Plaque is a collection of excess cholesterol covered by a scar that is deposited on artery walls. In most cases, this buildup results after years of having high cholesterol. The largest buildups are most likely to cause angina. Small buildups of plaque are thought to be unstable and more likely to rupture, releasing their contents into the bloodstream, possibly causing a blood clot that may trigger a heart attack.

Plaque: An Overview

When talking about cholesterol and heart disease, it is helpful to understand plaque. The effect of plaque buildup in the arteries is the main cause of heart disease and heart attacks in people with high cholesterol.

 

How Does Plaque Develop?

Cholesterol is a major ingredient in the plaque that builds up in the coronary arteries (the blood vessels that supply blood to the heart) and causes heart disease.

 

Excess cholesterol is deposited on the artery walls as it travels through the bloodstream. Then, special cells in the artery wall gobble up this excess cholesterol, creating a "bump" in the artery wall. This cholesterol-rich "bump" then is covered by a scar that produces a hard coat or shell over the cholesterol and cell mixture. It is this collection of cholesterol covered by a scar that is called plaque. The buildup of plaque is known as atherosclerosis.

 

Impact of Plaque

The plaque buildup narrows the space in the coronary arteries through which blood can flow, decreasing the supply of oxygen and nutrients to the heart. If not enough oxygen-carrying blood can pass through the narrowed arteries to reach the heart muscle, the heart may respond with a pain called angina. The pain is often felt during exercise, when the heart needs more oxygen. It is typically felt in the chest or sometimes in other places, like the left arm and shoulder. This same inadequate blood supply, however, may cause no symptoms.

 

This plaque buildup does not occur over days, weeks, or months. Plaque buildup, in most cases, occurs over many years.

 

Size and Shapes of Plaque

Plaque comes in various sizes and shapes. Throughout the coronary arteries, many small buildups of plaque build themselves into the walls of the arteries, blocking less than half of the artery opening. These small buildups are often invisible on many of the tests doctors use to identify coronary heart disease.

 

It used to be thought that the most dangerous buildups of plaque -- and the ones most likely to cause total blockage of coronary arteries -- were the largest ones. The largest buildups of plaque are, in fact, the ones most likely to cause angina. But small buildups of plaque that are full of cholesterol and covered by a scar are now thought to be highly unstable and more likely to rupture or burst, releasing their cholesterol contents into the bloodstream. When this happens, it triggers blood clotting inside the artery. If the blood clot totally blocks the artery, it stops blood flow and a heart attack occurs. The muscle on the far side of the blood clot does not get enough oxygen and begins to die. The damage can be permanent.

 

Reducing Plaque Buildup

Lowering cholesterol levels can slow, stop, or even reverse the buildup of plaque. This can reduce your risk of a heart attack by lowering the cholesterol content in unstable plaque, making it more stable and less prone to rupture. This is why lowering your LDL cholesterol is such an important part of reducing your risk of a heart attack. Even in people who have had one heart attack, the chances of having future attacks can be substantially reduced by lowering cholesterol.