspondence
: Dr. David S. Frankel, Cardiovascular Division, Electrophysiology Section, Hospital of the University of Pennsylvania, 9 Founders Pavilion, 3400 Spruce Street, Philadelphia, Pennsylvania 19104.
Objectives This study determined whether obesity increased the risk of failed shocks and complications among subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients.
Background The S-ICD is an established treatment for patients at high risk for ventricular arrhythmias. Obesity may increase the transvenous defibrillation threshold and the rate of complications.
Methods We analyzed data from the 321 patients enrolled in the S-ICD Investigational Device Exemption (IDE) study. They were categorized into 3 body mass index (BMI) groups: <25 kg/m2 (underweight and normal), 25 to 30 kg/m2 (overweight), and >30 kg/m2 (obese). Patients underwent implantation followed by defibrillation testing at 65 J. Chronic defibrillation testing was repeated >150 days post implantation in a subset of patients.
Results Seventy-nine patients had BMI <25 kg/m2, 105 had BMI 25 to 30 kg/m2, and 137 had BMI >30 kg/m2. A failed first shock of any kind occurred in 52 patients, including 41 patients during implant defibrillation testing, 11 patients during chronic defibrillation testing, and 5 patients during spontaneous ventricular arrhythmias. The rate of failed first shocks during implant defibrillation testing increased across BMI categories (5.1% among underweight and normal patients, 13.3% among overweight patients, and 16.9% among obese patients; p = 0.04). Among obese patients, shock impedance was higher during failed first shocks than successful first shocks (103.5 ohms vs. 84.6 ohms; p = 0.001). The rate of failed first shocks during chronic defibrillation testing and spontaneous ventricular arrhythmias did not significantly differ among BMI groups, nor did the rate of complications. Of the 8 underweight patients, there were no failed shocks or complications.
Conclusions Obese patients are at increased risk of failed first S-ICD shocks during defibrillation testing. Whether this can be overcome by optimal implantation techniques remains unknown. Rates of complications were not increased among obese patients.
This work was supported by the Koegel Family Fund.
Dr. Frankel has received lecture honoraria from Boston Scientific and Medtronic. Dr. Burke has received lecture honoraria from Boston Scientific, Medtronic, and Abbott; and has received research support from Boston Scientific, Cameron Health, AJ Medical, Inc., Medtronic, and Abbott. Dr. Callans has received fees as a consultant and speaker for Boston Scientific. Mr. Stivland and Ms. Duffy are employees of Boston Scientific. Dr. Epstein has received honoraria for committee membership and research support from Boston Scientific, Medtronic, and Abbott.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institution and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received October 3, 2017.
- Revision received November 27, 2017.
- Accepted November 30, 2017.
- 2018 American College of Cardiology Foundation