Should I panic?

My husband's aortic aneurysm has recently grown to 5.0, and while his doctor is not concerned, I am. He is 76 years old, does not exercise at all, eats a lot of junk and processed food, and has recently started smoking. His attitude is that if he has to go, he might as well enjoy himself. Additionally, he is dealing with dementia. If I can break through his thick skull, is there still a chance to repair or halt the damage?