If the arteriogram detects severe renal artery stenosis, this should be treated with angioplasty if possible. The recurrence rate at the treated site is low. Obviously, he needs to stop smoking completely as of right now. Continued control of his blood pressure and cholesterol are also important. Your doctors' concerns are that, even with appropriate treatment from here on in, in all likelihood, a substantial amount of damage has already been sustained by the arteries to the heart and brain. A proper diet and medications will help prevent further damage and will cause some reduction in the damage his arteries have sustained, though will not reverse all the damage. I think there is little point in worrying about damage that has already occurred or trying to predict the future. Instead, your husband should just focus on improving what can be improved and remain optimistic about the future.