Remodeling of atherosclerotic coronary arteries varies in relation to location and composition of plaque

The aim of this study was to determine the contribution of morphologic char acteristics and location of plaque in remodeling of atherosclerotic coronar y arteries. Consecutive intravascular ultrasound studies performed in nativ e coronary arteries before an intervention were included in the study. Tota l vessel, lumen and plaque + media areas were measured at target lesion, an d distal and proximal references. Remodeling index was calculated as target total vessel area/proximal reference total vessel area, and categorized in to 3 groups based on relative total vessel-area ratio: (1) >1.1 (group A, a dequate remodeling); (2) 0.9 to 1.1 (group B, failure of compensatory enlar gement); and (3) <0.9 (group C, coronary shrinkage). Eighty-nine narrowings were assessed in 80 intravascular ultrasound studies. thirty-eight lesions (43%) were defined as soft and 51 (57%) as hard. Soft plaques were more pr evalent in group A than in groups B and C (p = 0.001). Conversely, the are of calcium was larger in group C lesions (p = 0.005). At distal segments, g roup A lesions were more prevalent than those in groups B and C, whereas at proximal segments group C lesions were more prevalent (p = 0.007). Multiva riate analysis identified the are of calcium and the location of plaque at distal segments as independent predictors of compensatory enlargement (odds ratio 0.94, 95% confidence interval 0.90 to 0.99; odds ratio 4.6; 95% conf idence interval 1.4 to 15.7, respectively), whereas hard plaques were on in dependent predictor of coronary shrinkage (odds ratio 4.6; 95% confidence i nterval 1.7 to 12.5). In conclusion, composition and location of plaque app eared to be major determinants of vessel remodeling during the process of a therosclerosis. (C) 1999 by Excerpta Medica, Inc.