Mitral regurgitation (MR) is a common valvular heart disease worldwide, and untreated severe MR is associated with an elevated risk of heart failure and mortality. According to causes, MR could be divided into primary or secondary MR. The risk factors of mortality or heart failure hospitalization in different types of MR patients are under intensive investigation. MItral Regurgitation risk Assessment and CLinical modElling (MIRACLE) study is a prospective cohort study including adult patients diagnosed with ≥ moderate MR during hospitalization. Comprehensive echocardiographic examination was conducted at baseline evaluating valvular heart disease severity, atrial and ventricular systolic/diastolic function, pulmonary artery systolic pressure (PASP), etc. We aim to evaluate the prognostic risk factors of patients with MR and construct a prognostic clinical model to guide clinical decision-making.