Abstract 13620: Comparison of Endothelial Shear Stress (ESS) Computation Utilizing Non-Invasive Coronary Computed Tomography Angiography (CCTA) vs Invasive Intravascular Ultrasound (IVUS) Imaging

Abstract

Introduction: Risk-stratification of individual coronary plaques is an important goal to detect high-risk plaques likely to progress/destabilize, which could inform preemptive intervention to prevent adverse cardiac events. IVUS imaging, the current gold standard to assess plaque risk, has shown that biomechanical variables, particularly local ESS, contributes critical synergistic prognostic insight when combined with anatomic high-risk plaque features. Non-invasive risk assessment of coronary plaques with CCTA would be invaluable to enable broad population risk screening, but it is unknown whether CCTA, which has less spatial resolution than IVUS, can adequately measure the critical local biomechanical and anatomic variables. Aim: To compare the accuracy of ESS computation of local ESS metrics by non-invasive CCTA vs invasive IVUS imaging. Methods: We analyzed 30 arteries (22 LAD, 4 LCx,4 RCA) from 30 patients selected from a registry of patients who underwent both IVUS and CCTA of the same artery for suspected CAD. CCTA images were acquired using a CCTA with either 64 or 256 detector rows. We segmented lumen, vessel, and plaque areas with both IVUS (manual segmentation) and CCTA (AI based software; Cleerly Inc, NY). Co-registration of IVUS and CCTA Images was performed using fiduciary anatomic landmarks. Images from IVUS and CCTA were used to generate a 3-D arterial reconstruction, and local ESS distribution was assessed by computational fluid dynamics and reported in consecutive 3-mm segments. Results: Table Conclusion: Compared to IVUS values, 256-slice is more accurate than 64-slice CCTA to measure lumen and vessel areas, but computation of detailed local ESS (average, low and high) is similar by both CCTA methods. Local ESS evaluation using non-invasive CCTA is feasible and comparable to invasive gold standard IVUS and is suitable to characterize the local flow patterns that play an important role in plaque development, progression, and destabilization