The objective of this study is to collect in a prospective registry all cases of French patients undergoing an assessment for percutaneous treatment of mitral valve disease on a native valve or due to deterioration after surgical valve repair or replacement. In these patients, valvular surgery should be considered contra-indicated or at prohibitive risk. This registry will evaluate the morbidity and mortality up to 24 months for those patients with severe mitral valve disease who are not included in a clinical trial. The association of demographic, clinical, laboratory, echocardiographic variables and treatment options with morbidity and mortality will be evaluated by univariate and multivariate analyses.