Coronary thrombosis. Illustration of the human heart and coronary artery during a heart attack caused by obstruction of the coronary artery. The right-hand part of the heart muscle has died (myo- cardial infarction, white area) as a result of interruption of its blood supply through the coronary artery. The artery, shown expanded and in section, is blocked by a red blood clot that has formed where the wall is narrowed by fatty deposits (atheroma, yellow). Coronary artery disease is the single most common cause of death in developed countries. Only 35-40% of heart attack sufferers survive more than a year after an attack.