For me, it was different.

A cardiologist told me (after a calcium test showed 95th percentile for calcium) that what I was looking for was a rapid drop in ability. Not over a decade, but over a couple weeks or a month. Well, I play ultimate, and one day I realized "I didn't get this winded a month ago". So I got a stress test, and it showed "abnormal motion of the heart wall under stress" (that is, not enough oxygen getting to all the heart muscles). They did a catheterization, and I wound up with two stents.

I mean, look, if you get the chest pains, don't ignore that. But it doesn't have to be that way. If you lose athletic ability, or wind, or endurance, in a short amount of time, get a stress test.