Mitral regurgitation (MR) is one of the most common valvular heart diseases in China, causing heart failure. Patients with moderate to severe MR have a very poor clinical prognosis if no intervention is performed. When symptoms are still poorly controlled after guideline-directed medical therapy (GDMT) or when surgical intervention is not suitable, transcatheter mitral valve edge-to-edge repair (TEER) can improve the patient's quality of life and reduce the hospitalization rate and mortality rate. However, some patients develop into afterload mismatch (AM) after TEER, persistent adverse ventricular remodeling, and a high mortality rate, which limits the surgical benefits of TEER surgery in these MR patients. Therefore, how to scientifically predict AM and intervene as early as possible has become a research hotspot for optimizing the postoperative management of TEER patients. Afterload Mismatch Predictive modLE for Transcatheter Edge-to-Edge Repair (AMPLE-TEER) study is a prospective cohort study including adult patients undergoing TEER during hospitalization. We aim to evaluate whether the patients develop into AM after TEER, evaluate the prognostic risk factors of AM and construct a prognostic clinical model to guide clinical decision-making.