Understanding the Guidelines

A series of three case studies evaluating the use of ICD Therapy

Provided courtesy of Dr Andrea Russo

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Case 1 – A.G. – Primary Prevention

60 year old female, coronary disease, anterior wall MI 10 years ago

MUGA LVEF 32% (1 year ago)

Now dyspnea after 1/2 block, progressive worsening of symptoms over past 2 months

Medications: enalapril 20 BID, carvedilol 25 BID, digoxin 0.25 qd, spironolactone 25 mg qd, ASA 81 qd, furosemide 80 mg BID

Exam: JVP 9 cm, Lungs clear, Heart with laterally displaced PMI, +S3, III/VI holosystolic murmur radiating apex to axilla, no edema

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12-lead ECG reveals the following:

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Prior testing:

ECHO 2 months ago: anterior akinesis with apical dyskinesis, overall EF ~ 30%, moderate mitral regurgitation

Cardiac catheterization 8 months ago (for angina): Totally occluded LAD with collaterals, no other significant CAD

No further angina on increased beta blocker

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Now admitted with CHF.Inpatient telemetry reveals the following:

7 beats NSVT

The patient denies symptoms of palpitations, chest pain, syncope or presyncope.

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Question 1

Appropriate therapy for this patient includes:A. ACE inhibitor

B. Beta blocker

C. Device implantation

D. A and C

E. All of the above

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Question 1 Answer

Appropriate therapy for this patient includes:A. ACE inhibitor

B. Beta blocker

C. Device implantation

D. A and C

E. All of the above

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Question 2

You would specifically recommend:A. Implantation of a single chamber ICD

B. Implantation of dual chamber ICD

C. Implantation of CRT pacemaker

D. Implantation of CRT-ICD

E. Implantation of an insertable loop monitor

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Question 2 Answer

You would specifically recommend:A. Implantation of a single chamber ICD

B. Implantation of dual chamber ICD

C. Implantation of CRT pacemaker

D. Implantation of CRT-ICD

E. Implantation of an insertable loop monitor

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Supporting Data

Primary Prevention ICD Trials:• MADIT I• MUSTT • MADIT II• DEFINITE • SCD-HeFT• COMPANION

Ischemic CM (CAD)

Non-ischemic CM

Ischemic & Non-ischemic CM

CRT (Ischemic & Non-ischemic)

ReferencesMADIT I: Moss NEJM 1996;335:1933MUSTT: Buxton NEJM 1999;341:1882-90MADIT II: Moss NEJM 2002;346:877DEFINITE: Kadish NEJM 2004;350:2151-8SCD-HeFT: Bardy NEJM 2005;352:225-37 COMPANION: Bristow MR NEJM 2004;350:2140

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What are the Guidelines?

ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD - ICD Indications: Primary Prevention, CAD & LV dysfunction

Class I: ICD recommended to reduce mortality by reduction in SCD in pts with LV dysfunction due to prior MI who are at least 40 days post-MI, LVEF ≤ 30-40%, NYHA class II or III, & receiving chronic optimal medical therapy, and have reasonable expectation of survival with good functional status for > 1 yr (level evidence A)

Class IIa: ICD reasonable in pts with LV dysfunction due to prior MI who are at least 40 days post-MI, LVEF ≤ 30-35%, NYHA class I on chronic optimal medical therapy, and have reasonable expectation of survival with good functional status for > 1 yr (level evidence B)

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Zipes et al., ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD, Circulation 2006;114:e385-484

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What are the Guidelines?

ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD - ICD Indications: Primary Prevention, Dilated CM (non-ischemic)Class I: ICD recommended to reduce mortality by reduction in SCD in pts with non-ischemic DCM, LVEF ≤ 30-35%, NYHA class II or III, who are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with good functional status for > 1 yr (level evidence B)Class IIa: ICD can be beneficial for pts with unexplained syncope, significant LV dysfunction, and non-ischemic DCM who are receiving chronic optimal medical therapy, and who have reasonable expectation of survival with good functional status for > 1 yr (level evidence C)Class IIb: ICD might be considered in pts who have non-ischemic DCM, LVEF ≤ 30-35%, NYHA class I receiving chronic optimal medical therapy, and who have reasonable expectation of survival with good functional status for > 1 yr (level evidence C)

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Zipes et al., ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD, Circulation 2006;114:e385-484

www.HRSonline.org

What are the Guidelines?

ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD - ICD Indications: Heart Failure – CRT recommendations

Class IIa: ICD combined with BiV pacing can be effective for primary prevention to reduce mortality by reduction in SCD in pts with NYHA class III or IV receiving optimal medical therapy, in SR with QRS complex ≥ 120 ms who have reasonable expectation of survival with good functional status for > 1 yr (level evidence B)

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Zipes et al., ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD, Circulation 2006;114:e385-484

www.HRSonline.org

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Outcome:

The patient underwent implantation of a CRT-ICD

Heart failure symptoms improved, and she was able to walk 1 mile on flat ground without problems

1 year later, she experienced a defibrillator shock, associated with pre-syncope

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A

V(rate)

V(shock)

ICD interrogation revealed a total of 6 events. An example of the intracardiac electrograms revealed the following:

Amiodarone initiated, without further ICD shocks for 6 months

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Topics for discussion:

When do you consider adding anti-arrhythmic drug therapy with device therapy?

Any potential problems with amiodarone (“hybrid”) therapy?

This may be added to reduce frequent ICD therapy for recurrent episodes of VT or atrial arrhythmias.

Amiodarone may result in an increase in the defibrillation threshold or an increase in VT cycle length, which may impact on VT detection and effective therapy. Therefore, the ICD should be tested in the EP lab on this antiarrhythmic agent.

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Topics for discussion

What would you have done differently if the patient had a non-ischemic dilated cardiomyopathy without CAD? Was an ICD still indicated?

Based on current guidelines, an ICD is indicated for patients with ischemic or nonischemic heart disease and an LVEF ≤ 35%.

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Case 2 – W.S. – Secondary Prevention

59 year old female

Syncope while shopping in mall

EMT arrival: BP 60, HR 205 bpm, semi-conscious, wide complex tachycardia

Successful cardioversion to sinus rhythm

In ER, ECG reveals sinus rhythm with left bunch branch block

Recent history: dyspnea on exertion, progressive over past 3 months

PMH: No other known medical problems

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Additional history and testing:

Medications: None

Exam: JVP 12 cm, Lungs bibasilar rales, Heart S4 & S3 gallops, II/VI holosystolic murmur apex, Extremities trace pedal edema

ECHO: 4 chamber dilatation, severe LV dysfunction, mild RV dysfunction

Cardiac catheterization: normal coronary arteries, LVEF 20%, non-ischemic dilated cardiomyopathy, PCWP 25, CI 2.3

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Question 1

What would you recommend next?A. Initiation of ACE inhibitor, diuretic, and digoxin

B. Beta blocker therapy after volume status improves

C. ICD implantation for syncopal VT

D. All of the above

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Question 1 Answer

What would you recommend next?A. Initiation of ACE inhibitor, diuretic, and digoxin

B. Beta blocker therapy after volume status improves

C. ICD implantation for syncopal VT

D. All of the above

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Initial treatment:

ACE inhibitor, diuretic, digoxin, and beta blocker initiated

Symptoms improve

Undergoes ICD implantation using single chamber device before hospital discharge

6 months later, reports increasing dyspnea, orthopnea, and PND

Medications: • Captopril 50 mg TID• Furosemide 120 mg BID• Metolazone 5 mg qd• Carvedilol 12.5mg BID• Warfarin 5 mg qd• Digoxin 0.25 mg qd

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Outpatient follow-up:

Exam remarkable for BP 80/50 mmHg and biventricular CHF, with shortness of breath at rest

Also “mentions” episode of loss of consciousness 1 week ago while watching TV (but unsure if “fell asleep”)

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Shock

ICD interrogation revealed the following:

One shock was delivered, as above, with 9 other aborted shocks for long non-sustained VT (asymptomatic).

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Question 2

You would now recommend:

A. Hospital admission for intravenous inotropic therapy

B. Antiarrhythmic drug therapy with amiodarone

C. Repeat right heart catheterization

D. All of the above

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Question 2 Answer

You would now recommend:

A. Hospital admission for intravenous inotropic therapy

B. Antiarrhythmic drug therapy with amiodarone

C. Repeat right heart catheterization

D. All of the above

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Treatment decisions

Amiodarone is being used to suppress frequent episodes of VT, in order to reduce the frequency of shocks and aborted shocks

Right heart catheterization is performed to re-assess volume status and cardiac output on medical therapy for congestive heart failure, in the setting of a low resting blood pressure

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Following hospitalization:

Repeat right heart catheterization on milrinone reveals mean RA 12, PA 50/28, wedge 30 mmHg, CI 1.7 L/min/m2

Milrinone increased

BP systolic remains in the 80s

Normal renal function

Very supportive family, present at hospitalization and outpatient follow-up visits

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Question 3

You would now recommend:

A. Consideration of upgrade to a device which allows biventricular pacing for resynchronization therapy

B. Initiation of heart transplantation evaluation

C. Both A and B

D. No further evaluation or treatment indicated at this time

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Question 3 Answer

You would now recommend:

A. Consideration of upgrade to a device which allows biventricular pacing for resynchronization therapy

B. Initiation of heart transplantation evaluation

C. Both A and B

D. No further evaluation or treatment indicated at this time

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Topics for discussion:

Should a biventricular device have been placed with the initial implantation? (Was she a candidate with new onset CHF?)

When do you decide to refer for heart transplantation evaluation? Should you wait to see if her status improves following biventricular pacing?

No, she was not a strict candidate for CRT device implantation upon presentation with new onset CHF, in the absence of prior medical therapy.

It’s acceptable to make an early referral, but many patients may improve after CRT device implantation and no longer be candidates for transplantation.

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What are the Guidelines?

ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: Secondary PreventionClass I: ICD therapy is indicated in pts who are survivors of cardiac arrest due to VF or hemodynamically unstable sustained VT after evaluation to define the cause of the event and to exclude any completely reversible causes (Level of evidence A)

Class I: ICD therapy is indicated in pts with structural heart disease and spontaneous sustained VT, whether hemodynamically stable or unstable (Level of evidence B)

Class IIa: ICD implantation is reasonable for pts with sustained VT and normal or near-normal ventricular function (Level of evidence C)

Epstein et al., ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities, Circulation 2008;117:e350-408

www.HRSonline.org

What are the Guidelines?

ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD - ICD Indications: Heart Failure – CRT recommendations

Class IIa: ICD combined with BiV pacing can be effective for primary prevention to reduce mortality by reduction in SCD in pts with NYHA class III or IV receiving optimal medical therapy, in SR with QRS complex ≥ 120 ms who have reasonable expectation of survival with good functional status for > 1 yr (level evidence B)

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Zipes et al., ACC/AHA/ESC 2006 Guidelines for Management of Patients with Ventricular Arrhythmias & SCD, Circulation 2006;114:e385-484

www.HRSonline.org

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Case 3 – M.P. - Syncope and Dilated CM

76 y.o. female

Episode of loss of consciousness while walking to mailbox

Exam: JVP 6 cm, cardiomegaly, S4 gallop, no S3 or murmurs

Labs: Normal

ECG: Sinus rhythm and LBBB

Echo: 4 chamber dilatation, global LV hypokinesis, trace MR, and LVEF 35-40%

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Question 1

Diagnostic evaluation should include:

A. Cardiac catheterization, to evaluate for significant CAD

B. Signal averaged ECG, to determine if EP testing is indicated

C. Invasive electrophysiological testing, to evaluate for AV conduction disease or inducible ventricular arrhythmias

D. Endomyocardial biopsy

E. A & C

F. None of the above

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Question 1 Answer

Diagnostic evaluation should include:

A. Cardiac catheterization, to evaluate for significant CAD

B. Signal averaged ECG, to determine if EP testing is indicated

C. Invasive electrophysiological testing, to evaluate for AV conduction disease or inducible ventricular arrhythmias

D. Endomyocardial biopsy

E. A & C

F. None of the above

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Evaluation Decisions:

Cardiac catheterization should be performed to exclude significant coronary artery disease, which may first require revascularization.

Invasive electrophysiological testing may be performed to evaluate for significant conduction system disease or inducible sustained ventricular arrhythmias.

However, EP testing may have low yield in patients with non-ischemic heart disease. Therefore, some electrophysiologists may opt to proceed directly to ICD implantation in patients with non-ischemic cardiomyopathy.

Signal averaging would not be useful in this case, and results would not change further evaluation and treatment decisions.

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Results of Testing:

Cardiac catheterization: Normal coronary arteries, global LV hypokinesis, LVEF 37%

EPS: Normal sinus node function, resting HV interval = 62 msec, 1:1 AV conduction to atrial pacing cycle length of 420 msec, no inducible sustained or nonsustained ventricular arrhythmias

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Question 2

The best treatment option is:

A. Empiric treatment with procainamide

B. Pacemaker implantation, since the patient has an underlying LBBB

C. Implantation of a cardioverter defibrillator

D. Implantation of an insertable loop monitor

E. No treatment aimed at arrhythmias, since the EP study was negative

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Question 2 Answer

The best treatment option is:

A. Empiric treatment with procainamide

B. Pacemaker implantation, since the patient has an underlying LBBB

C. Implantation of a cardioverter defibrillator

D. Implantation of an insertable loop monitor

E. No treatment aimed at arrhythmias, since the EP study was negative

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Why is ICD the best option?

EP testing has a low yield for inducing sustained ventricular arrhythmias in the setting of non-ischemic heart disease (as arrhythmias may not be related to reentry)

Syncope portends a poor prognosis in patients with a non-ischemic cardiomyopathy, and these patients frequently have symptomatic ventricular arrhythmias detected on ICD interrogation during follow-up

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Intervention and Clinical Outcome:

Dual chamber ICD implanted

Syncopal episode 4 months after implantation – and the patient was concerned because her ICD “did not work”

Interrogation of the device revealed the following event, coinciding with the time of the syncopal episode:

A

V

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Outcome:

Appropriate ICD therapy occurred within 10 seconds after the onset of the arrhythmia

Loss of consciousness resulted due to the rapid rate of the tachycardia

Continued observation was elected, without the addition of antiarrhythmic agents

No additional events so far

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What are the Guidelines?

ACC/AHA/HRS Guidelines for ICD Implantation

“Patients with cardiac conditions associated with a high risk of sudden death who have unexplained syncope that is likely to be due to ventricular arrhythmias are considered to have a secondary indication” for ICD implantation

Class IIa: ICD implantation is reasonable for patients with unexplained syncope, significant LV dysfunction, and nonischemic dilated cardiomyopathy (Level of evidence C)

Epstein et al., ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities, Circulation 2008;117:e350-408