One thing I forgot to mention. For multiple reasons - he was eating right, he was exercising, and he appears to have been living a heart friendly life, your father is about to be introduced to the wonderful world of chemistry. He will be told that "his body just does this stuff no matter how well he does things." Weigh out what they say very carefully before jumping on the drug bandwagon! I'm always leery of concerns about the liver, kidneys, blood sugars, etc. We focus on the heart and brain, but you can't live without a liver or kidneys either.
I won't go to deep into it, because this is the thing that gets people labeled: There are a lot of common sense, old fashioned remedies and cures out there. Balanced diets, cider, cider vinegar, oatmeal, fresh fruits, juices, bran, grapes, etc. that have a scientific base and have been proven to help as well. Do the research, get the opinions, and weigh all forms of treatment the same.