Mitral Valve Edge-to-Edge Repair in Patients With Exercise-Induced Severe Mitral Regurgitation (MARCER)

The goal of this clinical trial is to learn whether mitral valve transcatheter edge-to-edge repair (TEER) in addition to guideline-directed medical therapy (GDMT) can improve clinical outcomes and symptoms in heart failure patients with non-severe secondary mitral regurgitation (SMR) at rest and exercise-induced severe SMR. The main questions it aims to answer are: * Does mitral valve TEER in addition to GDMT lead to better overall clinical outcomes than GDMT alone in patients with heart failure and exercise-induced severe SMR? * Does mitral valve TEER reduce the risk of death, heart failure hospitalization, or worsening SMR during 12 months of follow-up compared with GDMT alone? * Does mitral valve TEER improve patients' quality of life compared with GDMT alone? Participants will: * Undergo screening assessments to confirm eligibility for the study. * Be randomly assigned to receive either GDMT alone or GDMT plus mitral valve TEER. * Attend follow-up visits at approximately 3 time points during a 12-month follow-up period. * Undergo clinical evaluations that are routinely…

• Four-step hierarchical composite primary endpoint; win ratio based on the following parameters: time to all-cause mortality at 12 months, time to first HF hospitalization, SMR progression (3+/4+) at rest, change in KCCQ score from baseline to 12 months.

1. Study completion expected

   Jun 2030

2. Primary completion expected

   Jun 2029

3. Last registry update

   5 Oct 2026

4. Started

   16 Sept 2026

5. Registered

   16 Jul 2026