How does an atheroma increase the risk of death?

An atheroma is defined as fatty material in the wall of an artery. This increases the risk of a blood clot forming in the artery. If a blood clot forms in a coronary artery, which supplies the heart muscle, there is reduced oxygen reaching these muscles of the heart. This results in cells of the heart muscles dying due to a lack of oxygen supply, meaning the heart contracts less. Less blood is pumped by the heart and this results in a heart attack, also known as a myocardial infarction. If an artery which supplies blood to the brain is blocked, this results in a stroke.