valvular aortic stenosis: study of myocardiac fibrosis by magnetic resonance imagery

Conditions: Aortic Valve Stenosis

Summary: aortic valve stenosis (avs) is the most frequent valvular disease. the severity of the obstruction of the left ventricle (lv) is essentially analyzed today by echocardiography doppler, which assesses two key markers that are aortic valve pressure gradient and the aortic valve area. however these marker are a poor reflect of the clinical severity of avs. the aim of the study is to validate new markers assessing cardiac fibrosis that might best or complementary markers.

to validate new markers assessing cardiac fibrosis three groups of subjects were studied in controls subjects and patients with avs in order to : 1. analyze myocardial fibrosis markers in mri, the degree of hypertrophy, remodeling and wall shear stress in a control population and in three groups of subjects to ra progressively increasing risk: asymptomatic subjects without symptomatic subjects lv dysfunction, symptomatic patients with lv dysfunction. the factors favoring the appearance of fibrosis observed in mri will be analyzed on all subjects. 2. to validate these fibrosis markers estimated by mri by histological analysis of biopsies performed in patients undergoing aortic valve replacement. 3. monitoring compliance with the distribution of markers of fibrosis and wall stress estimated on initial mri are factors of aggravation or not improved function and / or remodeling remote myocardial. public hospitals in paris

Eligibility criteria:
patients : inclusion criteria: * echocardiography considered as normal and / or age-related * patients who have received prior clinical examination * patient receiving a social security scheme or entitled, or cmu * after having giving written informed consent. * patients symptomatic with indication of surgery (group surgery) or not exclusion criteria: * with one of the following cardiac abnormalities: atrial fibrillation, more than moderate either aortic or mitral valve regurgitation * heart valve surgery history (aortic, mitral, tricuspid and pulmonary). * indication for cardiac surgery other than on the aortic valve. * usual counter-indications of mri: pace-maker, defibrillator, metallic objects including gadolinium allergy. * patients with severe renal insufficiency with a clearance \<30 ml / min estimated by the cockcroft \& gault formula. * patient who cannot be followed over the duration of a year. controls (healthy volunteers) inclusion criteria: * normal ekg * echocardiography considered normal and / or age-related * patients who have received prior clinical examination * patient receiving a french national social security * after having obtain written informed consent. criteria for non-inclusion * history of known or detectable infarction on ekg * known primary or secondary cardiomyopathy or detectable on echocardiography * thoracic radiotherapy or chemotherapy history * subject with usual contra-indications of mri: claustrophobia, metallic objects. * patients with significant renal insufficiency with a clearance \<90 ml / min estimated by the cockcroft \& gault formula. * subject who could be planned for 2 cmr within two weeks

Keywords: fibrosis magnetic resonance imaging