VASCULAR REMODELING IN CORONARY-ARTERY DISEASE

Traditionally, the diagnosis of significant coronary atherosclerotic d isease has relied on angiographic techniques. Both histologic analyses and, more recently, intravascular ultrasonography techniques have rev ealed that a significant atherosclerotic plaque load may be present in epicardial coronary arteries without significant luminal narrowing, c onsistent with compensatory vessel enlargement or remodeling. In patie nts with coronary atherosclerosis, more limited structural changes are present in the smaller resistance arterioles, whereas a decrease in l uminal area with an increase in wall thickness and perivascular fibros is are the characteristic structural changes observed in resistance ar teries in the presence of systemic hypertension. Further, functional c hanges, such as impairment of endothelium-mediated vasodilation, are p resent in epicardial and resistance Vessels of patients with coronary atherosclerosis and may influence the progression of this disease and development of ischemic syndromes. The introduction of two-dimensional intravascular and Doppler ultrasonography enables us to study in vivo these morphologic and functional changes. In this article, the knowle dge acquired in humans on the mechanisms and clinical relevance of vas cular remodeling with the use of these two ultrasonography-based techn iques is reviewed. The possibility of using pharmacologic intervention s to improve or normalize the vascular response to endothelium-depende nt and independent vascular interventions is discussed, with special a ttention to the efficacy of the inhibition of the angiotensin-converti ng enzyme.