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.

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.

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 Virtual fractional flow reserve derived from coronary angiography – artery and lesion specific correlations

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
T Mano ◽  
V Ferreira ◽  
R Ramos ◽  
P Bras ◽  
J Reis ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Fractional Flow Reserve ◽  
Invasive Coronary Angiography ◽  
False Negative ◽  
Lesion Site ◽  
Fractional Flow ◽  
Coronary Syndrome ◽  
Flow Reserve ◽  
Tertiary Center

Abstract Introduction Virtual Fractional flow reserve (vFFR) from standard non-hyperaemic invasive coronary angiography (ICA) has emerged as a promising non-invasive test to assess hemodynamic severity of coronary artery disease (CAD). Purpose To investigate the difference in vFFR analysis between vessels and specific lesions. Methods Retrospective analysis of consecutive patients (pts) who underwent invasive functional assessment (iFA) in a tertiary center between 2019 and 2020. vFFR was calculated using dedicated software (CAAS Workstation 8.4) based on coronary angiograms of the acquired in ≥2 different projections, by operators blinded to iFA results. Diagnostic performance of vFFR was evaluated and correlated with iFA, according to coronary vessel, vessel diameter at stenosis, diameter stenosis and area stenosis at lesion. vFFR was considered positive when <0.80. FFR <0.8 and iFR/RFR <0.90 were classified as positive according to current clinical standards. Results 106 coronary arteries of 95 pts (78% male, mean age 67.8±9.7 years) underwent vFFR evaluation. ICA indications were chronic coronary syndrome in 63% or acute coronary syndrome (non-culprit lesion) in the remaining pts. VFFR accuracy was good (AUC 0.839 (p<0.001) and Pearson's correlation coefficient 0.533 (p<0.001) when vFFR was measured in the distal vessel segment. The correlation improved when vFFR were assessed at lesion site (r=0.631, p<0.001) or up to 1cm below the stenosis (0.610, p<0.001). Binary concordance of 89% were observed in RCA and LAD (Sensibility -S 68%, Specificity-Sp 96%, False positive -FP 3.8%, False negative - FN 31%, predictive positive value-PPV 87%, predictive negative value- PNV 89%), while in the circumflex coronary artery binary concordance were of 77% (S 50%; Sp 82%; FP 18%; FN 50%; PPV 33% and PNV 90%). Correlation between vFFR and iFA was higher in vessels ≥2mm (r=0.730, p<0.001). and in lesions in the extremes of the severity spectrum (Table 1). Conclusion vFFR has a moderate to high linear correlation to iFA, depending on the artery and type of lesion studied. The higher correlation was found when vFFR were measured at lesion site, in non-circumflex artery stenosis, in vessels ≥2mm and in vessels with mild or severe stenosis. FUNDunding Acknowledgement Type of funding sources: None.

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 Performance of Angiography-Based Fractional Flow Reserve for Functional Evaluation of Coronary Artery Stenosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Changling Li ◽  
Xiaochang Leng ◽  
Jingsong He ◽  
Yongqing Xia ◽  
Wenbing Jiang ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Stable Angina ◽  
Predictive Value ◽  
Diagnostic Performance ◽  
Coronary Artery Stenosis ◽  
Artery Stenosis ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Sensitivity Specificity

Background: A new method for calculating fraction flow reserve (FFR) without pressure-wire (angiography-derived FFR) based on invasive coronary angiography (ICA) images can be used to evaluate the functional problems of coronary stenosis.Objective: The aim of this study was to assess the diagnostic performance of a novel method of calculating the FFR compared to wire-based FFR using retrospectively collected data from patients with stable angina.Methods: Three hundred patients with stable angina pectoris who underwent ICA and FFR measurement were included in this study. Two ICA images with projections >25° apart at the end-diastolic frame were selected for 3D reconstruction. Then, the contrast frame count was performed in an angiographic run to calculate the flow velocity. Based on the segmented vessel, calculated velocity, and aortic pressure, AccuFFRangio distribution was calculated through the pressure drop equation.Results: Using FFR ≤ 0.8 as a reference, we evaluated AccuFFRangio performance for 300 patients with its accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Comparison of AccuFFRangio with wire-measured FFR resulted in an area under the curve (AUC) of 0.954 (per-vessel, p < 0.0001). Accuracy for AccuFFRangio was 93.7% for Pa set from measurement and 87% for Pa = 100 mmHg in this clinical study. Overall sensitivity, specificity, PPV, and NPV for per-vessel were 90, 95, 86.7, 96.3, and 57.5, 97.7, 90.2, 86.3%, respectively. Overall accuracy, sensitivity, specificity, PPV, and NPV for 2-dimensional (2D) quantitative coronary angiography (QCA) were 63.3, 42.5, 70.9, 34.7, and 77.2%, respectively. The average processing time of AccuFFRangio was 4.30 ± 1.87 min.Conclusions: AccuFFRangio computed from coronary ICA images can be an accurate and time-efficient computational tool for detecting lesion-specific ischemia of coronary artery stenosis.

scholarly journals Fractional Flow Reserve in Choosing the Tactics of Interventional Treatment of Multilevel Coronary Artery Lesions

2021 ◽  
pp. 26-29
Author(s):  
Andrii Yu. Gavrylyshyn ◽  
Sergii V. Salo ◽  
Olena V. Levchyshyna ◽  
Andrii K. Logutov ◽  
Vasyl V. Lazoryshynets
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Coronary Arteries ◽  
Fractional Flow Reserve ◽  
Invasive Coronary Angiography ◽  
Stable Coronary Artery Disease ◽  
Interventional Treatment ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Artery Disease

When choosing tactics for the treatment of patients with stable coronary artery disease, invasive coronary angiography remains the gold standard for diagnosis and is a crucial method in choosing tactics and volume of revascularization. However, in the presence of borderline (>50-70%), multilevel lesions of the coronary artery, there is a need for additional assessment of the physiological significance of each stenosis. The aim. To develop an algorithm to optimize the use of fractional flow reserve (FFR) measurement in interventional treatment of borderline (>50-70%), multilevel lesions of coronary arteries, to show the safety of “functional revascula­ rization” in comparison with traditional angiography. Materials and methods. The study included 32 patients who were treated at the National Amosov Institute of Cardiovascular Surgery in the period from 2017 to 2021 (the vast majority were men – 25 patients (67%) and 7 (33%) women) aged 60.3±8.3 years who had >50-75% multilevel lesions of one of the main coronary arteries according to selective invasive coronary angiography. The patients were divided into two groups: 1) Angiographic group (n = 17, 53%), where the volume and tactics of revascularization were determined only by angiography (maximum complete anatomical revascularization); 2) Functional group (n=15, 47%) (combination of angiography data and FFR measurement, the so-called “functional revascularization”). Conclusions. An effective and safe algorithm for measuring FFR in multilevel lesions (reducing the number of implanted stents) is shown.

scholarly journals Diagnostic accuracy of coronary computed tomography angiography-derived fractional flow reserve

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Wenbing Jiang ◽  
Yibin Pan ◽  
Yumeng Hu ◽  
Xiaochang Leng ◽  
Jun Jiang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Diagnostic Accuracy ◽  
Fractional Flow Reserve ◽  
Computed Tomography Angiography ◽  
Predictive Value ◽  
Diagnostic Performance ◽  
Coronary Computed Tomography Angiography ◽  
Fractional Flow ◽  
Non Invasive ◽  
Flow Reserve

Abstract Background Fractional flow reserve (FFR) is a widely used gold standard to evaluate ischemia-causing lesions. A new method of non-invasive approach, termed as AccuFFRct, for calculating FFR based on coronary computed tomography angiography (CCTA) and computational fluid dynamics (CFD) has been proposed. However, its diagnostic accuracy has not been validated. Objectives This study sought to present a novel approach for non-invasive computation of FFR and evaluate its diagnostic performance in patients with coronary stenosis. Methods A total of 54 consecutive patients with 78 vessels from a single center who underwent CCTA and invasive FFR measurement were retrospectively analyzed. The CT-derived FFR values were computed using a novel CFD-based model (AccuFFRct, ArteryFlow Technology Co., Ltd., Hangzhou, China). Diagnostic performance of AccuFFRct and CCTA in detecting hemodynamically significant coronary artery disease (CAD) was evaluated using the invasive FFR as a reference standard. Results Diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for AccuFFRct in detecting FFR ≤ 0.8 on per-patient basis were 90.7, 89.5, 91.4, 85.0 and 94.1%, respectively, while those of CCTA were 38.9, 100.0, 5.71, 36.5 and 100.0%, respectively. The correlation between AccuFFRct and FFR was good (r = 0.76 and r = 0.65 on per-patient and per-vessel basis, respectively, both p < 0.0001). Area under the curve (AUC) values of AccuFFRct for identifying ischemia per-patient and per-vessel basis were 0.945 and 0.925, respectively. There was much higher accuracy, specificity and AUC for AccuFFRct compared with CCTA. Conclusions AccuFFRct computed from CCTA images alone demonstrated high diagnostic performance for detecting lesion-specific ischemia, it showed superior diagnostic power than CCTA and eliminated the risk of invasive tests, which could be an accurate and time-efficient computational tool for diagnosing ischemia and assisting clinical decision-making.

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