Coronary arteries bring oxygen rich blood to the heart muscle. Coronary artery disease (CAD) is blockage of these arteries. If the blockage is complete, areas of the heart muscle may be damaged. In severe case the heart muscle dies. This can lead to a heart attack, also known as a myocardial infarction (MI).
Coronary artery disease is the most common form of heart disease. It is the leading cause of death worldwide.