Heart Valve Replacement: When a Diseased Heart Valve Needs to Be Replaced

The heart has four valves that keep blood moving in the correct direction through the chambers and into the major arteries.

When a valve becomes severely narrowed or fails to close properly, the heart may have to work harder to maintain adequate circulation. Some valve problems can be monitored or treated medically for years. Others eventually require an intervention to repair or replace the damaged valve.

Heart valve replacement involves removing or bypassing a diseased native valve and implanting a prosthetic valve that can regulate blood flow.

But replacement is not always the first choice.

For some patients, the damaged valve can be repaired while preserving the patient’s own valve tissue. In others, replacement provides a more appropriate or durable solution. The decision depends on the valve involved, the underlying disease, anatomy, severity, symptoms, ventricular function, age, surgical risk and available treatment options.

What do the heart valves do?

The heart has four valves:

• Aortic valve — controls blood flow from the left ventricle into the aorta.
• Mitral valve — controls blood flow from the left atrium into the left ventricle.
• Tricuspid valve — controls blood flow from the right atrium into the right ventricle.
• Pulmonary valve — controls blood flow from the right ventricle into the pulmonary artery.

Each valve needs to perform two basic functions:

1. open sufficiently to allow blood to move forward
2. close adequately to prevent blood from flowing backward

A valve can therefore become problematic in two fundamentally different ways.

Stenosis

Stenosis means the valve does not open adequately.

The narrowed opening creates resistance to forward blood flow.

Regurgitation

Regurgitation, or insufficiency, means the valve does not close properly.

Blood leaks backward when the valve should be closed.

A patient can have stenosis, regurgitation, or a combination of both. Harrison’s describes rheumatic disease, congenital abnormalities, degenerative disease and other conditions as causes of valve stenosis and/or regurgitation involving different valves.

When does a valve problem become serious?

The presence of a valve abnormality does not automatically mean that surgery is necessary.

A person can have mild valve disease and require nothing more than periodic monitoring.

The treatment decision becomes more important when valve disease becomes severe, produces symptoms, affects ventricular function or creates other important consequences.

Symptoms may include:

• shortness of breath
• reduced exercise tolerance
• fatigue
• chest discomfort
• dizziness
• fainting
• palpitations
• swelling of the legs
• abdominal swelling

However, some patients with severe valve disease may have few symptoms, particularly early in the disease course.

This is one reason regular cardiac imaging can be important.

How is valve disease evaluated?

Echocardiography is central to evaluating heart valve disease.

A transthoracic echocardiogram (TTE) can assess:

• valve structure
• valve opening and closure
• severity of stenosis or regurgitation
• chamber size
• ventricular function
• pressure estimates
• associated abnormalities

Harrison’s describes TTE as the most commonly used imaging modality for characterising multiple or mixed valvular disease.

A transesophageal echocardiogram (TEE) may provide more detailed information in selected situations, particularly when mitral valve anatomy requires closer assessment or infective endocarditis is suspected.

Additional tests may include:

• electrocardiography
• chest imaging
• cardiac CT
• cardiac MRI
• exercise testing
• cardiac catheterisation

The purpose is not simply to determine whether the valve looks abnormal.

The treating team needs to understand how severely the valve is affecting circulation and the heart itself.

Repair or replacement?

This is one of the most important decisions in valve surgery.

Valve repair

Repair preserves the patient’s native valve while correcting the structural problem.

Depending on the valve and underlying pathology, repair may involve techniques such as:

• reshaping or removing abnormal tissue
• repairing or replacing supporting structures
• correcting leaflet prolapse
• reducing or stabilising the valve annulus
• reconstructing damaged valve tissue

Repair can be particularly valuable in selected mitral valve diseases.

Harrison’s specifically notes that mitral valve repair is preferred over replacement when feasible in patients with mitral valve prolapse or flail mitral leaflets.

Valve replacement

Replacement is considered when the native valve cannot be repaired adequately or when replacement is otherwise the appropriate treatment.

The diseased valve is replaced with a prosthetic valve.

The choice is then not simply repair versus replacement.

For replacement, another major decision follows:

What type of prosthetic valve should be used?

Mechanical vs biological heart valves

The two major categories of surgical prosthetic valves are:

• mechanical valves
• bioprosthetic or tissue valves

Each has different characteristics.

Mechanical valves

Mechanical valves are constructed from durable artificial materials.

Their major advantage is durability.

Their major disadvantage is the tendency for blood clots to form on the prosthesis, meaning long-term anticoagulation is generally required.

Harrison’s identifies warfarin as the anticoagulant required for patients with mechanical heart valves.

This creates an important lifelong consideration.

Patients receiving mechanical valves need reliable anticoagulation management and monitoring.

Bioprosthetic valves

Biological valves are made from animal tissue or human donor tissue, depending on the prosthesis.

They generally have a lower long-term thrombogenic burden than mechanical valves, but tissue valves can undergo structural degeneration over time.

This creates a different trade-off:

mechanical valve → greater durability but lifelong anticoagulation

bioprosthetic valve → limited structural durability but different anticoagulation considerations

The appropriate choice depends on the individual patient’s circumstances rather than one universally preferred valve.

Which valve is replaced most often?

Valve replacement can involve any of the four heart valves, but the aortic and mitral valves are particularly important in adult valve surgery.

Aortic valve disease commonly involves stenosis or regurgitation.

Mitral disease commonly involves stenosis or regurgitation.

Tricuspid valve disease can also require intervention, although repair is frequently considered when surgery is necessary.

Pulmonary valve replacement is less common in adults but can be important in selected congenital heart disease and other conditions.

The cause of valve disease also matters.

For example, rheumatic disease can affect multiple valves, while degenerative calcification is particularly important in aortic stenosis. Congenital bicuspid aortic valve disease can produce aortic stenosis or regurgitation and may also be associated with aortic enlargement.

Aortic valve replacement

Aortic valve replacement (AVR) is used when severe aortic valve disease produces an indication for intervention.

One of the most important conditions is severe aortic stenosis.

In aortic stenosis, the aortic valve becomes narrowed and obstructs blood leaving the left ventricle.

The left ventricle must generate higher pressure to eject blood through the narrowed valve.

Over time, this increased workload can produce structural changes in the ventricle and eventually contribute to heart failure.

Symptoms of significant aortic stenosis can include:

• exertional breathlessness
• chest pain
• dizziness or syncope
• reduced exercise capacity

Harrison’s describes surgical intervention for severe aortic stenosis particularly when patients are symptomatic or when left ventricular systolic function has deteriorated.

The exact thresholds and treatment recommendations used in contemporary practice should be assessed using current guidelines because the Harrison’s edition used for this article dates from 2018.

Surgical aortic valve replacement

Traditional surgical aortic valve replacement requires cardiac surgery.

The surgeon removes the diseased native aortic valve and implants a prosthetic valve.

Depending on the patient’s circumstances, the prosthesis may be mechanical or biological.

Surgical AVR remains an important treatment option, particularly when the patient’s anatomy, age, associated disease or need for other cardiac surgery makes a surgical approach appropriate.

Mitral valve replacement

Mitral valve replacement may be necessary in selected patients with severe mitral stenosis or regurgitation when repair is not possible or is unlikely to provide an adequate result.

However, mitral valve replacement should not automatically be equated with mitral valve surgery.

For certain forms of mitral regurgitation, repair is preferred when a durable repair can be achieved.

Harrison’s notes that mitral repair is preferred over replacement for mitral valve prolapse or flail leaflet when technically feasible.

This distinction is important because preserving the patient’s native valve can have advantages over replacing it.

Why is mitral valve repair often preferred?

The mitral valve has a complex three-dimensional structure involving:

• anterior and posterior leaflets
• chordae tendineae
• papillary muscles
• annulus
• left ventricular geometry

A successful repair can preserve this native apparatus.

Harrison’s notes that surgical expertise is important in determining whether repair can be successfully achieved, particularly with more complex mitral pathology.

For example, isolated posterior leaflet prolapse can often be repaired more straightforwardly than complex bileaflet disease or extensive degenerative changes.

This is one reason that the experience of the valve centre and surgeon can be relevant when repair is being considered.

What about tricuspid valve replacement?

Tricuspid valve disease requires a different approach.

Significant tricuspid regurgitation may occur together with left-sided valve disease.

When patients undergo left-sided valve surgery, the tricuspid valve may also require assessment and, in selected circumstances, repair.

Harrison’s notes that surgery for severe primary tricuspid regurgitation can involve either repair or replacement, while repair is often an important component of treatment.

The decision depends on:

• severity of regurgitation
• symptoms
• right ventricular function
• pulmonary pressures
• annular dilation
• whether another cardiac operation is already being performed

What happens during valve replacement surgery?

The precise operation varies according to the valve being treated.

For conventional surgical valve replacement, the patient undergoes general anaesthesia and cardiac surgery.

Cardiopulmonary bypass is used to maintain circulation while the surgeon operates on the heart.

The diseased valve is exposed and removed or otherwise prepared for replacement.

The prosthetic valve is then positioned and secured.

Before completing the operation, the surgical team assesses valve function and cardiac performance.

The patient is subsequently transferred for intensive postoperative monitoring.

The complexity of surgery can increase when valve disease is accompanied by:

• coronary artery disease
• aortic disease
• multiple valve abnormalities
• previous cardiac surgery
• reduced ventricular function
• pulmonary hypertension
• infective endocarditis

In some patients, more than one cardiac procedure may therefore be performed during the same operation.

Is every valve replacement an open-heart operation?

No.

This distinction is particularly important for the aortic valve.

Some patients can undergo transcatheter valve replacement, in which a prosthetic valve is delivered through a catheter rather than through conventional open-heart surgery.

The best-known example is:

TAVR/TAVI — transcatheter aortic valve replacement/transcatheter aortic valve implantation.

Harrison’s describes TAVR as an established treatment for selected patients with severe aortic stenosis and discusses both balloon-expandable and self-expanding valves.

The indications and patient selection criteria for TAVR have evolved considerably since the 2018 Harrison’s edition.

Therefore, current TAVR eligibility should be determined using contemporary guidelines and a specialist Heart Team assessment rather than applying older textbook thresholds directly.

Our next article in this cluster will examine TAVR/TAVI separately.

What are the possible complications of valve replacement?

Valve surgery is major cardiac surgery, and complications can occur.

Potential complications include:

• bleeding
• infection
• stroke
• arrhythmias
• kidney injury
• heart failure
• blood clots
• prosthetic valve dysfunction
• paravalvular leak
• prosthetic valve thrombosis
• infective endocarditis
• need for repeat intervention

The actual risk varies according to the valve involved, procedure type and the patient’s health.

What is prosthetic valve thrombosis?

A prosthetic valve can develop a thrombus that interferes with normal valve function.

Mechanical valves are particularly important in this context because anticoagulation is required to reduce thromboembolic risk.

Harrison’s describes prosthetic mechanical valve dysfunction caused by thrombus or pannus and notes that dysfunction may present with heart failure, embolic events, shock or an increasing valve gradient.

A sudden change in symptoms after valve replacement should therefore not be ignored.

What is prosthetic valve degeneration?

Biological valves can gradually deteriorate.

Structural degeneration may eventually produce:

• stenosis
• regurgitation
• mixed valve dysfunction

Harrison’s describes bioprosthetic valve failure as a cause of recurrent symptoms and notes that a new murmur or change in heart sounds may be an early clue to prosthetic dysfunction.

Depending on the prosthesis, anatomy and patient’s surgical risk, treatment may involve repeat surgery or a transcatheter valve-in-valve procedure.

Harrison’s describes valve-in-valve treatment as an option for selected failing aortic and mitral bioprostheses.

What is a paravalvular leak?

A paravalvular leak occurs when blood flows around the outside of a prosthetic valve rather than through it.

This can occur because the prosthesis does not form a complete seal with the surrounding tissue.

Potential causes include:

• incomplete seating
• tissue degeneration
• infection
• dehiscence of the prosthesis

The clinical significance varies.

A small leak may require observation, whereas a significant leak can produce haemolysis, heart failure or other complications.

Harrison’s identifies paravalvular regurgitation as an important cause of abnormal murmurs and prosthetic valve dysfunction.

What happens after valve replacement?

The immediate recovery period focuses on:

• cardiac and respiratory monitoring
• bleeding surveillance
• rhythm monitoring
• kidney function
• infection prevention
• pain control
• gradual mobilisation

Longer-term management depends heavily on the type of valve implanted.

Patients may need:

• anticoagulation
• antiplatelet therapy
• blood-pressure management
• periodic echocardiography
• monitoring for prosthetic valve dysfunction
• management of cardiovascular risk factors
• dental and infection-related precautions where appropriate

Patients with mechanical valves have an especially important long-term anticoagulation requirement.

Do people with artificial heart valves need regular follow-up?

Yes.

A prosthetic valve is not simply implanted and then forgotten.

Follow-up allows clinicians to assess:

• valve function
• ventricular function
• pressure gradients
• prosthetic degeneration
• regurgitation
• thrombosis
• rhythm abnormalities
• symptoms

A new murmur, unexplained breathlessness, reduced exercise tolerance, swelling, fainting or other cardiovascular symptoms after valve replacement should be assessed.

Harrison’s notes that a change in heart sounds or appearance of a new murmur can be an early clue to prosthetic valve dysfunction.

Can someone live normally after valve replacement?

Many patients can return to active lives after recovery, but the answer depends on:

• the underlying heart disease
• the valve replaced
• ventricular function
• other cardiac conditions
• the type of prosthesis
• anticoagulation requirements
• postoperative recovery

Valve replacement corrects an important mechanical problem, but it does not necessarily remove every cardiovascular risk.

Long-term follow-up remains part of treatment.

Heart valve replacement vs repair

The table is a simplified overview. The actual decision requires detailed imaging and specialist assessment.

Questions to ask before valve surgery

Patients considering valve intervention may want to ask:

1. Which valve is diseased and what is wrong with it?
2. How severe is the valve disease?
3. Do I need an intervention now or can I be monitored?
4. Can my valve be repaired instead of replaced?
5. If replacement is needed, should I have a mechanical or biological valve?
6. Would a transcatheter procedure be appropriate in my case?
7. Will I need lifelong anticoagulation?
8. What complications are particularly relevant to my operation?
9. How often will the prosthetic valve need to be monitored?
10. How will the procedure affect my exercise, travel and daily activities?

The key point

Heart valve replacement is not a single operation but a group of treatments used for severe disease affecting one of the heart’s valves.

The central decision is often not simply whether to replace a valve, but whether the valve should be monitored, treated medically, repaired, surgically replaced or treated through a transcatheter approach.

For selected mitral valve disease, repair may be preferred when a durable repair is feasible.

For severe aortic valve disease, surgical aortic valve replacement remains an important treatment, while transcatheter replacement provides another option for appropriately selected patients.

The choice of prosthetic valve also has lifelong implications. Mechanical valves offer durability but require anticoagulation, while biological valves have different long-term considerations including structural degeneration.

Ultimately, the appropriate approach depends on the valve involved, disease severity, anatomy, ventricular function, surgical risk, expected durability and the patient’s individual circumstances.

Written and Reviewed By Dr. Munaf Ahmad Ansari

Medical information note: This article is written for information purpose only. Individual treatment decisions should be based on contemporary clinical guidelines and assessment by an appropriately qualified medical team.