BackgroundFractional flow reserve (FFR) has emerged as the invasive gold standard for assessing vessel‐specific ischemia. However, FFR measurements are influenced by the hydrostatic effect, which might adversely impact the assessment of ischemia.AimsThis study aimed to investigate the impact of hydrostatic pressure on FFR measurements by correcting for the height and comparing FFR with [15O]H2O positron emission tomography (PET)‐derived relative flow reserve (RFR).MethodsThe 206 patients were included in this analysis. Patients underwent coronary computed tomography angiography (CCTA), [15O]H2O PET, and invasive coronary angiography with routine FFR in every epicardial artery. Height differences between the aortic guiding catheter and distal pressure sensor were quantified on CCTA images. An FFR ≤ 0.80 was considered significant.ResultsThe study found a reclassification in 7% of the coronary arteries. Notably, 11% of left anterior descending (LAD) arteries were reclassified from hemodynamically significant to nonsignificant. Conversely, 6% of left circumflex (Cx) arteries were reclassified from nonsignificant to significant. After correcting for the hydrostatic pressure effect, the correlation between FFR and PET‐derived RFR increased significantly from r = 0.720 to r = 0.786 (p = 0.009). The average magnitude of correction was +0.05 FFR units in the LAD, −0.03 in the Cx, and −0.02 in the right coronary artery.ConclusionHydrostatic pressure has a small but clinically relevant influence on FFR measurements obtained with a pressure wire. Correcting for this hydrostatic error significantly enhances the correlation between FFR and PET‐derived RFR.

中文翻译：

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静水压对有创冠状动脉压力测量的影响：与[15O]H2O-正电子发射断层扫描血流数据的比较


背景血流储备分数（FFR）已成为评估血管特异性缺血的侵入性金标准。然而，FFR 测量受到静水效应的影响，这可能会对缺血的评估产生不利影响。目的本研究旨在通过校正高度并将 FFR 与 [15O]H2O 正电子发射断层扫描进行比较，研究静水压力对 FFR 测量的影响。 PET）衍生的相对血流储备（RFR）。方法本次分析纳入了 206 名患者。患者接受了冠状动脉计算机断层扫描血管造影 (CCTA)、[15O]H2O PET 和侵入性冠状动脉血管造影，并在每条心外膜动脉中进行常规 FFR。主动脉引导导管和远端压力传感器之间的高度差异在 CCTA 图像上进行量化。 FFR ≤ 0.80 被认为是显着的。结果研究发现 7% 的冠状动脉发生了重新分类。值得注意的是，11% 的左前降支 (LAD) 动脉从血流动力学显着性重新分类为不显着性。相反，6% 的左旋支 (Cx) 动脉从不重要重新分类为重要。校正静水压力影响后，FFR 和 PET 衍生的 RFR 之间的相关性从 r = 0.720 显着增加到 r = 0.786 (p = 0.009)。 LAD 中的平均校正幅度为 +0.05 FFR 单位，Cx 中为 -0.03 FFR 单位，右冠状动脉中为 -0.02。结论静水压对使用压力线获得的 FFR 测量值影响虽小，但具有临床相关性。纠正这种静水压力误差可显着增强 FFR 和 PET 衍生的 RFR 之间的相关性。