Aortic stenosis (AS) is the most frequent valvulopathy in Western countries. The prevalence of AS is constantly increasing due to the aging of the population. Although significant progress has been made in understanding the pathophysiological mechanisms underlying the onset and progression of AS, there is no medical treatment to slow or prevent its progression. The only treatment available is Aortic Valve Replacement (AVR) performed by surgery or by catheterization (TAVI).

AS is associated with an increase of post-load which leads the left ventricular myocardium to hypertrophy. Associated with hypertrophy, myocardial fibrosis will gradually develop. Despite interesting data, many unknowns persist and remain to be identified.

The aim of the study is to characterize prospectively the left ventricular remodeling and assess its changes after AVR and within 1 year in 500 patients using clinical, biological, echocardiographic and MRI parameters.

Inclusion Criteria:

• Aortic stenosis
• Indication of Aortic Valve Replacement (Surgery or TAVI)

Exclusion Criteria:

• Rheumatismal or congenital aortic stenosis
• Aortic insufficiency (grade >= 2/4)
• Associated valvulopathy (grade >= 2/4)
• Myocardial infarction antecedent
• Severe renal failure
• Cardiac surgery (Aorta abdominal) antecedent
• Complex congenital cardiopathy

Patients with at least moderate aortic stenosis and in whom an intervention is programmed or indicated