Plaque regression and improved clinical outcomes following statin treatment in atherosclerosis

3-hydroxy-3-methylglutaryl-coenzymeA reductase inhibitors, or statins, represent an important class of agents that improve clinical outcomes in atherosclerotic cardiovascular disease. Aside from lowering total and low density lipoprotein cholesterol, statins have important pleiotropic effects that include anti-inflammatory, antioxidant, antithrombotic actions as well as mobilization of endothelial progenitor cells and modification of plaque cholesterol crystallization. These combined effects lead to atherosclerotic plaque stabilization that is both quantitative (slowing of plaque progression or plaque volume regression) as well as qualitative (reduced inflammation and amount of lipid rich necrotic plaque) in nature. Statins have been shown to reduce overall mortality when used for either primary or secondary prevention of cardiovascular disease in multiple randomized clinical trials, but such trials involve a large sample size, long treatment duration and enormous financial cost. Imaging of change in plaque burden by various means such as coronary angiography, intravascular and B mode ultrasound and magnetic resonance imaging represents a means of measuring surrogate endpoints by directly assessing statin effects on plaque regression. Multiple imaging studies have demonstrated plaque stabilization or regression with statin treatment that paralleled improvement in lipid profile and clinical outcomes, although it is unlikely that imaging modalities can replace hard clinical outcomes in assessing treatment efficacy.