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 ◽  
...  

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.

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
T Mano ◽  
V Ferreira ◽  
R Ramos ◽  
E Oliveira ◽  
A Santana ◽  
...  

Abstract Introduction Invasive functional assessment (iFA) of coronary artery disease (CAD) needs expensive devices, has potential procedure-related complications and is still underutilized. Virtual Fractional Flow Reserve (vFFR) derived from invasive coronary angiography (ICA) has the potential to overcome these limitations. Purpose To investigate the feasibility of vFFR analysis and its correlation with iFA (iFR, RFR or FFR). Methods Retrospective analysis of consecutive patients (pts) who underwent iFA in a tertiary center between 2019 and 2020. vFFR was calculated using a dedicated software (CAAS Workstation 8.4) based on standard non-hyperaemic coronary angiograms acquired in ≥2 different projections, by operators blinded to iFA results. Diagnostic performance and accuracy of vFFR were evaluated. 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 Out of 113 coronary arteries of 102 pts, vFFR was successfully analysed in 106 (94%). Reasons for vFFR analysis failure were: vessel projection overlap (48%), <2 angiographic projections (28%) and table movement while acquisition (24%). From 106 coronary arteries of 95 pts with analysable vFFR (78% male, mean age 67.8±9.7 years), 90 (85%) showed agreement with the respective iFA result. The vFFR predicted which lesions were physiologically significant and which were not with accuracy, sensitivity, specificity, positive and negative predictive values of 73%, 73%, 83%, 53%, and 92% respectively. The mean difference between vFFR and iFA were −0.0484±0.096 and Pearson's correlation coefficient was 0.533 (p<0.001). The ROC area under the curve was 0.839 (0.751–0.928, p<0.001). Conclusion FFR were feasible in 94% of cases analysed retrospectively. As compared to gold-standard iFA, vFFR had an overall moderate accuracy in detecting ischemia-producing lesions and a negative predictive value >90%. vFFR has the potential to substantially simplify physiological coronary lesion assessment and thus improve its current uptake. FUNDunding Acknowledgement Type of funding sources: None. Bland-Altman plot between vFFR and IFA


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Ray ◽  
K Green ◽  
A Shamsi ◽  
A Mahmood ◽  
A Hatrick ◽  
...  

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


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 ◽  
...  

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.


Author(s):  
Stefan Möhlenkamp

Invasive coronary angiography is used in symptomatic athletes with clinical suspicion of coronary artery disease which presumably requires interventional therapy, i.e. mainly in acute coronary syndrome and myocardial infarction. Because of its invasive nature, it is not used in asymptomatic athletes. Advanced intra-coronary artery imaging, including intra-vascular ultrasound (IVUS), intra-coronary Doppler ultrasound (ICDUS) and assessment of fractional flow reserve (FFR), can help to improve understanding of epicardial and intra-myocardial microvascular causes of symptoms. Plaque rupture, plaque erosion, coronary vasospasm, and thrombotic coronary occlusion have been demonstrated subsequent to athletic activities, but it is uncertain to what extent exhaustive exercise triggered the symptoms that led to invasive angiography. Because of radiation exposure, use of contrast agent, and the costs of the test careful risk–benefit assessment is necessary, especially in asymptomatic athletes with risk factors and in young athletes.


Author(s):  
Andrii Yu. Gavrylyshyn ◽  
Sergii V. Salo ◽  
Olena V. Levchyshyna ◽  
Andrii K. Logutov ◽  
Vasyl V. Lazoryshynets

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.


2019 ◽  
Vol 116 (7) ◽  
pp. 1349-1356 ◽  
Author(s):  
Jianping Li ◽  
Yanjun Gong ◽  
Weimin Wang ◽  
Qing Yang ◽  
Bin Liu ◽  
...  

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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