It is the patient's choice of valve type, tissue or mechanical. Sometimes other options are available to choose from, such as TAVR, a Ross Procedure or a Homograft.
In my situation, I also had the choice of which mechanical valve, St. Jude or On-x. In fact, I scheduled my second consultation with my surgeon specifically to discuss the St. Jude vs the On-x and that consultation lasted almost an hour, for which I was very grateful for his time. He clearly preferred the St Jude, based on their long proven success record. He also made it clear to me that if I preferred to go with the On-x, then that is what he would go with.
Having the 2nd consult was my idea, as I had already met with him before. I'm sure that most people just leave it to the surgeon, even for the decision on tissue vs mechanical, and you will get what he prefers both in valve type and manufacturer. There is an argument to not be involved at all and let the surgeon decide based on his expertise. But, as the patient is the one who will have to live with the trade offs, I believe that the patient should be very involved in this discussion.
Once the valve type has been decided on, probably the vast majority don't get involved in the discussion beyond there. But, I think that there is a good reason to be involved at that point as well. For example, if one chooses tissue, does the patient want to go with the more proven track record of the Magna Ease, or do they want to go with the relatively new Resilia valve, with 5 years of data, but the hope that it might last longer due to its treatment meant to delay calcification? Similarly, if one chooses mechanical, do they go with the long track record of the St. Jude or the newer On-x valve?
Personally, I like to know the trade offs and be very involved in the decision process. I understand that some don't feel the same way. I'm glad that I have medical professionals that welcome this involvement and are willing to get into deep discussions with me about trade offs, as well as discuss the medical literature. I had input from my cardiologist and surgeon on valve type, but ultimately going mechanical or tissue was very much a personal choice. I'm the one that has to live with reoperation or a life on warfarin. As to valve manufacturer, it was also my decision. Ultimately, I went with the St. Jude, as recommended by my surgeon. At that point, it probably would have taken a lot for me to choose a valve manufacturer different than that preferred by my surgeon. But, I was glad to have had the discussion with him as to why he preferred the St. Jude over the On-x.