Combined Mitral and Tricuspid Versus Isolated Mitral Transcatheter Edge-to-Edge Repair for Mitral Regurgitation With Tricuspid Regurgitation (DUAL-TEER Trial)

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