1 American Heart Association. Heart and Stroke Statistical

1
Sudden Cardiac Arrest

• Prepared for Referring MD Group
• Insert Presentation Date

2
Sudden Cardiac Arrest (SCA)

• SCA claims an estimated 325,000 lives each year
• 1,000 lives every day, one life every two minutes
• SCA accounts for half of all cardiac-related
  deaths
• Over half of SCA victims have no prior symptoms
• Survival requires emergency medical intervention
  and defibrillation within the first minutes
  following arrest
• The survival rate is as high as 90 percent if
  treatment is initiated within the first minutes
  following arrest
• An estimated 95 percent of SCA victims die before
  they reach a hospital or other source of
  emergency help

3
Sudden Cardiac Arrest (SCA)

• 85-90 percent of SCAs are actually the first
  arrhythmic event a patient experiences
• Death from SCA can frequently be predicted and
  prevented by identifying individuals at high risk
  and intervening

4
What Causes SCA?

• Ventricular tachycardia
• Ventricular fibrillation
• Hypertrophic cardiomyopathy
• Inherited and acquired electrical diseases, e.g.
  Long QT syndromes
• Congenital anomalous coronary artery
• Reduced Ejection Fraction

5
Sudden Cardiac Arrest
6
Impact of Sudden Cardiac Arrest

• More people die from Sudden Cardiac Arrest than
  from AIDS, Breast Cancer and Lung Cancer combined

Heart Rhythm Society 2005 American Cancer
Society 2005, CDC 2003 Est.
7
Urgency of Sudden Cardiac Arrest

• Resuscitation Success vs. Time

Chance of success reduced 7-10 each minute


Success
Success
Non
Non
-
-
linear
linear
Adapted from text Cummins RO, Annals Emerg Med.
1989, 181269-1275.
8
Risk Factors

• High-risk patient populations have been
  identified
• Prior Sudden Cardiac Arrest
• Prior Myocardial Infarction
• Heart Failure (Class II to IV)
• Ejection Fraction less than 40
• Family History of Sudden Cardiac Arrest

9
Risk Factors

• Additional risk factors include
• Recurrent unexplained syncope
• Idiopathic cardiomyopathy with syncope or VT
• Hypertrophic cardiomyopathy with syncope or VT
• Right ventricular dysplasia
• Long-QT syndrome

10
SCA and Coronary Heart Disease

• An estimated 13 million people had CHD in the
  U.S. in 20021
• Sudden death was the first manifestation of
  coronary heart disease in 50 of men and 63 of
  women1
• CHD accounts for at least 80 of sudden cardiac
  deaths in Western cultures3

Etiology of Sudden Cardiac Death2,3
ion-channel abnormalities, valvular or
congenital heart disease, other causes
1 American Heart Association. Heart Disease and
Stroke Statistics2003 Update. Dallas, Tex.
American Heart Association 2002. 2 Adapted from
Heikki et al. N Engl J Med, Vol. 345, No. 20,
2001. 3 Myerberg RJ. Heart Disease, A Textbook of
Cardiovascular Medicine. 6th ed. P. 895.
11
SCA and Heart Failure

• In people diagnosed with CHF, sudden cardiac
  death occurs at 6-9 times the rate of the general
  population1
• CHF significantly increased sudden death and
  overall mortality in both men and women2

1 American Heart Association. Heart and Stroke
Statistical 2003 Update. Dallas, Tex.
American Heart Association 2002.2 Redrawn from
Kannel WB, Wilson PWF, D'Agostino RB, Cobb J.
Sudden coronary death in women. Am Heart J 1998
Aug 136 205-212 3 Framingham Heart Study (1948
1988) in Atlas of Heart Diseases. 4 American
Heart Association. Heart Disease and Stroke
Statistics2003 Update
12
SCA and Myocardial Infarction

• The prevalence of Myocardial Infarction (MI) in
  the U.S. in 2002 was 7.6 million1
• MIs are identified in as many as 50-75 of sudden
  cardiac arrest victims2,3,4
• Within 6 years of a recognized MI, 7 of men and
  6 of women will experience sudden death1
• Individuals with a prior MI have a sudden death
  rate 4-6 times that of the general population1

1 American Heart Association. Heart Disease and
Stroke Statistics2003 Update. Dallas, Tex.
American Heart Association 2002. 2 Myerberg RJ.
Heart Disease, A Textbook of Cardiovascular
Medicine. 6th ed. Philadelphia WB Saunders Co
1997chapter 24. 3 Lombardi G. JAMA.
1994271678-683. 4 Bigger JT. Circulation.
198469250-258.
13
Ejection Fraction

• Reduced left ventricular ejection fraction (LVEF)
  remains the single most important risk factor for
  overall mortality and sudden cardiac death1
• Post-MI patients with LV dysfunction (lt 40) have
  a sudden death rate thats similar to a CHF
  population

LVEF and SCA Incidence2
1 Prior SG, Aliot E, Blonstrom-Lundqvist C, et
al. Task Force on Sudden Cardiac Death of the
European Society of Cardiology. Eur Heart J,
Vol. 22 16 August 2001. 2 Vreede-Swagemakers
JJ. J Am Coll Cardiol. 1997301500-1505.
14
Treatment

• Risk Factor Modification
• Healthy diet
• Regular exercise
• Weight loss
• Smoking cessation
• Medical Therapy
• Beta blockers
• ACE inhibitors
• Lipid therapy
• Interventional Procedures
• Implantable cardioverter defibrillator (ICD)
• Revascularization

15
Medical Therapy

• General Measures
• RBP lt130 systolic, lt80 diastolic
• Glycemic control
• Prevent Ischemia
• Revascularization
• Beta-blockers
• Nitrates
• Calcium channel blockers
• ACE Inhibitors
• Statins
• Stabilize Plaque
• Lipid therapy
• ACE inhibitors

• Improve Pump Function
• ACE inhibitors
• Beta-blockers
• Aldosterone antagonists
• Prevent Arrhythmias
• Beta-blocker
• ACE inhibitors
• Aldosterone antagonists
• Terminate Arrhythmias
• ICDs
• AEDs

Adapted fromZipes DP. Circulation.
1998982334-2351. Pitt B. N Engl J Med.
20033481309-1321.
16
ACE Inhibitors

• Patients with a history of coronary artery
  disease, stroke, or peripheral vascular disease,
  or diabetes plus one other cardiovascular risk
  factor
• Patients at high risk for heart attack or stroke
  can reduce the risk of sudden cardiac arrest by
  21 by taking ACE inhibitors

Heart Outcomes Prevention Evaluation Study
Investigators N Engl J Med. 2000 Jan
20342(3)145-53.
17
Beta Blockers

• Beta blockers can reduce the risk of sudden
  cardiac arrest by up to 50 and overall risk of
  death by 25-40

CIBIS-II Investigators, Lancet, 353 9, 1999
18
Effect of Spironolactone on Morbidity and
Mortality
Pitt et al, N Engl J Med, 341 709, 1999
19
Lipid Lowering Therapies

• Statins have consistently shown the greatest
  benefits in patients with low HDL-C and average
  LDL (CARE, LIPID,AFCAPS/TexCAPS) or high LDL-C
  94S, WOSCOPS)
• Fibrates have shown benefits in patients with
• - High triglycerides and low HDL-C (Helsinki)
• - Normal LDL-C and low HDL-C (VA-HIT)

20
ICD Therapy

• First-line therapy for ventricular tachycardia
  (VT)/ventricular fibrillation (VF) patients
• Transvenous, single incision
• Local anesthesia conscious sedation
• Short hospital stay
• Perioperative mortality lt 1
• Programmable therapy options
• Single- or dual-chamber therapy
• Battery longevity up to 7 years
• More than 100,000 implants/year

21
ICD Therapy
22
ICD Trials MADIT I

• Nearly 200 patients randomized to ICD or
  conventional medical therapy over 63 months
• Prior MI
• LVEF ? 35
• Inducible/nonsuppressible sustained VT and
• Asymptomatic NSVT (330 beats)
• ICD therapy reduced total mortality by 54
• ICD therapy reduced arrhythmic mortality by 74
• Trial stopped early due to significantly superior
  survival for ICD patients

23
ICD Trials MADIT II

• Over 1,200 patients randomized to ICD or
  conventional medical therapy
• Coronary artery disease
• MI ? 30 days prior
• LVEF ? 30
• EP studies results considered
• ICD therapy reduced total mortality by 31
• Subsequent analysis shows risk of SCA in this
  population does not decrease over time

24
ICD Trials MADIT II
Moss et al. New Engl J Med. 2002 346 (12) 877
25
ICD Trials MUSTT

• Over 1,250 registry patients followed over 60
  months to evaluate the efficacy of
  anti-arrhythmic therapy guided by
  electrophysiology (EP) studies
• Coronary artery disease
• Asymptomatic or minimally symptomatic NSVT
• LVEF ? 40
• ICD therapy reduced overall mortality by 55-60
• EP-guided therapy provided no survival benefit

26
ICD Trials MUSTT
Buxton, et al. New Engl J Med. 1999 341 1882-90.
27
ICD Trials SCD-HeFT

• Largest ICD trial to date following 2,500
  patients in 150 center with 2 ½ year follow-up
• Symptomatic CHF (NYHA class II and III) due to
  ischemic or nonischemic dilated cardiomyopathy
• CHF ? 3 months
• LVEF ? 35
• ACE I and Beta Blocker therapy if tolerated
• ICD therapy reduced overall mortality by 23 in
  patients with moderate heart failure

28
ICD Trials SCD-HeFT
Bardy et al. , et al. New Engl J Med. 352 (3)
225, Figure 1  
29
ICD Trials DEFINITE

• First trial to study ICD therapy as primary
  prevention in non-ischemic patients
• Mild to moderate heart failure
• LVEF lt 35
• 450 patients randomized to conventional medical
  therapy (CMT) or CMT plus ICD
• At two years, ICD group showed mortality of 8
  compared with mortality of nearly 14 in the CMT
  group

30
ICD Trials COMPANION

• Largest heart failure trial to date following
  over 1,500 chronic CHF patients at 128 centers
• CHF (NYHA class III or IV)
• CHF-related hospitalization within 12 months
• QRS width of 120 ms due to ischemic or
  nonischemic cardiomyopathy
• Patients were randomized to
• 20 received OPT (optimal pharmacologic therapy)
  alone
• 40 received OPT plus CRT-P (device with pacing
  stimulation)
• 40 received OPT plus CRT-D (device with
  defibrillation)
• OPT plus CRT-D reduced overall mortality by 36

31
Trial Implications

• Recent clinical trials have shown ICDs to be
  effective in a variety of patient populations
• Medicare has recently expanded coverage of ICD
  placement for up to 500,000 individuals
• Criteria for coverage include specific history
  of
• Cardiomyopathy
• Previous heart attack
• Heart failure
• Low Ejection Fraction (lt 35)
• Medicare coverage for an ICD is approximately
  30,000

32
Summary

• SCA is leading cause of death and can frequently
  be predicted and prevented
• Individuals with a prior SCA event, prior MI or
  heart failure are at risk for SCA
• Ejection Fraction is a key indicator of risk
  level for SCA. EF less than 40 warrants further
  cardiac evaluation
• Medical therapies (Beta Blockers, ACE Inhibitors
  and Lipid therapy) have been effective in
  reducing the risk of SCA
• A series of clinical trials have demonstrated the
  effectiveness of ICD therapy in a variety of
  patient populations