What are the management maneuvers for mitral regurgitation?

Management of Mitral Regurgitation

The management of mitral regurgitation fundamentally depends on whether it is primary (degenerative) or secondary (functional), with primary MR requiring early surgical intervention when severe, while secondary MR mandates aggressive medical optimization first, followed by transcatheter edge-to-edge repair (TEER) in selected patients who remain symptomatic despite optimal therapy. 1, 2

Initial Classification and Assessment

• Echocardiography is essential to determine whether MR is primary (valve pathology) or secondary (left ventricular dysfunction), as this distinction completely changes the management algorithm 2, 3
• Severe MR is defined by vena contracta ≥7 mm, EROA ≥0.4 cm² for primary MR, regurgitant fraction ≥50%, and regurgitant volume ≥60 mL/beat 2, 3
• For secondary MR, the threshold may be lower at EROA ≥0.3 cm² if the regurgitant orifice is elliptical 1, 2
• Use cardiovascular magnetic resonance (CMR) when echocardiographic measurements are ambiguous or uncertain 1, 2
• Perform exercise echocardiography in patients with exercise-induced symptoms to assess dynamic worsening of MR 2, 3

Management Algorithm for Primary (Degenerative) MR

Symptomatic Severe Primary MR

• Surgery is indicated for all symptomatic patients with severe primary MR regardless of left ventricular function (even if LVEF <30%) 1, 2, 3
• Mitral valve repair is strongly preferred over replacement when anatomically feasible, as it reduces mortality by approximately 70% 1, 4
• Surgery should be performed at a heart valve center with high repair rates (≥80-90%) and low operative mortality (<1%) 1, 4

Asymptomatic Severe Primary MR

• Surgery is indicated when LVEF ≤60% and/or LV end-systolic diameter ≥40 mm (Stage C2), as these represent early left ventricular dysfunction 1, 2
• Surgery should be considered when left atrial volume index ≥60 mL/m², new-onset atrial fibrillation, or pulmonary artery systolic pressure >50 mmHg develops 1, 3
• Surgery may be considered if there is progressive LV enlargement or declining ejection fraction on ≥3 serial imaging studies 1
• Transcatheter edge-to-edge repair (TEER) is reserved only for high surgical risk patients with suitable valve morphology who have prohibitive surgical risk 1

Management Algorithm for Secondary (Functional) MR

Step 1: Optimize Medical Therapy (Mandatory First Step)

• Guideline-directed medical therapy (GDMT) is the mandatory first-line treatment for all patients with secondary MR 2, 3, 5
• GDMT includes ACE inhibitors/ARBs, beta-blockers, and mineralocorticoid receptor antagonists 2, 3
• Use rapid medication titration protocols to reduce heart failure hospitalizations and facilitate earlier device therapy consideration 5
• GDMT alone reduces MR severity in 40-45% of patients 5
• Diuretics are first-line for fluid overload manifestations such as lower extremity edema 3
• Nitrates may be useful for acute dyspnea in patients with a large dynamic component of MR 3

Step 2: Rhythm and Device Management

• Pursue restoration and maintenance of sinus rhythm in patients with atrial fibrillation, as this significantly reduces MR severity 5
• Cardiac resynchronization therapy (CRT) should be implemented in patients who meet guideline-directed criteria, as it may reduce MR severity through increased closing force and resynchronization of papillary muscles 1, 3, 5
• Reassess MR severity 3-6 months after optimization of GDMT and CRT 1

Step 3: Interventional Therapy (After Medical Optimization)

• Transcatheter edge-to-edge repair (TEER) should be considered for patients with severe secondary MR, LVEF 20-50%, persistent NYHA class II-IV symptoms despite optimal medical therapy (including CRT if indicated), and no indication for coronary revascularization 1, 2, 5
• TEER has a number needed to treat of 3.1 to reduce heart failure hospitalization and 5.9 to reduce all-cause death at 24 months 5
• TEER significantly reduces 24-month mortality compared with medical therapy alone (OR 0.57,95% CI 0.34-0.96) 6
• Surgical correction of secondary MR may improve symptoms and quality of life but has not been shown to improve survival 1
• Surgery is indicated when severe secondary MR is present and the patient is undergoing coronary artery bypass grafting (CABG) with LVEF >30% 1, 3
• Consider cardiac transplant or left ventricular assist device therapy if TEER is not feasible in patients with refractory symptoms 1

Surveillance and Follow-up

• Asymptomatic patients with severe MR require clinical and echocardiographic follow-up every 6-12 months 2, 3
• Patients with moderate MR should have clinical evaluation every 6-12 months with annual echocardiography 3
• Patients with mild MR should be monitored every 3-5 years 3
• Serum biomarkers (e.g., BNP) may help guide optimal timing of intervention in asymptomatic patients with severe MR 1, 2, 3

Multidisciplinary Team Approach

• All intervention decisions should involve multidisciplinary team (MDT) discussion by the heart team 1, 3
• The heart team should consider valve morphology, MR etiology, patient comorbidities, surgical risk (STS-PROM score), frailty, organ system compromise, and procedure-specific impediments 2, 3
• Input from a cardiologist with experience managing heart failure and MR is essential for secondary MR decisions 1

Critical Pitfalls to Avoid

• Do not delay surgery in asymptomatic primary MR once LVEF falls to ≤60% or LVESD reaches ≥40 mm, as delay after onset of LV dysfunction worsens prognosis 1
• Do not proceed to intervention for secondary MR without first optimizing GDMT and considering CRT, as 40-45% will improve with medical therapy alone 5
• Do not perform mitral valve replacement when repair is feasible, as repair provides superior outcomes 1, 4
• Do not use TEER as first-line therapy for primary MR in surgical candidates, as surgery remains superior 1