If the person is in a coma then it means the heart attack went to an advanced stage where severe hypoxia set in. What was the reason for the heart attack? Coronary artery disease, or something else? Are you sure it wasn't a stroke (which would be about brain blood vessels, not the heart). Is there brain damage?
Clot busting drugs in western medicine must be administered within a few hours of a stroke to work. There are Chinese herbal formulas that can be used up to a month later to undo some damage, but I won't give you their names because their criteria for use is very specific and if you use a formula that does not match the person's etiology, they could get a lot worse. Also, given that the person is in a coma, the formula would have to be administered through a feeding tube which won't be happening in western hospitals.
In general, neural regeneratives include: hydergine, aniracetam/piracetam, vinpocetine, ginkgo, gotu kola, prickly ash bark, schisandra berry, eleuthero root. However, these all have specific indications and counter-indications, so don't just go ahead and use them. Research each one, and always consult the attending doctor before trying anything out. A person in a coma is serious business, don't mess with that.
