PPT

Increasing Survival in Sudden Cardiac Arrest

(SCA): The Role of ICD Therapy

ObjectivesUpon completion of this activity, participants will be able to:

• Describe current trends in the epidemiology and etiology of sudden cardiac arrest (SCA).

• Assess the risk of SCA in ischemic and non-ischemic populations, including post-MI patients and HF patients.

• Describe the current evidence underlying the most recent ACC/AHA/ESC guidelines (2006) for the use of ICDs in patients at risk of SCA, and apply those guidelines.

• List risk-assessment tools being used in clinical practice or under investigation, and describe the current evidence for each.

• Describe the current CMS coverage for use of ICDs in patients at risk of SCA, and compare the economics of such use to other medical interventions.

• Assess their current use of ICDs in patients at risk for SCA.

Patient CaseHistory

76-y.o. white male

Type II DM, low-grade renal dysfunction; both well-controlled

3 years post-MI, successfully revascularized

NYHA functional class II; stable

LVEF is 32% (echo)

Compliant with meds: antiplatelet, beta-blocker, ACE-I, statin, DM regimen

Patient Case

Clinical Decisions

Should this patient be referred for an ICD evaluation?

What factors enter into your decision?

Is there anything else you'd want to know before making the decision?

Epidemiology and Etiology

Cardiovascular Disease Mortality Trends for Males and Females: United States: 1979-2003*

Heart Disease and Stroke Statistics — 2006 Update. CDC/NCHS. * Preliminary. AHA. www.americanheart.org

State-Specific Mortality from Sudden Cardiac Death. www.cdc.gov

400

420

440

460

480

500

520

79 80 85 90 95 00 03

Years

Dea

ths

in T

hous

ands

Males Females

0

SCA Mortality Trends

Age-adjusted cardiovascular deaths have

declined; however mortality due to Sudden

Cardiac Death has not.

Over 60% of coronary artery deaths are

attributable to sudden cardiac arrest

Goraya TY, et al. Am J Epidemiol. 2003; 157:763-770.

Centers for Disease Control. 1999. MMWR Morb Mortal Wkly Rep 2002; 57: 123-126

Leading Causes of Death in the US

National Vital Statistics Report. 2001;49;11.MMWR. 2002;51:123-126.

Sudden Cardiac Arrest (SCA)

0% 5% 10% 15% 20% 25%

Septicemia

Nephritis

Alzheimer’s Disease

Influenza/Pneumonia

Diabetes

Accidents/Injuries

Chronic Lower Respiratory Diseases

Cerebrovascular Disease

Other Cardiac Causes

All Cancers

SCA is a leading cause of death in the U.S., second to all cancers combined.

SCA Survival & Mortality Data

• At least 335,000 SCA deaths in the U.S. each year

• Only 5 to 10% survive first episode of SCA

• Roughly two-thirds of SCA deaths occur out-of-hospital

Seidl K, Senges J. Card Electrophysiol Rev. 2003;7:5-13.

Heart Disease and Stroke Statistics — 2005 Update. AHA. www.americanheart.org

Crespo EM, Kim J, Selzman KA. Am J Med Sci. 2005;329:238-246.

Zheng ZJ, et al. Circulation. 2001;104:2158-2163.

Zipes, DP, et al. 2006 ACC/AHA/ESC Practice Guidelines 5. Circulation. 2006;114;385-484.

Secondary Prevention of

Sudden Cardiac Arrest

Patient Case

History • 54-y.o. African-American female• Ischemic cardiomyopathy• NYHA functional class I• LVEF = 28% per echo at your institution• Long-time heavy smoker; has COPD• Compliant and stable on optimal medical therapy• Syncopal episodes

Patient Case

Clinical Decisions




Key Randomized Clinical Trials

Adapted from: DiMarco JP. N Engl J Med. 2003;349:1836-47. www.medscape.com

Young JB. Sudden cardiac death in heart failure. www.medscape.com

ICD therapy for the secondary prevention of SCA

Mortality

(%)

Trial N Age (yrs) Mean LVEF (%)

Follow-up (mos)

Control Therapy

Control ICD P

AVID 1016 65 ± 10 35 18 ± 12 Amiodarone or sotalol

24.0 15.8 .02

CIDS 659 64 ± 9 34 36 Amiodarone 29.6 25.3 .14

CASH 288 58 ± 11 45 57 ± 34 Amiodarone or metoprolol

44.4 36.4 .08

2006 ACC/AHA/ESC Guidelines for the Management of Ventricular

Arrhythmias: Secondary Prevention of SCD

ICD Class I Recommendation:• Patients with a history of SCA, VF, hemodynamically

unstable VT, or unexplained syncope

Zipes, DP, et al. 2006 ACC/AHA/ESC Practice Guidelines 5. Circulation. 2006;114;385-484

Myerburg RJ, et al. Circulation. 1998. 97:1514-1521.

Patients with a previous cardiac arrest are at high risk for subsequent SCA events but account for a small percentage

of annual sudden deaths

MADIT I, MUSTT

AVID, CASH, CIDS

SCD-HeFT,MADIT II

Primary Prevention of Sudden Cardiac

Arrest

Patient Case

History • 52 year old woman• Moderate alcohol consumption, has stopped

since MI• Lives alone in rural community; manages on-line

content for a large dog food manufacturer• PMHX: MI 1 year ago, echo on discharge

was 35%• Medications: BB, ACE-I, lipid-lowering agent,

clopidorgrel, omega-3

Patient Case

Clinical Decisions




SCA Relationship to MI

• A previous MI can be identified in as many as 75% of SCA patients.

• A previous MI as a single risk-factor raises the one-year risk of SCA by 5%.

• The five-year risk of SCA is 32% for patients with all of these risk-factors:• history of MI • non-sustained, inducible, non-suppressible VT• LVEF ≤ 40%

Sudden Cardiac Arrest Fast Facts. HRS. www.hrsonline.org

Risk factors for sudden cardiac death. www.heartinstitute.org.au/Community/scdMain.asp

Buxton AE, et al. N Engl J Med. 1999;341:1882-1890.

Time Dependence of Mortality Risk Post-MI

Prediction of Sudden Cardiac Death After Myocardial Infarction in the Beta-Blocking Era1

• 700 post-MI patients; ~ 95% on beta-blockers 2 years after discharge.

• The epidemiologic pattern of SCD was different from that reported in previous studies.

Arrhythmia events did not concentrate early after the index event; most occurred > 18 months post-MI.

1 Huikuri HV. J Am Coll Cardiol. 2003;42:652-658.

TotalMortality

CardiacMortality

Non-SCD

SCDCu

mu

lati

ve

Ev

en

ts (

%)

18

15

12

9

6

3

18

15

12

9

6

3

20 40 60 20 40 60

Follow-Up (months) Follow-Up (months)

14

11.6

8.47.89

8.2

4.9

7.2

0

2

4

6

8

10

12

14

16

1-17 mo 18 - 59 mo 60 - 119 mo > 120 mo

ConvICD

(n = 300) (n = 283) (n = 284) (n = 292)Hazard Ratio .98

(p = 0.92)0.52

(p = 0.07)0.50

(p = 0.02)0.62

(p = 0.09)

Wilber, D. Circulation. 2004;109:1082-1084.

Relation of Time from MI to ICD Benefit

in the MADIT-II Trial

Time from MI

% M

ort

alit

y fo

r E

ach

T

ime

Per

iod

SCA Relationship to HF

• Patients with HF are overall at 6-9 times higher risk for SCD than general population

• As HF progresses, pump failure (rather than SCA) becomes relatively more likely as the cause of death

Heart Disease and Stroke Statistics – 2005 Update. AHA. www. americanheart.org

Severity of Heart FailureModes of Death

MERIT-HF Study Group. Lancet.1999;353:2001-2007.

12%

24%64%

CHF

Other

SuddenDeath(N = 103)

NYHA II

26%

15%59%

CHF

Other

SuddenDeath(N = 103)

NYHA III

56%

11%

33%

CHF

Other

SuddenDeath(N = 27)

NYHA IV SCA Pump Failure

NYHA Class II 64% 12%

NYHA Class III 59% 26%

NYHA Class IV 33% 56%

SCA Relation to LVEF

0

1

2

3

4

5

6

7

8

0-30% 31-40% 41-50% >50%

Gorgels PMA. European Heart Journal. 2003;24:1204-1209.

LVEF

% S

CA

Vic

tim

s

7.5%

5.1%

2.8%

1.4%

EF is an Important Risk Stratifier

Key Randomized Clinical Trials

Adapted from: DiMarco JP. N Engl J Med. 2003;349:1836-47. www.medscape.comKadish A, et.al. N Engl J Med 2004;350:2151-8.Young JB. Sudden cardiac death in heart failure. www.medscape.com

ICD therapy for the primary prevention of SCA

Mortality (%)

Trial N Age (yrs)

Mean LVEF (%)

Follow-up (mos)

Control Therapy

Control ICD P

SCD-HeFT

2521 60.1 25 45.5 Optimal Medical Therapy

36.1 28.9 .007

MADIT 196 63 ± 9 26 27 Conventional 38.6 15.7 .009

MADIT II 1232 64 ± 10 23 20 Optimal Medical Therapy

19.8 14.2 .007

MUSTT 704 67 ± 12 30 39 No EP-guided therapy

48 24 .06

DEFINITE 458 58 21 29.0±14.4 Optimal Medical Therapy

14.1 7.9 .08

http://www.medscape.com/


Heart Failure and Left Ventricular Dysfunction are indicators of SCA risk

MADIT I, MUSTT

AVID, CASH, CIDS

SCD-HeFT,MADIT II

2006 ACC/AHA/ESC Guidelines for the Management of Ventricular

Arrhythmias: Primary Prevention of SCD

ICD Class I Recommendations:• Patients with ischemic cardiomyopathy who are at least 40 days post-

MI with an LVEF ≤ 30 - 40% and NYHA functional class II or III

• Patients with NYHA Class II-III, LVEF ≤ 30 - 35%, non-ischemic cardiomyopathy

• Patients who are at high risk of SCA due to genetic disorders such as long QT syndrome, Brugada syndrome, hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplagia (ARVD).

ICD Class II Recommendation:• Ischemic and non-ischemic patients with NYHA functional class I,

LVEF ≤ 30-35%

Zipes, DP, et al. 2006 ACC/AHA/ESC Practice Guidelines 5. Circulation. 2006;114;385-484

Current CMS ICD Coverage*• In brief, this policy expands coverage for:

1) Patients with ischemic dilated cardiomyopathy (IDCM), prior MI, NYHA Class II & III heart failure, LVEF less than or equal to 35%

2) Patients with non-ischemic dilated cardiomyopathy (NIDCM) > 3 months, NYHA Class II & III heart failure, LVEF less than or equal to 35%

Overall, this NCD covers the SCD-HeFT population and all the MADIT II population.

* ICD coverage expanded in January 2005 and updated in April 2006.

Discussion: ICD Contraindications

• Standard Contraindications for ICD Therapy– Hospitalized patients with advanced age– Advanced (NYHA class IV) HF and limited life expectancy– Patients whose VT’s may have transient or reversible causes– Patients with incessant VT or VF– Patients who have a unipolar pacemaker

• Questions

Are there patients who are indicated but who should not get an ICD?Who makes the decision on whether or not an ICD is offered?

Beyond EF

Microvolt T-Wave Alternans

• Noninvasive, ECG-based test• HR elevation by exercise, atrial pacing,

or dobutamine infusion• Measures beat-to-beat microvolt

variations in the shape, amplitude, or timing of the ECG T-wave

Microvolt T-Wave Alternans• Sometimes used as a risk-stratification tool

• Negative result may suggest low risk of SCA• High negative-predictive value, low positive-

predictive value• CMS has approved Medicare coverage when

spectral-analytic method used• Microvolt T-wave alternans has received a Class IIa

recommendation in the 2006 ACC/AHA/ESC Guidelines

• The guidelines do not state that an ICD is not recommended if the T-wave test is negative.

• The outcome of the test also does not change the indication for ICD.

Bloomfield DM, et al. J Am Coll Cardiol. 2006:47:456-463Gehi AK, et al. J Am Coll Cardiol. 2005:46(1):75-82Zipes, DP, et al. 2006 ACC/AHA/ESC Practice Guidelines 5. Circulation. 2006;114;385-484CMS: Decision Memorandum for Microvolt T-wave Alternans Testing. www.cms.hhs.gov

Microvolt T-Wave Alternans: Issues

• Patients must be in sinus rhythm (but up to 30% of patients at risk have AF)

• A patient must sustain a heart rate of 105 for 10 minutes, which may be difficult for patients on beta-blockers.

• Can be indeterminate• Non-sustained MTWA in up to 10% of normals• Value beyond LVEF not fully established, further

studies underway• Cost-effectiveness being assessed

Many methods to further risk stratify patients at risk for SCA have been studied...

Test Objective Sensitivity

(%)

Specificity

(%)

Limitations

Echo Measurement of LVEF

55–65 75–80

HR

variability

Assessment of low heart rate variability

38–62 75–88 Multiple non-standardized methods

EP Study Induction of VA’s 48–73 65–93 Invasive, expensive

Signal

Averaged ECG

(SAECG)

Induction of late potentials

56-68 74–81 Not useful in non-ischemic cardiomyopathy

Microvolt

T-Wave

Alternans (MTWA)

Identification of repolarization abnormalities

77–93 37–83 Cannot be used in AF

Siddiqui A, Kowey PR. Curr Opin Cardiol. 2006;21:517-25.

Prior SG, et al. Eur Heart J, Vol 22:16:August 2001

But a reduced EF remains the single most important risk factor for overall mortality and sudden cardiac death.

The Economics of Therapy

$0

$20,000

$40,000

$60,000

$80,000

$100,000

$120,000

$140,000

$160,000

$180,000

$200,000

Incremental Cost-EffectivenessCardiovascular Interventions

HypertensionTherapy(diastolic95 - 104mmHg)

Expensive

BorderlineCost-Effective

Cost-Effective

HighlyCost-Effective

Incr

emen

tal

Co

st p

er L

ife-

Yea

r S

aved

EconomicallyUnattractive

Lovastatin(chol. =

290 mg/dL,50 yrs old,

male, no riskfactors)

PTCA(chronic CAD,severe angina

1 VD)

CABG(chronic

CADmild angina,

3 VD)

End Stage Renal

Disease Treatment

Exercise SPECT (atypical

angina who can walk

on treadmill)

RoutineCoronary

Angiography(35 - 84 yrs

old, low risk MI,has CHF)

$8,461$17,701

$40,750

$67,000

$135,000

$150,000

Carotid Disease

Screening(65 yrs old,

male, no

symptoms)

$1,000,000

$120,000

Moss AJ. Satellite Symposium, 2003.

Kupersmith J. Progress in Cardiovascular Diseases. 1995;37:5:307-346.

Stanton M. Circulation. 2000;101:1067-1074.

Incremental Cost-Effectiveness

of ICD Therapies

Al-Khatib SM, et al. Ann Intern Med. 2005;142:593-600.Larsen G, et al. Circulation. 2002;105:2049-2057.Mark DB. Circulation. 2006;114:135-142. http://circ.ahajournals.org

Incr

emen

tal

Co

st p

er L

ife-

Yea

r S

aved

MADIT-IIICD2

AVIDICD3

$50,000$67,000

Expensive

BorderlineCost-Effective

Cost-Effective

HighlyCost-Effective

EconomicallyUnattractive

SCD-HeFTICD1

$38,000

$0

$20,000

$40,000

$60,000

$80,000

$100,000

$120,000

$140,000

$160,000

$180,000

$200,000

Number-Needed-to-Treat (NNT) to Save One Life for ICDs and

Various Drugs

Camm J, Klein H, Nisam S. European Heart Journal. doi:10.1093/eurheart/eji166; 2006

MADIT II(3 year)

Incr

emen

tal

Co

st p

er L

ife-

Yea

r S

aved

SAVE(3.5 year)

MUSTT(5 year)

MADIT(2.4 year)

AVID(3 year)

SCDHeFT(5 year)

Merit-HF(1 year)

4S(6 year)

4

11

9

20

26

28

14

0

5

10

15

20

25

30

Implications for Real-World Practice

Patient CaseHistory • 78 year old man• Wheelchair bound due to automobile accident• Plays bridge competitively• Lives in assisted-living• PMHX: NIDCM, HF class II, sinus node

dysfunction treated with a pacemaker, EF measured in 2000 was 30%

• Medications: ACE-I, BB, Diuretic

Patient Case

Clinical Decisions Should this patient be referred for an ICD

evaluation?




Sudden Death Risk

MADIT I, MUSTT

AVID, CASH

SCD-HeFT,MADIT II

How can a practice effectively identify patients at-risk?

Discussion: Practice Realities

• QuestionsIf you were to implement a new SCA algorithm

in your practice, what would happen?

What do you see as possible problems in

implementing the guidelines?

Are there situations that are unique to your

practice?

ICD Treatment Algorithms

EF Clinic Program Patient Screening Pathway

(The Ohio Heart & Vascular Center)

Determine EF

Does patient havehistory of cardiac

arrest, VF, orsymptomatic VT?

Non-Ischemic

Consult EP for possible CRT-D

Optimize therapies or consult HF specialist

EF ≤ 35%

Ischemic

PATIENT

40 days post MI with EF ≤ 30%

NYHA Class I CHF

EF > 35%

40 days post MI OR

3 months post revascularization

Consult EP for possible ICD

3 months post diagnosis

1. Consider referral to HF Specialist or HF Program.

2. Repeat diagnostics with change of symptoms.

Class III or IV CHFand QRS > 120 ms



Is patient on optimal medical

therapy?YES

YES

NO

Note: Pathway only begins after optimal medical therapy & coronary evaluation / intervention as appropriate


NYHA Class II or III CHF

This is a general protocol to assist in the management of patients. This protocol is not designed to replace clinical judgment or individual patient needs.

ICD

ICD Practical FlowchartLVEF ≤ 35% Optimal Medical Therapy

NYHA Class III – IV, Wide QRS? YESNO

CRT-D

NO

Prior MI No Prior MI

EF ≤30%MADIT II

NYHA II/III

EPS + MADIT-1

NYHA II/III

Syncope

OROR

Source: Narayan SM. Current Issues in Cardiology. 2005:32:3.

COMPANION

SCD-HeFT

Key Points

• The majority of cases are in patients with:– Coronary artery disease, previous MI– Low left ventricular ejection fraction– Dilated cardiomyopathy and heart failure

• Defibrillation is the only effective treatment option• High-risk patients can be evaluated for known

risk factors before they experience a Sudden Cardiac Arrest– EF remains a key indicator

In Summary…

• SCA is a leading cause of death

• There is solid clinical evidence for ICDs as:– The only effective means to prevent SCD– Superior to optimal medical therapy

• ICDs are cost-effective

• There are practical ways to assess SCA risk in ischemic and non-ischemic populations

Sudden Cardiac Death CAN be Prevented With an ICD

Brief Statement

Medtronic ICDs

IndicationsMedtronic implantable cardioverter defibrillators (ICDs) are indicated for ventricular antitachycardia pacing and ventricular defibrillationfor automated treatment of life-threatening ventricular arrhythmias.

ContraindicationsMedtronic ICDs are contraindicated in patients whose ventricular tachyarrhythmias may have transient or reversible causes, patientswith incessant VT or VF, patients who have a unipolar pacemaker, and patients whose primary disorder is bradyarrhythmia.

Warnings/PrecautionsChanges in a patient¹s disease and/or medications may alter the efficacy of the device¹s programmed parameters. Patients shouldavoid sources of magnetic and electromagnetic radiation to avoid possible underdetection, inappropriate sensing and/or therapydelivery, tissue damage, induction of an arrhythmia, device electrical reset, or device damage. Do not place transthoracic defibrillationpaddles directly over the device.

Potential ComplicationsPotential complications include, but are not limited to, rejection phenomena, erosion through the skin, muscle or nerve stimulation,oversensing, failure to detect and/or terminate tachyarrhythmia episodes, acceleration of ventricular tachycardia, and surgicalcomplications such as hematoma, infection, inflammation, and thrombosis.

See the device manual for detailed information regarding the implant procedure, indications, contraindications, warnings, precautions,and potential complications/adverse events. For further information, please call Medtronic at 1 (800) 328-2518 and/or consultMedtronic¹s website at www.medtronic.com.

Caution: Federal law (USA) restricts this device to sale by or on the order of a physician.

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