Unless you are an M.D. you SHOULD NOT give asprin to a suspected heart attack victim.
Get them to lie down. Elevate their limbs. Keep them calm. Call 911.
The reason thay you DO NOT give it is that it is very difficult for untrained individuals to differentiate between a heart attack victim and someone who is suffering a stroke.
If it is a stroke you will kill them.
Stroke and MI are in two different part of the bodies... MI or heart attack is manifested by chest pain while stroke by headache, one sided weakness, slurred speech and facial droop. Not much to mix up there. You may never know if your chest pain guy ever had a real deal MI or was it just angina (unless you do EKG). Same with the stroke; you will not know if the stroke is ischemic or hemorragic or if this even was a stroke. But if I came upon a guy who is having a chest pain, sharp, radiating or non radiating than he would get 2 baby aspirins.