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

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

doi:10.1016/j.ijcha.2021.100815

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

Int J Cardiol Heart Vasc. 2021 Jun 11:35:100815. doi: 10.1016/j.ijcha.2021.100815. eCollection 2021 Aug.

Authors

Yui O Nozaki¹, Shinichiro Fujimoto¹, Chihiro Aoshima¹, Yuki Kamo¹, Yuko O Kawaguchi¹, Kazuhisa Takamura¹, Ayako Kudo¹, Daigo Takahashi¹, Makoto Hiki¹, Yoshiteru Kato¹, Iwao Okai¹, Tomotaka Dohi¹, Shinya Okazaki¹, Nobuo Tomizawa², Kanako K Kumamaru², Shigeki Aoki², Tohru Minamino^{1

3}

Affiliations

¹ Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
² Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
³ Japan Agency for Medical Research and Development-Core Research for Evolutionary Medical Science and Technology (AMED-CREST), Japan Agency for Medical Research and Development, Tokyo, Japan.

Abstract

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-FFR_{1cm, 2cm}) and the vessel terminus (CT-FFR_lowest). 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-FFR_1cm and _2cm were comparable, while the AUC for CT-FFR_lowest was significantly lower than CT-FFR_1cm 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-FFR_lowest were 100%. The reclassification rates from positive CT-FFR_lowest to negative CT-FFR_1cm 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-FFR_lowest. The lesion-specific CT-FFR could reclassify false positive cases in patients with positive CT-FFR_lowest, while all patients with negative CT-FFR_lowest were diagnosed as negative by invasive FFR.

Keywords: Coronary CT angiography; Fluid structure interaction; Fractional flow reserve; Lesion-specific ischemia.