Hypertrophic Cardiomyopathy Guidelines

Summary from the:ACC/ESC Clinical Expert Consensus Statement on Hypertrophic Cardiomyopathy

Maron BJ, et al. J Am Coll Cardiol 2003; 42: 1687-713

And ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm

AbnormalitiesEpstein AE et al. Heart Rhythm 2008;5:934-55

Hypertrophic CardiomyopathyGuidelines

Joseph Blackshear, MDMayo Clinic

Jacksonville, FL

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Hypertrophic Cardiomyopathy: LVH ≥ 15 mm, without hypertension, aortic stenosis etc25% with LVOT obstruction

Maron BJ et al. JACC 2003;42:1687

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HCM, epidemiology and genetics

1:500 persons

600,000 persons in US

Most common cause of SCD, age < 40 yr

Most common cause of SCD, competitive athletes

Data on management derived from registries, practice

With no SCD risk factors: 90 % predictive value for freedom from SCD, BUT 3-

5% may still suffer SCD

Heritable: 11 genes, > 1,000 mutations

60% have identifiable abnormal genotype

Predominantly autosomal dominant inheritance

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Approach to Hypertrophic Cardiomyopathy

Symptomatic treatment

Exertional dyspnea

Angina

Arrhythmias, including leading to SCD

Prevention of sudden cardiac death

ICD for primary or secondary prevention

Screening of relatives

History, exam, ECG, echo, MRI

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Symptomatic treatment

Class I: no drugs.

Class II: beta blocker, verapamil, or disopyramide.

possibly low dose diuretics. Avoid vasodilators and

inotropes.

Class III/IV: despite maximal medical management,

surgical septal myectomy; consideration of alcohol

septal ablation (or pacing) in selected patients.

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Prevention of Sudden Cardiac Death

Data from Registry, mean age 42, n=506, 4 yr follow up.

Resuscitated cardiac arrest or sustained VT: 11%

appropriate shocks per year after ICD implantation.

Primary prevention, ≥ 1major risk factor: 4% appropriate

shocks per year after ICD implantation.

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Risk Factors for SCD in HCM

Major, established

Cardiac arrest/ Sustained VT

Family history of SCD

Unexplained syncope

LV thickness ≥ 30 mm

Abnormal BP response to

exercise

NSVT on Holter

Possible

LV outflow obstruction ≥ 30 mm Hg

Intense physical exertion (competitive

sports)

Late gadolinium enhancement (scar) on

contrast MRI

Alcohol septal ablation

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Registry of 506 patients who received ICDs at 42 medical centers in US, Europe, and AustraliaMean age 42 yearsFunctional class: I: 55%, II: 32%, III/IV: 13%≥ 30 mm Hg mean gradient: 25%3.7 year mean follow upComplications: 27 % inappropriate shocks, 4% infection, 2% hemorrhage or thrombosis, 7% lead fracture

Maron BJ et al JAMA 2007; 298: 405

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Indications for ICD

Secondary protection

Cardiac arrest

Spontaneous sustained VT

Primary prevention

One or more major risk factors

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Genetic Testing and Screening (Irrelevant for risk stratification)

Only a few mutations predict a high risk for sudden death or

rapid progression to terminal CHF.

If (+) for causal mutations, relatives may be ruled in/out by

testing.

If (–) for causal mutation, clinical screen of family of affected

proband: begin at age 12, annually with echo, ECG, Holter,

exam. If negative by age 18, continue Q 5 yr.