I get a checkup twice a year. My cardio has me doing the dreaded treadmill twice a year as well even though I am totally asymptomatic of any heart disease. But, me thinks when reading stories such as yours, perhaps the preventive medicine is the best route afterall.
Yes, going for check-ups does help, but there's much that you can do for yourself before medics have to step in with advice: FWIW I'd say cut out cheese, processed delicatessen meats, booze, pastries containing suet, cigarettes (which nobody sane should even consider these days!), colas and absolutely all animal fats.
For a while, you'll believe that everything you could possibly enjoy is bad for you; and you are probably right!
But better to live modestly and enjoy your time without being victim to your own excesses, when so many of them can be avoided with but a modicum of willpower.
P.S. As I was leaving hospital after the first event, I was told that sex was definitely good for one... what they didn't mention was that some of the meds you end up taking for the rest of your life think otherwise.