What is coronary artery disease?

Coronary artery disease is the narrowing or blockage of the coronary arteries caused by atherosclerosis. Atherosclerosis (sometimes called “hardening” or “clogging” of the arteries) is the buildup of cholesterol and fatty deposits (called plaque) on the inner walls of the arteries that restricts blood flow to the heart. Without adequate blood, the heart becomes starved of oxygen and the vital nutrients it needs to work properly. This can cause chest pain called angina. When one or more of the coronary arteries are completely blocked, a heart attack (injury to the heart muscle) may occur.

The process of coronary artery disease

Your coronary arteries are shaped like hollow tubes through which blood can flow freely. The walls of the coronary arteries are normally smooth and elastic.

Coronary artery disease starts when you are very young. Before your teen years, the blood vessel walls begin to show streaks of fat.

With coronary artery disease, as you get older, the fat builds up, causing slight injury to your blood vessel walls. In an attempt to heal the blood vessel walls, the cells release chemicals that make the blood vessel walls stickier. Other substances traveling through your blood stream, such as inflammatory cells, cellular waste products, proteins and calcium, begin to stick to the vessel walls. The fat and other substances combine to form a material called plaque.

Over time, with coronary artery disease, the inside of the arteries develop plaques of different sizes. Many of the plaque deposits are soft on the inside with a hard fibrous “cap” covering the outside. If the hard surface cracks or tears, the soft, fatty inside is exposed. Platelets (disc-shaped particles in the blood that aid clotting) come to the area, and blood clots form around the plaque. 

This causes the artery to narrow even more. Sometimes, the blood clot breaks apart, and blood supply is restored.