Type and extent of vascular remodeling in significant coronary lesions: Anintravascular ultrasound study

The purpose of this study was to assess the dimension of regional vascular remodeling and its influence on lumen narrowing in vivo. Sixty-three patien ts with 68 coronary lesions were imaged by intravascular ultrasound before transcatheter therapy. Quantitative measurements of lumen area, vessel area , and plaque area were performed at the lesion site and at the proximal and distal reference site. Area stenosis was calculated as plaque area/vessel area . 100. The extent of remodeling was quantified by a remodeling index ( RI = stenosis vessel area mean reference vessel area/mean reference vessel area 100). Additionally, three different groups of vascular remodeling were defined: 1) positive remodeling = stenosis vessel area > maximal reference vessel area; 2) intermediate remodeling = maximal reference vessel area 2 stenosis vessel area 2 minimal reference vessel area; 3) negative remodelin g = stenosis vessel area < minimal reference vessel area. In 57% of lesions stenosis vessel area was not inbetween the proximal and distal reference a rea: 29% of lesions (20/68) had positive, 28% (19/68) negative, and 33% (29 /68) intermediate remodeling. Overall remodeling index averaged -0.8 +/- 19 .7%. In the negative remodeling group, reduction of vessel area contributed to 40 +/- 21% of lumen narrowing, in the positive remodeling group, stenos is vessel area was 21 +/- 12% enlarged (p < 0.001). Lesions with negative r emodeling exhibit a lesser plaque area, lesions with positive remodeling a larger than other vessels (8.2 +/- 2.4 mm(2), 13.8 +/- 3.7 mm(2), 10.8 +/- 3.7 mm(2); p < 0.001). Distinct vascular remodeling occured in the majority of atheosclerotic lesi ons and is a bidirectional process. Overall, the extent and the frequency o f positive and negative remodeling was almost balanced. In lesions with neg ative remodeling the plaque area was significantly lesser than in other les ions.