Coronary Artery Disease

Arteries are vessels that carry blood away from the heart to the rest of the body. Coronary arteries are vessels that bring blood to the heart. Blood carries oxygen and nutrients; thus, the coronary arteries are responsible for supplying the heart with the necessary amount of oxygen and nutrients. Coronary artery disease occurs when these vessels narrow.

Cholesterol and other fatty materials are deposited on the walls of the vessels. The body surrounds these materials, as it does with all foreign agents in the body, with scar tissue. All of this forms a scar-covered lump within the vessel. This lump is called arterial plaque.

Over time, the plaque builds. New cholesterol and fatty deposits surround the existing plaque. Eventually, the arteries harden, leading to a condition called atheroscleorosis. Coronary atherosclerosis often has no symptoms, so heart attacks and death may occur suddenly, with little or no warning.

As time passes, plaque buildup narrows the vessel and restricts the flow of blood to the heart. In some cases, the plaque buildup completely blocks the artery. The reduced blood flow means less oxygen goes to the heart. This lack of oxygen can lead to:

• angina pectoris (Heart pain)
• myocardial infraction (heart attack)

Coronary artery disease is the most prevalent form of disease in Europe and in North America, taking about 150,000 lives a year.

Unfortunately, it can be difficult for doctors to detect blocked heart arteries. They are small structures in constant motion, and do not appear on x-ray images or regular ultrasound techniques. Doctors typically “guess” the existence of atherosclerosis by assesing risk factors in a patient. Risk factors for atherosclerosis include:

• Cigarette smoking
• High cholesterol
• Diabetes
• Age (women over 55; men over 45)
• Family history of heart disease
• Obesity

However, risk factor assessment is not a foolproof technique. Statistics reveal that many cases of atheroscelrosis occur in the average-risk segment of the population. Thus, many cases of atherosclerosis are missed. Meanwhile, people in the “high risk” category may never develop coronary disease at all.

Other tests exist to predict the existence of blocked arteries, but these tests are not ideal. Stress tests, for example, reveal blockages that have enlarged to the point where they are affecting the blood supply to the heart; such tests cannot detect blockages in their earliest stages, when they can still be treated.

Another type of test, called an angiogram, can detect plaque on arterial walls, but this is an expensive and time-consuming test that, again, requires the blockage to have enlarged slightly.