Abstract 11768: Role of Endothelial Shear Stress and Endothelial Shear Stress Gradient in Plaques Associated With Acute Erosion vs. Stable Control Plaques and Relationship Between Plaque Slope and Localization of Plaque Erosion

Abstract

Introduction: The role of endothelial shear stress (ESS) in the development of coronary plaque erosion is unknown. High ESS gradient (ESSG) has been hypothesized to promote plaque erosion, but no studies have included matched control stable plaques with the same minimal and reference lumen area (MLA, RLA, respectively). No studies examined the location of plaque erosion (proximal vs distal to MLA of the culprit plaque) related to the max magnitude of upslope vs downslope of the lumen obstruction. Aims: (1) to compare ESSG between plaques with erosion and similar control plaques that remained stable; (2) among erosion plaques, to study the effect of max slope steepness (Δ lumen area/frame) up- and down-stream from the culprit plaque MLA on thrombus location. Methods: We studied 46 patients from TOTAL and COMPLETE trials who underwent angiography and OCT imaging: 46 arteries: 27 LAD, 6 LCX, 13 RCA. Plaques were divided into Plaque Erosion (n=24) with OCT features of erosion before PCI (17 definite, 7 probable erosion) and matched coronary plaques from separate control patients (n=22) without plaque disruption. Orthogonal angiographic views were used to generate a 3-D arterial reconstruction, and angio centerline was combined with OCT centerline. Local ESS distribution was assessed by computational fluid dynamics and reported in consecutive 3-mm segments. Among the plaque erosions, we calculated the up- and down-slope (Δ lumen area/frame) of lumen obstruction for each culprit plaque. Results: See Table Conclusion: In plaques with similarly severe obstruction, plaque erosion is associated with higher max ESS and max ESSG vs plaques that remain stable. Proximal plaque erosion/thrombus is associated with steeper plaque upslope vs downslope, and distal plaque erosion/thrombus is associated with steeper plaque downslope vs upslope. Absolute ESSG is higher in downslope vs upslope erosions. These features may help prognosticate individual plaques at risk for future erosion.