Hi Alex, Welcome, Sorry for the reason you had to look for us, its tough when you are relatively young and having to make these tough choices my son is 24 and Ive belonged to diferent heart boards for quite a while, mainly for Congenital heart defects that require surgeries thru out their childhood, so I can understand not being able to do everything you want because of your heart or Coumadin, I might be wrong, but think its probably even harder to stop doing what you love than not ever being able to play it, so you dont know how much you enjoy it.. As others said the main concern with Coumdin is internal bleeds, especially head injuries and not so much cuts. As for extreme sports, I'm sure there are people on Coumadin who do everything, but it probably isnt advised to do sports where head injuries are pretty common. Something that would cause a concussion in people not on Coumadin, COULD be alot worse, on Coumadin, especially if it would take a while to get to a Trauma center. As I'm sure you know, most of the sports you are talking about Concussions are pretty common even WITh the best helmets. Helmets dont help that much with your brain bouncing around in your skull when you hit your head hard. As for snowboarding, I think alot would depend on what kind of snowboarding you do. Downhill, probably would be relatively low risk, even tho people often mention hitting a treee wont matter much if you are on Coumadin or not, the chances of hitting a tree are so low, I doubt that is the main concern, other more common things like falling or having someone run into you would probably be the thing you'd worry about going down hill, so probably wouldnt be that big a worry, sure you would most likely have some pretty big bruising, but it would most likely not be life threatening, or ended up with perm brain damage.. but if you are talking about terrain parks and rails, where broken bones and hitting your head isnt that rare and even personally I've known a couple kids who got bad concussions even with helmets or broke bones in terraine parks or halfpipe. White water kyacking or rafting probably would not be reccomended, especially if you are not very close to good medical care, mountain biking agan would depend on how extrememe you are talking about and IF injured how far /long would it be to get to a hospital.
Travelling would not be a big concern, especially since IF you are on Coumadin, you coud get a home tester for your INR and be able to test no matter whre you are. As for weeks in the wilderness, it depends what you would be doing there, just camping and hiking for weeks wouldnt be a problem.
Its always possible to get a tissue valve now, while so much of what you love to do would probably not being reccomended on anticoagulants, and then when this valve needs replaced get a mechanical valve. There have been a few people here who've gone that route thinking by the time they need a new valve, they will be at a different point in their lives busy starting a family raising kids etc Having any heart surgeris is not something people want to do, but a first time REDO right now, the risks are about the same as a first heart surgery and who knows what will be common or available by the time you would need a new valve.
It's alot to think about, I dont envy you. Even tho your in your late 20s by the time you need your first surgery, you might also want to check out the forums at the Adults with Congenital Heart defects site
http://www.achaheart.org/ most members had surgeries as babies or young children, but many are pretty young (20s-30s) and been on Coumadin for valve or other reasons as well as had multiple REDOs
I don't believe having a graft for part of your Aorta would be a reason you would have to be on Coumadin, since many people wit tissue valves also have grafts and arent on any meds, but anything is possible.