As we get older, more stuff happens. I had a heart valve replaced a few years ago and some other cardiac work done. As I worked through rehab, I also learned about health and fitness. At very close to 60 now, I'm sure I am in the best shape of my life. Working out is part of my life now and has paid a number of dividends.
Take care of the blockage and get back on your bike.
Goof luck