Mitral Valve in Hypertrophic Cardiomyopathy

Role of Mitral Valve in the Obstruction of Left Ventricular Outflow Tract in Patients With Hypertrophic Cardiomyopathy

The purpose of the study is to assess the role of mitral valve apparatus in the development of outflow tract obstruction in patients with hypertrophic cardiomyopathy and to identify the best surgical treatment modality to relieve outflow tract obstruction in such patients

It is well-known that mitral valve plays an important role in the development of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy. In order to further investigate this phenomenon, the following study aims to compare mitral valve geometry indices, as assessed by transthoracic echocardiography, two- and three-dimentional transesophageal echocardiography and mitral valve quantification analysis, and papillary musles' function, as assessed by 2D speckle tracking imaging, in patients with hypertrophic obstructive cardiomyopathy, patients with arterial hypertension and left ventricular hypertrophy and people without structural heart disease. This will provide information on the geometric characteristics of mitral valve that predispose to the development of obstruction. Futhermore, patients with hypertrophic obstructive cardiomyopathy that are eligible for the surgical relief of obstruction will be randomised into four groups according to the modality of intervention. These groups are as follows: 1) isolated extended septal myectomy; 2) extended septal myectomy + edge to edge mitral valve repair; 3) extended septal myectomy + posterior lealfet sliding plasty; 4) extended septal myectomy + secondary chordae transection. After surgery, said indices will be reassessed and the degree of outflow tract obstruction relief noted, in order to elicit which geometrical changes are produced by each type of intervention. Patients will be followed long-term, up to 5 years, in order to define whether the addition of the intervention on mitral valve helps abolish the residual gradient more effectively, and whether it translates into any survival benefit.

Patients with hypertrophic obstructive cardiomyopathy who will undergo septal myectomy and edge-to-edge mitral valve repair (O. Alfieri technique)

Patients with hypertrophic obstructive cardiomyopathy who will undergo septal myectomy and posterior leaflet sliding plasty ( A. Carpentier technique)

Patients with hypertrophic obstructive cardiomyopathy who will undergo septal myectomy and secondary chordae transection

Patients with arterial hypertension with left ventricular hypertrophy whose mitral valve geometry and papillary muscles' function will be compared to those of the patients with hypertrophic cardiomyopathy

Patients without structural heart disease whose mitral valve geometry and papillary muscles' function will be compared to those of the patients with hypertrophic cardiomyopathy

degree of mitral regurgitation assessed by color doppler, regurgitant volume measured using PISA method

indices of mitral valve geometry assessed by 2D transthoracic and transesophageal echocardiography and mitral valve quantification analysis

Inclusion Criteria: Age >18 years Signed informed consent to participate in the study For patients with hypertrophic cardiomyopathy only: resting or latent peak left ventricular outflow tract gradient >50 mmHg, NYHA class III-IV For patients with arterial hypertension only: hystory of arterial pressure increase >140/90 mmHg, increased left vantricular wall thickness (>10 mm) and myocardial mass indexed to BSA (>95 g/m2 for women and >115 g/m2 for men), as assessed by 2D transthoracic echocardiography Exclusion Criteria: Age < 18 years Persistent form of atrial fibrillation Intrinsic mitral or aortic valve disease Coronary artery disease Reduced left ventricular ejection fraction For control group only: presence of any structural heart disease