Impact of coronary calcium score and lesion characteristics on the diagnostic performance of machine-learning-based computed tomography-derived fractional flow reserve

2021 ◽  
Author(s):  
Hyun Jung Koo ◽  
Joon-Won Kang ◽  
Soo-Jin Kang ◽  
Jihoon Kweon ◽  
June-Goo Lee ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computed Tomography ◽  
Coronary Artery ◽  
Coronary Angiography ◽  
Fractional Flow Reserve ◽  
Diagnostic Performance ◽  
Lesion Length ◽  
Fractional Flow ◽  
Flow Reserve ◽  
The Impact

Abstract Aims To evaluate the impact of coronary artery calcium (CAC) score, minimal lumen area (MLA), and length of coronary artery stenosis on the diagnostic performance of the machine-learning-based computed tomography-derived fractional flow reserve (ML-FFR). Methods and results In 471 patients with coronary artery disease, computed tomography angiography (CTA) and invasive coronary angiography were performed with fractional flow reserve (FFR) in 557 lesions at a single centre. Diagnostic performances of ML-FFR, computational fluid dynamics-based CT-FFR (CFD-FFR), MLA, quantitative coronary angiography (QCA), and visual stenosis grading were evaluated using invasive FFR as a reference standard. Diagnostic performances were analysed according to lesion characteristics including the MLA, length of stenosis, CAC score, and stenosis degree. ML-FFR was obtained by automated feature selection and model building from quantitative CTA. A total of 272 lesions showed significant ischaemia, defined by invasive FFR ≤0.80. There was a significant correlation between CFD-FFR and ML-FFR (r = 0.99, P < 0.001). ML-FFR showed moderate sensitivity and specificity in the per-patient analysis. Diagnostic performances of CFD-FFR and ML-FFR did not decline in patients with high CAC scores (CAC > 400). Sensitivities of CFD-FFR and ML-FFR showed a downward trend along with the increase in lesion length and decrease in MLA. The area under the curve (AUC) of ML-FFR (0.73) was higher than those of QCA and visual grading (AUC = 0.65 for both, P < 0.001) and comparable to those of MLA (AUC = 0.71, P = 0.21) and CFD-FFR (AUC = 0.73, P = 0.86). Conclusion ML-FFR showed comparable results to MLA and CFD-FFR for the prediction of lesion-specific ischaemia. Specificities and accuracies of CFD-FFR and ML-FFR decreased with smaller MLA and long lesion length.

scholarly journals Accuracy of computational pressure-fluid dynamics applied to coronary angiography to derive fractional flow reserve: FLASH FFR

2019 ◽  
Vol 116 (7) ◽  
pp. 1349-1356 ◽  
Author(s):  
Jianping Li ◽  
Yanjun Gong ◽  
Weimin Wang ◽  
Qing Yang ◽  
Bin Liu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Coronary Artery ◽  
Coronary Angiography ◽  
Fractional Flow Reserve ◽  
Predictive Value ◽  
Diagnostic Performance ◽  
Characteristic Curve ◽  
Fractional Flow ◽  
Performance Goal ◽  
Flow Reserve

Abstract Aims Conventional fractional flow reserve (FFR) is measured invasively using a coronary guidewire equipped with a pressure sensor. A non-invasive derived FFR would eliminate risk of coronary injury, minimize technical limitations, and potentially increase adoption. We aimed to evaluate the diagnostic performance of a computational pressure-flow dynamics derived FFR (caFFR), applied to coronary angiography, compared to invasive FFR. Methods and results The FLASH FFR study was a prospective, multicentre, single-arm study conducted at six centres in China. Eligible patients had native coronary artery target lesions with visually estimated diameter stenosis of 30–90% and diagnosis of stable or unstable angina pectoris. Using computational pressure-fluid dynamics, in conjunction with thrombolysis in myocardial infarction (TIMI) frame count, applied to coronary angiography, caFFR was measured online in real-time and compared blind to conventional invasive FFR by an independent core laboratory. The primary endpoint was the agreement between caFFR and FFR, with a pre-specified performance goal of 84%. Between June and December 2018, matched caFFR and FFR measurements were performed in 328 coronary arteries. Total operational time for caFFR was 4.54 ± 1.48 min. caFFR was highly correlated to FFR (R = 0.89, P = 0.76) with a mean bias of −0.002 ± 0.049 (95% limits of agreement −0.098 to 0.093). The diagnostic performance of caFFR vs. FFR was diagnostic accuracy 95.7%, sensitivity 90.4%, specificity 98.6%, positive predictive value 97.2%, negative predictive value 95.0%, and area under the receiver operating characteristic curve of 0.979. Conclusions Using wire-based FFR as the reference, caFFR has high accuracy, sensitivity, and specificity. caFFR could eliminate the need of a pressure wire, technical error and potentially increase adoption of physiological assessment of coronary artery stenosis severity. Clinical Trial Registration URL: http://www.chictr.org.cn Unique Identifier: ChiCTR1800019522.

scholarly journals Comparison of Machine Learning Computed Tomography-Based Fractional Flow Reserve and Coronary CT Angiography-Derived Plaque Characteristics with Invasive Resting Full-Cycle Ratio

2020 ◽  
Vol 9 (3) ◽  
pp. 714
Author(s):  
Stefan Baumann ◽  
Markus Hirt ◽  
Christina Rott ◽  
Gökce H. Özdemir ◽  
Christian Tesche ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computed Tomography ◽  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Fractional Flow ◽  
Luminal Diameter ◽  
Coronary Computed Tomography ◽  
Flow Reserve ◽  
Pressure Wire

Background: The aim is to compare the machine learning-based coronary-computed tomography fractional flow reserve (CT-FFRML) and coronary-computed tomographic morphological plaque characteristics with the resting full-cycle ratio (RFRTM) as a novel invasive resting pressure-wire index for detecting hemodynamically significant coronary artery stenosis. Methods: In our single center study, patients with coronary artery disease (CAD) who had a clinically indicated coronary computed tomography angiography (cCTA) and subsequent invasive coronary angiography (ICA) with pressure wire-measurement were included. On-site prototype CT-FFRML software and on-site CT-plaque software were used to calculate the hemodynamic relevance of coronary stenosis. Results: We enrolled 33 patients (70% male, mean age 68 ± 12 years). On a per-lesion basis, the area under the receiver operating characteristic curve (AUC) of CT-FFRML (0.90) was higher than the AUCs of the morphological plaque characteristics length/minimal luminal diameter4 (LL/MLD4; 0.80), minimal luminal diameter (MLD; 0.77), remodeling index (RI; 0.76), degree of luminal diameter stenosis (0.75), and minimal luminal area (MLA; 0.75). Conclusion: CT-FFRML and morphological plaque characteristics show a significant correlation to detected hemodynamically significant coronary stenosis. Whole CT-FFRML had the best discriminatory power, using RFRTM as the reference standard.

scholarly journals Real world utilization of CT derived fractional flow reserve in stable angina from contemporary practice: impact on downstream utilization of invasive coronary angiogram and clinical decision making

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Ray ◽  
K Green ◽  
A Shamsi ◽  
A Mahmood ◽  
A Hatrick ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coronary Artery ◽  
Coronary Angiography ◽  
Fractional Flow Reserve ◽  
Invasive Coronary Angiography ◽  
Severe Disease ◽  
Fractional Flow ◽  
Coronary Cta ◽  
Flow Reserve ◽  
Artery Disease

Abstract   Background/Introduction - Fractional flow reserve (FFR), a pressure wire-based index used during coronary angiography to assess the severity of potential coronary stenosis, is considered as the reference standard for evaluating the severity of stenosis in coronary artery disease (CAD). Recently, computed tomography angiography-derived fractional flow reserve (FFRct) has been recommended for evaluating functional severity of stenoses as it improves diagnostic accuracy and reduces the need for invasive coronary angiography. Purpose To determine whether non-invasive FFRct predicts severity of coronary artery disease and whether its addition improves efficiency of proceeding to revascularisation and invasive coronary angiography (ICA) compared to coronary computed tomography angiography (CTA) without FFR. Methods This observational retrospective single center study included two cohorts of patients who presented in a District General Hospital in UK. The first group consisted of all patients who underwent coronary CTA for chest pain from January 2013 to December 2014. The second cohort consisted of all patients who proceeded to have measurement of FFRct from April 2018 to June 2019 after routine coronary CTA for chest pain. The two groups showed similar demographics. FFRct was analysed using the software HeartFlow. We determined the agreement of FFRct (positive if <0.80) with stenosis on CTA and ICA (positive if >50% left main or >70% other coronary artery) and whether it correlated with need for revascularisation. We also assessed if adding FFRct <0.80 improved efficiency of referral to ICA, defined as decreased diagnosis of mild or moderate stenosis (<70%) and higher yield of severe disease (>70%). The two cohorts were compared to determine the above specific end-points. Results In the first cohort, data was collected for 915 patients. 240 (26.2%) of these patients proceeded to ICA, which showed severe disease in 31 (3.3%) patients needing revascularisation. In the second cohort of patients, 824 patients underwent coronary CTA and 201 (24.4%) proceeded to have FFRct measurements. 99 (49%) of these patients had a negative FFR and 65 (32%) patients had a positive result (<0.80). There was agreement between FFRct and invasive coronary angiography/stress echo in 44 (77%) patients, with regards to severity /revascularisation. The need for ICA was significantly reduced if coronary CTA and FFRct were both done (240/915; 26.2% vs 54/824; 6.5%: p value <0.00001). Conclusion Reserving ICA for patients with a positive FFRct (<0.80) could reduce the number of ICA after coronary CTA and augment the number of ICA leading to revascularisation. Use of FFRct as a gatekeeper to ICA will improve appropriate selection of patients referred and this in-turn will reduce the burden of complications associated with invasive procedures, reduce costs and ensure better utilization of Cath-lab resources. Funding Acknowledgement Type of funding source: None

scholarly journals Diagnostic accuracy of on-site coronary computed tomography-derived fractional flow reserve in the diagnosis of stable coronary artery disease

2021 ◽  
Author(s):  
J. Peper ◽  
J. Schaap ◽  
B. J. W. M. Rensing ◽  
J. C. Kelder ◽  
M. J. Swaans
Keyword(s):  
Computed Tomography ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Diagnostic Accuracy ◽  
Fractional Flow Reserve ◽  
Diagnostic Performance ◽  
Reference Standard ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Artery Disease

Abstract Purpose Invasive fractional flow reserve (FFR), the reference standard for identifying significant coronary artery disease (CAD), can be estimated non-invasively by computed tomography-derived fractional flow reserve (CT-FFR). Commercially available off-site CT-FFR showed improved diagnostic accuracy compared to coronary computed tomography angiography (CCTA) alone. However, the diagnostic performance of this lumped-parameter on-site method is unknown. The aim of this cross-sectional study was to determine the diagnostic accuracy of on-site CT-FFR in patients with suspected CAD. Methods A total of 61 patients underwent CCTA and invasive coronary angiography with FFR measured in 88 vessels. Significant CAD was defined as FFR and CT-FFR below 0.80. CCTA with stenosis above 50% was regarded as significant CAD. The diagnostic performance of both CT-FFR and CCTA was assessed using invasive FFR as the reference standard. Results Of the 88 vessels included in the analysis, 34 had an FFR of ≤ 0.80. On a per-vessel basis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 91.2%, 81.4%, 93.6%, 75.6% and 85.2% for CT-FFR and were 94.1%, 68.5%, 94.9%, 65.3% and 78.4% for CCTA. The area under the receiver operating characteristic curve was 0.91 and 0.85 for CT-FFR and CCTA, respectively, on a per-vessel basis. Conclusion On-site non-invasive FFR derived from CCTA improves diagnostic accuracy compared to CCTA without additional testing and has the potential to be integrated in the current clinical work-up for diagnosing stable CAD.

scholarly journals Validation of the diagnostic performance of ‘HeartMedi V.1.0’, a novel CT-derived fractional flow reserve measurement, for patients with coronary artery disease: a study protocol

BMJ Open ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. e037780
Author(s):  
Soo-Hyun Kim ◽  
Si-Hyuck Kang ◽  
Woo-Young Chung ◽  
Chang-Hwan Yoon ◽  
Sang-Don Park ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Fractional Flow Reserve ◽  
Predictive Value ◽  
Diagnostic Performance ◽  
Invasive Coronary Angiography ◽  
Fractional Flow ◽  
Non Invasive ◽  
Link Type ◽  
Flow Reserve

IntroductionCoronary CT angiography (CCTA) is widely used for non-invasive coronary artery evaluation, but it is limited in identifying the nature of functional characteristics that cause ischaemia. Recent computational fluid dynamic (CFD) techniques applied to CCTA images permit non-invasive computation of fractional flow reserve (FFR), a measure of lesion-specific ischaemia. However, this technology has limitations, such as long computational time and the need for expensive equipment, which hinder widespread use.Methods and analysisThis study is a prospective, multicentre, comparative and confirmatory trial designed to evaluate the diagnostic performance of HeartMedi V.1.0, a novel CT-derived FFR measurement for the detection of haemodynamically significant coronary artery stenoses identified by CCTA, based on invasive FFR as a reference standard. The invasive FFR values ≤0.80 will be considered haemodynamically significant. The study will enrol 184 patients who underwent CCTA, invasive coronary angiography and invasive FFR. Computational FFR (c-FFR) will be analysed by CFD techniques using a lumped parameter model based on vessel length method. Blinded core laboratory interpretation will be performed for CCTA, invasive coronary angiography, invasive FFR and c-FFR. The primary objective of the study is to compare the area under the receiver–operator characteristic curve between c-FFR and CCTA to non-invasively detect the presence of haemodynamically significant coronary stenosis. The secondary endpoints include diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value and correlation of c-FFR with invasive FFR.Ethics and disseminationThe study has ethic approval from the ethics committee of Seoul National University Bundang Hospital (E-1709/420-001) and informed consent will be obtained for all enrolled patients. The result will be published in a peer-reviewed journal.Trial registration numberKCT0002725; Pre-results.

P6179Correlation of computed tomography-based fractional flow reserve with instantaneous wave free ratio to detect hemodynamically significant coronary stenoses

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Baumann ◽  
M Hirt ◽  
U J Schoepf ◽  
M Renker ◽  
S J Buss ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coronary Artery ◽  
Coronary Angiography ◽  
Diagnostic Accuracy ◽  
Fractional Flow Reserve ◽  
Gold Standard ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Coronary Stenoses ◽  
Lesion Level

Abstract Background Based on coronary computed tomography angiography (cCTA), stenoses can be detected but provides anatomical assessment solely. Fractional flow reserve based on coronary CT angiography (ML-cFFR) is gaining in importance for non-invasive hemodynamic assessment of obstructive coronary artery disease (CAD), as several large trials demonstrated significantly improvements in diagnostic accuracy to cCTA. Comparably instantaneous wave free ratio (iFR) is a novel resting index for the invasive determination of haemodynamic relevant stenoses, finds consideration in the ESC guideline on myocardial revascularization and is now of equal standing with FFR as a class IA recommendation. Purpose The aim of our study was to evaluate the on-site ML-cFFR in terms of diagnostic accuracy and clinical practicability in comparison to the iFR as the current invasive gold standard to detect hemodynamically significant coronary artery stenoses. Methods In our prospective, multi-center study, patients with CAD who had a clinically indicated cCTA and subsequent invasive coronary angiography with iFR-measurement were included. To analyse the acquired cCTA dataset we used a third-generation dual-source CT with on-site prototype ML-cFFR software that is based on a machine-learning algorithm, to determine the hemodynamic relevance of coronary stenoses. Results Between July 2017 and December 2018, in 40 of 42 cases (95%), the on-site ML-cFFR calculation was successful. Finally we enrolled 40 patients (72.5% males, mean age 66.7±11.9 years) with ML-cFFR calculation based on cCTA and iFR-measurement during ICA. The mean calculation time of the ML-cFFR values was 10.6±1.9minutes. 57 vessel specific lesions were analysed, of which 15 (26%) were determined as hemodynamically relevant stenoses by iFR (iFR≤0.89) whereas ML-cFFR classified only 14 (24.5%) as hemodynamic significant coronary stenoses (ML-cFFR≤0.80). We observed that cCTA overestimated the severity of stenoses in 27 of 40 cases, which might lead to unnecessary coronary angiographies. However, ML-cFFR detected no obstructive CAD in 26 of 40 patients (65%) and this would have resulted in a reduction of initially performed pure diagnostic coronary angiography. Estimated values sensitivity, specificity, PPV and NPV were 86.7%, 97.4%, 92.9% and 95.0%. The diagnostic accuracy of ML-cFFR in terms of iFR on a per-patient and per-lesion level was 95.0% and 96.5%. The area under the curve (AUC) on a per-lesion and per-patient basis by ML-cFFR to detect lesion specific ischemia was 0.97 and 0.96. The analysis of the correlation (Pearson's product-moment) on a per-lesion level was r=0.82 (p<0.0001) between the ML-cFFR algorithm and iFR. Conclusion(s) On-site ML-cFFR correlates excellently with the novel gold standard iFR to non-invasively detect hemodynamic significant coronary stenoses in routine clinical practice. Acknowledgement/Funding Doctor S. Baumann receives research support from Siemens and Philips Volcano. All other authors declare that they have no financial disclosure.

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