Many factors contribute to risk of renal impairment post-contrast administration:
Diabetes (and how well-controlled it is)
Renal function pre-contrast administration
Exposure to nephrotoxic drugs
Amount of contrast used (if PCI done as well as diagnostic cath (likely for STEMI pt), more contrast will likely be used = greater risk for renal injury)
Interesting and applicable article here: Medscape: Medscape Access
Per the article, pre-existing renal impairment is most important to be aware of and one of the most important predictors of possible CIN, contrast-induced nephropathy.
It behooves all of us to be aware of the risks and mitigate when and where we can.