Atherosclerosis
By Rear Adm. Joyce Johnson, D.O., M.A.

What is atherosclerosis?

Atherosclerosis is a disease of the blood vessels that contributes to about half of the deaths in the United States each year. Coronary artery disease is another term for atherosclerosis of the arteries of the heart. (Arteriosclerosis is a more general term describing thickening and hardening of the arteries; the two terms commonly refer to the same thing.)

Atherosclerosis is caused by a buildup of plaque—calcium, cellular waste products, cholesterol, and other fatty residues—in the arteries. When the inside of the artery (endothelium) is damaged by high cholesterol, high blood pressure, diabetes, smoking, natural aging, or other causes, the endothelium deposits more cellular substances.

Plaque inside the artery reduces the open diameter where blood can flow, affecting arteries in the extremities, heart, brain, and other vital organs. Over a period of years plaque eventually hardens, causing arteries to lose their elasticity and ability to respond to the pressure caused by the pumping heart. This stresses the vessel and, especially in someone with high blood pressure, can cause it to rupture and bleed. In the heart, this bleeding acutely reduces blood flow and can lead to a heart attack. In the brain, bleeding or reduced blood flow causes strokes or transient ischemic attacks (ministrokes, which are a sign of major disease and require follow-up medical care).

After a rupture, small pieces of plaque or dislodged blood clots can circulate in the bloodstream, where they are called emboli. Emboli can clog vessels and cause problems such as heart attacks or strokes.
Atherosclerosis generally has no symptoms until it is advanced and often is first recognized when someone experiences chest pain, a heart attack, or stroke. Some atherosclerosis is inevitable as we age, but we can limit it and reduce its consequences. Controlling cholesterol and other fat levels in the blood—through diet, exercise, and possibly medication—helps. Controlling blood pressure is critical and reduces the chances of heart attack and stroke. Anti-coagulants (such as a daily low-dose aspirin) might be appropriate to reduce the risk of blood clots. Diabetes should be diagnosed early and managed carefully.

When atherosclerosis becomes advanced, invasive treatments can minimize the acute affects. Balloon angioplasty can open a vessel. A stent can be inserted to keep an artery open. Plaque in the large carotid arteries leading to the brain often is surgically removed (endarterectomy). For more information, visit www.americanheart.com.