Author + information
- Received December 4, 2012
- Revision received January 30, 2013
- Accepted February 5, 2013
- Published online May 28, 2013.
- Jay Chen, MD⁎,
- George Johnson, BSEE†,
- Anne S. Hellkamp, MS‡,
- Jill Anderson, BSN†,
- Daniel B. Mark, MD‡,
- Kerry L. Lee, PhD‡,
- Gust H. Bardy, MD† and
- Jeanne E. Poole, MD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Jeanne E. Poole, University of Washington, 1959 NE Pacific Street, Box 256422, Seattle, Washington 98195
Objectives The aim of this study was to examine rapid-rate nonsustained ventricular tachycardia (RR-NSVT) during routine implantable cardioverter-defibrillator (ICD) evaluation in patients with heart failure and its relationship to outcomes.
Background The clinical implications of RR-NSVT identified during routine ICD interrogation are unclear. In this study, the occurrence of RR-NSVT and its association with ICD shocks and mortality in SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) were examined.
Methods The 811 patients who received ICDs in SCD-HeFT constituted the study population. The occurrence of RR-NSVT and its association with ICD shocks and mortality in SCD-HeFT were examined.
Results RR-NSVT was documented on ICD interrogation in 186 of 811 patients (22.9%). The mean duration of RR-NSVT was 26.4 ± 9.1 beats (7.5 ± 2.6 s), with a mean cycle length of 259 ± 32 ms. Polymorphic RR-NSVT accounted for 56% of episodes. Compared with patients without RR-NSVT, those with RR-NSVT were less likely to be taking beta-blockers, statins, or aspirin at enrollment. After adjusting for other known predictors of mortality in SCD-HeFT, RR-NSVT was independently associated with appropriate ICD shocks (hazard ratio: 4.25; 95% confidence interval: 2.94 to 6.14; p < 0.0001), with all-cause mortality (hazard ratio: 2.40; 95% confidence interval: 1.62 to 3.54; p < 0.0001), and with a composite of all-cause mortality and appropriate ICD shocks (hazard ratio: 3.03; 95% confidence interval: 2.21 to 4.15; p < 0.0001).
Conclusions RR-NSVT identified on routine ICD interrogation should be considered an important clinical event. RR-NSVT during ICD interrogation is associated with appropriate ICD shocks and all-cause mortality. The clinical evaluation of patients with RR-NSVT should include intensification of medical therapy, particularly beta-blockers, or other appropriate clinical interventions. (Sudden Cardiac Death in Heart Failure Trial [SCD-HeFT]; NCT00000609)
This study was supported by grants U01 HL55766, U01 HL55297, and U01 HL55496 from the National Heart, Lung, and Blood Institute and by Medtronic. Ms. Anderson is a consultant for Boston Scientific Corporation. Dr. Mark has received research funding from Eli Lilly & Company, Medtronic, Gilead, and AstraZeneca. Dr. Lee performs limited consulting for Medtronic. Dr. Bardy has received research funding from St. Jude Medical, is a consultant for and board member of Cameron Health Corporation and has equity and intellectual property rights with the company, and has received research funding from and has intellectual property with Cardiac Science. Dr. Poole has received lecture fees from Biotronik, Boston Scientific Corporation, Medtronic, and St. Jude Medical; has received compensation for scientific advisory board memberships from Boston Scientific Corporation, Cardiac Science, and Cameron Health; and has equity options in Cameron Health. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received December 4, 2012.
- Revision received January 30, 2013.
- Accepted February 5, 2013.
- American College of Cardiology Foundation