What are the indications and treatment guidelines for a MitraClip (mitral valve clip) in an adult patient with severe mitral regurgitation, symptomatic despite optimal medical therapy, and at high risk for surgical mitral valve repair or replacement?

MitraClip Therapy for Severe Mitral Regurgitation

Direct Answer

MitraClip is indicated for symptomatic patients with severe mitral regurgitation at high surgical risk who meet specific anatomic and clinical criteria, with different thresholds for primary versus secondary MR. 1, 2

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Primary (Degenerative) Mitral Regurgitation

First-Line Treatment

• Surgical mitral valve repair remains the gold standard and should be performed whenever feasible, reducing mortality by approximately 70% compared to medical management 2, 3
• Surgery is indicated for all symptomatic patients regardless of left ventricular function 2, 3
• Asymptomatic patients require surgery when LVEF ≤60%, LVESD ≥40mm, new-onset atrial fibrillation, or pulmonary artery systolic pressure >50mmHg 1, 2

MitraClip Indications for Primary MR

• Reserve MitraClip exclusively for severely symptomatic patients (NYHA class III-IV) with prohibitive surgical risk due to severe comorbidities 1, 2
• Patients must have favorable anatomy, reasonable life expectancy (>1 year), and meet specific echocardiographic criteria 4, 1
• Procedural success rate is approximately 75% with MR reduction to ≤2+, but it is less effective than surgery at reducing MR 4, 5

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Secondary (Functional) Mitral Regurgitation

Mandatory Pre-Intervention Steps

• Optimize guideline-directed medical therapy (GDMT) FIRST before considering any intervention - this is the most critical step to avoid poor outcomes 4, 1, 2
• GDMT includes ACE inhibitors/ARBs (or sacubitril/valsartan), beta-blockers, mineralocorticoid receptor antagonists, SGLT2 inhibitors, and diuretics 3
• Implement cardiac resynchronization therapy (CRT) if indicated, as it may reduce MR severity through improved papillary muscle synchronization 4, 3
• Evaluate for revascularization in ischemic etiology 2

MitraClip Indications for Secondary MR

• Severe secondary MR (3+ or 4+) persisting AFTER optimized GDMT 1, 2
• LVEF between 20% and 50% 1, 2
• LVESD <70mm 1, 2
• The COAPT trial demonstrated 47% reduction in heart failure hospitalizations and 38% reduction in all-cause mortality at 24 months when these specific criteria are met 1, 2

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Absolute Contraindications

Anatomic Contraindications

• Do NOT use MitraClip when leaflets are restricted in both systole and diastole (Carpentier Type IIIA, such as rheumatic or radiation heart disease) - this will cause mitral stenosis 1, 2
• Pre-existing mitral stenosis: valve area <4.0 cm² or mean transmitral gradient >4-5 mmHg 1, 2
• Active endocarditis 1, 2
• Intracardiac thrombus 2

Unfavorable Echocardiographic Criteria

• Commissural pathology (medial or lateral segments) - MitraClip works best for central A2/P2 pathology 1, 2
• Severe valvular or annular calcification, especially in the grasping area 1
• For primary MR: flail width >15mm or flail height >10mm 1
• For secondary MR: coaptation length <2mm or coaptation depth >11mm 1
• Excessive LV dilatation: LVESD >70mm 1, 2

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Diagnostic Requirements

Echocardiographic Assessment

• Transthoracic echocardiography for initial screening and severity assessment 2, 3
• Transesophageal echocardiography (ideally with 3D) is mandatory to confirm anatomic eligibility and guide the procedure 2, 6
• Severe primary MR defined by: vena contracta ≥7mm, EROA ≥0.4 cm², regurgitant volume ≥60 mL/beat 1, 3
• Severe secondary MR defined by: EROA ≥0.2 cm², regurgitant volume ≥30 mL/beat 4, 1

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Critical Pitfalls to Avoid

Most Common Error

• Proceeding with MitraClip in secondary MR before optimizing GDMT leads to poor outcomes, as demonstrated by the negative MITRA-FR trial 1, 2
• The difference between COAPT (positive) and MITRA-FR (negative) trials was patient selection and GDMT optimization 1

Other Critical Errors

• Using MitraClip in patients with excessive LV dilatation (LVESD >70mm) results in poor outcomes 1, 2
• Attempting MitraClip when leaflet restriction would create mitral stenosis, particularly in rheumatic disease 1, 2
• Treating non-central pathology (lateral or medial segments) has poor outcomes 1, 2

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Outcomes and Durability

Short-Term Outcomes

• 30-day mortality: 3.2% for MitraClip versus 16.8% for surgical MVR in high-risk patients 5
• 30-day stroke: 1.1% for MitraClip versus 4.5% for surgical MVR 5
• Hospital length-of-stay: 2 days (IQR 2-4) for MitraClip versus 7 days (IQR 5-11) for surgery 7

Long-Term Durability

• Recurrent moderate or severe MR is significantly higher with MitraClip: 66.7% at 1 year versus 33.3% with surgery 7
• Mitral valve re-intervention at 12 months: 3% for functional MR 8
• 1-year survival: 82% in high-risk patients with functional MR 8
• In primary degenerative MR, surgery remains more durable with 100% freedom from reintervention at 1 year versus 87.5% for MitraClip 7

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Heart Team Evaluation

• All patients must be evaluated by a multidisciplinary Heart Team including interventional cardiologists, cardiac surgeons, heart failure specialists, and imaging experts 2, 7
• The team should assess surgical risk, anatomic suitability, comorbidities, and life expectancy 2
• Patient preferences should be incorporated into the decision-making process 2