My Son Was Put Into A Medically Induced Coma After

My son was put into a medically induced coma after a heart attack. This was five years ago and he has changed in some ways. His short term memory is still affected and he does not finish things at work like he used to. He says he does not feel like working very much . He is an accountant.
He is short tempered, will not exercise or watch his weight.
How can we help?