They are RELATED but not the same thing. Cholesterol and protein carry fats around bundled as lipoproteins. Depending on the carrier protein and the amount of fat you can have different types of things called cholesterol. Plaque is basically a reaction to an injury that the body tries and tries to fix and the injury gets more and more low density lipoproteins (LDL bad cholesterol) laid down...they stick to the injury and the body continues to force the removal of the LDL with macrophage (white cell attack). This creates "foam cells" added to the mess. The mix of dead white cells, foam cells, cholesterol, protein and fats then gets walled off by smooth muscle and scar tissue when they body realized that removal is impossible. What the body can't remove, it tries to wall off.
Then it can be further sealed over time with a calcium rich layer that hardend making a stable plaque that is hard to reduce but also hard to break into. They are usually not the ones that break and cause a heart attack but they do diminish the diameter of the artery where they are located and compromise blood flow.
Thus cholesterol and other blood fats are a necessary part of plaque formation but plaque itself is a complicted and variable entity. Once the hardened old plaques have formed, it is unlikely much dietary or drug intervention can be done to get rid of them, they must be ignored, pushed back, ground off or bypassed, The goal of tight cholesterol management is to keep the old ones from growing and, very important, to keep from making any newer, high fat, fragile, medium aged ones that can break open readily, discharging the fats, scar tissue and "necrotic core" (like a gangrenous center) that the body attacks immediately and forms a clot that is the killer of a heart attack or ischemic stroke.
I WISH Lipitor did ALL the work. But even with Lipitor (I've taken it for 7 years) it's a wise idea to lower the fat content of our diets as much as humanly possible or at least as much as we can without moving mountains and also make sure that we aren't making too much fat from food excess. So getting lean, howerver it's done, is wise.
Let that stent be your warning. I'm gonna guess it was in your RCA (right coronary artery.) Do I get a point for a correct guess?
I'll go for a second point and guess your HDL is very low.
(If my lingo was a bit clumsy, it's because this was my first post while waiting for my first tank of coffee!