But if you do have symptoms, get to hospital too late, then there is no hope
of saving any
of that muscle either. Paramedics can get a good idea if it's MI or Acute MI by giving you GTN. A 100% blockage will not respond to GTN, but a 95-99% blockage will usually give SOME relief.
So, I guess the answer to your question is, it depends on how quickly you receive treatment.