RESUMO
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/REEM0.05). 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.