People often think of atherosclerotic disease as a problem that primarily afflicts developed Western countries, but it is a global health problem. It is estimated that 80% of deaths from cardiovascular disease worldwide occur in low-income and middle-income countries. Cardiovascular disease is the number one cause of death worldwide, and it has become the leading cause of death in many developing countries. Cardiovascular disease in developing countries currently claims an estimated 12 billion lives annually, and the toll that it takes continues to climb. The high mortality is partly due to lack of access to care in many areas, but the problem will not be solved by better medical care. In the United States cardiovascular disease continues to claim about 800,000 deaths per year, despite the widespread use of statins to lower cholesterol and angioplasty to open blocked blood vessel.

Atherosclerosis is a complex process by which arteries become progressively narrowed, impairing the supply of oxygen and nutrients to tissues. Impaired blood flow can result in ischemia and cause symptoms such as angina or intermittent claudication. Atherosclerotic plaques can also rupture, triggering acute formation of a clot and an abrupt loss of blood supply to tissues that results in infarction. Eventually, progression of atherosclerosis can manifest itself clinically in three general ways:

Learning Objectives

After successfully completing this section, the student will be able to:

> The response to injury theory.

> The role of inflammation.

> The role of lipoproteins (LDL).

> The role of smooth muscle cell proliferation.

> The role of clotting of blood.

> The importance of "plaque stability".