Prognostic Value of Coronary CT Angiography-Derived Quantitative Flow Ratio in Suspected Coronary Artery Disease

Abstract

Background The prognostic value of coronary CT angiography (CTA)-derived quantitative flow ratio (CT-QFR) remains unknown. Purpose To determine the prognostic value of CT-QFR in predicting the long-term outcomes of patients with suspected coronary artery disease (CAD) in comparison with invasive coronary angiography (ICA)/SPECT and to determine the influence of prior percutaneous coronary intervention (PCI) on the prognostic value of CT-QFR. Materials and Methods In this secondary analysis of the prospective international CORE320 study, 379 participants who underwent coronary CTA and SPECT within 60 days before ICA between November 2009 and July 2011 were included for follow-up. The coronary CTA images were analyzed to determine CT-QFR. The primary outcome was major adverse cardiovascular events (MACEs) in the 5-year follow-up. Kaplan-Meier curves, multivariable Cox regression models adjusted for clinical variables, and areas under the receiver operating characteristic curves (AUCs) were used to assess and compare the predictive ability of CT-QFR and ICA/SPECT. Results CT-QFR computation and 5-year follow-up data were available for 310 participants (median age, 62 years), of whom 205 (66%) were male. CT-QFR (hazard ratio, 1.9 [95% CI: 1.0, 3.5]; P = .04) and prior myocardial infarction (hazard ratio, 2.5 [95% CI: 1.5, 4.0]; P < .001) were independent predictors of MACE occurrence in the 5-year follow-up. MACE-free survival rates were similar in participants with normal CT-QFR and ICA/SPECT (82% vs 80%; P = .45) and in participants with abnormal CT-QFR and ICA/SPECT findings (60% vs 57%; P = .40). In participants with prior PCI, CT-QFR had a lower AUC in predicting MACEs than in participants without prior PCI (0.44 vs 0.70; P < .001). Conclusion CT-QFR was an independent predictor of MACEs in the 5-year follow-up in participants with suspected CAD and showed similar 5-year prognostic value to ICA/SPECT; however, prior PCI affected CT-QFR ability to predict MACEs. Clinical trial registration no. NCT00934037 © RSNA, 2024 Supplemental material is available for this article.

Graphical abstract

Figure 1:

Flow diagram of the study participants and follow-up analyses. CAD = coronary artery disease, CTA = CT angiography, CT-QFR = CTA-derived quantitative flow ratio.

Figure 2:

Images in a 53-year-old man with suspected coronary artery disease. (A) The curved planar reformation images reconstructed from CT angiography (CTA) demonstrate intermediate stenosis on the middle segment of the left anterior descending artery (LAD) (arrow on the left panel) and another intermediate stenosis on the distal segment of the right coronary artery (RCA) (arrow on the right panel). (B) Coronary artery tree reconstructed from CTA, with CTA-derived quantitative flow ratios presented at the distal end of each main vessel (left anterior descending artery, 0.83; left circumflex artery [LCX], 0.98; right coronary artery, 0.95). (C) Images from invasive coronary angiography show a lesion with 30% diameter stenosis by visual estimation of the left anterior descending artery (arrow on the left panel) and another lesion with 40% diameter stenosis by visual estimation of the right coronary artery (arrow on the right panel). (D) SPECT images were obtained with technetium 99m–labeled imaging agents. The middle planes of the three principal axes (left, apex to base; middle, septal to lateral; and right, anterior to inferior) show normal myocardial perfusion with no apparent perfusion defect.

Figure 3:

Graph of receiver operating characteristic curves shows the diagnostic performance of the CT angiography–derived quantitative flow ratio (CT-QFR) and invasive coronary angiography (ICA)/SPECT combination test for identifying participants who experienced major adverse cardiovascular events (MACEs) in the 5-year follow-up.

Figure 4:

Graph of Kaplan-Meier curves of 5-year event-free survival in 310 participants according to the diagnosis (abnormal [+] or normal [-]) based on the CT angiography–derived quantitative flow ratio (CT-QFR) and invasive coronary angiography (ICA)/SPECT combination test for identifying hemodynamically significant coronary artery disease. MACE = major adverse cardiovascular event.