Hemodynamic Estimation of the Result of the MitraClip Technique: Interest of the Ratio of Mean Arterial Pressure (MAP) to Pressure of the Mean Left Atrium (POG) (MitraPOG)

Inclusion Criteria: * Woman or man over 18 years old * Patient with symptomatic mitral leakage (grade 3+ or 4+) at high surgical risk defined as: * Age ≥ 75 years and an STS score ≥ 6%, or, according to MVARC, at least 1 fragility index or at least 1 organ fragility criterion or at least 1 operative risk criterion. MVARC recommendations are defined in the appendix. * Age \<75 years and an STS score\> 8%, or, according to MVARC, at least 1 fragility index or at least 1 organ fragility criterion or at least 1 operative risk criterion. MVARC recommendations are defined in the appendix. * Patient rejected for surgery. * Patient with a life expectancy of over 1 year. * Patient affiliated or beneficiary of a social security scheme. * Patient having been informed and having signed a written consent. Exclusion Criteria: * Patient with unfavorable ultrasound parameters (for example: patient with insufficient mitral surface). * Patient with recent or active infection. * Patient with a contraindication to the transseptal puncture. * Patient with valve anatomy incompatible with the placement of the device. * Patient with an anomaly of the tricuspid valve justifying a surgical intervention. * Patient who has had a percutaneous cardiovascular procedure within the previous 30 days. * Patient who had heart surgery in the previous 30 days. * Patient with a history of surgery on the mitral valve. * Patient having had a stroke in the previous 30 days. * Patient participating in another clinical study. * Protected patient: adult under guardianship, curatorship or other legal protection, deprived of liberty by judicial or administrative decision. * Pregnant, breastfeeding or parturient woman. * Patient hospitalized without consent.