Hi--
My dad, who turns 85 next month, had heart surgery (aortic valve replacement, bypass, and aneurysm repair) 2 years ago. I can't recall the exact statistics the doctors gave, but I know the chances for successfully surviving the surgery without debilitation (like pneumonia, surgical site infection, stroke, etc.) were about at least 80%, and that was taking into consideration his other medical conditions like diabetes which wasn't that well controlled.