Hi Anne,
First of all let me say that the decision between a mechanical and a tissue valve is ultimately yours. It’s your body. With that said you really need to make an informed decision - evaluating the pros and cons as they pertain to your individual situation. I am 52 years old and recently had my aortic valve replaced (Oct 11, 2013) at the Mayo Clinic in Rochester. I am still in recovery and expect to return to work in about 3 weeks. The decision is a very personal decision that the impacted person is in the best position to answer once he/she has all of the information and have given proper consideration to make a fully informed decision.
I am fortunate in that I happen to work for the worlds largest medical technology company and have access to my companies top engineers and scientists that work in our heart valve division. I have worked at this company as an electrical engineer in the product development group for implantable cardiac pacemakers and defibrillators for 23 years. As a result, I do know quite a bit about the physiologic aspects of the human cardiac system especially from an electrical perspective. I do not work with our heart valve products but do have access to those who do.
I met with experts in our heart valve product development groups (engineers and scientists) for many hours and spent scores of hours on my own researching and gathering data and learning more about my disease and the treatment options. In addition, I had numerous discussions with my surgeon and my cardiologists. I knew at the end of the day the decision to go with tissue or mechanical has to be an informed decision made by me because I know my likes/dislikes, priorities, must haves, etc. better than anybody else. There is no one size fits all generic black and white answer - even though there are some who believe this is the case. They are most likely the same people who think that everyone should have the same taste in movies, food, entertainment, etc. as them… On a lighter note just know that either way you go (mechanical or tissue) your life will be saved…
In my case I chose the Magna Ease tissue valve (Edwards Lifesciences). I thought that I would share with you and others how I arrived at this choice – hoping that it may help someone else. So this is a brief summary of the data I gathered and a description of my decision making process:
Longevity
Statistically speaking – a mechanical heart valves will outlast most people’s lives. Very few valve redo surgeries are required for mechanical valves as it’s very durable.
Tissue valves aren’t as durable as mechanical valves. In addition, the valves last longer in older people and not so long in younger people. Example: for a 60 year old person a tissue valve typically has a ~ 70%-80% probability to last 15 years or more. For me, 52 year old, a tissue valve typically has a ~ 60% probability to last ~ 12 years. The data does vary somewhat from study to study but this is on average what the data shows.
For me – this suggests that I will require a redo surgery which will most likely occur when I am in my mid 60s but could occur sooner or even later. I did have a 2 hour conference call with a lead engineer and medical doctor from Edwards Lifesciences (manufacturer of my heart valve) to discuss and learn more about the Magna Ease valve and the new anti-calcium treatment they are using. The primary failure mode for tissue valves is calcification. This newer treatment has the potential to extend the life of the valve beyond what is typically being seen today.
Surgical Risk
Valve replacement surgery carries a fairly significant surgical mortality risk. It is basically the same for tissue and mechanical valves. For my age and having the surgery performed at the Mayo Clinic I was told the mortality risk was somewhere between 1% and 2%. The surgical risk for a redo surgery (which I will need) is approximately twice this. Worthy of note is that surgical risk continues to be reduced over time as improvements to valve replacement surgery are made.
Sound
Tissue valves do not make sound when they open/close.
Mechanical valves do make a sound when they open/close. The volume of the sound is what varies from person to person. Unfortunately there is no way to predict if the sound will be loud or soft for an individual without actually putting in the valve. For the vast majority of people the sound does not bother them or they get used to it over time to the point where it they aren’t bothered by it. For a small minority of people (data shows single digit percent) it is very bothersome and they never get used to it. In fact it has a fairly significant impact on their sleep and impacts their overall quality of life.
Since I have been battling quite severe insomnia for the past 15 years the potential that a mechanical valve would exacerbate this was a real possibility for me. My surgeon concurred that this should definitely be considered in my decision making process.
Again, for most people it’s a non-issue. However, you are in the best position to make this assessment.
Coumadin
Coumadin is not necessary for tissue valves.
Coumadin is necessary for mechanical valves. Coumadin is needed to mitigate the likelihood of dangerous blood clots that can be caused by mechanical valves. It’s a lifelong regiment consisting of the following: - periodic blood testing for INR level; - changes to Coumadin dose to keep INR in range; diet regiment. Can establish your own diet and adjust Coumadin dose accordingly but must adhere to the diet to keep the INR in range.
Coumadin interacts with numerous drugs causing INR level changes thus necessitating Coumadin dose changes and other possible issues. Surgeries including non-cardiac related generally require management of Coumadin before and during the surgery.
Being on Coumadin brings about a 1%-2% per patient year change of having a significant internal bleed requiring prompt medical attention. Although this is a relatively small number for one specific year, the cumulative risk over say 20 years becomes not so insignificant… In fact, I read several medical journal articles concluding that this risk is actually a fair amount higher than the mortality risk presented by a redo surgery required for a younger person receiving a tissue valve.
Being on Coumadin requires lifestyle changes for some people to mitigate the chances of bleeding to death from external wounds. It would require lifestyle changes for me as I am a ‘motor-head’. I love to ride motorcycle, snowmobile, 4-wheel, and tinker in the garage. On several occasions I have received injuries requiring emergency room visits to receive stiches that might have become very dangerous if I were on Coumadin (blood clotting compromised). In fact, my doctor told me I should really consider stopping some of these activities if I go with the mechanical valve. In my case this would be taking away some of my greatest enjoyments in life. For others, this may not be a big deal. Again, you are in the best position to make this individual assessment.
Bruising also occurs from time to time while on Coumadin. Some bruises can get fairly nasty looking. In general they are just cosmetic and for me this isn’t a very big concern. However, I can understand that for others it would be more of a concern. This is an issue to be evaluated on a personal level.
Worthy of consideration is the fact that as one ages the statistical probability of being put on Coumadin for other cardiac related issues increases and is not insignificant. In other words, you may end up being put on Coumadin anyways. I can’t recall the exact data on this (you could research this) but in general I believe the general lifetime probability was somewhat less than 50% but more than say 20%.
For me, not being on Coumadin means I continue to live the life that I love to live without change or compromise. This means a great deal to me. It also means that I am not reminded daily of my disease by watching my diet, taking more pills, and monitoring the INR level in my blood. Data I found did show that statistically speaking – people with tissue valves were found to have a more positive opinion of their health than those with mechanical valves. My guess is that the Coumadin regiment can be attributable at least in part to this.
Medical Advancement
When a mechanical valve is implanted it should last your lifetime. This is the most often used criteria when considering between mechanical valve and tissue valve. It was especially significant years ago when the risk of redo surgery was much higher. However, this surgical risk has been and continues to be reduced as time goes on. In addition, some very viable advancements with even less risk are potential options available to me when my redo surgery is required (TAVR, less invasive surgeries, etc.). These advancements are available for redo surgeries of tissue valves but generally not for redo surgeries of mechanical valves. I spoke at length with both the project development manager for my company’s TAVR system and the high level manager in charge of overall tissue valve product development. Both are extremely excited about the current research going on as well as the product pipeline for prosthetic heart valves.
In engineering terms we say that the risk associated with mechanical valves is front-end loaded. That is, the lifetime risk is established and set prior to the surgery and isn’t changed. This risk includes the risk of the valve replacement surgery and the risk associated with being on Coumadin for lifetime. Regarding tissue valves, the lifetime risk is not necessarily established and set prior to the surgery as it can change. The maximum risk is set and includes the risk of the valve replacement surgery and the risk of the redo valve replacement surgery. However, due to medical advancements the risk may and most likely will be reduced for the redo surgery with options that become available at that time.
By the way the current general guideline used by the American Heart Association and thus most doctors as they tend to follow this guideline (as they probably should) is that for age 65 and older the recommendation is to go with a tissue valve and for age under 65 the recommendation is to go with a mechanical valve. They do offer a more advanced guideline that includes some other criteria (e.g. are you currently on Coumadin) but the age is the primary consideration that is used - as it ties together valve longevity and human longevity.
I could go on and on but I think I captured the highlights of my decision making process. The bottom line is that you need to gather data and evaluate it as objectively as possible as it applies to your individual perspective. A very important point I want to make for you and everyone reading this is that just because I concluded that a tissue valve was the best choice for me doesn’t necessarily mean that it’s the best choice for you. Investigate and make an informed decision based on what you know is right for you.
