Grandma--what should she do?

My grandma (age 77) went to the doctor the other day and was told she needed her arteries cleaned out and stents put in or she was going to have a heart attack soon. My grandmother does not trusts doctors (I sure don't either!) and so she decided to forgo the doctor's advice and do her own thing. The problem is she doesn't know what she is going to do, and I just found out that the last few days she has been having bad chest pains, arm pains, shortness of breath, etc. I am no expert on any of this, but this is scary to me and I think maybe she might need to do what the doctor says considering she doesn't have a back up plan and I know her too well to know she isn't going to make any drastic changes on anything with her lifestyle. But I'm turning here hoping for any advice. My family is pulling together right now and trying to help her do the right thing and quickly. Thanks everyone!