My Good Friend Suffered A Massive Heart Attack, And Was

my good friend suffered a massive heart attack, and was placed in an induced coma for 72 hrs. they do not know exactly how long he went w/out oxygen to his brain, but cpr was administered immediately. he is very fit, healthy and is breathing on his own, and has a strong pulse, and heart beat.
what will happen to him when we wakes up? will he wake up?