The way to dusty death?

A s cardiologists know to their cost, the course of coronary artery disease is highly unpredictable. Although the disease accounts for about 20% of all deaths in developed countries and high levels of morbidity, in most cases the disease is clinically silent. Autopsy studies reveal that more than half of all people over the age of 60 and over a quarter of adults under this age have coronary artery disease. Even when this is manifest as angina, the annual event rate is only about 3%. When adverse events occur, however, they usually do so without apparent cause and without warning. About half of the deaths due to coronary artery disease are sudden and, of these, half are due to plaque rupture and intracoronary thrombosis. In the remainder, although severe coronary artery disease is often present, no evidence of thrombus is found at autopsy and the cause of death is believed to be arrhythmic. If most adult residents of the western world are walking around with coronary artery disease, what are the factors that determine whether, on any given day, the disease remains silent or presents with an acute coronary syndrome or sudden arrhythmic death? Could external environmental factors increase the chances of plaque rupture or arrhythmia? If so, what are the mechanisms?