Quantitative flow ratio to predict long-term coronary artery bypass graft patency in patients with left main coronary artery disease

Cameron Dowling, Adam J. Nelson, Ren Yik Lim, Jun Michael Zhang, Kevin Cheng, Julian A. Smith, Sujith Seneviratne, Yuvaraj Malaiapan, Sarah Zaman, Dennis T.L. Wong

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2 Citations (Scopus)


Purpose: Fractional flow reserve (FFR) has been demonstrated in some studies to predict long-term coronary artery bypass graft (CABG) patency. Quantitative flow ratio (QFR) is an emerging technology which may predict FFR. In this study, we hypothesised that QFR would predict long-term CABG patency and that QFR would offer superior diagnostic performance to quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS). Methods: A prospective study was performed on patients with left main coronary artery disease who were undergoing CABG. QFR, QCA and IVUS assessment was performed. Follow-up computed tomography coronary angiography and invasive coronary angiography was undertaken to assess graft patency. Results: A total of 22 patients, comprising of 65 vessels were included in the analysis. At a median follow-up of 3.6 years post CABG (interquartile range, 2.3 to 4.8 years), 12 grafts (18.4%) were occluded. QFR was not statistically significantly higher in occluded grafts (0.81 ± 0.19 vs. 0.69 ± 0.21; P = 0.08). QFR demonstrated a discriminatory power to predict graft occlusion (area under the receiver operating characteristic curve, 0.70; 95% confidence interval [CI], 0.52 to 0.88; P = 0.03). At long-term follow-up, the risk of graft occlusion was higher in vessels with a QFR > 0.80 (58.6% vs. 17.0%; hazard ratio, 3.89; 95% CI, 1.05 to 14.42; P = 0.03 by log-rank test). QCA (minimum lumen diameter, lesion length, diameter stenosis) and IVUS (minimum lumen area, minimum lumen diameter, diameter stenosis) parameters were not predictive of long-term graft patency. Conclusions: QFR may predict long-term graft patency in patients undergoing CABG.

Original languageEnglish
Pages (from-to)2811-2818
Number of pages8
JournalInternational Journal of Cardiovascular Imaging
Issue number12
Publication statusPublished - Dec 2022


  • Computed tomography coronary angiography
  • Coronary artery bypass grafting
  • Graft occlusion
  • Quantitative flow reserve

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