This study aims to investigate the efficacy and safety of combined mitral and tricuspid transcatheter edge-to-edge repair (TEER) versus isolated mitral TEER in the treatment of patients with mitral regurgitation (MR) combined with tricuspid regurgitation (TR). The expected objective is to provide a more precise treatment strategy for patients with MR combined with TR, reduce surgical risks, improve survival rates and quality of life, and offer evidence for clinical practice. The main research content involves enrolling 404 patients with severe MR combined with TR, who will be randomly assigned to either the group receiving simultaneous mitral and tricuspid TEER or the group receiving isolated mitral TEER. The primary endpoint is the composite endpoint at one year postoperatively, including death during the one-year follow-up, mitral and/or tricuspid surgery or intervention due to mitral and/or tricuspid dysfunction, rehospitalization for heart failure, and an increase of <15 points in the KCCQ score.

Inclusion Criteria General Inclusion Criteria

• Age ≥ 18 years
• Moderate-to-severe or severe (≥3+) degenerative mitral regurgitation (DMR) or functional mitral regurgitation (FMR) combined with severe (≥3+) functional tricuspid regurgitation (FTR)
• New York Heart Association (NYHA) functional class II, III, or IVa
• Anatomically suitable for transcatheter edge-to-edge repair, as assessed by the Heart Team
• Willing and able to comply with the protocol requirements and data collection procedures
• Capable of understanding the purpose of the trial and voluntarily providing written informed consent, either personally or via a legally authorized representative DMR Inclusion Criteria
• Symptomatic moderate-to-severe or severe degenerative mitral regurgitation (MR ≥3+)
• High surgical risk FMR Inclusion Criteria
• Symptomatic moderate-to-severe or severe functional mitral regurgitation (MR ≥3+)

For ventricular FMR:

• Left ventricular ejection fraction (LVEF) < 50%
• Persistent symptoms despite optimized guideline-directed medical therapy (GDMT) and cardiac resynchronization therapy (CRT), if indicated
• Clinically stable for at least 30 days prior to enrollment

For atrial FMR:

• Unsuitable for surgery
• Persistent symptoms despite optimized medical therapy
• Clinically stable for at least 30 days prior to enrollment TR Inclusion Criteria
• Severe functional tricuspid regurgitation (TR ≥3+)
• Persistent symptoms despite guideline-directed medical therapy (GDMT)
• Clinically stable for at least 30 days prior to enrollment

Exclusion Criteria:

• Hypertrophic cardiomyopathy, restrictive cardiomyopathy, constrictive pericarditis, or other structural heart disease causing heart failure (except dilated cardiomyopathy of ischemic or non-ischemic etiology)
• Infiltrative cardiomyopathies (e.g., amyloidosis, hemochromatosis, sarcoidosis)
• Refractory heart failure requiring advanced therapies (e.g., left ventricular assist device or heart transplantation)
• Left ventricular end-systolic diameter (LVESD) > 70 mm
• Left ventricular ejection fraction (LVEF) ≤ 20%
• Pulmonary arterial hypertension as assessed by right heart catheterization (RHC)
• Severe right ventricular dysfunction, defined as:

Tricuspid annular plane systolic excursion (TAPSE) < 10 mm, or Right ventricular tissue Doppler imaging S' < 6 cm/s, or Fractional area change (FAC) ≤ 22%

-Hemodynamic instability, defined as: Systolic blood pressure < 90 mmHg with afterload reduction, or Cardiogenic shock requiring inotropic support, intra-aortic balloon pump, or ther mechanical circulatory support

• Severe uncontrolled hypertension (systolic blood pressure ≥ 180 mmHg and/or diastolic blood pressure ≥ 110 mmHg)
• Myocardial infarction or unstable angina within 30 days prior to enrollment
• Significant untreated coronary artery disease requiring revascularization, or coronary intervention performed within 30 days prior to enrollment
• Moderate or greater aortic valve or pulmonary valve stenosis or regurgitation Mitral valve anatomy deemed unfavorable for transcatheter edge-to-edge repair by the Heart Team, including:Moderate-to-severe calcification in the grasping zone; Mitral valve orifice area < 3.5 cm²; Posterior mitral leaflet length < 7 mm; Mitral stenosis; Leaflet perforation; Multi-segment disease or multiple chordal rupture Tricuspid valve anatomy deemed unfavorable for transcatheter edge-to-edge repair by the Heart Team, including:Moderate-to-severe calcification in the grasping zone; Coaptation gap ≥ 10 mm; Severe leaflet perforation, cleft lesions, or other conditions preventing device implantation
• Congenital Ebstein's anomaly
• Prior surgical or interventional procedure involving the mitral or tricuspid valve
• Pacemaker or implantable cardioverter-defibrillator (ICD) leads interfering with proper device positioning
• Intracardiac thrombus, vegetation, mass, or tumor in the atria or ventricles
• Cerebrovascular accident (stroke) within 3 months prior to enrollment
• Chronic obstructive pulmonary disease requiring continuous home oxygen therapy or long-term outpatient oral steroid treatment
• End-stage renal disease requiring chronic dialysis
• Vascular access limitations, including inferior vena cava filter, severely tortuous or obstructed caval system, or difficult transseptal puncture
• Contraindications to antithrombotic therapy, or history of intracerebral hemorrhage, gastrointestinal bleeding, or bleeding disorders within 3 months prior to enrollment
• Uncontrolled active infection, including active bacterial endocarditis
• Severe comorbidities that may complicate treatment evaluation (e.g., coma, malignancy, or severe psychiatric disorders)
• Pregnancy or breastfeeding
• Life expectancy < 1 year
• Participation in another clinical trial that has not yet reached its primary endpoint
• Investigator judgment that the patient is non-compliant or unlikely to complete follow-up as required