Comparison of diagnostic performance in on-site based CT-derived fractional flow reserve measurements

• Main Authors: Yui O. Nozaki, Shinichiro Fujimoto, Chihiro Aoshima, Yuki Kamo, Yuko O. Kawaguchi, Kazuhisa Takamura, Ayako Kudo, Daigo Takahashi, Makoto Hiki, Yoshiteru Kato, Iwao Okai, Tomotaka Dohi, Shinya Okazaki, Nobuo Tomizawa, Kanako K. Kumamaru, Shigeki Aoki, Tohru Minamino
• Format: Article
• Language: English
• Published: Elsevier 2021-08-01
• Series: International Journal of Cardiology: Heart & Vasculature
• Subjects: Coronary CT angiography; Fractional flow reserve; Fluid structure interaction; Lesion-specific ischemia
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352906721001032

Background: Computed tomography fractional flow reserve (CT-FFR), which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phase, has an incremental diagnostic value over conventional coronary computed tomography angiography (CCTA). However, the appropriate location for CT-FFR measurement remains to be clarified. Method: A total of 115 consecutive patients with 149 vessels who underwent CCTA showing 30–90% stenosis with invasive FFR within 90 days were retrospectively analyzed. CT-FFR values were measured at three points: 1 and 2 cm distal to the target lesion (CT-FFR1cm, 2cm) and the vessel terminus (CT-FFRlowest). The diagnostic accuracies of CT-FFR ≤ 0.80 for detecting hemodynamically significant stenosis, defined as invasive FFR ≤ 0.80, were compered. Result: Fifty-five vessels (36.9%) had invasive FFR ≤ 0.80. The accuracy and AUC for CT-FFR1cm and 2cm were comparable, while the AUC for CT-FFRlowest was significantly lower than CT-FFR1cm and 2cm. (lowest/1cm, 2 cm = 0.68 (95 %CI 0.63–0.73) vs 0.79 (0.72–0.86, p = 0.006), 0.80 (0.73–0.87, p = 0.002)) The sensitivity and negative predictive value of CT-FFRlowest were 100%. The reclassification rates from positive CT-FFRlowest to negative CT-FFR1cm and 2cm were 55.7% and 54.2%, respectively. Conclusion: The diagnostic performance of CT-FFR was comparable when measured at 1-to-2 cm distal to the target lesion, but significantly higher than CT-FFRlowest. The lesion-specific CT-FFR could reclassify false positive cases in patients with positive CT-FFRlowest, while all patients with negative CT-FFRlowest were diagnosed as negative by invasive FFR.