In a simple model of atherosclerosis and heart disease, the compound that forms plaques that adhere to the walls of the blood vessels is

cholesterol

Explanation:

Atherosclerosis and several heart diseases are caused by the development of atherosclerotic plaques. There is thickening of the walls of the arteries and loss of elasticity. LDLs (low-density lipoproteins) transport cholesterol from the liver to body cells so that is can be used in processes like cell membrane repair and the production of steroid hormones, etc. However, the excess amounts of LDLs promote atherosclerosis as the excess of the cholesterol is deposited in the walls of certain arteries. The arteries are damaged, inflamed and become narrow due to deposition of cholesterol leading eventually to impaired circulation and heart disease.