written by Mustafa Ahmed MD and David Mcgiffin MD
Mitral Valve Replacement vs Mitral Valve Repair – When should the mitral valve be repaired and when should the mitral valve be replaced?
Decision making in valvular heart disease is complex. Operation may be required for mitral regurgitation, mitral stenosis, or both. Mitral regurgitation is a leaky mitral valve. Mitral stenosis is a tight mitral valve. The key is that all decisions regarding operations on the mitral valve be discussed with dedicated specialists with a proven track-record of successful mitral valve surgeies. Unfortunately, in the US many valves that could be repaired are replaced, simply because of a lack of experience and interest in mitral valve repair by the surgeons involved. In many circumstances, there is a clear advantage of mitral valve repair over replacement. There are cases; however, where mitral valve replacement will be the preferred method. Again, the key is that cardiologists and cardiac surgeons with a special interest in mitral valve disease make these decisions.
Should I get a metallic or a tissue mitral valve?
Many factors need to be taken in to account before deciding on the type of prosthetic heart valve. It’s important to take in to account the preference of the patient and how the choice will affect lifestyle. For example, a tissue valve does not require long-term blood thinning medication, whereas a metallic valve does. Therefore, patients with a lifestyle that may include sports or other activities that would preferably avoid blood-thinning medication may benefit from a tissue valve.
There are advantages and disadvantages to both types of valve. Metallic valves have the advantage of lasting a long time and are generally not subject to wear and tear over time. This of course means that the chance of needing a further operation is low. The major disadvantage to a metallic mitral valve replacement is the need for blood thinning medication, typically in the form of a Coumadin blood thinner. Patients with metallic valves need their blood to be 2-3 times thinner than usual to avoid the risk of clot formation on the valves. Formation of a clot can lead to stroke or valve dysfunction. Of course when the blood is thinner, there is an increased risk of bleeding.
Tissue valves have the advantage of not requiring long-term blood thinner. The major disadvantage of tissue valves is the fact that they will wear and tear over time and eventually require further mitral valve surgery. This may not be a concern for an 80 year-old, as it is not even known if they will be suitable for reoperation when they are over 90 years old. It is, however, an issue for someone in their 40’s, who would be in their 50’s when another valve is required.
The whole decision of tissue vs. metallic mitral valve replacement is getting even more interesting given the development of minimally invasive techniques such as TAVR by which a valve replacement can be performed without the need for open heart surgery. These valves can be placed inside existing tissue valves, but not metallic valves. As of now, this is still early technology and shouldn’t influence decision-making regarding the choice of mitral valve replacement. Even more interesting is the development of super minimally invasive techniques such as the mitraclip for mitral regurgitation.
The current guidelines make some general recommendations that can be helpful.
- The choice of mitral valve replacement needs to be a shared decision between patients and specialists with multiple medical and lifestyle factors taken in to consideration.
- Patients who cannot tolerate or for some reason do not want to consider the use of blood thinning medication should have a tissue mitral valve replacement recommended.
- In general, in patients below 60 years of age, who are able to tolerate blood-thinning medication, a mechanical mitral valve replacement is reasonable. In patients over 70 years of age, a tissue valve is considered reasonable. In those between 60-70, either is considered reasonable.
Even though the valve has been replaced, it’s important to realize that mitral valve replacement patients have significant heart disease and require close follow-up care and attention to detail after the mitral valve replacement. Many patients undergoing mitral valve replacement have accompanying problems such as heart failure, other valve disease, and pulmonary hypertension (high pressures in the lung arteries) that will require ongoing management.
How often will valve replacement patients have to see their heart doctor?
This depends on factors such as other ongoing health issues, the type of valve and other factors that will be determined by the MD or DO in charge of your care. After the surgery and the hospital discharge, patients will follow up with the surgeon in the 1-2 weeks after the mitral valve replacement to ensure there are no immediate problems from the surgery and that everything is going well. Moving forward the cardiologist may see patients in weeks to months after the surgery. If all is well, mitral valve replacement patients typically are seen on a yearly basis.
Patients with metallic valves will require check for effect of blood thinning medications.
For those patients with metallic valves, it’s important to pay close attention to blood tests such as the INR, that monitor the response to Coumadin blood thinner. This is important, because it prevents the valve from developing clots that can lead to strokes or valve failure.
How often do metallic mitral valve replacement patients need imaging studies?
If all goes well after surgery and the patient is doing well without issues, there is usually a yearly follow up to assess how the patient is clinically doing. After surgery there will be an echocardiogram performed to ensure normal valve functioning. This is usually done in the weeks to months after mitral valve replacement and is also important to establish a baseline. Stable patients don’t require routine follow-up imaging. After this point, imaging is only typically required if there is a change in the clinical status, i.e. development of symptoms, or a new finding on the physical exam such as an increasing murmur.
How often do tissue (i.e. animal) mitral valve replacement patients need follow up imaging?
This is slightly different for patients with metallic valves. Tissue valves are subject to degeneration over time. Degeneration isn’t likely in the first 10 years after a tissue mitral valve replacement. But, afterwards this it is increasingly likely to occur with each year that passes. For this reason it is recommended that after 10 years, even if there are no symptoms or clinical signs of concern, that an echocardiogram is performed to assess the valve. It is very important that patients with tissue mitral valve replacement are educated to report signs and symptoms such as shortness of breath, dizziness, swelling etc. so they can be evaluated in a timely fashion.
What tests are needed before mitral valve replacement surgery?
Typically most patients have had an ultrasound scan of the heart known as an echocardiogram before they are sent to a surgeon. For patients with risk factors for coronary artery disease, and in general those over 35-40, a coronary angiogram will be performed to ensure there are no heart artery blockages that need bypassing at the time of valve replacement.
How long will the mitral valve replacement operation take?
In general the whole process in and out the operating room takes 2-4 hours. It also depends on whether there are other things being fixed, such as additional valve or bypass surgery. The usual time from stopping the heart to getting the heart beating again is around 45 minutes. After that the various tubes are removed, and the heart is check to ensure there is no bleeding. Finallu, the chest is closed.
How long do patients need to stay in hospital?
A lot depends on the patient and how quickly they are up walking. If things go well and the patient is up and walking within a few days, the usual hospital stay will be roughly 5 days.
When can patients go back to work after a mitral valve replacement?
This of course depends on the job. Most patients can be driving within 2 weeks of leaving hospital. If they are involved in heavy manual work, then it’s advised they avoid any type of heavy work for 8. If it’s a desk job, for example, then patients can basically go back to work whenever they feel like it, although its advised not to start with a full day. With robotic heart surgery the recovery time is likely to be more rapid.
Are there any special restrictions after mitral valve replacement?
Patients with valve replacement should be sure to ask about antibiotic prophylaxis before certain procedures to help prevent infection from reaching the heart. Also in patients with metallic valves who are taking blood-thinning medicines, activities with more than an ordinary risk of injury should be avoided due to the risk of hemorrhage.