Progression of coronary arteriosclerosis as monitoring the therapeutic success of hyperlipidemia

Abstract

Coronary calcium represents an integral part of coronary atherosclerosis. It results from an actively regulated process and already appears in early stages of the disease. Studies using electron-beam computed tomography (EBCT) have demonstrated that an accelerated progression of coronary calcified atherosclerosis is associated with an increased rate of clinical events. In experimental animal models, effective lowering of LDL cholesterol stops the progression of coronary calcified atherosclerosis. A number of EBCT-derived retrospective analyses have consistently reported that LDL cholesterol values are the most important factor influencing the progression of coronary calcified atherosclerosis. In high-risk patients with no clinical coronary artery disease who were not specifically treated, a mean annual progression of coronary calcium of 52% was observed. In the presence of statin drug therapy, progression ranged from -7% through 22%, depending on the LDL cholesterol levels during therapy. A preliminary prospective investigation has confirmed these results and, in particular, suggested that reaching low LDL cholesterol levels < 100 mg/dl effectively stops the progression of coronary calcified atherosclerosis. LDL cholesterol independent ("pleiotropic") effects of statin drugs could not be demonstrated by using EBCT. At present, two large prospective, randomized trials are being conducted which analyze the effects of intensified versus standard statin drug therapy on the progression of coronary calcified atherosclerosis by EBCT. Serial EBCT studies enable analysis of the interaction between therapeutic measures, progression of coronary calcified atherosclerosis and clinical course of the patients by virtue of direct visualization of the activity of coronary plaque disease. This has already been successfully implemented in small patients groups. Validation in the individual patient is pending. Prospective, randomized therapeutic trials are expected to yield valuable knowledge for clinical practice.