[Progression and regression of atherosclerotic plaques. New results based on intracoronary ultrasound].

Intravascular ultrasound has been established as the gold standard for analyzing alterations in coronary artery atherosclerosis during monitoring investigations. Cross-sectional imaging can be used to visualize the area of the lumen and the vessel size and the plaque size as the difference between them. New technology allows the 3-D reconstruction of the volume for prespecified vessel segments using specific algorithms. Investigations on the natural course demonstrated predominantly progression. Even regression of coronary atherosclerosis can be visualized and quantified. Regression can only be expected when the level of low-density lipoprotein (LDL) cholesterol is below the critical level of 75 mg/dl. Prospective randomized studies with highly effective statins showed that regression occurred in up to two thirds of patients when LDL cholesterol was below a cut-off of 78 mg/dl and was, therefore, very close to the threshold, which was calculated based on investigations of the natural course. Although the absolute values for plaque volume are in the range of 1 % over 1-2 years, it must be taken into consideration that coronary artery diseases are chronic diseases and a 1 % change per year will correspond to an enormous effect on plaque growth of coronary vessels. The great success of statins in reducing cardiovascular events is due to the possibility for reduction of progression and induction of regression. New developments in medication will be measured against the effectiveness of statins.