Author + information
- Received September 15, 2017
- Revision received October 13, 2017
- Accepted October 16, 2017
- Published online December 18, 2017.
- Bo Xu, MBBSa,
- Shengxian Tu, PhDb,∗∗ (, )
- Shubin Qiao, MDa,
- Xinkai Qu, MDc,
- Yundai Chen, MDd,
- Junqing Yang, MDe,
- Lijun Guo, MDf,
- Zhongwei Sun, MSca,
- Zehang Li, BScb,
- Feng Tian, MDd,
- Weiyi Fang, MDc,
- Jiyan Chen, MDe,
- Wei Li, PhDg,
- Changdong Guan, MSca,
- Niels R. Holm, MDh,
- William Wijns, MD, PhDi and
- Shengshou Hu, MDa,∗ ()
- aFu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Beijing, China
- bBiomedical Instrument Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
- cShanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
- dChinese PLA General Hospital, Beijing, China
- eGuangdong General Hospital, Guangzhou, China
- fPeking University Third Hospital, Beijing, China
- gMedical Research and Biometrics Center, National Center for Cardiovascular Diseases, Beijing, China
- hAarhus University Hospital, Skejby, Denmark
- iThe Lambe Institute for Translational Medicine and Curam, National University of Ireland, Galway, and Saolta University Healthcare Group, Galway, Ireland
- ↵∗Address for correspondence:
Dr. Shengshou Hu, National Clinical Research Center of Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, A 167, Beilishi Road, Xicheng District, Beijing, 100037, China.
- ↵∗∗Dr. Shengxian Tu, Biomedical Instrument Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, No. 1954, Huashan Road, Xuhui District, Shanghai, 200030, China.
Background Quantitative flow ratio (QFR) is a novel angiography-based method for deriving fractional flow reserve (FFR) without pressure wire or induction of hyperemia. The accuracy of QFR when assessed online in the catheterization laboratory has not been adequately examined to date.
Objectives The goal of this study was to assess the diagnostic performance of QFR for the diagnosis of hemodynamically significant coronary stenosis defined by FFR ≤0.80.
Methods This prospective, multicenter trial enrolled patients who had at least 1 lesion with a diameter stenosis of 30% to 90% and a reference diameter ≥2 mm according to visual estimation. QFR, quantitative coronary angiography (QCA), and wire-based FFR were assessed online in blinded fashion during coronary angiography and re-analyzed offline at an independent core laboratory. The primary endpoint was that QFR would improve the diagnostic accuracy of coronary angiography such that the lower boundary of the 2-sided 95% confidence interval (CI) of this estimate exceeded 75%.
Results Between June and July 2017, a total of 308 patients were consecutively enrolled at 5 centers. Online QFR and FFR results were both obtained in 328 of 332 interrogated vessels. Patient- and vessel-level diagnostic accuracy of QFR was 92.4% (95% CI: 88.9% to 95.1%) and 92.7% (95% CI: 89.3% to 95.3%), respectively, both of which were significantly higher than the pre-specified target value (p < 0.001). Sensitivity and specificity in identifying hemodynamically significant stenosis were significantly higher for QFR than for QCA (sensitivity: 94.6% vs. 62.5%; difference: 32.0% [p < 0.001]; specificity: 91.7% vs. 58.1%; difference: 36.1% [p < 0.001]). Positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio for QFR were 85.5%, 97.1%, 11.4, and 0.06. Offline analysis also revealed that vessel-level QFR had a high diagnostic accuracy of 93.3% (95% CI: 90.0% to 95.7%).
Conclusions The study met its prespecified primary performance goal for the level of diagnostic accuracy of QFR in identifying hemodynamically significant coronary stenosis. (The FAVOR [Functional Diagnostic Accuracy of Quantitative Flow Ratio in Online Assessment of Coronary Stenosis] II China study]; NCT03191708)
Funding for this study was provided by Pulse Medical Imaging Technology (Shanghai) Co., Ltd., the National Key Research and Development Program of China (grant no. 2016YFC0100500), and the Natural Science Foundation of China (grant no. 31500797 and 81570456). Dr. Tu has received research support from Medis Medical Imaging and Pulse Medical Imaging. Dr. Holm has received institutional research grants from Abbott, Medis Medical Imaging, and Boston Scientific; and speaker fees from Boston Scientific and Abbott. Dr. Wijns has received research grants from Abbott, MiCell, MicroPort, and Terumo; and is co-founder of Argonauts Partners. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Xu and Tu contributed equally to this work.
- Received September 15, 2017.
- Revision received October 13, 2017.
- Accepted October 16, 2017.
- 2017 American College of Cardiology Foundation