John, I had a pig valve but not the regular kind of pig valve. Mine was a " full root" pig valve meaning the surgeon replaced the whole section of aorta that contained the valve with the corresponding section from a pig.
It has been 3.5 years. My biking seems fine but I take care not to let my bpm's get too high. I try to keep below 135. As I said in my earlier respond, I think the Lipitor I took for the first year after surgery did damage to the muscles in my torso. Anyone reading this should use extreme caution in using ant statin. In fact I advise against it. Some report using statins for several years and then the muscle damage began and some suspect they can lead to Parkinson's.
Now if I do anything that tends to put much tension on the muscles in my torso -- either gym machines or yard work, I get real sore torso and even feel nausea and flu like aches. Jim B