From Cardiovascular Research Center Aalst OLV Clinic, Aalst, Belgium (J.A., B.D.B., V.F., G.D.G., A.F., M.P., G.G.T., J.B., M.V., G.R.H., W.W., E.B.); Division of Cardiology, Department of Advanced Biomedical Sciences, University of Naples Federico II, Italy (G.D.G., M.P., E.B.); and University Heart Centre Graz, Medical University Graz, Austria (G.G.T.).
Circulation. 2016 Feb 2;133(5):502-8. doi: 10.1161/CIRCULATIONAHA.115.018747. Epub 2016 Jan 5.
The fractional flow reserve (FFR) value of 0.75 has been validated against ischemic testing, whereas the FFR value of 0.80 has been widely accepted to guide clinical decision making. However, revascularization when FFR is 0.76 to 0.80, within the so-called gray zone, is still debatable.
From February 1997 to June 2013, all patients with single-segment disease and an FFR value within the gray zone or within the 2 neighboring FFR strata (0.70-0.75 and 0.81-0.85) were included. Study end points consisted of major adverse cardiovascular events (death, myocardial infarction, and any revascularization) up to 5 years. Of 17 380 FFR measurements, 1459 patients were included. Of them, 449 patients were treated with revascularization and 1010 patients were treated with medical therapy. In the gray zone, the major adverse cardiovascular events rate was similar (37 [13.9%] versus 21 [11.2%], respectively; P=0.3) between medical therapy and revascularization, whereas a strong trend toward a higher rate of death or myocardial infarction (25 [9.4] versus 9 [4.8], P=0.06) and overall death (20 [7.5] versus 6 [3.2], P=0.059) was observed in the medical therapy group. Among medical therapy patients, a significant step-up increase in major adverse cardiovascular events rate was observed across the 3 FFR strata, especially with proximal lesion location. In revascularization patients, the major adverse cardiovascular events rate was not different across the 3 FFR strata.
FFR in and around the gray zone bears a major prognostic value, especially in proximal lesions. These data confirm that FFR≤0.80 is valid to guide clinical decision making.
0.75 的分比流量储备（FFR）值已经通过缺血性试验进行了验证，而 0.80 的 FFR 值被广泛接受用于指导临床决策。然而，在所谓的灰色区域内（即 0.76 到 0.80 之间），FFR 值为 0.76 到 0.80 时进行血运重建仍然存在争议。
从 1997 年 2 月到 2013 年 6 月，所有单节段病变且 FFR 值处于灰色区域或相邻两个 FFR 分层（0.70-0.75 和 0.81-0.85）内的患者都被纳入研究。研究终点为 5 年内主要不良心血管事件（死亡、心肌梗死和任何血运重建）。在 17380 次 FFR 测量中，有 1459 名患者被纳入。其中，449 名患者接受了血运重建治疗，1010 名患者接受了药物治疗。在灰色区域内，药物治疗和血运重建之间的主要不良心血管事件发生率相似（分别为 37[13.9%]和 21[11.2%]；P=0.3），但药物治疗组的死亡或心肌梗死发生率（25[9.4%]比 9[4.8%]，P=0.06）和全因死亡率（20[7.5%]比 6[3.2%]，P=0.059）有升高的趋势。在药物治疗患者中，随着 FFR 值逐渐升高，主要不良心血管事件发生率也呈显著上升趋势，尤其是在近段病变部位。在血运重建患者中，3 个 FFR 分层之间的主要不良心血管事件发生率没有差异。
灰色区域内及附近的 FFR 值具有重要的预后价值，尤其是在近段病变部位。这些数据证实，FFR≤0.80 可用于指导临床决策。
