Skip Navigation Archive: U.S. Department of Health and Human Services U.S. Department of Health and Human Services
Archive: Agency for Healthcare Research Quality
Archival print banner

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

Implantable Cardioverter Defibrillators to Prevent Sudden Cardiac Death: Background

Slide Presentation from the AHRQ 2011 Annual Conference

On September 21, 2011, Frederick Masoudi made this presentation at the 2011 Annual Conference. Select to access the PowerPoint® presentation (2.3 MB). Plugin Software Help.

Slide 1

Implantable Cardioverter Defibrillators to Prevent Sudden Cardiac Death: Background

Frederick A. Masoudi, MD, MSPH.
Associate Professor of Medicine (Cardiology).
University of Colorado Denver & Colorado Cardiovascular Outcomes Research Group (C-COR).
AHRQ Annual Meeting, Bethesda, MD.
Wednesday, September 21, 2011.

Slide 2


  • Frederick A Masoudi, MD, MSPH: Implantable Cardioverter Defibrillators for Primary Prevention.
  • Research Grants: AHRQ, National Heart, Lung, and Blood Institute (NHLBI) .
  • Contracts: American College of Cardiology Foundation (Senior Medical Officer, National Cardiovascular Data Registries); Oklahoma Foundation for Medical Quality.

Slide 3

Defibrillation Treats Malignant Cardiac Arrhythmias

Image: An electrical defibrillatior and ECG report is shown.

Slide 4

Implantable Cardioverter Defibrillators (ICDs): Preventing Sudden Cardiac Death (SCD)

Image: An x-ray of a chest with an implanted ICD is shown.

Slide 5

The ICD: Revolution in Preventing Sudden Cardiac Death

  • First ICD implantation: Johns Hopkins Hospital 2/4/1980.
  • Implantation criteria:
    • ≥2 cardiac arrests.
    • Not associated with myocardial infarction.
    • Documented ventricular fibrillation.

Image: The Johns Hopkins Hospital is shown.

Cannom DS and Prystowsky E. PACE 2004;27:419-431.

Slide 6

ICDs for Secondary SCD Prevention

AVID Investigators. N Engl J Med 1997;337:1576-83.

Images: The headline from an article in the New England Journal of Medicine is shown: "A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias." A line graph from the article compares the survival rate of the defibrillator group with the antiarrhythmic-drug group.

Slide 7

ICDs for Primary Prevention: Dual Evolution

Eligible Population for 1o Prevention ICD

Images: A yellow triangle captioned "Eligible Population for 1o Prevention ICD" is placed between a photograph of a pacemaker and a graph showing survival rates for patients (in months).

Slide 8

ICDs: Rapidly Evolving Technology

Images: A photograph of Thomas Edison in 1877 and an iPod is shown.

Slide 9

MADIT I: ICDs Prevent Death in Ischemic LVSD

Enrollment criteria:

  • NYHA functional class I-III.
  • Prior myocardial infarction.
  • LVEF ≤0.35.
  • Documented asymptomatic non-sustained VT.
  • Inducible, non-suppressible ventricular tachyarrhythmia on EP study (on procainamide).


  • 54% relative reduction (23% absolute reduction) in the risk of death from all causes.

Moss AJ et al. N Engl J Med 1996;335:1933-40.

Slide 10

More Studies, More Success

(EPS vs. no AAR)
  • CAD
  • LVEF ≤0.40
  • NSVT
  • Inducible VT
  • Death (arrhythmic)
  • Cardiac arrest
0.24 (0.13-0.45)*
ARR 19.5%
  • Prior MI
  • LVEF ≤0.30
  • No EPS required
  • Death (any)
0.69 (0.51-0.93)
ARR: 5.4%
  • LVEF ≤0.35
  • Includes non-ischemic
  • Death (any)
0.77 (0.62-0.96)
ARR: 7.2%

Buxton AE et al. NEJM 1999;341:1882-1890.
Moss AJ et al. NEJM 2002;346:877-83.
Bardy GH et a. NEJM 2005;352:225-37.

Slide 11

Primary Prevention ICDs: Cost-Effective

Image: A line graph shows the following data:

ICD-Associated Reduction
in Death Risk (%)
($ per QALY)

Sanders GD et al. NEJM 2005;353:1471-80.

Slide 12

ACC/AHA Guideline Recommendations for Primary Prevention ICD Therapy

Image: Four colored blocks in a row are shown. The first, green, is captioned "I" and has the letter "A" inside. The second, yellow, is captioned "IIa." The third, orange, is captioned "IIb." The final block, red, is captioned "III."

Jessup M et al. J Am Coll Cardiol 2009;53.
Epstein AE et al. Circulation 2008;117.

Slide 13

Current Indications for ICDs

  • "Secondary prevention" for patients who have been successfully resuscitated from SCD.
  • "Primary Prevention" for patients without a history of SCD but at high risk, including some patients with:
    • Severe left ventricular dysfunction (LVSD).
    • Long QT syndrome.
    • Arrhythmogenic RV dysplasia.
    • Hypertrophic cardiomyopathy.

Slide 14

CMS Coverage for ICDs Expands in Response to RCTs

YearCovered Indication
1999Documented familial or inherited high-risk conditions (HCM or LQTS)
  • Prior MI >40 days prior to implantation
  • LVEF ≤0.35
  • Inducible sustained VT/VF at EPS
  • If LVEF ≤0.30 and QRS >120 ms, then EPS not needed
  • Ischemic CM, NYHA II-III, LVEF ≤0.35
  • Non-ischemic CM >9 months, NYHA II-III, LVEF ≤0.35
  • Meeting CRT criteria and NYHA IV"ncd_version=3&basket =ncd%3A20%2E4%3A3%3AImplantable+Automatic+Defibrillators

Slide 15

Theory and Practice

"In theory there is no difference between theory and practice. In practice there is."
—Yogi Berra

Image: A picture of Yogi Berra is shown.

Photo: Googieman, Creative Commons,

Slide 16

Clinical Trials to the Real World: Big "Voltage Loss"

Image: A flowchart shows connections between the following data in text boxes:

Older Hospitalized Patients with HF

Subjects meeting SOLVD enrollment criteria
n= 3,579 (18%)

Preserved EF
n=10,943 (54%)


n=3,566 (17%)

Exclusionary condition
n= 523 (3%)


Age >80
n= 1,777 (9%)

Masoudi FA et al. Am Heart J 2003;146:250-7.

Slide 17

Theory and Practice Collide

Image: The title and conclusion of the JAMA article referred to below.

Al-Khatib SM et al. JAMA 2011;305:43-49.

Slide 18

Where Are We Now?

Images: A statue of the Greek goddess Demeter and a painting titled "Old Woman Dozing over a Book" by Dutch painter Nicolaes Maes are shown.

Slide 19

Expanding Knowledge of ICDs in the Real World

  • Assessing ICD shocks: Cardiovascular Research Network (CVRN) Longitudinal Study of ICDs.
  • Comparative effectiveness in the elderly: Outcomes of ICDs in Medicare population.
  • Outcomes in Clinical Subgroups: Bayesian statistical methods with patient-level data from clinical trials.
Page last reviewed October 2014
Internet Citation: Implantable Cardioverter Defibrillators to Prevent Sudden Cardiac Death: Background. October 2014. Agency for Healthcare Research and Quality, Rockville, MD.


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care