Slides courtesy of Mark Estes, MD

Role of AED’s

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1940 Concept Developed

1977 Implantable cardioverter defibrillator

1979 AED developed

2000 American Airlines Trial

1960 Bedside defibrillators

1967 Portable defibrillators

2002 Casino Trial2003 OHare Trial

2005 PAD Trial2004 Miami Trial

AED Milestones

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Approaches to Treatment of Sudden Cardiac Arrest

Out-of-hospital sudden cardiac arrest (SCA) accounts for over 300,000 deaths annually in the U.S.

In 1991, The American Heart Association (AHA) introduced the 4-step “Chain of Survival”Early activation of emergency response system

CPR

Early defibrillation

Advanced Life Support Measures

Operation Heartbeat

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Time in VF in minutes

SCD From VF

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0

10

20

30

40

50

First RespondersFirst Responders

Mossesso WeaveWeaverr

Weaver

% S

urv

ival

Survival RatesFirst responders (AED) vs EMT

EMTEMT

WhiteWhite

P <0.01P <0.001

P<0.02

NS

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AEDs Improve Survival

White RD. Ann Emer Med. 96;28:480-485. Cobb LA. Circ. 92;85:I98-102. Smith SC. Circ. 97;13:1321-1324.

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

National Average Boston,MA Seattle,WA Rochester,MN

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Boston-Survival from SCA

Comparison of AED Training and Survival of Utstein Cardiac Arrest in Boston, 1993-1999

245

686

1393 14821719

3272

2369

14%

18%

21%

26%

20.5%

25%

34%

1993 1994 1995 1996 1997 1998 1999

Year

AED Certified

UtsteinSurvival Rate(%)

USA Today July 30, 2003

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Role of the AED in Preventing SCDLas Vegas Casinos

Valenzuela TD NEJM 2003

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Evidence Based Medicine AEDs

Report Design % Survival STD Rx

AED P Value Benefit

White OBS 42 46 <.02 √

Weaver OBS 18 38 <.001 √

Smith OBS 22 36 <.001 √

Mossenco OBS 8 26 <.01 √

Weaver OBS 28 30 NS X

Page OBS 44 √

Myerburg RCT 11 28 <0.05 √

Valenzuela OBS 44 √

Caffrey OBS 48 √

Capucci RCT 21 44 <.01 √

PAD RCT 15* 29* <.04 √

HAT RCT 6.5** 6.4** 0.77 X

*# of Survivors **total mortality

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To evaluate whether adding AEDs to a CPR based, community volunteer response system increases survival in victims of out-of-hospital cardiac arrest

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

The Public Access Defibrillation Trial: Main Study Objective

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PAD Trial Design

High Risk Community Units

Call 911CPR

Call 911CPRAED

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

Prospective, randomized, controlled clinical trialCompared two lay volunteer-based OOH-CA response systems

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PAD Trial

• 993 Community sites selected based on a 50% probability of OOH-CA in 15 months, EMS response < 15 minutes and no existing AED program

• 24 US and Canadian cities

• 20,000 lay volunteers received standard training

• 1600 AEDs placed

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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PAD Trial Location of Cardiac Arrest

0

10

20

30

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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PAD Location of Cardiac Arrest

Non-residential Non-residential 85 % 85 %

Residential Residential 15%

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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PAD Trial-292 Resuscitation attempts

Survivors44

CPR and 911Survivors

15

CPR, 911, AEDSurvivors

29

Residental 1

Non-residental 14

Residental 1

Non-residental 28

P=0.74

P=0.042

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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PAD Trial Results

•Volunteer rescuers responded twice as frequently at CPR & AED sites (23%) as at CPR sites(11%) alone

•No inappropriate shocks

•No failure to shock

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

www.HRSonline.org

PAD Trial Results

•292 resuscitation attemptsSurvivors: 15-CPR

29-CPR &AED (p=0.04)

•Use of public access defibrillators doubles survival from cardiac arrest

•Results better in public versus residential locations (75% of cardiac arrests are at residential locations)

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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PAD Trial Conclusions

•Trained laypersons can use AEDs safely to provide early defibrillation

•Survival doubles when AEDs are added to CPR trained volunteer response systems

•The survival rate in residential facilities is very low

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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AEDs Available for Home Use With Rx

Estes NAM Circulation 2005

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PAD Trial-Implications

•The PAD Study strengthens the concept that AEDs should be widely available in public locations

•Survival was dependent on the presence of the AED, trained lay persons, and the presence of an emergency response plan

PAD Investigators The Public Access to Defibrillation Study NEJM 2004;637-645

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Bethesda 36 Guidelines: AEDs

Myerberg R, Estes NAM, Fontaine J, Link, M Zipes Bethesda #36 Conference AEDs, JACC 2005

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AED-Public Policy, Legislation and Legal Liability

State and Federal Polices

Legal Protection for Owners, Users,Medical Directors

Court OpinionsAs evidence-based medicine has defined the

clinical benefits of AED use, public policy, laws, funding programs, and court decisions have served the societal interest of promoting use of AEDs by minimizing legal liability.

England, H Weinberg P, Estes N JAMA 2006

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AED Initiatives

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•Good Samaritan legislation in all states

•Public Access to Defibrillation Programs

•AED in Schools-NY, PA, WI, MA

•Neigborhood AEDs

•AEDs should be available in all schools and public locations where the emergency medical response time for a cardiac arrest is 5 minutes or greater

•AEDs should be used in cardiac arrest for all children older than 2 years of age

AED Initiatives

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Future research

•Home AED Trial (HAT)

•Prospective randomized trial of high risk patients post MI

•Randomized to AED &CPR Training versus CPR training in high risk post MI patients

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Role of the AED in Preventing SCA-The US Experience

•Evidence based medicine demonstrates decreased time to definitive therapy with defibrillation with AED use

•This results in improved survival in victims of SCA

•The benefit of AEDs is mainly in non-residential settings

•Organizational, institutional, state and federal policies, legislation, a laws serve to promote the widespread use of AED

•Further research is need to define optimal strategies for use of AEDs to improve outcomes from SCD