There's not always a lot in the way of warning signs, and people tend not to get casual arteriograms just for kicks. The apparently-healthy suddenly dropping dead isn't exactly a rare phenomenon, and "being in shape" can be misleading. Jim Fixx[1] was kind of the poster child for this sort of thing; his death pretty much kicked off the over-40 checkup routine.
Unfortunately you can't really get a heart arteriogram done as a checkup and anything else is actually guesswork.
Both MRA and CTA are really expensive.
Bloodwork can point to problems but there is still a plenty of differential diagnosis involved... You need a bunch of history (main factors are currently age and family history) to reasonably evaluate risk using e.g. European joint guidelines.
You can perhaps guess better based on local doppler USG of some big extremity artery or of carotid. Doppler of heart is not precise enough to show anything useful.
[1]https://en.wikipedia.org/wiki/Jim_Fixx