Accuracy of Intravascular Ultrasound-Based Fractional Flow Reserve in Identifying Hemodynamic Significance of Coronary Stenosis
Wei Yu, Toru Tanigaki, Daixin Ding, Peng Wu, Haiyan Du, Ling Li, Biao Huang, Guanyu Li, Wei Yang, Su Zhang, Fuhua Yan, Munenori Okubo, Bo Xu, Hitoshi Matsuo, William Wijns, Shengxian Tu
Abstract
Background: Ultrasonic flow ratio (UFR) is a novel method for fast computation of fractional flow reserve (FFR) from intravascular ultrasound images. The objective of this study is to evaluate the diagnostic performance of UFR using wire-based FFR as the reference. Methods: Post hoc computation of UFR was performed in consecutive patients with both intravascular ultrasound and FFR measurement in a core lab while the analysts were blinded to FFR. Results: A total of 167 paired comparisons between UFR and FFR from 94 patients were obtained. Median FFR was 0.80 (interquartile range, 0.68–0.89) and 50.3% had a FFR≤0.80. Median UFR was 0.81 (interquartile range, 0.69–0.91), and UFR showed strong correlation with FFR ( r =0.87; P <0.001). The area under the curve was higher for UFR than intravascular ultrasound-derived minimal lumen area (0.97 versus 0.89, P <0.001). The diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio for UFR to identify FFR≤0.80 was 92% (95% CI, 87–96), 91% (95% CI, 82–96), 96% (95% CI, 90–99), 96% (95% CI, 89–99), 91% (95% CI, 93–96), 25.0 (95% CI, 8.2–76.2), and 0.10 (95% CI, 0.05–0.20), respectively. The agreement between UFR and FFR was independent of lesion locations ( P =0.48), prior myocardial infarction ( P =0.29), and imaging catheters ( P =0.22). Intraobserver and interobserver variability of UFR analysis was 0.00±0.03 and 0.01±0.03, respectively. Median UFR analysis time was 102 (interquartile range, 87–122) seconds. Conclusions: UFR had a strong correlation and good agreement with FFR. The fast computational time and excellent analysis reproducibility of UFR bears the potential of a wider adoption of integration of coronary imaging and physiology in the catheterization laboratory.