I'm not certain, but I believe the dye used for the catheter angiogram might be similar to that used in a CAT scan, as they are both viewed via X-Ray. I believe less is used for the catheter angiogram. It is not uncommon for patents to have a mild reaction to the dye.
The contrast dye used in an MRA would contain something that would affect or be affected by a magnetic field or radio waves. A very small segment of the population (PamO!) have a reaction to the MRA contrast dye. Unlike x-rays, the fields generated by an MRI unit have never been shown to have any deleterious effect on a patient.
Both dyes can create a sensation of heat, cold, or numbness when injected, that can be unpleasant, but not painful. My own response has been that it's similar to the unfortunate sensation you get when a toddler's diaper leaks onto your pants leg.
In any event, a catheter angiogram is not done by a technician. It's done by an interventional cardiologist, so by definition, a heart doctor is right there. Aspirin sensitivity itself is probably not related to sensitivity to the dyes, or they would be even more troublesome than they are.
However, it wouldn't hurt to note to your IC before the procedure that you have some chemical sensitivities. If getting an MRA or CAT scan, stay in sight of hospital personnel for fifteen minutes or so after the procedure, to avoid Pam's predicament.
Best wishes,