Controversies in

Hypertrophic Cardiomyopathy:

Case Presentation

Ethan Rowin, MD

Associate Director, Hypertrophic Cardiomyopathy Center

Tufts Medical Center, Boston MA

Chanin T. Mast Center for Hypertrophic Cardiomyopathy

Morristown Medical Center, Morristown NJ

HCM Case Presentation

• 40-year-old male with HCM referred for management of progressive heart failure symptoms over the past 3 years.

• Limiting exertional dyspnea (stairs and gradual inclines; NYHA Class II) and atypical chest pain despite Toprol XL 150mg.

• In addition, severe post-prandial SOB resulting in significant limitation, even walking on level ground (class III); and 30 pound weight loss

• One syncopal episode, 1 year prior, occurred with exertion, 30 minutes after ingestion of a large meal

Past Medical History

• Atypical chest pain prompted cardiac catheterization

which demonstrated no CAD

• No other significant medical history

• Employed as a transporter of raw materials

• No family history of HCM or unexplained sudden death

• 14 year-old asymptomatic daughter underwent a recent

screening echocardiogram without LV hypertrophy

• No NSVT on 24 hour Holter monitoring

Exercise

Echocardiogram…

Echocardiogram at Rest

Parasternal Long-Axis Apical 4-Chamber

Post Exercise Echocardiogram…

LV

LA

Ao

2.6 m/s

Cardiac MRI…

16mm

LV

RV

LV

RV

2% LGE

Basal Short-Axis Contrast Enhanced CMR

HCM Case

• Maximum LV wall thickness of 16mm

• Ejection Fraction of 60%

• SAM at rest and with exercise but no LVOT

obstruction

• Trace mitral regurgitation

• Normal BP response to exercise

• Minimal LGE on CMR (2% of LV myocardium)

• MYPC3 Arg502Trp positive pathogenic mutation

What is the next step?

1. Evaluation/ management of his

symptoms

2. Risk stratification

3. Family Screening

Exercise echo was

repeated several days

later off medications for

24 hours and one hour

after a small meal…

6:00 minutes on Bruce Protocol…

Mild MR 130 mmHg

LV

LA

Ao

Management

• Initially not interested in moving forward with invasive option

• Started on Disopyramide…

• Limiting symptoms improved for several months before eventually recurred

• An exercise echocardiogram was repeated which confirmed prior findings

• At this point patient elected to move forward with invasive option…

Management

• Alcohol Septal Ablation

• Surgical Myectomy

• Mitral valve replacement

Pre-operative TEE

Rest Isuprel

Pre-operative TEE

Isuprel Isuprel

Post-operative Myectomy + MV plication

Isuprel MR

One Year Later…

Asymptomatic… Able to eat all

foods without symptoms. Very

happy with his improved quality

of life.

Symptomatic HCM

patient without

obstruction at rest

Exercise

Echocardiography

Provocable

obstruction

(≥30mmHg)

Nonobstructive

(<30mmHg)

Myectomy/

Alcohol

Ablation

Uncertainty

Persists BB/CCB/Norpace

Pharmacologic

Provocation

Transplant

BB/CCB

Provocable

obstruction

n=220

I/II

80%

III/IV

20% NYHA

Class

I/II

6.5 ± 2

Rate of Heart Failure

progression = 3.2%/year

Exercise Echocardiogram Predicts Progressive

Heart Failure Symptoms in HCM Patients with

No/Mild Symptoms

What is the next step?

1. Evaluation/ management of his

symptoms

2. Risk stratification

3. Family Screening

Sudden Death Risk Assessment

• Maximum LV wall thickness = 16mm

• Ejection Fraction of 60%

• Unexplained Syncope 2 years ago

• Normal BP response to exercise

• No FH of SD due to HCM

• No NSVT on Holter

• MYPC3 Arg502Trp positive pathogenic mutation

• CMR with 2% LGE

Family evaluation

• Underwent genetic testing which returned positive for MYPC3 Arg502Trp positive pathogenic mutation

• He has an asymptomatic 14 year old daughter who has had a recent echocardiogram without LV hypertrophy

• Next step in the approach to screening his family?

0.50

0.60

0.70

0.80

0.90

1.00

Free

do

m f

rom

Pro

gres

sio

n t

o

NYH

A C

lass

III/

IV

0 2 4 6 8 10

Time from Initial Visit (years)

p=.003

Nonobstructive

Provocable Obstruction

1.5%/yr

3.2%/yr

0.40

Exercise Echocardiogram Predicts Progressive

Heart Failure Symptoms in HCM Patients with

No/Mild Symptoms

Family evaluation

• Underwent genetic testing which

returned positive for MYPC3 Arg502Trp

positive pathogenic mutation

• He has a 14 year old daughter who has

had a recent echocardiogram without

LV hypertrophy

• Next step in the approach to

screening his family?

Non-

obstructive

Provocable

obstruction

n=220

I/II

90%

III/IV

10%

I/II

80%

III/IV

20%

NYHA Class

n=249

NYHA

Class

I/II

NYHA

Class

I/II

6.5 ± 2

6.5 ± 2

1.5%/year

3.2%/year

p=0.003

Exercise Echocardiogram Predicts Progressive

Heart Failure Symptoms in HCM Patients with

No/Mild Symptoms

HCM patients

without LV outflow

obstruction at rest

(<30mmHg) and

NYHA class I or II

n=469

Exercise

Echocardiogram

Provocable

Obstruction

(≥ 30mmHg)

n=220

Progression to

Class III/IV

n=43 (20%)

Myectomy or

Alchol Septal Ablation

n=32/43

Class I/II

N=30/32

(94%)

Nonobstructive

(<30mmHg)

n=249

Progression to

Class III/IV

N=24 (10%)

Heart

Transplant

n=10/24

(42%)

Follow-up

6.5 ± 2 yrs

Rate of

heart failure

progression

to NYHA

class III/IV

= 1.5%/year

Rate of

heart failure

progression

to NYHA

class III/IV

= 3.2%/year

Outflow obstruction can be effectively relieved with

myectomy even in HCM patients with minimal hypertrophy

without need for MV replacement…

Table 1. Demographic and Clinical Variables of 22 HCM Patients with Minimally

Increased Left Ventricular Wall Thickness who Underwent Surgery

Age at myectomy, yrs 56 ± 10

Male, n (%) 13 (59%)

Time between diagnosis and surgery, months 23 ± 31

Family history of HCM, n (%) 7 (32%)

NYHA class at time of surgery:

Class III

Class IV

19 (86%)

3 (14%)

Max basal septal thickness (mm) 13.7 ± 1.7

LA size (mm) 40 ± 5.2

LVED (mm) 42 ± 4.9

Ejection Fraction (%) 64 ± 4

LVOT gradient at rest or provocation:

Rest LVOT gradient, mm Hg 91 ± 34

Range LVOT gradient, mm Hg 50-160

Mitral regurgitation: n (%)

Trace-Mild 17 (77%)

Moderate-Severe 5 (23%)

Pre-Op

Gradient/MR

100±35 mmHg

Mild MR (n=9)

Post-Op

Complications

Post-Op

Gradient/MR

Complete Heart Block

(n=3*)

6±2 mmHg

Mild MR (n=9)

*1 patient with pre-op right bundle branch block

93±34 mmHg

Mild-Mod MR (n=10)

Severe MR (n=2) Complete Heart Block (n=1)

Tamponade (n=2)

6±1 mmHg

Mild MR (n=12)

60 mmHg

Mild MR

None

9 mmHg

Mild MR

Should this patient be

considered for primary

prevention ICD

placement?

Surgical Approach?

• Extended Myectomy

• Myectomy plus MV repair (plication)

• Mitral valve replacement