Is arteriosclerosis fatal?

It can be: Hardening of the arteries, specially those of the heart , due to plaque formation from cholesterol, can cause a fatal heart attack among other things, thus low saturated fats consumption, exercise, may decrease the level of cholesterol, LDL and your risk of heart disease and death from arteriosclerosis.

Not at all: Atherosclerosis is very treatable with medications and lifestyle changes. The earlier its treated, the better.