Leading expert in cardiac surgery, Dr. Juergen Ennker, MD, explains the critical factors in choosing between mechanical and biological aortic valves, highlighting the shift toward tissue valves due to lower anticoagulation risks, improved durability, and safer reoperation options—especially for elderly patients and those under 70.
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Mechanical vs. Biological Aortic Valve Replacement: Key Factors for Patient Safety
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- Mechanical Valve Risks: Bleeding and Thrombosis
- Biological Valve Advantages: No Anticoagulation Needed
- Age Threshold Changes: Younger Patients Now Eligible
- Reoperation Safety: Low Mortality Rates
- Valve Failure Differences: Emergency vs. Planned Surgery
- Patient Decision-Making: Anticoagulation vs. Future Interventions
- Full Transcript
Mechanical Valve Risks: Bleeding and Thrombosis
Dr. Juergen Ennker, MD, emphasizes that mechanical aortic valves require lifelong anticoagulation therapy, posing significant risks. Elderly patients face higher fall-related bleeding dangers, while inconsistent medication use can lead to valve thrombosis—a life-threatening emergency. Historical data shows a 0.7%–1% annual complication rate, accumulating to 7%–10% over a decade.
Biological Valve Advantages: No Anticoagulation Needed
Biological valves (pig or bovine) eliminate the need for blood thinners, reducing stroke and embolism risks. Dr. Juergen Ennker, MD, notes patients only require 100mg aspirin daily—a regimen also beneficial for cardiovascular prevention in adults over 50. The Medtronic Freestyle valve exemplifies this low-maintenance option.
Age Threshold Changes: Younger Patients Now Eligible
Previously reserved for patients over 70, biological valves are now implanted in 50-year-olds. Dr. Juergen Ennker, MD, explains that modern reoperation safety makes 10–15 years of anticoagulation-free life preferable, even if future replacement becomes necessary. This paradigm shift reflects improved surgical outcomes and valve durability.
Reoperation Safety: Low Mortality Rates
Repeat aortic valve surgeries now carry just 1%–3% mortality risk—comparable to initial operations. Dr. Juergen Ennker, MD, highlights this as a key factor in choosing biological valves for younger patients, as the cumulative risks of long-term anticoagulation often outweigh surgical risks.
Valve Failure Differences: Emergency vs. Planned Surgery
Mechanical valve failure causes acute thrombosis requiring emergency care, while biological valve deterioration (e.g., leaflet tearing) allows for planned intervention. Dr. Juergen Ennker, MD, stresses this critical safety difference: tissue valve patients avoid sudden crises and can consider transcatheter options like TAVI for subsequent treatment.
Patient Decision-Making: Anticoagulation vs. Future Interventions
Dr. Ennker advocates personalized choice: patients must weigh daily anticoagulation against potential future surgeries. Younger patients may prefer biological valves despite possible reoperations, while older adults benefit from avoiding blood thinners altogether. Shared decision-making ensures alignment with lifestyle and risk tolerance.
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.
Dr. Anton Titov, MD: 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?
Dr. Anton Titov, MD: 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. Juergen Ennker, MD: This is a very important point. 20 years ago we started surgery in our institution. We implanted more than 90% mechanical valves. Now it's just the other way around.
Dr. Juergen Ennker, MD: 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.
Dr. Juergen Ennker, MD: 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. After 10 years we have 7% to 10% risk of aortic valve thrombosis. This led us to the current practice that more patients are getting biological aortic valves.
Dr. Juergen Ennker, MD: 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. Juergen Ennker, 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. Juergen Ennker, MD: 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. 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.
Dr. Juergen Ennker, MD: 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.
Dr. Juergen Ennker, MD: 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.
Dr. Juergen Ennker, MD: 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: 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.
Dr. Anton Titov, MD: So basically a patient with a tissue valve has a little bit more time to get an appropriate operation as a planned operation.
Dr. Juergen 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.
Dr. Anton Titov, MD: 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. Juergen 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?