Mechanisms of plaque stabilization with statins

The traditional view of cardiovascular disease held that the degree of stenosis defined high-risk lesions and that removal of cholesterol shrank these lesions and thereby enlarged the lumen. Advances in understanding of the pathophysiology of the acute coronary syndromes refute this view. We now appreciate that vascular biology determines plaque stability and that statins stabilize plaque by favorably altering this biology. They do so chiefly (but probably not exclusively) by cholesterol lowering. In addition to reducing the cholesterol content of plaque, lipid lowering inhibits inflammation, and decreases collagenolytic activity and thrombotic potential. The role of lipid-independent effects remains unclear because many studies used statin concentrations too high to have any clinical relevance. However, data suggest that statin-induced alterations in the function of small G proteins may contribute to the anti-inflammatory and antithrombotic actions of statins in clinical practice.