I Am A 6'1", 160 Pound, 64-year-old Male In Decent

I am a 6'1", 160 pound, 64-year-old male in decent physical shape. I had a stress-evoked stent implanted in 2013. I've known about a 1+ mitral valve prolapse since 2010. I just had a vein/artery heart catheterization and am the disheartened (pun intended) candidate for a 80-90% widowmaker bypass and in need of a mitral valve replacement. I was told not to wait weeks to have the valve replacement and bypass surgery. Please be circumspect in what I can expect pre and post surgery.