This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Google Scholar Articles by Blatt, J. A. PubMed Articles by Blatt, J. A. Related Collections Related Articles

CLINICAL RESEARCH: HEART RHYTHM DISORDER

No Benefit From Defibrillation Threshold Testing in the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial)

Joseph A. Blatt, MD^_*,_*, Jeanne E. Poole, MD^_*, George W. Johnson, BSEE, David J. Callans, MD, Merritt H. Raitt, MD, Ramakota K. Reddy, MD^||, Francis E. Marchlinski, MD, Raymond Yee, MD^¶, Thomas Guarnieri, MD^#, Mario Talajic, MD^_**, David J. Wilber, MD, Jill Anderson, RN, Kiyon Chung, MD, MPH, Wai Shun Wong, MD, Daniel B. Mark, MD^||||, Kerry L. Lee, PhD^||||, Gust H. Bardy, MD^_*, for the SCD-HeFT Investigators

^_* University of Washington, Seattle, Washington
Seattle Institute for Cardiac Research, Seattle, Washington
The University of Pennsylvania, Philadelphia, Pennsylvania
Portland Veterans Affairs Medical Center, Portland, Oregon
^|| Oregon Cardiology, P.C., Eugene, Oregon
^¶ University of Western Ontario, London, Ontario, Canada
^# John Hopkins University, Baltimore, Maryland
^_** Montreal Heart Institute, Montreal, Quebec, Canada
Loyola University Health System, Maywood, Illinois
The Everett Clinic, Everett, Washington
University of Michigan, Ann Arbor, Michigan
^|||| Duke University School of Medicine, Durham, North Carolina.

Manuscript received November 27, 2007; revised manuscript received March 19, 2008, accepted April 3, 2008.

^_* Reprint requests and correspondence: Dr. Joseph A. Blatt, University of Washington, Department of Cardiology, Box 356422, 1959 NE Pacific Street, Seattle, Washington 98195. (Email: jablatt{at}u.washington.edu).

Objectives: This study investigated whether defibrillation threshold (DFT) testing during implantable cardioverter-defibrillator (ICD) implantation predicts clinical outcomes.

Background: Defibrillation testing is often performed during insertion of ICDs to confirm shock efficacy. There are no prospective data to suggest that this procedure improves outcomes when modern ICDs are implanted for primary prevention of sudden death.

Methods: The analysis included the 811 patients who were randomized to the ICD arm of the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) and had the device implanted. The DFT testing protocol in SCD-HeFT was designed to limit shock testing in a primary prevention heart failure population.

Results: Baseline DFT data were available for 717 patients (88.4%). All 717 patients had a DFT of 30 J, the maximum output of the device in this study. The DFT was 20 J in 97.8% of patients. There was no survival difference between patients with a lower DFT (10 J, n = 547) and a higher DFT (>10 J, n = 170) (p = 0.41). First shock efficacy was 83.0% for the first clinical ventricular tachyarrhythmia event; there were no differences in shock efficacies when the cohort was subdivided by baseline DFT.

Conclusions: Low baseline DFTs were obtained in patients with stable, optimally treated heart failure during ICD implantation for primary prevention of sudden death. First shock efficacy for ventricular tachyarrhythmias was high regardless of baseline DFT testing results. Baseline DFT testing did not predict long-term mortality or shock efficacy in this study.

Key Words: sudden cardiac death • implantable cardioverter-defibrillator • defibrillation threshold testing • DFT testing

Abbreviations and Acronyms   DFT = defibrillation threshold   EGM = electrogram   ICD = implantable cardioverter-defibrillator   SCD = sudden cardiac death   VF = ventricular fibrillation   VT = ventricular tachycardia

Related Articles

Defibrillation Threshold Testing in Implantable Cardioverter-Defibrillators: Might Less Be More Than Enough?

Anne B. Curtis
J. Am. Coll. Cardiol. 2008 52: 557-558. [Full Text] [PDF]

This article has been cited by other articles:

				A. B. Curtis Defibrillation Threshold Testing in Implantable Cardioverter-Defibrillators: Might Less Be More Than Enough? J. Am. Coll. Cardiol., August 12, 2008; 52(7): 557 - 558. [Full Text] [PDF]