Mohdnazri Shah R, Keeble Thomas R, Sharp Andrew Sp
The Essex Cardiothoracic Centre, Basildon, UK.
Anglia Ruskin University, Chelmsford, UK.
Interv Cardiol. 2016 May;11(1):17-26. doi: 10.15420/icr.2016:7:2.
Fractional flow reserve (FFR) has been shown to improve outcomes when used to guide percutaneous coronary intervention (PCI). There have been two proposed cut-off points for FFR. The first was derived by comparing FFR against a series of non-invasive tests, with a value of ≤0.75 shown to predict a positive ischaemia test. It was then shown in the DEFER study that a vessel FFR value of ≥0.75 was associated with safe deferral of PCI. During the validation phase, a 'grey zone' for FFR values of between 0.76 and 0.80 was demonstrated, where a positive non-invasive test may still occur, but sensitivity and specificity were sub-optimal. Clinical judgement was therefore advised for values in this range. The FAME studies then moved the FFR cut-off point to ≤0.80, with a view to predicting outcomes. The ≤0.80 cut-off point has been adopted into clinical practice guidelines, whereas the lower value of ≤0.75 is no longer widely used. Here, the authors discuss the data underpinning these cut-off values and the practical implications for their use when using FFR guidance in PCI.
血流储备分数（FFR）已被证明用于指导经皮冠状动脉介入治疗（PCI）时可改善治疗结果。关于FFR有两个提议的临界值。第一个临界值是通过将FFR与一系列非侵入性检查进行比较得出的，结果显示FFR值≤0.75可预测缺血试验呈阳性。随后在DEFER研究中表明，血管FFR值≥0.75与安全推迟PCI相关。在验证阶段，证实了FFR值在0.76至0.80之间存在一个“灰色区域”，在此区域非侵入性检查仍可能呈阳性，但敏感性和特异性并不理想。因此，建议对该范围内的值进行临床判断。随后FAME研究将FFR临界值调整为≤0.80，旨在预测治疗结果。≤0.80的临界值已被纳入临床实践指南，而≤0.75这个较低的值不再被广泛使用。在此，作者讨论了支撑这些临界值的数据以及在PCI中使用FFR指导时其应用的实际意义。
