Joe Cool
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I would have posted the link, but it won't get you there. You would have to register as a user.
Joe
From Medscape Cardiology
Expert Interview
Heart Valve Replacement Surgery: 20 Years' Experience Using a Bioprosthetic Valve -- An Expert Interview With Pia S. Mykén, MD, PhD
Posted 05/25/2006
Editor's Note
Pia S Mykén, MD, PhD, is a cardiothoracic surgeon who does mostly cardiac surgery and also pulmonary and transplant surgery in the Department of Thoracic and Cardiovascular Surgery at Sahlgrenska University Hospital in Göteborg, Sweden. Dr. Mykén's main research interests are valve surgery and transplants. She has accumulated more than 20 years' experience in heart valve surgery and has actively participated in the hospital's transplant program since its inception more than 15 years ago. Dr. Mykén is also Assistant Professor at the University of Sahlgrenska. She is a reviewer for many major European and North American cardiology and surgery journals.
Since 1983, researchers at Sahlgrenska University Hospital have been studying the long-term outcomes of patients who have undergone aortic or mitral valve replacement with the Biocor porcine prosthetic heart valve (St Jude Medical, St Paul, Minnesota). The Biocor prosthesis is a third-generation triple composite prosthesis fixed in glutaraldehyde in the resting state. Through 2003, a total of 1832 Biocor prostheses were inserted in either aortic or mitral valves at the hospital, representing a total follow-up time of 8843 patient-years for aortic and 1195 patient-years for mitral valve patients. Dr. Mykén joined this study in 1986 and recently talked with Linda Brookes, MSc, at Medscape about the results of this investigation, which now has accumulated more than 20 years of data on the valve's durability and its associated complications. Earlier analyses of data at 15 years[1] and at 17 years[2] showed a low incidence of valve-related complications and improved valve durability. At 20 years, freedom from valve-related death was 93% and freedom from reoperation due to structural valve deterioration was 97% in patients older than 65 years.[3]
In the United States, approximately 65,000 valve repairs and replacements are performed in the United States annually. The Biocor stented tissue valve was approved by the United States Food and Drug Administration (FDA) in August 2005, and the first US implant of the device was performed later the same month. This approval was based on the clinical experience accumulated by Dr. Mykén and her colleagues. In addition to the Biocor aortic and mitral valves, the FDA has also approved the Biocor Supra stented tissue aortic valve, a valve that is implanted above the annulus.
Medscape: Rather than discussing how to perform a valve repair or replacement, we think our readers would like to hear about your experience with bioprosthetic valve replacement in your institution in Sweden. How do patients who need heart valve repair or replacement surgery come to you at your hospital?
Dr. Mykén: You should recall that in Sweden there is almost no private healthcare and there are no private cardiac centers. Cardiac surgery is only performed at the 7 university centers in Sweden, and every center serves a specific region. Sahlgrenska University Hospital, where I work, is the largest university hospital in Sweden and also one of the largest in Northern Europe. We serve the western region of Sweden, which has about 2.5 million inhabitants.
There are some benefits to this [socialized medicine], namely that we know our region, we know the cardiologists within the region, and we get all our patients from that region. If the patients do not relocate, they will keep coming back to the same center, which makes it a bit easier to follow and treat the patients once you have operated on them. You also get to know the referring cardiologists very well, so you know that whenever they have a problem they will contact you or send the patient to you straightaway. So there is a very close connection to everyone within our region.
In the department of cardiac surgery we perform about 1800 operations a year, including about 400 cases in pediatric cardiac surgery. We do about 300 valve surgical procedures per year on average; in 2005 it was 280.
Medscape: Have these numbers changed much over the last 2 decades?
Dr. Mykén: No, the incidence of valve disease has not changed over the past 20 years, but the patients who can be operated on are increasingly older. The reason for this is that they are much healthier. It is the same situation as in the United States. Ten years ago we never operated on someone who was aged ≥ 80 years, but these days we do, every now and then. It is not that we have changed the strict indications -- the patients still have to be very healthy apart from their heart valve disease to be able to undergo surgery -- but they are older.
Medscape: Given that these are the patients, how are they diagnosed and referred to you, and how do you proceed with them once they are seen by you?
Dr. Mykén: The patients first come to the general practitioner or a cardiologist within the region, and then they are referred to us. With valve disease it often takes some time for a patient to be referred to a cardiologist because the symptoms are so vague. For example, if a patient is 75 years old and comes to the general practitioner complaining of an inability to keep up with the other people on a Sunday walk, the general practitioner will often just say something like, "You are 75 years old, so you will have to accept that." So it can take time before the patient is referred. But, if the general practitioner listens to the heart and can hear a murmur, then the patient will be referred either directly to a cardiologist or directly for echocardiography at the nearest hospital.
Medscape: Is echocardiography the best diagnostic test for these patients?
Dr. Mykén: Echocardiography is the only way to really examine a valve. The test allows you to see the condition of the heart and the degree of stenosis or insufficiency in the valve. Mostly it is the cardiologists who decide whether a patient may need surgery, but the cardiologist does not have the final decision as to whether a patient should undergo surgery. As soon as the cardiologist in the region has discovered that there is a patient who could benefit from surgery, they present the case to us. We have case conferences 3 times a day, and we speak to every hospital within the region at least once a week. Then we hold a teleconference where the echocardiograms are shown and we decide whether the patient should be operated on and, if so, how soon.
Medscape: Can you usually say at that stage whether valve surgery will involve repair or replacement?
Dr. Mykén: Most of the time, we can decide immediately during the teleconference whether it should be a repair or a valve replacement. Of course, when the patient comes to the hospital, we usually do echocardiography again the day before surgery, as a second evaluation. However, this almost never results in a change about the decision to go to surgery; it is to get more appropriate information about the condition of the heart and how to proceed.
Medscape: Once you have identified a patient like that, is it necessary to get him or her to hospital and into surgery as soon as possible?
Dr. Mykén: No. Most of these patients can wait weeks or months because most of them have been followed for several years before they come to the point where they need surgery. A stenosis in an aortic valve increases very gradually. Sometimes it has been known for many years that there is a stenosis and that one day we will have to operate on it. There are, of course, patients who happen to come to hospital or to a doctor very late, and suddenly it is revealed that they have aortic stenosis and should have undergone surgery much earlier.
Medscape: Are the patients who wait monitored by the cardiologists?
Dr. Mykén: Where there is minimal or moderate stenosis with a normal ventricle, a patient can be followed with echocardiography every 6 months. If patients have heart failure when they present for the first time, they may have to be monitored regularly, returning to see the cardiologist several times before being stabilized, or they may have to be referred more quickly for surgery.
Medscape: Do the patients that you see with aortic, mitral, or mixed valve disease have different characteristics?
Dr. Mykén: The mitral patients tend to be little bit younger.
Medscape: Is there any behavioral component involved in patients who end up needing heart valve surgery?
Dr. Mykén: There is a little overrepresentation of coronary atherosclerosis among patients who present with aortic stenosis. However, the people who present are usually quite healthy, and there is absolutely nothing in their way of living that would make them develop valvular heart disease. So you cannot blame the patients for anything, and they cannot blame themselves, either. There is definitely nothing specific.
Medscape: Do you follow any European or Swedish national guidelines for the management of valve disease and the use of different prostheses?
Dr. Mykén: Usually I read the guidelines issued by the American College of Cardiology/American Heart Association.[4,5] The guidelines are very broad, however, and not very strict about what to do and how to do it.
Medscape: Before you started using the Biocor bioprosthesis in 1983, what would have happened to these patients who required aortic or mitral valve repair or replacement?
Dr. Mykén: There was an interest in using bioprosthetic valves ever since the first mechanical heart valves were introduced around 1963. In the late 1960s and early 1970s, there were a lot of different bioprostheses on the market in Europe, although not in the United States, but several failed after just a few years. At our hospital we were using a Carpentier-Edwards bioprosthetic valve, but we had to do a lot of reoperations quite early because of valve deterioration. So there was some reluctance about bioprostheses overall and very few surgeons wanted to use them, especially in Sweden, where we were having success with the Bjork-Shiley mechanical valve.
Then the Biocor valve was introduced to us by Mario P. Vrandecic, MD (Biocor Institute, Belo Horizonte, Brazil), who developed the valve in the United States, and in 1983, we decided that we should start using this valve. At that time, everyone in Sweden was hesitant about using bioprostheses, and so we knew that we had to follow those patients very closely. In 1986, I started to do follow-up every other year so that we would know if it worked. I think these patients are more closely followed than any other patients we have had. We have 1 or 2 persons working full time to follow these patients.
Medscape: Did you decide at the start that this valve would be more suitable for old patients?
Dr. Mykén: No, in fact, we did not think like that in the beginning. We thought that this would be a good option for younger patients, in their 40s, who could be active and do whatever they wanted, or women who wanted to have children, without worrying about anticoagulation. So at the start we used the valve in younger patients. That has changed over time, and now we use it in very few young people.
Medscape: So then, unlike persons with mechanical valves, those with bioprostheses do not need anticoagulation?
Dr. Mykén: That is correct. They will not need anticoagulation unless there are other indications for anticoagulation therapy.
Medscape: Is there anything else about the aftercare that was different with the bioprosthesis?
Dr. Mykén: No, as long as the surgery is successful, postoperative care and duration of hospital stay and convalescence do not differ between patients with mechanical valves and those with bioprosthetic valves. Discharge is usually within 1 week of surgery.
Medscape: Has the introduction of the bioprosthetic valve affected the proportion of decisions to repair or replace the valves?
Dr. Mykén: There are very few aortic valves that can be repaired. Mitral valves can be repaired, and we always try to repair the valve first. If repair is not possible, we will replace the valve with a mechanical valve or a bioprosthetic valve.
Medscape: What other advantages does the bioprosthesis have, apart from the absence of anticoagulation? Does the metal valve cause any external problems such as the clicking sound a mechanical valve makes in the chest?
Dr. Mykén: There is a sound with the mechanical valve, and a few people have difficulty accepting this sound.
Medscape: This must cause some psychological difficulties.
Dr. Mykén: Sometimes. We have had 1 suicide due to the sound of the mechanical valve, but mostly it is the spouse and other people around the patient who suffer from the sound. It varies among patients; a valve will audibly click in some patients, whereas in others it never does. We do not know why this is, although we know that it is not related to whether or not the patient is overweight.
Medscape: Which kinds of patients will get a mechanical valve?
Dr. Mykén: The mechanical valve is the best option for patients who are younger, because if they get a bioprosthetic valve, in time they will need repeat surgery to replace it, due to the limited durability of tissue valves. Many patients who receive bioprosthetic valves are aged 70 and upward, even up to age 85 years. A bioprosthetic valve is very good for older patients, because they will not need to monitor their anticoagulation INR, especially since older patients are more prone to both thrombosis and bleeding complications. I think that the younger patients should have a mechanical valve, especially since in many parts of the world, they can monitor their own INR levels.
Medscape: Does that mean that a patient could wait for surgery until age 70 and then have a bioprosthetic valve?
Dr. Mykén: You do not know whether a patient's stenosis will progress slowly or quickly, which is why patients have to be monitored every 6 months. Some patients go from a minimal stenosis to one that has to be operated on within 3 years, whereas in others it takes 8 to 12 years before they need an operation. You never know how fast a patient's stenosis will progress. So it is critical that you do not wait too long, because that may result in irreversible damage of the ventricle.
Medscape: Has the proportion of patients who get valve replacement with a bioprosthesis changed over time?
Dr. Mykén: It has changed a little. About 25% of patients were getting bioprostheses when we began this follow-up, but now it is up to 40% of the entire group of patients who undergo valve surgery. That is not due to any changes in indications for putting in bioprostheses vs mechanical valves, but rather to the fact that the patient group is a little older now.
Medscape: The figure for freedom from reoperation is 97%, which seems the best possible result. Would you expect this percentage to increase, especially with better selection of patients?
Dr. Mykén: No. I think there are limitations for bioprostheses. We have not reached the point where we can say that we have a perfect bioprosthesis, but it is as good as it could be for the moment.
Medscape: Is there any consistent proportion of people who say they do not want one type of valve vs another for any reason?
Dr. Mykén: Of course, the decision about which valve to use is always made on the basis of a discussion between the patient and the surgeon, even though it is very difficult for the patient to reach any specific opinions. I sometimes feel sorry for patients; they try to get all the information from the Internet, and then when we see them, they have already made a decision. They meet someone who has worked in this field for 35 years, but they are convinced that after the 2 hours they spent in front of their computer, they know best. This is a pity, because this takes so many years to see a pattern for what you want to suggest for each patient. In the end, however, most patients ask the surgeon to make the decision.
Medscape: What is your view of the late introduction of the Biocor valve in the United States compared with the length of time you have been using it in Sweden?
Dr. Mykén: I think it is a great pity that the device took so long to get into the US market, because I think many older patients would benefit from it. However, I should also emphasize that a bioprosthesis is not appropriate in younger patients. People in the United States are increasingly frightened about anticoagulation, so they think that the only option is a bioprosthesis. I think that is a pity.
References
Mykén P, Bech-Hanssen O, Phipps B, Caidahl K. Fifteen years follow-up with the St. Jude Medical Biocor porcine bioprosthesis. J Heart Valve Dis. 2000;9:415-422. Abstract
Mykén PS. Seventeen-year experience with the St. Jude Medical Biocor porcine bioprosthesis. J Heart Valve Dis. 2005;14:486-492. Abstract
Mykén P. Two decades with the St Jude Med. Biocor bioprosthesis. Presented at the Third Biennial Meeting of The Society for Heart Valve Disease; June 17-20, 2005; Vancouver, British Columbia, Canada. Poster P99. Abstract available online at http://www.shvd.org/.
Bonow RO, Carabello B, de Leon AC Jr, et al. Guidelines for the management of patients with valvular heart disease: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). Circulation. 1998;98:1949-1984. Abstract
ACC/AHA guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association. Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). J Am Coll Cardiol. 1998;32:1486-1588. Abstract
Funding Information
Supported by an independent educational grant from St. Jude Medical.
Pia Myken, MD, PhD, Assistant Professor, Sahlgrenska University Hospital, Göteborg, Sweden
Disclosure: Linda Brookes, MSc, has disclosed no relevant financial relationships.
Disclosure: Pia Myken, MD, PhD, has disclosed no relevant financial relationships.
Joe
From Medscape Cardiology
Expert Interview
Heart Valve Replacement Surgery: 20 Years' Experience Using a Bioprosthetic Valve -- An Expert Interview With Pia S. Mykén, MD, PhD
Posted 05/25/2006
Editor's Note
Pia S Mykén, MD, PhD, is a cardiothoracic surgeon who does mostly cardiac surgery and also pulmonary and transplant surgery in the Department of Thoracic and Cardiovascular Surgery at Sahlgrenska University Hospital in Göteborg, Sweden. Dr. Mykén's main research interests are valve surgery and transplants. She has accumulated more than 20 years' experience in heart valve surgery and has actively participated in the hospital's transplant program since its inception more than 15 years ago. Dr. Mykén is also Assistant Professor at the University of Sahlgrenska. She is a reviewer for many major European and North American cardiology and surgery journals.
Since 1983, researchers at Sahlgrenska University Hospital have been studying the long-term outcomes of patients who have undergone aortic or mitral valve replacement with the Biocor porcine prosthetic heart valve (St Jude Medical, St Paul, Minnesota). The Biocor prosthesis is a third-generation triple composite prosthesis fixed in glutaraldehyde in the resting state. Through 2003, a total of 1832 Biocor prostheses were inserted in either aortic or mitral valves at the hospital, representing a total follow-up time of 8843 patient-years for aortic and 1195 patient-years for mitral valve patients. Dr. Mykén joined this study in 1986 and recently talked with Linda Brookes, MSc, at Medscape about the results of this investigation, which now has accumulated more than 20 years of data on the valve's durability and its associated complications. Earlier analyses of data at 15 years[1] and at 17 years[2] showed a low incidence of valve-related complications and improved valve durability. At 20 years, freedom from valve-related death was 93% and freedom from reoperation due to structural valve deterioration was 97% in patients older than 65 years.[3]
In the United States, approximately 65,000 valve repairs and replacements are performed in the United States annually. The Biocor stented tissue valve was approved by the United States Food and Drug Administration (FDA) in August 2005, and the first US implant of the device was performed later the same month. This approval was based on the clinical experience accumulated by Dr. Mykén and her colleagues. In addition to the Biocor aortic and mitral valves, the FDA has also approved the Biocor Supra stented tissue aortic valve, a valve that is implanted above the annulus.
Medscape: Rather than discussing how to perform a valve repair or replacement, we think our readers would like to hear about your experience with bioprosthetic valve replacement in your institution in Sweden. How do patients who need heart valve repair or replacement surgery come to you at your hospital?
Dr. Mykén: You should recall that in Sweden there is almost no private healthcare and there are no private cardiac centers. Cardiac surgery is only performed at the 7 university centers in Sweden, and every center serves a specific region. Sahlgrenska University Hospital, where I work, is the largest university hospital in Sweden and also one of the largest in Northern Europe. We serve the western region of Sweden, which has about 2.5 million inhabitants.
There are some benefits to this [socialized medicine], namely that we know our region, we know the cardiologists within the region, and we get all our patients from that region. If the patients do not relocate, they will keep coming back to the same center, which makes it a bit easier to follow and treat the patients once you have operated on them. You also get to know the referring cardiologists very well, so you know that whenever they have a problem they will contact you or send the patient to you straightaway. So there is a very close connection to everyone within our region.
In the department of cardiac surgery we perform about 1800 operations a year, including about 400 cases in pediatric cardiac surgery. We do about 300 valve surgical procedures per year on average; in 2005 it was 280.
Medscape: Have these numbers changed much over the last 2 decades?
Dr. Mykén: No, the incidence of valve disease has not changed over the past 20 years, but the patients who can be operated on are increasingly older. The reason for this is that they are much healthier. It is the same situation as in the United States. Ten years ago we never operated on someone who was aged ≥ 80 years, but these days we do, every now and then. It is not that we have changed the strict indications -- the patients still have to be very healthy apart from their heart valve disease to be able to undergo surgery -- but they are older.
Medscape: Given that these are the patients, how are they diagnosed and referred to you, and how do you proceed with them once they are seen by you?
Dr. Mykén: The patients first come to the general practitioner or a cardiologist within the region, and then they are referred to us. With valve disease it often takes some time for a patient to be referred to a cardiologist because the symptoms are so vague. For example, if a patient is 75 years old and comes to the general practitioner complaining of an inability to keep up with the other people on a Sunday walk, the general practitioner will often just say something like, "You are 75 years old, so you will have to accept that." So it can take time before the patient is referred. But, if the general practitioner listens to the heart and can hear a murmur, then the patient will be referred either directly to a cardiologist or directly for echocardiography at the nearest hospital.
Medscape: Is echocardiography the best diagnostic test for these patients?
Dr. Mykén: Echocardiography is the only way to really examine a valve. The test allows you to see the condition of the heart and the degree of stenosis or insufficiency in the valve. Mostly it is the cardiologists who decide whether a patient may need surgery, but the cardiologist does not have the final decision as to whether a patient should undergo surgery. As soon as the cardiologist in the region has discovered that there is a patient who could benefit from surgery, they present the case to us. We have case conferences 3 times a day, and we speak to every hospital within the region at least once a week. Then we hold a teleconference where the echocardiograms are shown and we decide whether the patient should be operated on and, if so, how soon.
Medscape: Can you usually say at that stage whether valve surgery will involve repair or replacement?
Dr. Mykén: Most of the time, we can decide immediately during the teleconference whether it should be a repair or a valve replacement. Of course, when the patient comes to the hospital, we usually do echocardiography again the day before surgery, as a second evaluation. However, this almost never results in a change about the decision to go to surgery; it is to get more appropriate information about the condition of the heart and how to proceed.
Medscape: Once you have identified a patient like that, is it necessary to get him or her to hospital and into surgery as soon as possible?
Dr. Mykén: No. Most of these patients can wait weeks or months because most of them have been followed for several years before they come to the point where they need surgery. A stenosis in an aortic valve increases very gradually. Sometimes it has been known for many years that there is a stenosis and that one day we will have to operate on it. There are, of course, patients who happen to come to hospital or to a doctor very late, and suddenly it is revealed that they have aortic stenosis and should have undergone surgery much earlier.
Medscape: Are the patients who wait monitored by the cardiologists?
Dr. Mykén: Where there is minimal or moderate stenosis with a normal ventricle, a patient can be followed with echocardiography every 6 months. If patients have heart failure when they present for the first time, they may have to be monitored regularly, returning to see the cardiologist several times before being stabilized, or they may have to be referred more quickly for surgery.
Medscape: Do the patients that you see with aortic, mitral, or mixed valve disease have different characteristics?
Dr. Mykén: The mitral patients tend to be little bit younger.
Medscape: Is there any behavioral component involved in patients who end up needing heart valve surgery?
Dr. Mykén: There is a little overrepresentation of coronary atherosclerosis among patients who present with aortic stenosis. However, the people who present are usually quite healthy, and there is absolutely nothing in their way of living that would make them develop valvular heart disease. So you cannot blame the patients for anything, and they cannot blame themselves, either. There is definitely nothing specific.
Medscape: Do you follow any European or Swedish national guidelines for the management of valve disease and the use of different prostheses?
Dr. Mykén: Usually I read the guidelines issued by the American College of Cardiology/American Heart Association.[4,5] The guidelines are very broad, however, and not very strict about what to do and how to do it.
Medscape: Before you started using the Biocor bioprosthesis in 1983, what would have happened to these patients who required aortic or mitral valve repair or replacement?
Dr. Mykén: There was an interest in using bioprosthetic valves ever since the first mechanical heart valves were introduced around 1963. In the late 1960s and early 1970s, there were a lot of different bioprostheses on the market in Europe, although not in the United States, but several failed after just a few years. At our hospital we were using a Carpentier-Edwards bioprosthetic valve, but we had to do a lot of reoperations quite early because of valve deterioration. So there was some reluctance about bioprostheses overall and very few surgeons wanted to use them, especially in Sweden, where we were having success with the Bjork-Shiley mechanical valve.
Then the Biocor valve was introduced to us by Mario P. Vrandecic, MD (Biocor Institute, Belo Horizonte, Brazil), who developed the valve in the United States, and in 1983, we decided that we should start using this valve. At that time, everyone in Sweden was hesitant about using bioprostheses, and so we knew that we had to follow those patients very closely. In 1986, I started to do follow-up every other year so that we would know if it worked. I think these patients are more closely followed than any other patients we have had. We have 1 or 2 persons working full time to follow these patients.
Medscape: Did you decide at the start that this valve would be more suitable for old patients?
Dr. Mykén: No, in fact, we did not think like that in the beginning. We thought that this would be a good option for younger patients, in their 40s, who could be active and do whatever they wanted, or women who wanted to have children, without worrying about anticoagulation. So at the start we used the valve in younger patients. That has changed over time, and now we use it in very few young people.
Medscape: So then, unlike persons with mechanical valves, those with bioprostheses do not need anticoagulation?
Dr. Mykén: That is correct. They will not need anticoagulation unless there are other indications for anticoagulation therapy.
Medscape: Is there anything else about the aftercare that was different with the bioprosthesis?
Dr. Mykén: No, as long as the surgery is successful, postoperative care and duration of hospital stay and convalescence do not differ between patients with mechanical valves and those with bioprosthetic valves. Discharge is usually within 1 week of surgery.
Medscape: Has the introduction of the bioprosthetic valve affected the proportion of decisions to repair or replace the valves?
Dr. Mykén: There are very few aortic valves that can be repaired. Mitral valves can be repaired, and we always try to repair the valve first. If repair is not possible, we will replace the valve with a mechanical valve or a bioprosthetic valve.
Medscape: What other advantages does the bioprosthesis have, apart from the absence of anticoagulation? Does the metal valve cause any external problems such as the clicking sound a mechanical valve makes in the chest?
Dr. Mykén: There is a sound with the mechanical valve, and a few people have difficulty accepting this sound.
Medscape: This must cause some psychological difficulties.
Dr. Mykén: Sometimes. We have had 1 suicide due to the sound of the mechanical valve, but mostly it is the spouse and other people around the patient who suffer from the sound. It varies among patients; a valve will audibly click in some patients, whereas in others it never does. We do not know why this is, although we know that it is not related to whether or not the patient is overweight.
Medscape: Which kinds of patients will get a mechanical valve?
Dr. Mykén: The mechanical valve is the best option for patients who are younger, because if they get a bioprosthetic valve, in time they will need repeat surgery to replace it, due to the limited durability of tissue valves. Many patients who receive bioprosthetic valves are aged 70 and upward, even up to age 85 years. A bioprosthetic valve is very good for older patients, because they will not need to monitor their anticoagulation INR, especially since older patients are more prone to both thrombosis and bleeding complications. I think that the younger patients should have a mechanical valve, especially since in many parts of the world, they can monitor their own INR levels.
Medscape: Does that mean that a patient could wait for surgery until age 70 and then have a bioprosthetic valve?
Dr. Mykén: You do not know whether a patient's stenosis will progress slowly or quickly, which is why patients have to be monitored every 6 months. Some patients go from a minimal stenosis to one that has to be operated on within 3 years, whereas in others it takes 8 to 12 years before they need an operation. You never know how fast a patient's stenosis will progress. So it is critical that you do not wait too long, because that may result in irreversible damage of the ventricle.
Medscape: Has the proportion of patients who get valve replacement with a bioprosthesis changed over time?
Dr. Mykén: It has changed a little. About 25% of patients were getting bioprostheses when we began this follow-up, but now it is up to 40% of the entire group of patients who undergo valve surgery. That is not due to any changes in indications for putting in bioprostheses vs mechanical valves, but rather to the fact that the patient group is a little older now.
Medscape: The figure for freedom from reoperation is 97%, which seems the best possible result. Would you expect this percentage to increase, especially with better selection of patients?
Dr. Mykén: No. I think there are limitations for bioprostheses. We have not reached the point where we can say that we have a perfect bioprosthesis, but it is as good as it could be for the moment.
Medscape: Is there any consistent proportion of people who say they do not want one type of valve vs another for any reason?
Dr. Mykén: Of course, the decision about which valve to use is always made on the basis of a discussion between the patient and the surgeon, even though it is very difficult for the patient to reach any specific opinions. I sometimes feel sorry for patients; they try to get all the information from the Internet, and then when we see them, they have already made a decision. They meet someone who has worked in this field for 35 years, but they are convinced that after the 2 hours they spent in front of their computer, they know best. This is a pity, because this takes so many years to see a pattern for what you want to suggest for each patient. In the end, however, most patients ask the surgeon to make the decision.
Medscape: What is your view of the late introduction of the Biocor valve in the United States compared with the length of time you have been using it in Sweden?
Dr. Mykén: I think it is a great pity that the device took so long to get into the US market, because I think many older patients would benefit from it. However, I should also emphasize that a bioprosthesis is not appropriate in younger patients. People in the United States are increasingly frightened about anticoagulation, so they think that the only option is a bioprosthesis. I think that is a pity.
References
Mykén P, Bech-Hanssen O, Phipps B, Caidahl K. Fifteen years follow-up with the St. Jude Medical Biocor porcine bioprosthesis. J Heart Valve Dis. 2000;9:415-422. Abstract
Mykén PS. Seventeen-year experience with the St. Jude Medical Biocor porcine bioprosthesis. J Heart Valve Dis. 2005;14:486-492. Abstract
Mykén P. Two decades with the St Jude Med. Biocor bioprosthesis. Presented at the Third Biennial Meeting of The Society for Heart Valve Disease; June 17-20, 2005; Vancouver, British Columbia, Canada. Poster P99. Abstract available online at http://www.shvd.org/.
Bonow RO, Carabello B, de Leon AC Jr, et al. Guidelines for the management of patients with valvular heart disease: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). Circulation. 1998;98:1949-1984. Abstract
ACC/AHA guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association. Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). J Am Coll Cardiol. 1998;32:1486-1588. Abstract
Funding Information
Supported by an independent educational grant from St. Jude Medical.
Pia Myken, MD, PhD, Assistant Professor, Sahlgrenska University Hospital, Göteborg, Sweden
Disclosure: Linda Brookes, MSc, has disclosed no relevant financial relationships.
Disclosure: Pia Myken, MD, PhD, has disclosed no relevant financial relationships.
