What is Coronary artery disease? Coronary artery disease is a disease in which a waxy substance called plaque builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart muscle. When plaque builds up in these arteries, is it called coronary atherosclerosis. When significant atherosclerosis occurs in the arteries, it can cause chest pain (angina), shortness of breath, or other symptoms that can be warning signs of significant blockage. These signs can indicate an impending heart attack. Interventional cardiology is the aspect of cardiology that helps treat these blockages.