Vulnerable Plaque in Heart Disease

Swelling (inflammation) is the body's natural reaction to an injury. Inflammation can happen anywhere on the skin, within the body, and even inside the arteries. Scientists are now learning inflammation may play a part in many of the diseases that come with aging, including coronary artery disease.

For many years, doctors have thought that the main cause of a heart attack or stroke or was the buildup of fatty plaque within an artery, leading to the heart or brain. In time, the plaque buildup would narrow the artery so much, that the artery would close off or become clogged by a blood clot. The lack of oxygen-rich blood to the heart would then lead to a heart attack. However these types of blockages cause only about 3 out of 10 heart attacks.

Researchers are finding people who that heart attacks do not have arteries severely narrowed by plaque! Vulnerable plaque may be buried inside the artery wall, and not bulge out and block the blood flow through the artery. This is why researchers began to look at how inflammation affects the arteries, and to see if inflammation could lead to a heart attack.

What they found was that inflammation leads to the development of "soft" or vulnerable plaque. They also found that vulnerable plaque was more than just debris, clogging an artery, that it was filled with different cell types that help with blood clotting.

When this inflammation is combined with other stresses, like high blood pressure, it can cause the thin covering over the plaque to crack and bleed, spilling the entire contents of the vulnerable plaque into the bloodstream. The sticky cytokines on the artery wall capture blood cells (mainly platelets) that rush to the site of injury. When these cells clump together, they can form a clot large enough to block the artery.