Background: In patients with coronary artery disease who are being evaluated for percutaneous coronary intervention (), procedures can be guided by fractional flow reserve (FFR) or intravascular ultrasonography (IVUS) for decision making regarding revascularization and stent implantation. However, the differences in clinical outcomes when only one method is used for both purposes are unclear.
Methods: We randomly assigned 1682 patients who were being evaluated for PCI for the treatment of intermediate stenosis (40 to 70% occlusion by visual estimation on coronary angiography) in a 1:1 ratio to undergo either an FFR-guided or IVUS-guided procedure. FFR or IVUS was to be used to determine whether to perform PCI and to assess PCI success. In the FFR group, PCI was to be performed if the FFR was 0.80 or less. In the IVUS group, the criteria for PCI were a minimal lumen area measuring either 3 mm2 or less or measuring 3 to 4 mm2 with a plaque burden of more than 70%. The primary outcome was a composite of death, myocardial infarction, or revascularization at 24 months after randomization. We tested the noninferiority of the FFR group as compared with the IVUS group (noninferiority margin, 2.5 percentage points).
我们以1∶1的比例将因中度狭窄（冠状动脉造影目测40%～70%堵塞）接受PCI治疗评估的1,682例患者随机分组，分别接受FFR指导PCI或IVUS指导PCI。FFR或IVUS用于确定是否进行PCI并评估PCI成功与否。在FFR组中，如果FFR≤0.80，则进行PCI。在IVUS组中，PCI标准是最小管腔面积≤3 mm2或最小管腔面积为3～4 mm2并且斑块负荷＞70%。主要结局是随机分组后24个月时由死亡、心肌梗死或血运重建构成的复合结局。我们检验了FFR组与IVUS组相比的非劣效性（非劣效性界值，2.5个百分点）。
Results: The frequency of PCI was 44.4% among patients in the FFR group and 65.3% among those in the IVUS group. At 24 months, a primary-outcome event had occurred in 8.1% of the patients in the FFR group and in 8.5% of those in the IVUS group (absolute difference, -0.4 percentage points; upper boundary of the one-sided 97.5% confidence interval, 2.2 percentage points; P = 0.01 for noninferiority). Patient-reported outcomes as reported on the Seattle Angina Questionnaire were similar in the two groups.
Conclusions: In patients with intermediate stenosis who were being evaluated for PCI, FFR guidance was noninferior to IVUS guidance with respect to the composite primary outcome of death, myocardial infarction, or revascularization at 24 months. (Funded by Boston Scientific; FLAVOUR ClinicalTrials.gov number, NCT02673424.).