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Abstract：
Objective: To present a novel pipeline for rapid and precise computation of fractional flow reserve from an analysis of routine two-dimensional coronary angiograms based on fluid mechanics equations (FFR2D). Material and methods: This was a pilot analytical study that was designed to assess the diagnostic performance of FFR2D versus the gold standard of FFR (threshold ≤ 0.80) measured with a pressure wire for the physiological assessment of intermediate coronary artery stenoses. In a single academic center, consecutive patients referred for diagnostic coronary angiography and potential revascularization between 1 September 2020 and 1 September 2022 were screened for eligibility. Routine two-dimensional angiograms at optimal viewing angles with minimal overlap and/or foreshortening were segmented semi-automatically to derive the vascular geometry of intermediate coronary lesions, and nonlinear pressure-flow mathematical relationships were applied to compute FFR2D. Results: Some 88 consecutive patients with a single intermediate coronary artery lesion were analyzed (LAD n = 74, RCA n = 9 and LCX n = 5; percent diameter stenosis of 45.7 ± 11.0%). The computed FFR2D was on average 0.821 ± 0.048 and correlated well with invasive FFR (r = 0.68, p < 0.001). There was very good agreement between FFR2D and invasive-wire FFR with minimal measurement bias (mean difference: 0.000 ± 0.048). The overall accuracy of FFR2D for diagnosing a critical epicardial artery stenosis was 90.9% (80 cases classified correctly out of 88 in total). FFR2D identified 24 true positives, 56 true negatives, 4 false positives, and 4 false negatives and predicted FFR ≤ 0.80 with a sensitivity of 85.7%, specificity of 93.3%, positive likelihood ratio of 13.0, and negative likelihood ratio of 0.15. FFR2D had a significantly better discriminatory capacity (area under the ROC curve: 0.95 [95% CI: 0.91-0.99]) compared to 50%DS on 2D-QCA (area under the ROC curve: 0.70 [95% CI: 0.59-0.82]; p = 0.0001) in predicting wire FFR ≤ 0.80. The median time of image analysis was 2 min and the median time of computation of the FFR2D results was 0.1 s. Conclusion: FFR2D may rapidly derive a precise image-based metric of fractional flow reserve with high diagnostic accuracy based on a single two-dimensional coronary angiogram.
摘要：
目的：通过基于流体力学方程（FFR2D）的常规二维冠状动脉造影分析，提出一种快速，精确计算血流储备分数的新方法。材料和方法：这是一项初步分析研究，旨在评估FFR2D的诊断性能与用压力导线测量的FFR金标准（阈值≤0.80）的诊断性能，以用于中度冠状动脉狭窄的生理评估。在一个学术中心，我们对2020年9月1日至2022年9月1日期间进行诊断性冠状动脉造影和潜在血运重建的连续患者进行了筛选.以最小重叠和/或缩短的最佳视角对常规二维血管造影照片进行半自动分割，以得出中间冠状动脉病变的血管几何形状。并将非线性压力-流量数学关系应用于计算FFR2D。结果：分析了约88例具有单个中度冠状动脉病变的连续患者（LADn=74，RCAn=9，LCXn=5；直径狭窄百分比为45.7±11.0％）。计算的FFR2D平均为0.821±0.048，与侵入性FFR密切相关（r=0.68，p<0.001）。FFR2D和侵入性导线FFR之间的一致性非常好，测量偏差最小（平均差：0.000±0.048）。FFR2D诊断严重心外膜动脉狭窄的总体准确性为90.9％（总共88例中有80例正确分类）。FFR2D确定了24个真阳性，56个真正的底片，4个假阳性，4个假阴性，预测FFR≤0.80，灵敏度为85.7%，特异性为93.3%，正似然比为13.0，负似然比为0.15。与2D-QCA的50％DS（ROC曲线下面积：0.70[95％CI：0.59-0.82]；p=0.0001）相比，FFR2D具有明显更好的判别能力（ROC曲线下面积：0.95[95％CI：0.91-0.99]）。图像分析的中位时间为2分钟，FFR2D结果的中位计算时间为0.1s。结论：FFR2D可以快速得出基于图像的精确血流储备分数度量，并且基于单个二维冠状动脉造影具有很高的诊断准确性。
