CORONARY-ARTERY REMODELING IN ATHEROSCLEROTIC DISEASE - AN INTRAVASCULAR ULTRASONIC STUDY IN-VIVO

Background: Pathologic studies have revealed that coronary arteries un dergo compensatory enlargement in the presence of atherosclerosis. Met hods: In order to assess coronary artery remodeling in vivo, we used i ntravascular ultrasound to examine 46 patients (36 men and 10 women; a ged 58.2 +/- 6.8 years) with non-calcified plaques. The vessel, lumen, and plaque areas of the atherosclerotic and of normal proximal and di stal segments were determined. Results: A total of 92 atherosclerotic segments were analyzed. The degree of stenosis ranged from 9.2 to 92.8 % (mean 34.1 +/- 16.9%) and the plaque area from 2 to 19.6 mm2 (mean 6 .3 +/- 3.6 mm2). The vessel area of the atherosclerotic segment (mean 20.4 +/- 7.3 MM2) was larger than that of the proximal segment (mean 1 8.7 +/- 7.3 MM2, P = 0.018). The vessel area increased in proportion t o plaque area. This relationship can be described using the equation y = 23.5(1 - e-0.35x). The difference between the vessel area in the at herosclerotic segment and that in the proximal normal segment correlat ed with the percentage of stenosis (r = 0.53, P < 0.005) until the deg ree of stenosis exceeded 45%. Conclusion: This study indicates that co ronary artery remodeling, previously observed in pathologic studies, c an be evaluated using intravascular ultrasound in vivo. As a result of the compensatory enlargement of the vessel, coronary angiography cann ot be used to detect or exclude the early signs of coronary atheroscle rosis.