Dangerous complications of atherosclerosis

Atherosclerosis (atherosclerosis) is the degenerative process of the arteries, the formation of atherosclerotic plaques in the walls of the arteries, causing a gradual narrowing of the lumen of the arterial ducts.

The process progresses slowly, at first narrowing by 1%, 2%, 10%.

The older you get, the narrower the artery by 50-70%… until 100% completely blocked.

My mother discovered atherosclerosis, which led to a 40% coronary artery stenosis.

Is the disease dangerous? Does taking medication treat all the diseases?

My mother is 64 years old, has a history of hypertension for 8 years now, taking prescription medications.