Coronary artery disease is caused by a condition known as atherosclerosis, or “hardening of the arteries.” Atherosclerosis involves the development of plaque in the inner lining of large and medium sized arteries. Eventually the plaque matures into a structure consisting of 2 main parts: a soft “inner core” that consists of cholesterol, waste products, inflammatory cells and calcium, and a thin outer shell called the “fibrous cap.”

As a plaque builds up, it can begin to block the flow of blood through an artery. When this happens in the coronary arteries, the result is coronary artery disease. Stated simply, the normal flow of vital nutrients and oxygen to the heart is blocked by plaque build-up in the narrowed artery.

If one of these plaques ruptures or part of the fibrous cap fragments, exposing the inner core, a blood clot can rapidly form around it and completely block the vessel. If the vessel is a coronary artery, it can lead to a heart attack.

Atherosclerosis is usually caused by high cholesterol. However, high blood pressure, diabetes and smoking can also contribute to coronary artery disease. In fact, high blood pressure, diabetes and smoking can each double the chance of developing heart disease.

Obesity and physical inactivity are other factors that can lead to coronary artery disease. Being overweight increases the likelihood of developing high cholesterol and high blood pressure, and physical inactivity increases the risk of heart attack.