Department of Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK; Insigneo Institute for In-silico Medicine, Sheffield, UK; Department of Cardiology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
J Biomech. 2020 Apr 16;103:109698. doi: 10.1016/j.jbiomech.2020.109698. Epub 2020 Feb 26.
Recent efforts have demonstrated the ability of computational models to predict fractional flow reserve from coronary artery imaging without the need for invasive instrumentation. However, these models include only larger coronary arteries as smaller side branches cannot be resolved and are therefore neglected. The goal of this study was to evaluate the impact of neglecting the flow to these side branches when computing angiography-derived fractional flow reserve (vFFR) and indices of volumetric coronary artery blood flow. To compensate for the flow to side branches, a leakage function based upon vessel taper (Murray's Law) was added to a previously developed computational model of coronary blood flow. The augmented model with a leakage function (1D) and the original model (1D) were then applied to predict FFR as well as inlet and outlet flow in 146 arteries from 80 patients who underwent invasive coronary angiography and FFR measurement. The results show that the leakage function did not significantly change the vFFR but did significantly impact the estimated volumetric flow rate and predicted coronary flow reserve. As both procedures achieved similar predictive accuracy of vFFR despite large differences in coronary blood flow, these results suggest careful consideration of the application of this index for quantitatively assessing flow.
最近的研究表明，计算模型能够在无需进行有创仪器检测的情况下，通过冠状动脉成像预测分流量储备。然而，这些模型仅包括较大的冠状动脉，因为较小的侧支分支无法解析，因此被忽略了。本研究旨在评估在计算血管造影衍生的分流量储备（vFFR）和容积冠状动脉血流指数时忽略这些侧支分支的血流的影响。为了补偿侧支分支的血流，基于血管变细（Murray 定律）的泄漏函数被添加到之前开发的冠状动脉血流计算模型中。然后，将具有泄漏函数的增强模型（1D）和原始模型（1D）应用于预测 80 名接受有创冠状动脉造影和 FFR 测量的患者的 146 条动脉的 FFR 以及入口和出口流量。结果表明，泄漏函数并没有显著改变 vFFR，但却显著影响了估计的容积血流量和预测的冠状动脉储备。尽管冠状动脉血流量存在较大差异，但这两种方法在预测 vFFR 方面都取得了相似的准确性，这表明在定量评估血流时需要仔细考虑该指数的应用。
