Abstract 4363: Combined in-vivo Assessment of Endothelial Shear Stress and Arterial Remodeling for the Prediction of High-Risk Plaque Formation: A Serial, Natural History IVUS Study
Background Endothelial shear stress (ESS) and arterial remodeling are critical determinants of the natural history of atherosclerosis. Our purpose was to investigate the predictive value of the in-vivo assessment of ESS and remodeling to identify high-risk coronary plaques.
Methods Serial IVUS-based 3D reconstruction of major coronary arteries (n=15) was performed in-vivo at weeks 4, 11, 16, 23 and 36 in 5 diabetic, hyperlipidemic pigs. Each artery was divided into 3 mm segments. Local ESS was calculated in all segments (n=304) using computational fluid dynamics. Vascular remodeling was characterized at all time points as excessive expansive, compensatory or constrictive. Plaque severity was assessed by maximal intima-media thickness (maxIMT) by IVUS. We considered segments with maxIMT>1.0mm and excessive expansive remodeling at week 36 to represent high-risk plaques. A composite grading score (Predictive Score) consisting of local ESS, maxIMT, and the remodeling pattern was employed for each individual segment and time point.
Results At week 36, segments displayed remarkable heterogeneity of plaque severity and remodeling. Segments culminating in high-risk plaques (n=12, 3.9%) exhibited higher maxIMT, progressively lower ESS and higher values of the Predictive Score at preceding weeks 11, 16 and 23 compared to all other segments (n=292, 96.1%) (Figures A–C⇓).
Conclusions High-risk coronary plaques exhibit accelerated progression and are exposed to diminishing ESS throughout their evolution. The combined assessment of local ESS, plaque severity, and remodeling may enable the early identification of regions destined to evolve to high-risk lesions.