I don't think I would want him there either. By what I'm getting from your post he is not supportive and I would feel uncomfortable opening up if he is there. If he truly feels he has an MI he should talk to his Dr. so they can get him in with a Pdoc and that is exactly what I would tell him. You have enough on your plate just dealing with BP. Maybe suggest he goes to a family support group for ppl with MI's.
Sorry you are having to go through this.