And, how many people who have an actual panic attack and subsequently have a heart attack die?

Heart attack: Interesting question but I have no data to answer! in essence, panic attacks and heart attacks are two different entities and not related. However, people having heart attacks will feel anxious but that's different from a panic attack. A panic attack will not lead to a heart attack unless you have underlying heart disease.

Panic & heart attack: Not common, nocause & effect, unless cardiovascular status is already compromised & effect of medications add to that.