Hi, not much help here but sharing my experience as different to yours so hopefully reassure you? Maybe? Hope so!
The angiogram itself is very easy, no pain. It’s also a really good way for them to find stuff that’s wrong, I had every test in the book that found nothing, they were suggesting I was having panic attacks until the angiogram that showed I needed a bypass, that’s not suggesting you will need one.
My version of angina was very different to yours, I had heartburn that went away after I stopped walking for 10 seconds, then came back when I walked again, basically I got heartburn when my pulse went up. The spray is amazingly effective but sit down before you squirt it.
I also had a mini stroke, this for me was like my whole arm, up to my shoulder being plunged into a very warm bath, then when I stood up, the hot water flushed from my arm and down my whole left torso, it was very weird and hard to mistake for anything else. The tests showed zero damage from the TIA but the stroke consultant said as my symptoms were so text book he is treating me as having one. This means I don’t actually know if I had one but my travel insurance is more expensive so I’m hoping I did (joking).
I hope you get some good answers.