My grandfather was taking an antianginal drug for many years before he had his heart attack. One day we were eating lunch at a restaurant and he fell over on my grandmothers shoulder.
We immediately called 911 and he was taken to the hospital and had bypass surgery. He lived for many years after this surgery. I don't know if the drug postponed his heart attack or even helped keep him alive after he had the heart attack.
I am just thankful there are so many kinds of medications that can help when someone has heart problems like that.