Key result
Atherosclerotic lesions show ~25% lower mean endothelial shear stress than non-atherosclerotic segments on CCTA.
Why the study?
Because in vivo measurement of endothelial shear stress is not possible, it must be calculated using computational fluid dynamics; this study assessed the feasibility of CFD models from CCTA using individualized blood viscosity and pulsatile flow.
Does endothelial shear stress differ between atherosclerotic and non-atherosclerotic vessel segments when estimated using CFD models from CCTA?
Observational (n=25)
Does endothelial shear stress differ between atherosclerotic and non-atherosclerotic vessel segments when estimated using CFD models from CCTA?
Absolute Event Rate: 5% vs 6.7%
p-value: p=0.008
CFD simulations from CCTA using individualized flow profiles are feasible and demonstrate that endothelial shear stress is significantly lower in atherosclerotic lesions compared to non-atherosclerotic segments.
Lower ESS in lesions supports hemodynamic hypotheses; leaves open causal confirmation and clinical utility of CCTA-CFD.
INTRODUCTION: Endothelial shear stress (ESS) is a local hemodynamic factor that is dependent on vessel geometry and influences the process of atherogenesis. As in vivo measurements of ESS are not possible, it must be calculated using computational fluid dynamics (CFD). In this feasibility study we explore CFD-models generated from coronary CT-angiography (CCTA) using an individualised blood viscosity and a pulsatile flow profile derived from in vivo measurements. MATERIALS AND METHODS: We retrospectively recruited 25 consecutive patients who received a CCTA followed by a coronary angiography including intravascular ultrasound (IVUS) and generated 3D models of the coronary arteries from the CT-datasets. We then performed CFD-simulations on these models. Hemodynamically non-relevant stenosis were identified in IVUS. They were isolated in the CFD-model and separated longitudinally into a half with atherosclerotic lesion (AL) and one without (NAL). ESS was measured and compared for both halves. RESULTS: After excluding vessels with no IVUS data or relevant stenosis we isolated 31 hemodynamically non-relevant excentric AL from a total of 14 vessels. AL segments showed consistently significantly lower ESS when compared to their corresponding NAL segments when regarding minimum (0.9 Pa, CI [0.6, 1.2] vs. 1.3 Pa, CI [0.9, 1.8]; p = 0.004), mean (5.0 Pa, CI [3.4, 6.0] vs. 6.7 Pa, CI [5.5, 8.4]; p = 0.008) and maximum ESS values (12.4 Pa, CI [8.6, 14.6] vs. 19.6 Pa, CI [12.4, 21.0]; p = 0.005). Qualitatively ESS was lower on the inside of bifurcations and curvatures. CONCLUSION: CFD simulations of coronary arteries from CCTA with an individualised flow profile and blood viscosity are feasible and could provide further prognostic information and a better risk stratification in coronary artery disease. Further prospective studies are needed to investigate this claim.
No takes yet. Share an insight, caveat, or question.
Curta et al. (2021) conducted an observational in Coronary artery disease (n=25). Atherosclerotic lesion (AL) segments vs. Non-atherosclerotic lesion (NAL) segments was evaluated on Mean endothelial shear stress (ESS) (p=0.008). Atherosclerotic lesion segments showed significantly lower mean endothelial shear stress compared to non-atherosclerotic segments (5.0 Pa vs. 6.7 Pa; p=0.008) in CCTA-derived CFD models.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: