Thanks for all the interesting insight, comments, and links. Being in Massachusetts, my dad has access to great doctors (he's been going to Mass General), and they've put him on a beta blocker while they decide whether to put stents in or do bypass surgery - some doctors are less pessimistic about the condition of his arteries than others. However, they do want to do something within the next couple of weeks.
I didn't mean to cause a ruckus by posting some general information about my "diet." I am skeptical of anything that is labeled a "diet" (look what happened to the Atkins, and so many other "diets"). I have specific beliefs about moderation and being reasonably intelligent and generally giving some thought to what I eat. I cook most of my own food and do so with olive oil. My dad's parents probably used lard, Crisco and butter. I remember going to my grandparents' house and my grandmother boiling vegetables for two hours, leaching all the nutrients out of them. I enjoy the occasional prime rib - New York has some of the best steakhouses in the world - but don't eat red meat more than once or twice a week. I have eliminated fast food and soda from my diet, and eat almost no processed foods or refined sugar. I think people who suggest that diet is a non (or minor)-factor in heart health are a little delusional, or in denial.
I also tend to believe that we as Americans are overly obsessive about this stuff, and it gets us into trouble - it's well documented that despite their propensities for smoking, drinking too much, and not "watching what they eat," there is a lower incidence of obesity and coronary disease amongst the French, Italians and Japanese.
What I want to do is teach my dad about this stuff. Cooking less processed jasmine or basmati rice is almost as quick as fixing a pouch of Uncle Ben's (or what have you), and tastes better. Salads are quick and easy to prepare. Buying minimally processed whole grain bread is just as easy as buying a loaf of white. That kind of thing. It's really about breaking habits.
At least it'll be a start, and there's no doubt in my mind that it won't hurt.
Thanks again for the kind words.