What is this life expectancy for someone with coronary artery disease?

Hard to say: Many people with coronary artery disease have normal life expectancies. This depends on risk factor modifications and continued followup with your doctor. Risk factor modifications include stop smoking, exercise, weight control, good diet, etc.

Depends: Also depends nature of severity of disease process , life style and if the disease process is being address. You have to be more specific with the diagnose, for example, some one with severe 3 vessel disease without revasculizations will be different if he/she has surgery or medical tx.