QUESTIONS & ANSWERS: GLOSSARY
Atherosclerosis
Disease of the arterial wall which narrows arteries including coronary arteries, where it causes coronary heart disease (CHD). The inside of the artery may be narrowed on one side, or around the whole circumference. This occurs irregularly in clumps called plaques, which contain inflammatory cells and lipid. Rupture of a plaque sets off the acute coronary thrombosis that causes heart attack (myocardial infarction) and unstable angina.
There are many theories about the causes of this disease. A recently popular theory was that it was caused by raised cholesterol in the blood. However, half the sufferers have normal cholesterol levels. A more all-embracing idea is that the fundamental problem is inflammation of the arterial wall, and that in some cases this is caused by infection with bacteria of viruses (New Scientist, 11 Jan 2003, 36-39). Inflammation of the endothelium, the lining cells of the inside of the arteries, is also caused by raised homocysteine levels.
We still favour the theory put forward in 1885 by von Rokitanski, which says that thrombosis is the common factor in the way this disease develops. There is evidence of activation of thrombosis in all cases. People with bleeding disease (their blood won’t clot) do not get atheroscelosis or CHD; people with increased tendency to platelet thrombosis get more CHD than the average person. Inflammation, in accordance with the previous paragraph also causes thrombosis. If we are right, measures which can stop internal thrombosis safely might stop atherosclerosis progressing.
The CTT spends a large proportion of its effort in research designed to settle these questions.