Since the last two decades, aortic valve (AV) repair has emerged as an alternative for AV replacement, as surgery for patients with severe aortic regurgitation (AR). The aim of this thesis is to reevaluate the appropriateness of the guidelines for this new type of surgery, in particular to examine whether it might allow earlier treatment for the management of asymptomatic patients with normal ejection fraction. My works first show that the AV repair improves prognosis of patients. Subsequently we evaluated post operative survival after AV repair according to the guidelines and showed an interest to assess the benefit of an early surgery in asymptomatic patients. Despite that no benefit of an early surgery has been shown, we finally explored and measured a new parameter, the extracellular volume by cMR, able to assess myocardial fibrosis and which should add information in the management of asymptomatic patients with severe AR.(BIFA - Sciences biomédicales et pharmaceutiques) -- UCL, 201
