Acute coronary syndromes (ACS), a major cause of hospitalization in this country, is most often caused by plaque erosion or rupture leading to formation of an occlusive thrombus. Emerging data suggest that patients with ACS may derive benefit from aggressive statin treatment. Importantly, benefit may become evident early, within weeks. This monograph discusses the biological and physical interactions that, potentially, may be responsible for rapid passivation of disrupted or vulnerable plaques.