Point/Counterpoint: Mechanical vs. biological mitral valve for 50-year-old with rheumatic disease

Mechanical valve is the best choice

BY THORALF M. SUNDT III, M.D.

It’s not very sexy to talk about mechanical valves, but the reasons for placing a mechanical valve in a 50-year-old patient with rheumatic disease are obvious: Mechanical valves provide outstanding hemodynamics, they are beautifully engineered devices, their durability is beyond question, and, importantly, there’s no survival advantage to a biological prosthesis although one incurs the penalty of reoperation, which in a 50-year-old is going to be inevitable.

While this patient will have to continue on anticoagulation therapy with a mechanical valve, many patients who receive a biological valve, especially those with rheumatic disease, need anticoagulation for atrial fibrillation anyway. One can argue that a maze procedure might convert them to sinus rhythm, but this is least reproducible in the subset of patients with rheumatic disease. What’s more, the American Heart Association/American College of Cardiology Guideline for the Management of Patients With Valvular Heart Disease states that a mechanical prosthesis is reasonable for aortic or mitral valve replacement in patients aged 60 and younger with no contraindication to anticoagulation.

The fact that you have to use Coumadin (warfarin, Bristol-Myers Squibb), is not a condemnation of the mechanical valve; it just means we need to get smarter and better about how we manage anticoagulation in people with these prostheses.

While neither option is desirable, surprisingly morbidity with mechanical and biological valves is not demonstrably different. Stroke, embolic events, and bleeding complications have been found to be similar in numerous studies including a recent one authored by Dr. Vinay Badhwar and colleagues. Among 469 patients aged 65 years or younger who received a bileaflet mechanical prostheses or tissue valves, researchers found nearly identical rates of bleeding and thromboembolic complications when the anticoagulation was closely monitored (Ann. Thorac. Surg. 2012;93:748-53) Indeed, they even identified a mortality benefit among those with mechanical valves.

It’s also worth noting that the risk of anticoagulation-related complications is higher when the patient’s INR (international normalized ratio) is poorly controlled; up to 60% of INR values are outside the therapeutic range when thromboembolic complications occur. One can anticipate home INR testing and home management as ways to help patients stay within therapeutic range and reduce these risks. If the issue is anticoagulation, let’s improve it.

In summary, if you implant a biological valve in a 50-year-old patient, I guarantee that patient is going to be back for a reoperation and the prosthesis is going to deteriorate. For the surgeon, a biological valve can be an annuity of sorts. The mechanical valve has a clear advantage in durability, especially in younger patients.

Neither one is perfect, but there is no difference in morbidity between the two. A tissue prosthesis just buys you a reoperation – maybe valve-in-valve transcatheter valve. Maybe.

Dr. Sundt is chief of the division of cardiac surgery, Massachusetts General Hospital, Harvard Medical School, Boston. He is an adviser to Thrasos Innovation, but has no relevant relationships to disclose.

Why biological valve is the better choice

BY ANELECHI C. ANYANWU, M.D.

The reality is that whether you implant a mechanical or biological valve for mitral regurgitation, neither is good. The survival is poor. The half-life or median survival of a patient after either valve is about 15-20 years. The death rates are about 3% per year. The morbidity is high whether you have mechanical or biological valve, and none of them are good mitral substitutes.

Yet the biological valve is often a reasonable choice for a 50-year-old patient, despite studies that have shown a higher reoperation rate and decreased survival rate after biological mitral valve repair when compared to mechanical valve implantation in patients aged 65 and younger. But those study results may be skewed.

Dr. Tsuyoshi Kaneko and colleagues at Brigham and Women’s Hospital, Boston, showed that survival at about 20 years was much better with the mechanical valve. (J. Thorac. Cardiovasc. Surg. 2014;147:117-26). However, the difference in survival is greatest immediately after surgery. By 1 year the survival difference between mechanical valve and a tissue valve was more than 10%.

Why is this? I would argue this is a function of patient selection. We know in the United States that a patient with no insurance or low socioeconomic status does poorly compared to one who does have insurance. With a mechanical valve, they can thrombose; but with a biological valve, if they don’t take care of their health, of course they can die early. The reality is surgeons tend to use biological valves in patients of lower socioeconomic status and those with questionable compliance. None of these factors were considered in the propensity matching used in this study.

Dr. Joanna Chikwe and colleagues at Mount Sinai recently compared outcomes in several thousand patients who underwent biological or mechanical mitral valve replacement in New York State (JAMA 2015:323:1435-42). They found no survival difference in the first 30 or 90 days after surgery, or even at 15 years among patients aged 50-69 years. Indeed, a critical review of any study that has shown a survival advantage of the mechanical valve would find that the advantage occurred within the first few months after surgery, making it likely that such differences are due to patient selection, or other systematic bias, rather than a prostheses effect.

Mayo Clinic investigators, including Dr. Thoralf M. Sundt III, reported that among a cohort that received a mechanical valve, with an average age of 65 years, 16% had had a stroke at 5 years, compared with 8% of the biological valve group (J. Am. Coll. Cardiol. 2008;51:1203-11). You can only imagine what would happen at 10 or 20 years. They followed the data out to 10 years for thromboembolic events; that rate was 30% in the mechanical valve group. They concluded, “the mechanical valve is the least desirable correction of mitral regurgitation.”

As for managing anticoagulation, the literature provides no evidence that self-testing is superior to clinic testing. A trial published in the New England Journal of Medicine involving more than 2,000 patients, 700 of whom had a mechanical valve, showed a higher rate of stroke in patients who were randomized to home-INR monitoring compared with INR in the clinic. (N. Engl. J. Med. 2010;363:1608-20). Self-testing did not delay the time to first stroke, bleeding, or death.

Anticoagulation can be problematic if the patient needs to undergo another operation or medical procedure later, especially on an emergent basis. If the patient with a mechanical valve stops anticoagulation for even a short period of time, the risk of valve thrombosis is great. A patient with a biological valve can stop anticoagulation for a week or more without any consequence.

Finally, I relate the story of a man who could not bear the clicking sound of his mechanical valve. He asked for a new valve, but the surgeon would not take his request seriously. The man was taking drugs and started treatment for posttraumatic stress disorder. After 3 years, he killed himself. How many times have we sat down and talked to patients about what the clicking sound can do to them? Why don’t we make more of this? The patient should be given more choice.

Dr. Anyanwu is with the department of cardiac surgery, Mount Sinai Medical Center, New York. He has no relationships to disclose.

Mechanical valve is the best choice

BY THORALF M. SUNDT III, M.D.

It’s not very sexy to talk about mechanical valves, but the reasons for placing a mechanical valve in a 50-year-old patient with rheumatic disease are obvious: Mechanical valves provide outstanding hemodynamics, they are beautifully engineered devices, their durability is beyond question, and, importantly, there’s no survival advantage to a biological prosthesis although one incurs the penalty of reoperation, which in a 50-year-old is going to be inevitable.

While this patient will have to continue on anticoagulation therapy with a mechanical valve, many patients who receive a biological valve, especially those with rheumatic disease, need anticoagulation for atrial fibrillation anyway. One can argue that a maze procedure might convert them to sinus rhythm, but this is least reproducible in the subset of patients with rheumatic disease. What’s more, the American Heart Association/American College of Cardiology Guideline for the Management of Patients With Valvular Heart Disease states that a mechanical prosthesis is reasonable for aortic or mitral valve replacement in patients aged 60 and younger with no contraindication to anticoagulation.

The fact that you have to use Coumadin (warfarin, Bristol-Myers Squibb), is not a condemnation of the mechanical valve; it just means we need to get smarter and better about how we manage anticoagulation in people with these prostheses.

While neither option is desirable, surprisingly morbidity with mechanical and biological valves is not demonstrably different. Stroke, embolic events, and bleeding complications have been found to be similar in numerous studies including a recent one authored by Dr. Vinay Badhwar and colleagues. Among 469 patients aged 65 years or younger who received a bileaflet mechanical prostheses or tissue valves, researchers found nearly identical rates of bleeding and thromboembolic complications when the anticoagulation was closely monitored (Ann. Thorac. Surg. 2012;93:748-53) Indeed, they even identified a mortality benefit among those with mechanical valves.

It’s also worth noting that the risk of anticoagulation-related complications is higher when the patient’s INR (international normalized ratio) is poorly controlled; up to 60% of INR values are outside the therapeutic range when thromboembolic complications occur. One can anticipate home INR testing and home management as ways to help patients stay within therapeutic range and reduce these risks. If the issue is anticoagulation, let’s improve it.

In summary, if you implant a biological valve in a 50-year-old patient, I guarantee that patient is going to be back for a reoperation and the prosthesis is going to deteriorate. For the surgeon, a biological valve can be an annuity of sorts. The mechanical valve has a clear advantage in durability, especially in younger patients.

Neither one is perfect, but there is no difference in morbidity between the two. A tissue prosthesis just buys you a reoperation – maybe valve-in-valve transcatheter valve. Maybe.

Dr. Sundt is chief of the division of cardiac surgery, Massachusetts General Hospital, Harvard Medical School, Boston. He is an adviser to Thrasos Innovation, but has no relevant relationships to disclose.

Why biological valve is the better choice

BY ANELECHI C. ANYANWU, M.D.

The reality is that whether you implant a mechanical or biological valve for mitral regurgitation, neither is good. The survival is poor. The half-life or median survival of a patient after either valve is about 15-20 years. The death rates are about 3% per year. The morbidity is high whether you have mechanical or biological valve, and none of them are good mitral substitutes.

Yet the biological valve is often a reasonable choice for a 50-year-old patient, despite studies that have shown a higher reoperation rate and decreased survival rate after biological mitral valve repair when compared to mechanical valve implantation in patients aged 65 and younger. But those study results may be skewed.

Dr. Tsuyoshi Kaneko and colleagues at Brigham and Women’s Hospital, Boston, showed that survival at about 20 years was much better with the mechanical valve. (J. Thorac. Cardiovasc. Surg. 2014;147:117-26). However, the difference in survival is greatest immediately after surgery. By 1 year the survival difference between mechanical valve and a tissue valve was more than 10%.

Why is this? I would argue this is a function of patient selection. We know in the United States that a patient with no insurance or low socioeconomic status does poorly compared to one who does have insurance. With a mechanical valve, they can thrombose; but with a biological valve, if they don’t take care of their health, of course they can die early. The reality is surgeons tend to use biological valves in patients of lower socioeconomic status and those with questionable compliance. None of these factors were considered in the propensity matching used in this study.

Dr. Joanna Chikwe and colleagues at Mount Sinai recently compared outcomes in several thousand patients who underwent biological or mechanical mitral valve replacement in New York State (JAMA 2015:323:1435-42). They found no survival difference in the first 30 or 90 days after surgery, or even at 15 years among patients aged 50-69 years. Indeed, a critical review of any study that has shown a survival advantage of the mechanical valve would find that the advantage occurred within the first few months after surgery, making it likely that such differences are due to patient selection, or other systematic bias, rather than a prostheses effect.

Mayo Clinic investigators, including Dr. Thoralf M. Sundt III, reported that among a cohort that received a mechanical valve, with an average age of 65 years, 16% had had a stroke at 5 years, compared with 8% of the biological valve group (J. Am. Coll. Cardiol. 2008;51:1203-11). You can only imagine what would happen at 10 or 20 years. They followed the data out to 10 years for thromboembolic events; that rate was 30% in the mechanical valve group. They concluded, “the mechanical valve is the least desirable correction of mitral regurgitation.”

As for managing anticoagulation, the literature provides no evidence that self-testing is superior to clinic testing. A trial published in the New England Journal of Medicine involving more than 2,000 patients, 700 of whom had a mechanical valve, showed a higher rate of stroke in patients who were randomized to home-INR monitoring compared with INR in the clinic. (N. Engl. J. Med. 2010;363:1608-20). Self-testing did not delay the time to first stroke, bleeding, or death.

Anticoagulation can be problematic if the patient needs to undergo another operation or medical procedure later, especially on an emergent basis. If the patient with a mechanical valve stops anticoagulation for even a short period of time, the risk of valve thrombosis is great. A patient with a biological valve can stop anticoagulation for a week or more without any consequence.

Finally, I relate the story of a man who could not bear the clicking sound of his mechanical valve. He asked for a new valve, but the surgeon would not take his request seriously. The man was taking drugs and started treatment for posttraumatic stress disorder. After 3 years, he killed himself. How many times have we sat down and talked to patients about what the clicking sound can do to them? Why don’t we make more of this? The patient should be given more choice.

Dr. Anyanwu is with the department of cardiac surgery, Mount Sinai Medical Center, New York. He has no relationships to disclose.

Mechanical valve is the best choice

BY THORALF M. SUNDT III, M.D.

It’s not very sexy to talk about mechanical valves, but the reasons for placing a mechanical valve in a 50-year-old patient with rheumatic disease are obvious: Mechanical valves provide outstanding hemodynamics, they are beautifully engineered devices, their durability is beyond question, and, importantly, there’s no survival advantage to a biological prosthesis although one incurs the penalty of reoperation, which in a 50-year-old is going to be inevitable.

While this patient will have to continue on anticoagulation therapy with a mechanical valve, many patients who receive a biological valve, especially those with rheumatic disease, need anticoagulation for atrial fibrillation anyway. One can argue that a maze procedure might convert them to sinus rhythm, but this is least reproducible in the subset of patients with rheumatic disease. What’s more, the American Heart Association/American College of Cardiology Guideline for the Management of Patients With Valvular Heart Disease states that a mechanical prosthesis is reasonable for aortic or mitral valve replacement in patients aged 60 and younger with no contraindication to anticoagulation.

The fact that you have to use Coumadin (warfarin, Bristol-Myers Squibb), is not a condemnation of the mechanical valve; it just means we need to get smarter and better about how we manage anticoagulation in people with these prostheses.

While neither option is desirable, surprisingly morbidity with mechanical and biological valves is not demonstrably different. Stroke, embolic events, and bleeding complications have been found to be similar in numerous studies including a recent one authored by Dr. Vinay Badhwar and colleagues. Among 469 patients aged 65 years or younger who received a bileaflet mechanical prostheses or tissue valves, researchers found nearly identical rates of bleeding and thromboembolic complications when the anticoagulation was closely monitored (Ann. Thorac. Surg. 2012;93:748-53) Indeed, they even identified a mortality benefit among those with mechanical valves.

It’s also worth noting that the risk of anticoagulation-related complications is higher when the patient’s INR (international normalized ratio) is poorly controlled; up to 60% of INR values are outside the therapeutic range when thromboembolic complications occur. One can anticipate home INR testing and home management as ways to help patients stay within therapeutic range and reduce these risks. If the issue is anticoagulation, let’s improve it.

In summary, if you implant a biological valve in a 50-year-old patient, I guarantee that patient is going to be back for a reoperation and the prosthesis is going to deteriorate. For the surgeon, a biological valve can be an annuity of sorts. The mechanical valve has a clear advantage in durability, especially in younger patients.

Neither one is perfect, but there is no difference in morbidity between the two. A tissue prosthesis just buys you a reoperation – maybe valve-in-valve transcatheter valve. Maybe.

Dr. Sundt is chief of the division of cardiac surgery, Massachusetts General Hospital, Harvard Medical School, Boston. He is an adviser to Thrasos Innovation, but has no relevant relationships to disclose.

Why biological valve is the better choice

BY ANELECHI C. ANYANWU, M.D.

The reality is that whether you implant a mechanical or biological valve for mitral regurgitation, neither is good. The survival is poor. The half-life or median survival of a patient after either valve is about 15-20 years. The death rates are about 3% per year. The morbidity is high whether you have mechanical or biological valve, and none of them are good mitral substitutes.

Yet the biological valve is often a reasonable choice for a 50-year-old patient, despite studies that have shown a higher reoperation rate and decreased survival rate after biological mitral valve repair when compared to mechanical valve implantation in patients aged 65 and younger. But those study results may be skewed.

Dr. Tsuyoshi Kaneko and colleagues at Brigham and Women’s Hospital, Boston, showed that survival at about 20 years was much better with the mechanical valve. (J. Thorac. Cardiovasc. Surg. 2014;147:117-26). However, the difference in survival is greatest immediately after surgery. By 1 year the survival difference between mechanical valve and a tissue valve was more than 10%.

Why is this? I would argue this is a function of patient selection. We know in the United States that a patient with no insurance or low socioeconomic status does poorly compared to one who does have insurance. With a mechanical valve, they can thrombose; but with a biological valve, if they don’t take care of their health, of course they can die early. The reality is surgeons tend to use biological valves in patients of lower socioeconomic status and those with questionable compliance. None of these factors were considered in the propensity matching used in this study.

Dr. Joanna Chikwe and colleagues at Mount Sinai recently compared outcomes in several thousand patients who underwent biological or mechanical mitral valve replacement in New York State (JAMA 2015:323:1435-42). They found no survival difference in the first 30 or 90 days after surgery, or even at 15 years among patients aged 50-69 years. Indeed, a critical review of any study that has shown a survival advantage of the mechanical valve would find that the advantage occurred within the first few months after surgery, making it likely that such differences are due to patient selection, or other systematic bias, rather than a prostheses effect.

Mayo Clinic investigators, including Dr. Thoralf M. Sundt III, reported that among a cohort that received a mechanical valve, with an average age of 65 years, 16% had had a stroke at 5 years, compared with 8% of the biological valve group (J. Am. Coll. Cardiol. 2008;51:1203-11). You can only imagine what would happen at 10 or 20 years. They followed the data out to 10 years for thromboembolic events; that rate was 30% in the mechanical valve group. They concluded, “the mechanical valve is the least desirable correction of mitral regurgitation.”

As for managing anticoagulation, the literature provides no evidence that self-testing is superior to clinic testing. A trial published in the New England Journal of Medicine involving more than 2,000 patients, 700 of whom had a mechanical valve, showed a higher rate of stroke in patients who were randomized to home-INR monitoring compared with INR in the clinic. (N. Engl. J. Med. 2010;363:1608-20). Self-testing did not delay the time to first stroke, bleeding, or death.

Anticoagulation can be problematic if the patient needs to undergo another operation or medical procedure later, especially on an emergent basis. If the patient with a mechanical valve stops anticoagulation for even a short period of time, the risk of valve thrombosis is great. A patient with a biological valve can stop anticoagulation for a week or more without any consequence.

Finally, I relate the story of a man who could not bear the clicking sound of his mechanical valve. He asked for a new valve, but the surgeon would not take his request seriously. The man was taking drugs and started treatment for posttraumatic stress disorder. After 3 years, he killed himself. How many times have we sat down and talked to patients about what the clicking sound can do to them? Why don’t we make more of this? The patient should be given more choice.

Dr. Anyanwu is with the department of cardiac surgery, Mount Sinai Medical Center, New York. He has no relationships to disclose.