Bon-Kwon Koo, M.D., Xinyang Hu, M.D., Jeehoon Kang, M.D., Jinlong Zhang, M.D., Jun Jiang, M.D., Joo-Yong Hahn, M.D., Chang-Wook Nam, M.D., Joon-Hyung Doh, M.D., Bong-Ki Lee, M.D., Weon Kim, M.D., Jinyu Huang, M.D., Fan Jiang, M.D., Hao Zhou, M.D., Peng Chen, M.D., Lijiang Tang, M.D., Wenbing Jiang, M.D., Xiaomin Chen, M.D., Wenming He, M.D., Sung-Gyun Ahn, M.D., Myeong-Ho Yoon, M.D., Ung Kim, M.D., Joo-Myung Lee, M.D., Doyeon Hwang, M.D., You-Jeong Ki, M.D., Eun-Seok Shin, M.D., Hyo-Soo Kim, M.D., Seung-Jea Tahk, M.D., and Jian’an Wang, M.D. for the FLAVOUR Investigators*
From Seoul National University Hospital (B.-K.K., J.K., D.H., H.-S.K.), Samsung Medical Center (J.-Y.H., J.-M.L.), and Kyung Hee University Hospital (W.K.), Seoul, Keimyung University Dongsan Medical Center (C.-W.N.) and Yeungnam University Medical Center (U.K.), Daegu, Inje University Ilsan Paik Hospital, Goyang (J.-H.D.), Kangwon National University Hospital, Chuncheon (B.-K.L.), Wonju Severance Christian Hospital, Wonju (S.-G.A.), Ajou University Hospital, Suwon (M.-H.Y., S.-J.T.), Uijeongbu Eulji Medical Center, Uijeongbu (Y-.J.K.), and Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan (E.-S.S.) — all in South Korea; the Second Affiliated Hospital, Zhejiang University School of Medicine (X.H., J.Z., J.J., J.W.), Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine (J.H.), Hangzhou Normal University Affiliated Hospital (F.J.), and Zhejiang Hospital (L.T.), Hangzhou, the First Affiliated Hospital of Wenzhou Medical University (H.Z.), the Second Affiliated Hospital of Wenzhou Medical University (P.C.), and the Third Clinical Institute Affiliated to Wenzhou Medical University (W.J.), Wenzhou, and Ningbo First Hospital (X.C.) and the Affiliated Hospital of the Medical School of Ningbo University (W.H.), Ningbo — all in China.
Drs. Koo, Hu, and Kang contributed equally to this article.
corresponding authors: Seung-Jea Tahk, Jian'an Wang
Background: In patients with coronary artery disease who are being evaluated for percutaneous coronary intervention (PCI), 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).
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.).