Orlando, Florida – October 7-9, 2011
Hypertrophic Cardiomyopathy Update 2011
Rami Kahwash, MDAssistant Professor in Internal medicine
Division of Cardiovascular MedicineSection of Heart Failure/Transplant
The Ohio State University
What is Hypertrophic Cardiomyopathy?
Presence of left ventricular hypertrophy unexplained by the loading condition
Epidemiology of HCM
Common monogenetic cardiac disease Inherited as autosomal dominant with variable penetrance and expressionPrevalence is 0.2 % 1Incidence of sudden cardiac death (SCD) 1-2 % in children and adolescence and 0.5 to 1 % in adult 2, 3
1. Maron BJ et al, J Am Coll Cardiol. 20032. Elliot PM et al, J Am Coll Cardiol . 20003. Elliot PM et al, Lancet. 2004
Clinical Presentation of HCM
Asymptomatic
Diastolic heart failure ( Mild refractory symptoms brunt out stage)
Arrhythmia syncope
SDC
Genetics of HCM - 2011 Update
60 % of cases, HCM is caused by mutations in genes coding for cardiac sarcomere proteins
> 600 different sarcomeric gene mutations are reported , majority are missense
< 5 % of cases, mutations in genes encoding Z-disc proteins and proteins involved in Ca regulation
Autosomal dominant, but with incomplete penetrance and variable clinical expression
7Desai MY et al, Circ Cardiovac Imaging. 2011
Genes Mutations & Risk Stratification
Role of genes and risk stratifications is controversialEarly data suggested association:
a) MHC mutations and ↑ mortality
b) MYBPC mutations and later manifestation in life with milder form of the disease
c) Troponin T mutations and less hypertrophy but more disarray, fibrosis and SCD
d) ↑ CV events when positive genetic screening compared to negative test
e) Multiple mutations and more severe phenotype and ↑ SDC
a) Watkins H et al, N EngJ Med. 1992. b) Niimura H et al, N Eng J Med. 1998. C) Watkins H et al, N Eng J Med. 1995. d) Olivotto I et al, Mayo Clin proc. 2008. e) Ingles J et al, J Med Genet. 2005
Role of Genetic Testing in 2011Family studies showed heterogeneous expressions of the same mutation among individuals within the same family.
No Role in DiagnosisNo Role in ICD decision
A= B/C
Role of Genetic Testing in 2011Family Screening
Desai MY et al, Circ Cardiovac Imaging. 2011
IMAGING and HCM- 2011
1-Assessment of MorphologyLV GeometryEvaluation of mitral valve and subvalvular apparatusEvaluation of myocardial perfusionEvaluation of myocardial fibrosis
2-Functional AssessmentEvaluation of LV cavity obstructionEvaluation of systolic and diastolic LV function
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ADVANTAGEAssessment of LV thicknessMitral valveLVOT gradientGlobal and regional function
LIMITATIONOperator dependantLimited acoustic windowsSuboptimal assessment of subvalvualr apparatusLimited septal and temporal resolution
ECHO
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ADVANTAGEGold standard to assess cardiac structure/LV massPapillary muscle morphologyMyocardial fibrosisRegional myocardial mechanics
LIMITATIONlimited availabilityDevice related contraindicationsPrognostic value of fibrous assessment is not well established
MRI
27 year old man with HCM
Desai MY et al, Circ Cardiovac Imaging. 2011
35 year old man with HCM
Desai MY et al, Circ Cardiovac Imaging. 2011
Fibrosis and HCM Facts
Gadolinium-enhanced CMR provides an accurate method for detection of myocardial fibrosis 1
In HCM, fibrosis is patchy, midmyocardial and most commonly found in the regions of hypertrophy 2
The pattern and amount of fibrosis correlates closely with histolopathology 2
1)Simonetti OP et al, Radiology. 20012)Kwon DH et al, J Am Coll Cardiol. 2009
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O'Hanlon, R. et al. J Am Coll Cardiol 2010;56:867-874
Autopsy Correlation of Fibrosis With In Vivo LGE-CMR
Fibrosis and SCD in HCM - 2011
Extent of fibrosis in patients aged < 40 years is associated with clinical markers of SCD, whereas in older patients, it is associated with progressive ventricular dysfunction 1Studies demonstrated association between degree of fibrosis and ventricular arrhythmia 2, 3
Emerging data demonstrates incremental prognostic values of myocardial fibrosis in predicting hard outcomes 4, 5
1) Moon JC et al, JACC. 2003 2) Kwon DH et al, JACC. 2009 3) Rubinshtein R, Circ Heart Fail. 2009 4) O’Hanlon R et al, JACC. 20105) Bruder O et al, JACC. 2010
Fibrosis in HCM Conclusion - 2011
The long term clinical significance of fibrosis is uncertain
Long term prospective studies are still needed
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Sudden Cardiac Death in Hypertrophic Cardiomyopathy
Ommen S R , Gersh B J Eur Heart J 2009;eurheartj.ehp307
Who Needs an ICD?
Risk factors Recommendations
0 Reassurance1 Individualize (MRI?)
2 + ICDPrior SCD ICD
Sustained VT ICD
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HCM
decrease obstructive Sx(dyspnea, CP, fatigue) Prevention of SCD
SymptomaticObstructive HCM
Beta-blockade Verapamil or Diltiazem Disopyramide
Drug-refractorysymptoms
Surgical Septal Myectomy
Special Circumstances (i.e., comorbidity)
Septal Ablation
ACC/ESC Consensus Recommendation
Thank You