Narrowing of the arteries is sometimes accompanied by higher cholesterol. Sometimes not. At best there is a very weak correlation of some subgroups of the population, and even so does not imply a casual effect. It is just as likely that narrowing of the arteries causes high cholesterol than the reverse.

There is a study in Europe, simply tabulating the cholesterol levels of those entering the hospital for heart attacks. Their cholesterol levels are below the average for the population at large.

Related is the ongoing villainization of fat in the diet which causes, it is said, high cholesterol and CHD. The history of this belief is a study in free enterprise and politics. But that I suppose, is another topic.