The CT scan is a more sensitive test than hs-CRP but in addition to the radiation issue, is more expensive and I believe it has a high false positive rate.
I have never seen anything to indicate Calcium scores gives a higher false positive rate than other tests. And I'd be exceedingly surprised if that were true given all the stats I've seen - but I'll have to think through the logic to explain it on the board.
I remember reading that using both hs-CRP and Lp-PLA2 gives better diagnostic accuracy than either alone.
I am only peripherally aware of PLA2 data - will look into it.