A New Paradigm for Plaque Stabilization

The concept of plaque stabilization was developed to explain how lipid lowering could decrease adverse coronary events without a substantial reduction in the regression of atherosclerosis. Plaques were stabilized by reducing serum cholesterol leading to several favorable pathobiological changes in the vessel wall of lipid-rich plaques responsible for a majority of acute coronary events. However, this concept is limited for several reasons including that it does not incorporate strategies directed against either plaques that have already destabilized or non-lipid-rich plaques, which are the substrate for at least one third of major coronary thrombi and may or may not be stabilized by lipid lowering. For the destabilized plaque with overlying thrombus, either percutaneous intervention, long-term antithrombotic and/or anticoagulant therapy, or possibly aggressive lipid lowering stabilizes lesions by reducing subsequent thrombosis at the lesion site and, at least with lipid lowering, by improving endothelial function and possibly reducing inflammation. Short-term, in-hospital antithrombotic approaches alone with agents like the GP platelet IIb/IIIa inhibitors have not been effective in this situation. For other plaques not presently destabilized, the main goal of therapy is reducing future acute coronary events. Several classes of drugs, including ACE inhibitors, beta-blockers, and antithrombotic agents in addition to lipid-lowering agents, reduce events, and this may be attributable, at least in part, to plaque-stabilizing effects.