Comparison between Adaptive Arterial Remodeling and Inadequate Arterial Remodeling Assessed by Intravascular Ultrasound

Seo, Jeong Kee; Park, Keum Soo; Hong, Eui Soo; Lee, Hyo Jung; Kim, Dae Hyeok; Cho, Seong Wook; Kwan, Jun; Lee, Woo Hyung

Abstract

OBJECTIVES
Adaptive arterial remodeling (AAR) is a process to maintain luminal patency despite atherosclerotic plaque accumulation, whereas some of the lesions undergo a negative remodeling (vessel shrinkage), namely inadequate arterial remodeling (IAR). Histopathologic and intravascular ultrasound (IVUS) studies have shown lumen compromise is delayed until the atherosclerotic lesion occupies more than an estimated 40% to 50% of the potential area within the internal elastic lamina and proposed contributors to lumen compromise are medial and adventitial damage, superficial calcification, apoptosis. However the precise mechanisms and factors leading to these two vascular remodeling patterns are still unclear. The aim of this study is to investigate the effect of plaque accumulation on compensatory dilatation in arterial remodeling and their relationship according to their remodeling patterns.
METHODS
Preinterventional intravascular ultrasound images of 56 focal, de novo native and nonosteal lesions on coronary angiography were obtained. Cross sectional area of external elastic membrane (LEEM), Minimal lumen (MLA) and plaque plus media (P&M; P&M=EEM- MLA) in the target lesions were measured. Cross sectional area of external elastic membrane (REEM) and lumen (RLA) in proximal reference segments were measured. The lesions were divided into two groups according to their remodeling patterns ; adequate arterial remodeling (LEEM/REEM>0.78) and inadequate arterial remodeling (LEEM/REEM< or =0.78).
RESULTS
1) Forty-three patients (34 men, 9 women; mean age 58+/-11 years) who had not undergone previous coronary intervention were studied. 2) Adaptive arterial remodeling was observed in 47 (84%) of 56 lesions and inadequate arterial remodeling in 9 (16%). 3) No significant difference of clinical diagnosis, risk factors including hypertension, diabetes mellitus, smoking and lipid profiles was found between AAR and IAR group. 4) P&M/RLA of AAR was significantly higher than that of IAR (1.21+/-0.41 vs 0.91+/-0.23; p<0.001), whereas reference area stenosis (r-AST%) of AAR was significantly lower than that of IAR (59.8+/-23.0 vs 80.1+/-9.5; p<0.001). 5) In AAR group, P&M/RLA showed more significant correlation with LEEM/REEM (r=0.66, p<0.001) than r-AST% (r=0.36, p<0.05). 6) In IAR group, P&M/RLA showed significant correlation with r-AST% (r=0.79, p<0.05) but no correlation with LEEM/REEM (r=0.07, p>0.05).
CONCLUSION
In adaptive arterial remodeling, the amount of plaque accumulation seems to be an important determinant of compensatory arterial dilatation and contribute weakly to stenosis severity. On the contrary, in inadequate arterial remodeling, it seems to contribute greatly to stenosis severity.