Mechanical vs. Biological Aortic Valve: How to Choose the Best Option?

Aortic valve replacement is a life-saving operation for patients with valve disease. But choosing between a mechanical valve and a biological (tissue) valve is a major decision—especially for elderly patients. In this expert interview, world-renowned heart surgeon Dr. Jürgen Ennker, MD explains how anticoagulation risks, patient age, and evolving surgical techniques affect valve choice in modern cardiac surgery.

Jump to Section

• Why Mechanical Valves Carry Long-Term Risks
• The Rise of Biological Valves in Elderly—and Younger—Patients
• Aspirin Instead of Anticoagulation: A Safer Alternative
• What Happens If a Tissue Valve Fails?
• Empowering Patients to Choose the Right Valve
• Full Transcript

Why Mechanical Valves Carry Long-Term Risks

Mechanical aortic valves last a lifetime—but they require strict lifelong anticoagulation therapy. This poses a serious risk to elderly patients, who are more prone to falls, bleeding complications, and medication mismanagement. Dr. Ennker notes that if a patient forgets their medication or has fluctuating INR levels, the mechanical valve can thrombose—an emergency situation that can lead to stroke or death.

The estimated complication rate from anticoagulation is 0.7% to 1% per year, which adds up to a 7–10% risk over a decade. These numbers have led many cardiac teams—including Dr. Ennker’s—to reduce the use of mechanical valves dramatically over the past 20 years.

The Rise of Biological Valves in Elderly—and Younger—Patients

Dr. Ennker reports a major shift in practice at his institution—from implanting 90% mechanical valves two decades ago to now favoring biological tissue valves in the majority of cases. Biological valves like the Medtronic Freestyle don’t require anticoagulation and are made from pig or cow tissue.

Historically, biological valves were reserved for patients over 70, due to their limited durability. But modern surgical techniques and reoperation safety now allow implantation in younger patients, even in their 50s. If the valve fails after 10–15 years, the patient will have enjoyed years free from blood-thinners—and reoperation is now safer than ever.

Aspirin Instead of Anticoagulation: A Safer Alternative

Biological valve recipients usually take only 100 mg of aspirin per day. This low-dose aspirin is already widely recommended for people over 50 to prevent heart attacks and strokes. It presents a far lower bleeding risk than warfarin or other anticoagulants used for mechanical valves.

What Happens If a Tissue Valve Fails?

Biological valves may fail after a decade or more, but their failure is usually gradual and non-emergent. A torn valve leaflet may lead to shortness of breath and heart failure symptoms, but there’s time to plan a safe elective reoperation or TAVI (Transcatheter Aortic Valve Implantation).

This gives patients flexibility: at age 70 or 75, they may choose a second surgery or a catheter-based intervention rather than committing to anticoagulation from the start.

Empowering Patients to Choose the Right Valve

Dr. Ennker emphasizes that patients must be informed and actively involved in the valve selection process. While mechanical valves may still be preferred for certain younger patients, tissue valves offer many advantages in safety and lifestyle. Patients must decide:

• Do they want to take daily blood thinners for life?
• Or are they comfortable with the possibility of reoperation in 10–15 years?

Patient preference, lifestyle, age, and risk profile all guide the choice—and in Dr. Ennker’s experience, most patients now prefer biological valves.

Full Transcript

Dr. Anton Titov, MD: Aortic valve replacement with a mechanical valve requires anti-coagulation therapy. Use of blood-thinning medications is particularly dangerous in elderly people. They have a higher risk of falls. You have studied the risks of using mechanical and tissue aortic valves in aortic valve replacement surgery. What is your method of aortic valve replacement? What factors influence your choice of tissue aortic valve or mechanical aortic valve? How to choose the best type of aortic valve for replacement, especially in elderly patients?

Dr. Jürgen Ennker, MD: Yes, this is a very important point. Twenty years ago we started surgery in our institution. We implanted more than 90% mechanical valves. Now it's just the other way around. Why did this happen? The risk of anti-coagulation is bleeding, cerebral infarction, embolism. If the patient is not taking the medication correctly, he may get a thrombosed heart valve. That is an emergency situation. Because the valve will be obstructed. The patient will have risk of embolism of thrombotic material. So we have patients who are not able to take their medication correctly. This leads to a risk of 0.7% to 1% complications per year. So after 10 years we have 7% to 10% risk of aortic valve thrombosis.

This led to us to the current practice that more patients are getting biological aortic valves. You don't need oral anti-coagulation with a Medtronic Freestyle valve. This is true with other models of biological heart valves. These patients only get 100 milligrams of aspirin per day. Aspirin is also recommended for patients older than 50 years. It's a relatively low dose of Aspirin.

Dr. Anton Titov, MD: Absolutely, that's a very low dose. Actually I'm taking Aspirin myself because I'm over 50 now. Medical articles in The New England Journal of Medicine say you get less cerebral infarction and less myocardial infarctions if you take Aspirin.

Dr. Jürgen Ennker, MD: So we should come back to the aortic heart valves. In previous times, patients received only biological valves when they were older than 70 years of age. Because the idea was that the heart valve would be more durable than the life expectancy. Because the surgeons or the patients were afraid of re-operations. Nowadays re-operation is not such a big risk. For example, we implant biological aortic heart valves also in patients of 50 years of age. If the heart valve fails after 10 or 15 years, the patient enjoyed 10 or 15 years without oral anti-coagulation. He did not have any problems. Then we will see how the medical technology will be developed. If you have a patient 65 years of age, a re-operation is not as big a problem as it used to be. Repeat surgical operation should have the same risk, the same mortality, as the first operation. The risk of death is 1% or 2%. At least it is less than 3%. And patient is saved several percent of complications. This would happen if a patient would have used oral anti-coagulation. So we're using biological heart valves in younger patients. We don't wait until the age of 70.

Dr. Anton Titov, MD: Because, what happens if a biological heart valve fails? Most of the time a heart valve leaflet will tear. Then patient develops cardiac insufficiency, he gets shortness of breath. But this is not a cardiac emergency. This has to be operated the same day due to the risk of embolism or thrombosis. So basically a patient with a tissue valve has a little bit more of the time to get an appropriate operation as a planned operation.

Dr. Jürgen Ennker, MD: Absolutely, that's the point. Patient can make a decision.

Dr. Anton Titov, MD: Does he want to have another cardiac operation? If he is 70 or 75 years of age, does he want to have a transcatheter aortic valve implantation? There is more time for reconsideration. So in your hands it looks like the tissue aortic valves are really gaining our confidence. There is a wider use of indications at the younger age for pig or cow aortic heart valves for replacement.

Dr. Jürgen Ennker, MD: Yes, but there are other publications who will state that even at a younger age, mechanical heart valves are adequate. So we should inform our patients and they should make their own decision.

Dr. Anton Titov, MD: Do they want to take oral anti-coagulation every day? Or do they want to wait what happens to their implanted biological heart valve without having oral anti-coagulation?