California Medical Innovation Institute, San Diego, CA, USA.
Cardiovascular Division, University of Nebraska Medical Center, Omaha, NE, USA.
Comput Methods Programs Biomed. 2022 Apr;216:106674. doi: 10.1016/j.cmpb.2022.106674. Epub 2022 Feb 1.
Fractional flow reserve (FFR) is the gold standard for quantification of coronary stenosis and pressure wire is the gold standard for measuring FFR. Recently, computational fluid dynamics (CFD) methods have been used to compute FFR less invasively using images obtained from coronary angiography. This approach is, however, computationally intensive and solutions to reduce computation time are clearly required.
We hypothesized that FFR can be calculated instantly using a reduced order model (ROM) derived using response surface method (RSM) for simulation modeling in lieu of the computationally intensive CFD. Specifically, eleven physiological and anatomical factors known to affect FFR were selected as input variables, and Plackett-Burman analysis was performed in conjunction with CFD on model arteries to identify set of variables affecting FFR the most. Based on the Box-Behnken design, a mathematical model was developed to compute FFR using the retained set of variables.
The model fidelity was tested on a cohort of 90 patients (100 coronary arteries) with known pressure-wire FFR. FFR derived from this ROM had a strong correlation with pressure-wire FFR with sensitivity of 89.4%, specificity of 100% and area under curve of 0.947 (p < 0.05).
The ROM method can be used to reliably calculate FFR in patients with coronary stenosis and able to replace time-consuming CFD-based FFR estimation and provide instead a real-time calculation method.
分流量比值（FFR）是量化冠状动脉狭窄的金标准，压力导丝是测量 FFR 的金标准。最近，计算流体动力学（CFD）方法已被用于使用冠状动脉造影获得的图像进行 FFR 的无创计算。然而，这种方法计算量很大，显然需要解决方案来减少计算时间。
我们假设可以使用响应面法（RSM）衍生的降阶模型（ROM）来即时计算 FFR，而不是使用计算密集型的 CFD。具体来说，选择了 11 个已知会影响 FFR 的生理和解剖因素作为输入变量，并在模型动脉上结合 CFD 进行 Plackett-Burman 分析，以确定最能影响 FFR 的变量集。基于 Box-Behnken 设计，开发了一个使用保留变量集计算 FFR 的数学模型。
该模型的准确性在一组已知压力导丝 FFR 的 90 名患者（100 条冠状动脉）中进行了测试。该 ROM 得出的 FFR 与压力导丝 FFR 具有很强的相关性，灵敏度为 89.4%，特异性为 100%，曲线下面积为 0.947（p<0.05）。
ROM 方法可用于可靠地计算有冠状动脉狭窄的患者的 FFR，能够替代耗时的基于 CFD 的 FFR 估计，并提供实时计算方法。
