Mitral regurgitation:
when intervention is needed

Article written and reviewed by Dr Luca Moretti

The answer depends first of all on why the mitral valve is leaking. In primary mitral regurgitation, the problem originates in the valve or its apparatus, for example because of prolapse or rupture of the chordae tendineae. In secondary mitral regurgitation, the valve may be structurally almost normal but does not close properly because the ventricle or atrium has changed shape.
This distinction is fundamental because the timing and type of intervention are not the same.

For causes, classification and a complete echocardiographic overview, see the monograph on mitral regurgitation. This guide instead addresses the practical question: when follow-up is no longer sufficient.

First question: primary or secondary mitral regurgitation?

In primary mitral regurgitation, the defect directly affects the leaflets, chordae tendineae or other components of the mitral apparatus. Degenerative prolapse is a common cause in high-income countries. When regurgitation becomes severe, the aim is to correct the valve before the heart develops irreversible consequences.
In secondary mitral regurgitation, by contrast, the problem results mainly from remodeling of the ventricle or atrium. In this case, the disease that altered the geometry of the heart must be treated first.

The 2025 guidelines also distinguish ventricular from atrial secondary mitral regurgitation because they have different mechanisms and treatment strategies. Therefore, reading “severe mitral regurgitation” in a report is not enough to know which treatment is appropriate.

Primary mitral regurgitation: when intervention is performed

If primary mitral regurgitation is severe and causes symptoms, surgery is generally recommended in operable patients. When a durable repair is expected, mitral valve repair is preferred to replacement because it preserves the valve apparatus and avoids many problems associated with a prosthetic valve.
The presence or absence of symptoms, however, is not the only criterion.

Even in asymptomatic patients with severe primary mitral regurgitation, the 2025 ESC/EACTS guidelines recommend surgery when left ventricular ejection fraction is 60% or lower, end-systolic diameter is at least 40 mm, or indexed end-systolic diameter is at least 20 mm/m². These thresholds may be surprising because an ejection fraction of 60% seems normal in other settings, but in severe mitral regurgitation a reduction to this level may already indicate early ventricular dysfunction.

Other findings that bring the discussion about intervention forward include new-onset atrial fibrillation, resting systolic pulmonary pressure above 50 mmHg, marked left atrial dilation and at least moderate secondary tricuspid regurgitation. The decision is particularly favorable when operative risk is low and the likelihood of achieving a durable repair is high at an experienced center.

Secondary mitral regurgitation: treat the heart first, then reassess the valve

In ventricular secondary mitral regurgitation, the first step is optimal heart failure therapy. When indicated and tolerated, this includes the medications recommended for ventricular dysfunction and cardiac resynchronization therapy in patients who meet the criteria.
This step is not a formality: some patients show a reduction in mitral regurgitation after treatment is optimized and favorable ventricular remodeling occurs.

If, despite appropriate treatment, the patient remains symptomatic with severe ventricular secondary mitral regurgitation and favorable anatomy, TEER, or transcatheter edge-to-edge repair, can reduce heart failure hospitalizations and improve outcomes in carefully selected patients. The 2025 guidelines specify clinical and echocardiographic criteria to identify those most likely to benefit.

Surgery or TEER: why the choice is not based on age alone

In severe primary mitral regurgitation, if the patient is operable and the valve is repairable with a high probability of success, surgery remains the standard treatment. TEER may be considered in symptomatic patients with high surgical risk and favorable anatomy.
In ventricular secondary mitral regurgitation, TEER has a more central role, but only after optimization of heart failure therapy and Heart Team assessment.

The choice therefore depends on the mechanism of regurgitation, anatomy, ventricular function, symptoms, other heart diseases, procedural risk and the patient’s goals. Age alone is not enough. The presence of coronary artery disease requiring bypass surgery can also shift the strategy toward combined surgery.

If intervention is not performed immediately: what needs to be monitored

Follow-up is intended to identify progression before irreversible damage develops. In asymptomatic severe primary mitral regurgitation, symptoms, ejection fraction, ventricular and atrial dimensions, pulmonary pressure, heart rhythm and any tricuspid regurgitation are monitored.
If symptoms and the echocardiogram do not agree, an exercise test or stress echocardiography may be useful to determine whether the patient is truly asymptomatic.

Assessment should be brought forward if new shortness of breath, reduced exercise capacity, edema, persistent palpitations or atrial fibrillation develops. Severe acute mitral regurgitation, for example from rupture of a chord or papillary muscle, is a different situation and may require urgent treatment.

Frequently asked questions about mitral regurgitation

When is intervention needed?
In severe primary mitral regurgitation, intervention is performed mainly when symptoms or signs of early cardiac damage are present. In secondary mitral regurgitation, treatment of the underlying disease is optimized first and the need for a procedure is then reassessed.

Does a severe form without symptoms always require surgery?
No, but there are echocardiographic and clinical criteria that may indicate or support consideration of intervention before symptoms develop.

Is it better to repair or replace the valve?
In degenerative primary mitral regurgitation, when a durable repair is highly likely at an experienced center, repair is generally preferred.

Are MitraClip and surgery equivalent?
No. They are strategies with different indications. TEER is particularly important in selected ventricular secondary mitral regurgitation and in patients with primary mitral regurgitation who have high surgical risk.

Can medications reduce mitral regurgitation?
In ventricular secondary mitral regurgitation, yes, because heart failure treatment can improve ventricular geometry and reduce regurgitation. In primary mitral regurgitation, medications do not correct the anatomical defect of the valve.