Stents can have MRI if they've been in place long enough and are the right material. You should carry a card with that info.
You can have a relaxing drug before an MRI if you are claustrophobic. They should have asked you beforehand.
Stents can be re
opened or restented, but that my depend on the type and
My opinion of stress tests is that if you can walk to the center where it's being done, it's not going to show anything and are a waste of radiation. I passed a couple of them, one just before a heart attack, another when an angioplasty was closing back up and needed to be stented. I couldn't walk across a parking lot but passed the test.
I'd get another opinion. See an interventional cardiologist. The good ones can do an angioplasty or stent and close the artery with a stitch, leaving no bleeding of hematoma.