What are the indications and treatment guidelines for the MitraClip (mitral clip) in patients with mitral regurgitation?

MitraClip Therapy for Mitral Regurgitation

MitraClip is indicated for two distinct populations: (1) symptomatic patients with severe primary degenerative mitral regurgitation at prohibitive surgical risk, and (2) patients with severe secondary mitral regurgitation (LVEF 20-50%, LVESD <70mm) who remain symptomatic despite optimized guideline-directed medical therapy. 1, 2

Primary (Degenerative) Mitral Regurgitation

First-Line Treatment

• Surgical mitral valve repair remains the gold standard for severe primary MR and should be performed whenever feasible 1, 2
• Surgery is indicated for symptomatic patients or asymptomatic patients with LVEF ≤60% and/or LVESD ≥40mm 1, 2

MitraClip Indications for Primary MR

• MitraClip is reserved for severely symptomatic patients (NYHA class III-IV) with prohibitive surgical risk due to severe comorbidities who have favorable anatomy and reasonable life expectancy (>1 year) 1, 2
• The device is less effective than surgery at reducing MR but provides symptomatic improvement and reverse LV remodeling 1
• Approximately 75% procedural success rate with MR reduction to ≤2+ 1, 3

Anatomic Requirements for Primary MR

• Pathology must originate from central scallops (A2/P2 segments) 1
• Flail gap <10mm and flail/prolapse width <15mm 1
• Mitral valve area must be ≥4 cm² with mean gradient <4 mmHg at rest 1
• Exclude patients with significant leaflet calcification, short restrictive posterior leaflets (<8mm), or pathology in medial/lateral segments 1

Secondary (Functional) Mitral Regurgitation

Mandatory Pre-Intervention Steps

• Optimize guideline-directed medical therapy FIRST (ACE inhibitors/ARBs, beta-blockers, aldosterone antagonists, diuretics) 1, 2
• Consider cardiac resynchronization therapy if indicated 1
• Evaluate for revascularization in ischemic etiology 1

MitraClip Indications for Secondary MR

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

Anatomic Requirements for Secondary MR

• Coaptation length ≥2mm 1
• Coaptation depth <11mm 1
• Central jet origin from A2/P2 segments 1

Absolute Contraindications

Do not use MitraClip when:

• Leaflets are restricted in both systole and diastole (Carpentier Type IIIA, such as rheumatic or radiation heart disease) as this will cause mitral stenosis 1, 2
• Pre-existing mitral stenosis (valve area <4 cm² or mean gradient >4 mmHg) 1
• Active endocarditis 1
• Intracardiac thrombus 1

Echocardiographic Assessment

Pre-Procedural Evaluation

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

Intra-Procedural Guidance

• TEE guides transseptal puncture (superior-posterior position, 3.5-4cm above leaflets), clip positioning, leaflet grasping, and immediate assessment of residual MR 1
• Echocardiography is more critical than fluoroscopy for procedural success 1

Clinical Outcomes

Efficacy

• 86% of patients achieve MR ≤2+ post-procedure 4, 5
• 60-90% improve to NYHA class I-II 4, 5
• One-year survival approximately 75% in high-risk populations 4

Safety

• Negligible intraprocedural mortality 3, 6
• 30-day mortality 1-2% 4, 5
• Approximately 20% require reintervention within 1 year due to recurrent MR 1

Critical Pitfalls to Avoid

The most common error is proceeding with MitraClip in secondary MR before optimizing GDMT, as demonstrated by the negative MITRA-FR trial 2. This contrasts with the positive COAPT trial where medical therapy was optimized first.

Do not use MitraClip in patients with excessive LV dilatation (LVESD >70mm) as outcomes are poor 1, 2.

Avoid MitraClip when leaflet restriction would create mitral stenosis, particularly in rheumatic disease 1, 2.

Ensure the pathology is central (A2/P2) - lateral or medial pathology has poor outcomes 1.

Heart Team Approach

• All patients should be evaluated by a multidisciplinary Heart Team including interventional cardiologists, cardiac surgeons, heart failure specialists, and imaging experts 1
• Surgical risk assessment using STS score and clinical judgment 4
• Consider patient preferences, comorbidities, and life expectancy 1