Okay but so worried my grandpa has congestive heart failure & an aneurysm in his stomach. Will he die?

Someday. CHF implies he has a damaged heart and an aortic aneurysm has risk of rupture. However, it depends on how he is doing despite these diseases and what other conditions he has. His doctors will advise on course of treatment. Everybody dies someday no matter how healthy they've been. My advice is to make every day count with your loved ones, even those in perfect health.
Yes. Yes, we will all die. A better question is will this kill him. It is possible. If he is scheduled for surgery, he is definitely high risk because of the chf. If he was my grandpa, i would find out if it could be fixed through the artery in his leg. If it is possible, it may be much less risky for him.