The document defines plaque rupture as the structural failure of the fibrocellular cap separating an atheromatous core from the lumen of an atherosclerotic artery. It then discusses factors that increase the propensity of plaque rupture like a lipid-rich core and lack of a fibrous cap. Several studies are summarized that show plaque rupture is the cause of fatal thrombosis in 75-100% of cases of acute MI and sudden cardiac death when examined post-mortem. The role of traditional risk factors like age, sex, cholesterol levels, and smoking in rupture vs. non-rupture cases is then assessed based on multiple studies.