Mechanical and Tissue Valve Considerations
Mechanical and Tissue Valve Considerations
The fact is that at your age, it is a real crapshoot.
You would likely require two more surgeries to continue with tissue through your life. That is no small thing, although a growing number of people have decided that way as tissue valves have improved. There are are issues that go with more surgeries, largely around scar tissue, that affect your odds and affect your likelihood of having atrial fibrillation, the most common reason for people to take Coumadin (warfarin) other than having a mechanical valve.
However, warfarin is not a negligible addition to your life, either. Each person's response to anticoagulation therapy (ACT) is unique, so another person's experiences may not mirror your own. Many people do very well with it; others fare poorly. For some, there is not much difference in bruising levels or even bleeding. For others, it can exacerbate nosebleeds, menstrual issues, or ease of bruising. A look through the last year's worth of the Coumadin/anticoagulation forum's files will give you a better understanding of some of the concerns that can accompany ACT for those who are not as fortunate in their experiences.
It is to be remembered that warfarin is not an evil thing: it's what makes it possible to put mechanical valves into people's hearts without causing clots and strokes.
The fatality statistics are similar for mechanical and tissue. They are slightly more favorable for mechanical valve recipients in younger patients, and a little better for tissue owners in older patients. However, the data for those studies comes from prior-generation tissue valves, so it is an open question what those statistics will look like later on.
A lot of making the choice has to do with your perception of risks and your tolerance for daily regimen.
Mechanical valves have a fairly constant, low-level risk of stroke and its alter-ego, bleeding problems. While this risk is enhanced when some medical procedures are required, it is generally just a background noise most of the time. You may find that you can ignore that risk over time, or that you feel empowered by controlling your warfarin intake and INR.
You are not proof from further OHS because you have a mechanical valve. If you have a bicuspid valve syndrome, you may have aneurisms that occur over time that require surgical intervention. If you have deterioration of the heart due to endocarditis or radiation treatments, your problem may be progressive, affecting other valves, which may then require surgery themselves.
Warfarin does require regular testing, sometimes from labs, and most people do have to balance their eating (and drinking) habits to keep their INRs in range. Coumadin and its effects are interactive with many other drugs and some common herb supplements. This reduces the number of pharmaceutical remedies that may be available to you, including over-the-counter pain relievers, like aspirin, ibuprofen (Advil, Medipren), and Aleve, as well as prescription NSAIDs.
There seems to be little accuracy to the doomsaying doctors who would deny Coumadin users so many activites out of fear of bleeding events. Those which bear some concern are activities which may result in head injuries, as it may be more difficult to halt intercranial bleeding. However, when Sonny Bono died after skiing into a tree, he wasn't on warfarin to my knowledge, so the risk may be somewhat elevated, but remains relative.
There is still a fair amount of ignorance among doctors about the proper treatment of people on Coumadin ACT, and you will need to become your own advocate to ensure that one bad doctor or nurse doesn't do you more harm than good. Doctors may improperly order you to go off of your ACT for procedures that don't require it. Some dentists may also demand you go off of warfarin for extractions or similar procedures. Your primary risk from these unlearned professionals is stroke, due to being off of your Coumadin. When you do have bridging therapy with heparin or lovenox, such as for Colonoscopy and some other intrusive medical procedures, it may include self-delivered injections.
So, it would be hard to accept a blanket statement that the use of Coumadin or the risk of stroke is nothing. That said, a mechanical valve itself is highly reliable, runs trouble-free, and rarely deteriorates. It can be an answer for life for some, with no further surgeries.
Tissue valves have peak risks at operation time, and lower risk in between. They have periods when they are in decline, much as your current, original valve is having, before they are replaced. That means a year or more of valve function problems in the future for this new valve, when it hits its useful life limit. And it will happen again in your case, with a second valve, before you are likely to keep your third valve for the rest of your life.
Second or third surgeries tend to be more difficult and run longer, although in non-complicated cases, the risk factor is only mildly elevated. Scar tissue and adhesions tend to cause the most difficulty for the surgeon. However, other health issues, even unrelated to the heart, that come up as you age may make that surgery more difficult for you, or raise your risk level for it substantially.
With multiple surgeries, you also run the risk of restrictions to heart movement due to scar tissue in the heart or in the pericardium which surrounds the heart. Your likelihood of arrhythmias increases as well, as some electrical conductivity and contractility in the heart muscle is diminished in scarred areas.
Having a tissue valve does keep you free from the requirements of valve-related daily medication and testing. You are essentially normal between valve deterioration cycles, with no short-term restrictions on your activities or diet (getting fat is still not a good idea, as it causes overall stress on the heart).
However, having a tissue valve does not always make you free from having to take Coumadin. If you develop atrial fibrillation, or if you are felt to be susceptible to stroke, you doctor may prescribe it for you anyway. Paradoxically, having multiple surgeries is a causitive factor for atrial fibrillation, as is advancing age.
It is to be noted that, with a normal heart structure, you can switch from or to either valve type at any time a surgery is already required on the valve. For example, if you were to have a tissue valve now, and wind up on Coumadin anyway, you could change over to a mechanical valve when replacement of the current valve comes due.
Despite your surgeon's bent toward the stentless valve, the tissue valve with the best track record for longevity is the bovine valve, which has consistently averaged five years' longer useful life than any of the porcine valves to this point, stented or stentless. I would not consider going the tissue route without at least discussing that with your surgeon. His perception is currently based on marketing, not actual patient use study data. Although new anticalcification treatments and perservative techniques have recently been introduced for both types, the structures of the valves have not been changed from their predecessors, so the historical data is likely to still follow through.
Future advancements may change the scenery, but don't hold your breath - or your surgery. The On-X mechanical valve is undergoing trials to see if aspirin ACT provides enough anti-clot safety to allow patients to use it in place of warfarin. However, the results will be unknown for some time.
On the tissue side, if you are older and have other problems, your tissue valve might be replaceable with a catheter-introduced valve, in a more complicated angiogram-like procedure, rather than through more OHS. Some of this type of valve are undergoing trials at this time. However, catheter-placed valves are currently inferior with regard to valve opening size and longevity, and are only being used in compassionate cases.
Each choice is has its appeal and downsides. It is best to look within yourself for the choice that most works with your personal bent, your tolerance for different types of risk, and your ability to faithfully follow some elements of a required routine in life.
Best wishes,
