Metal valves are only used in the young (i.e. under 50) because they are the most durable and can last a lifetime. The caveat is that lifelong blood thinners are needed because the metal provides a surface for clots to form. Bovine valves are the typical favorite because the body does not form clots on a bovine valve. They're usually sterilized and all cells killed so that it doesn't trigger tissue rejection. In the end, it's just a connective tissue matrix. Unfortunately, this means it is less durable and cannot heal from damage so they only last 10-15 years.
That’s not really true around selection of valve, it’s all about fitness.
A lot of younger people will have tissue valves, because they can have another one after (probably, if they don’t have too many Comorbidities) and it’s a better trade off than being anticoagulated. A though some of the newer anti coagulants are much less of a pain in the arse to be on than 10 years ago. Also they tick, which some people don’t like.
Similarly, many cardiologists would give a 80 year old a tissue valve because they probably won’t need another one and again the anti coagulation trade offs work in their favour
You’re right — what I said was an oversimplification and a little bit untrue. I agree fitness and Compton dotier are a huge factor in selection of valve type.
That said, in my experience, cardiologists are really hesitant to use a tissue valve in someone under 50, especially if it is an open heart procedure. With an open heart, the adhesions (scar tissue) on a revision surgery makes it far riskier and less likely to heal well. So the follow up for a valve replacement after 10-20 years becomes much more high risk. Not a problem if they’re 70 and they would be 90 at the time a replacement is needed. Much more of a problem if they’re 30 and will likely need 4-5 artificial valves in their lifetime.
The new thing is to first do a TAVR/TPVR, which involves cutting into an artery - most commonly the leg - and placing a valve by routing it through the artery into the heart. But, any revision will need to be an open heart procedure. So the first replacement is trans catheter, then the second is open heart. Thus, the third replacement gets much more risky. So, if someone is 50, the second replacement is at 65, and the third would be at 85, so not a huge issue. By contrast, if they’re 30, the high risk 3rd surgery will happen at 65.
I may be speaking from 7-8 years ago when we were still in the dawn of TAVIs but the cardiothoracic surgeons I worked with generally put tissue valves in <50, as TAVIs last less. So tou could do tissue valve, plan for a TAVI later, then probably something new will be there next time they need one
