Effect of Coronary Calcification Severity on Measurements and Diagnostic Performance of CT-FFR With Computational Fluid Dynamics: Results From CT-FFR CHINA Trial

Aims: To explore the effect of coronary calcification severity on the measurements and diagnostic performance of computed tomography-derived fractional flow reserve (FFR; CT-FFR).Methods: This study included 305 patients (348 target vessels) with evaluable coronary calcification (CAC) scores from CT-FFR CHINA clinical trial. The enrolled patients all received coronary CT angiography (CCTA), CT-FFR, and invasive FFR examinations within 7 days. On both per-patient and per-vessel levels, the measured values, accuracy, and diagnostic performance of CT-FFR in identifying hemodynamically significant lesions were analyzed in all CAC score groups (CAC = 0, > 0 to <100, ≥ 100 to <400, and ≥ 400), with FFR as reference standard.Results: In total, the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under receiver operating characteristics curve (AUC) of CT-FFR were 85.8, 88.7, 86.9, 87.8, 87.1%, 0.90 on a per-patient level and 88.3, 89.3, 89.5, 88.2, 88.9%, 0.88 on a per-vessel level, respectively. Absolute difference of CT-FFR and FFR values tended to elevate with increased CAC scores (CAC = 0: 0.09 ± 0.10; CAC > 0 to <100: 0.06 ± 0.06; CAC ≥ 100 to <400: 0.09 ± 0.10; CAC ≥ 400: 0.11 ± 0.13; p = 0.246). However, no statistically significant difference was found in patient-based and vessel-based diagnostic performance of CT-FFR among all CAC score groups.Conclusion: This prospective multicenter trial supported CT-FFR as a viable tool in assessing coronary calcified lesions. Although large deviation of CT-FFR has a tendency to correlate with severe calcification, coronary calcification has no significant influence on CT-FFR diagnostic performance using the widely-recognized cut-off value of 0.8.

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P6175Prediction of coronary revascularization by coronary computed tomography angiography derived fractional flow reserve - different algorithms for interpretation

European Heart Journal ◽

10.1093/eurheartj/ehz746.0781 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

K T Madsen ◽

K T Veien ◽

B L Noergaard ◽

P Larsen ◽

L Deibjerg ◽

...

Keyword(s):

Chest Pain ◽

Fractional Flow Reserve ◽

Predictive Value ◽

Diagnostic Performance ◽

Coronary Revascularization ◽

Standard Of Care ◽

Fractional Flow ◽

Coronary Cta ◽

Flow Reserve ◽

Stable Chest Pain

Abstract Introduction Coronary CT angiography (CTA) derived fractional flow reserve (FFRct) is increasingly used for guiding referral to invasive procedures in patients with stable chest pain. However, optimal interpretation of FFRct-analysis in terms of location and threshold of applied FFRct-values is unclear. Purpose To evaluate the clinical performance of various vessel-specific physiological FFRct derived measures of ischemia for prediction of standard of care guided coronary revascularization in patients with stable chest pain and coronary artery disease as determined by coronary CTA. Methods Retrospective study in patients with stable chest pain referred for coronary angiography based on coronary CTA. Standard acquired coronary CTA data sets were transmitted for core-laboratory analysis at HeartFlow. Any FFRct value in the major coronary arteries ≥1.8 mm in diameter, including side branches, were registered. Lesions were categorized as positive for ischemia using 6 different algorithms: Lowest in vessel FFRct-value (1) ≤0.75 or (2) ≤0.80; 2 cm distal-to-lesion FFRct-value (3) ≤0.75 or (4) ≤0.80; ΔFFRct (5) ≥0.06 or a combination of 2 and 5. The personnel responsible for downstream patient management had no information regarding FFRct test results. Results A total of 172 patients were included. Revascularization was performed in 62 (35%) patients. The diagnostic performance of different FFRct algorithms for predicting standard of care guided coronary revascularization is shown in the Table. Revascularization Predictions by FFRct N=172 Diagnostic performance FFRCT false negative FFRCT false positive Values given as (%) No. of revasc vessels No. of abnormal vessels FFRCT Algorithm Sens Spec PPV NPV Acc 1 2 3 1 2 3 Distal FFRCT ≤0.75 77 68 58 84 72 12 2 0 29 5 1 Distal FFRCT ≤0.80 92 43 48 90 61 5 0 0 40 20 3 Lesion-specific FFRCT ≤0.75 68 86 74 83 80 17 3 0 12 3 0 Lesion-specific FFRCT ≤0.80 82 78 68 89 80 10 2 0 21 3 1 ΔFFRCT ≥0.06 98 36 47 98 59 1 0 0 51 19 0 Combinationa 92 54 53 92 67 5 0 0 39 12 0 aDistal FFRCT ≤0.80 and ΔFFRCT ≥0.06. Sens = sensitivity; Spec = specificity; PPV = positive predictive value; NPV = negative predictive value; Acc = accuracy; FFRCT = fractional flow reserve derived from coronary CTA; ΔFFRCT = difference between FFRCT-value immediately proximal and distal to lesion; Revasc = revascularized. Conclusion The diagnostic performance of FFRct in terms of predicting standard of care guided coronary revascularization is dependent on the applied algorithm for interpretation of the FFRct-analysis.

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

Cardiovascular Research ◽

10.1093/cvr/cvz289 ◽

2019 ◽

Vol 116 (7) ◽

pp. 1349-1356 ◽

Cited By ~ 5

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.

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P7 The impact of coronary calcification on diagnostic performance of workstation CT derived fractional flow reserve - a multicentre experience

European Heart Journal ◽

10.1093/ehjci/ehz872.014 ◽

2020 ◽

Vol 41 (Supplement_1) ◽

Author(s):

A R Ihdayhid ◽

S Motoyama ◽

S Fujimoto ◽

M Isa ◽

N Nerlekar ◽

...

Keyword(s):

Fractional Flow Reserve ◽

Diagnostic Performance ◽

Coronary Calcification ◽

Pooled Analysis ◽

Agatston Score ◽

Fractional Flow ◽

Reduced Order ◽

Flow Reserve ◽

Artery Disease ◽

The Impact

Abstract Background On-site workstation based computed tomography derived fractional flow reserve (CT-FFR) is an emerging method to assess the vessel specific ischaemia in coronary artery disease (CAD). The impact of coronary calcification on its diagnostic performance is unknown. Purpose To evaluate the impact of coronary calcification on the diagnostic performance of reduced-order CT-FFR at detecting vessel specific ischaemia. Methods This is a retrospective pooled analysis of 141 patients with suspected CAD enrolled from 3 global centres who underwent CT-coronary angiography (CTA), onsite CT-FFR and invasive FFR. Coronary calcification was assessed by Agatston score (AS). The diagnostic performance of CT-FFR (≤0.8) and CTA (≥50%) in evaluation of vessel specific ischaemia (FFR ≤ 0.8) was assessed across AS quartiles (Q1-4). A comparison of diagnostic performance of the low to mid AS (Q1 to Q3) versus high AS (Q4) was performed. Results Mean age and median AS was 65.8 ± 9.9 and 327.3 (interquartile range = 78.5 – 798.1). Diagnostic accuracy, sensitivity and specificity of CT-FFR for low-mid AS (0-798) and high AS (799-4019) were 77.4% vs 82.9%; 78.9% vs 94.7%; 68.8% vs 76.5% respectively with no statistical difference between the two groups. The AUC for ischaemia of CT-FFR in low to mid AS was comparable with AUC in the high AS (0.76 [95% CI: 0.66-0.86] vs 0.84 [0.69-0.99]; P = 0.397). The AUC for ischemia for CT-FFR in both low to mid AS and high AS was significantly higher than for CTA (0.76 [0.66-0.86] vs 0.57 [0.50-0.64]; P = 0.003 and 0.84 [0.69-0.99] vs 0.48 [0.38-0.57]; P < 0.001 respectively). Conclusion On-site workstation CT-FFR demonstrated consistently high diagnostic performance in patients with high AS. Its diagnostic performance was superior when compared with significant stenosis assessment on CTA across all spectrum of Agatston scores.

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Effect of lesion characteristics on diagnostic performance of CT-derived fractional flow reserve: exploring the indications for application based on CT-FFR CHINA trial (Preprint)

10.2196/preprints.35006 ◽

2021 ◽

Author(s):

Na Zhao ◽

Yang Gao ◽

Bo Xu ◽

Weixian Yang ◽

Lei Song ◽

...

Keyword(s):

Diagnostic Performance ◽

Coronary Calcification ◽

Lesion Group ◽

Lesion Length ◽

Fractional Flow ◽

Lesion Location ◽

Flow Reserve ◽

Bifurcation Lesions ◽

Coronary Lesions ◽

Sensitivity Specificity

BACKGROUND High diagnostic performance of coronary computed tomography angiography (CCTA)-derived fractional flow reserve (FFR; CT-FFR) in identifying flow-limiting stenosis has been confirmed. CT-FFR is recommended to assess the hemodynamic significance of coronary lesions. However, the optimal indications of CT-FFR relies on its ability to discriminating ischemia in situations of different types of lesions. And the effect of lesion-dependent factors on determining the diagnostic accuracy of CT-FFR have not been comprehensively evaluated yet. OBJECTIVE We aimed to investigate the effect of lesion-related factors on the diagnostic performance of CT-FFR with computational fluid dynamics algorithm, to promote the clinical application of it. METHODS This multicenter prospective clinical trial enrolled 317 patients with 30%–90% stenosis undergoing CCTA and invasive FFR from 5 centers across China. All target lesions were assigned into different lesion characteristics (target vessels, lesion location, lesion length, bifurcation lesions, and coronary calcification) subgroups. Diagnostic performance (accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under receiver operating characteristics curve (AUC)) of CT-FFR identifying ischemia were calculated and compared in all sub-groups. RESULTS Three hundred and sixty-six target vessels from 317 patients (mean age: 59.3 ± 9.6 years) were analyzed. The overall vessel-based diagnostic accuracy, sensitivity, specificity, PPV, NPV, and AUC of CT-FFR were 87.2%, 86.4%, 88.8%, 86.9%, 88.4%, and 0.90. Absence of bifurcation lesion group possessed the higher NPV of CT-FFR than presence of bifurcation lesion group (92.8% vs. 78.9%, p = 0.006). Whereas there was no statistically significant difference in diagnostic performance of CT-FFR among different target vessels, lesion location, lesion length, and coronary calcification sub-groups (all p > 0.05). CONCLUSIONS This study supported CT-FFR as a powerful noninvasive functional assessment tool for coronary lesions with different lesion characteristics, involving target vessel, lesion location, lesion length, and coronary calcification. While the diagnostic performance of CT-FFR was negatively affected by the presence of bifurcation lesions. CLINICALTRIAL https://clinicaltrials.gov; Unique identifier: NCT03692936.

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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 ◽

10.1136/bmjopen-2020-037780 ◽

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.

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Abstract 13372: Diagnostic Value of a Novel Coronary Computed Tomography Angiography-based Approach for Assessing Fractional Flow Reserve: Comparison with Invasive Measurement

Circulation ◽

10.1161/circ.130.suppl_2.13372 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Stefan Baumann ◽

Matthias Renker ◽

Rui Wang ◽

Felix G Meinel ◽

Jeremy D Rier ◽

...

Keyword(s):

Fractional Flow Reserve ◽

Predictive Value ◽

Diagnostic Performance ◽

Coronary Computed Tomography Angiography ◽

Diagnostic Value ◽

Reference Standard ◽

Fractional Flow ◽

Flow Reserve ◽

Coronary Lesions ◽

Invasive Measurement

Background: Noninvasive fractional flow reserve (FFR) from cCTA correlates well with invasive FFR and substantially improves the detection of obstructive CAD. However with current algorithms, CT-based FFR is derived off-site in an involved, time-consuming manner. We sought to investigate the diagnostic performance of a novel CT-based FFR algorithm (Siemens, Germany), developed for time-efficient in-hospital evaluation of hemodynamically indeterminate coronary lesions. Methods and Results: In a blinded fashion, CT-based FFR was assessed in 67 coronary lesions of 53 patients. Pressure guidewire-based FFR<0.80 served as the reference standard to define hemodynamically significant stenosis and assess the diagnostic performance of CT-based FFR compared to standard evaluation of cCTA (stenosis ≥50%). On a per-lesion and per-patient basis, CT-based FFR resulted in a sensitivity of 85% and 94%, specificity of 85% and 84%, positive predictive value of 71% and 71%, and negative predictive value of 93% and 97%. The area under the ROC curve on a per-lesion basis was significantly greater for CT-based FFR compared with standard evaluation of cCTA (0.92 vs. 0.72, p=0.0049). A similar trend, albeit not statistically significant, was observed on per-patient analysis (0.91 vs. 0.78, p=0.078). Mean total time for CT-based FFR was 37.5±13.8 min. Conclusions: The CT-based FFR algorithm evaluated here outperforms standard evaluation of cCTA for the detection of hemodynamically significant stenoses while allowing on-site application within clinically viable timeframes.

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

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.714077 ◽

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.

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

BioMedical Engineering OnLine ◽

10.1186/s12938-021-00914-3 ◽

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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