scholarly journals Estimating the accuracy of a reduced-order model for the calculation of fractional flow reserve (FFR)

2017 ◽  
Vol 34 (1) ◽  
pp. e2908 ◽  
Author(s):  
Etienne Boileau ◽  
Sanjay Pant ◽  
Carl Roobottom ◽  
Igor Sazonov ◽  
Jingjing Deng ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Reduced Order Model ◽  
Fractional Flow ◽  
Order Model ◽  
Reduced Order ◽  
Flow Reserve

scholarly journals An improved reduced-order model for pressure drop across arterial stenoses

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258047
Author(s):  
Konstantinos G. Lyras ◽  
Jack Lee
Keyword(s):  
Pressure Drop ◽  
Reduced Order Model ◽  
Accurate Estimation ◽  
Classification Error ◽  
Fractional Flow ◽  
Order Model ◽  
Reduced Order ◽  
Flow Reserve ◽  
Proposed Model ◽  
New Formulation

Quantification of pressure drop across stenotic arteries is a major element in the functional assessment of occlusive arterial disease. Accurate estimation of the pressure drop with a numerical model allows the calculation of Fractional Flow Reserve (FFR), which is a haemodynamic index employed for guiding coronary revascularisation. Its non-invasive evaluation would contribute to safer and cost-effective diseases management. In this work, we propose a new formulation of a reduced-order model of trans-stenotic pressure drop, based on a consistent theoretical analysis of the Navier-Stokes equation. The new formulation features a novel term that characterises the contribution of turbulence effect to pressure loss. Results from three-dimensional computational fluid dynamics (CFD) showed that the proposed model produces predictions that are significantly more accurate than the existing reduced-order models, for large and small symmetric and eccentric stenoses, covering mild to severe area reductions. FFR calculations based on the proposed model produced zero classification error for three classes comprising positive (≤ 0.75), negative (≥ 0.8) and intermediate (0.75 − 0.8) classes.

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

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.

scholarly journals Diagnostic performance of virtual fractional flow reserve derived from routine coronary angiography using segmentation free reduced order (1-dimensional) flow modelling

2020 ◽  
Vol 9 ◽  
pp. 204800402096757
Author(s):  
Kevin Mohee ◽  
Jonathan P Mynard ◽  
Gauravsingh Dhunnoo ◽  
Rhodri Davies ◽  
Perumal Nithiarasu ◽  
...  
Keyword(s):  
Coronary Angiography ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Diagnostic Performance ◽  
Fractional Flow ◽  
Conventional Angiography ◽  
Reduced Order ◽  
Flow Modelling ◽  
Flow Reserve ◽  
Coronary Lesions

Introduction Fractional flow reserve (FFR) improves assessment of the physiological significance of coronary lesions compared with conventional angiography. However, it is an invasive investigation. We tested the performance of a virtual FFR (1D-vFFR) using routine angiographic images and a rapidly performed reduced order computational model. Methods Quantitative coronary angiography (QCA) was performed in 102 with coronary lesions assessed by invasive FFR. A 1D-vFFR for each lesion was created using reduced order (one-dimensional) computational flow modelling derived from conventional angiographic images and patient specific estimates of coronary flow. The diagnostic accuracy of 1D-vFFR and QCA derived stenosis was compared against the gold standard of invasive FFR using area under the receiver operator characteristic curve (AUC). Results QCA revealed the mean coronary stenosis diameter was 44% ± 12% and lesion length 13 ± 7 mm. Following angiography calculation of the 1DvFFR took less than one minute. Coronary stenosis (QCA) had a significant but weak correlation with FFR (r = −0.2, p = 0.04) and poor diagnostic performance to identify lesions with FFR <0.80 (AUC 0.39, p = 0.09), (sensitivity – 58% and specificity – 26% at a QCA stenosis of 50%). In contrast, 1D-vFFR had a better correlation with FFR (r = 0.32, p = 0.01) and significantly better diagnostic performance (AUC 0.67, p = 0.007), (sensitivity – 92% and specificity - 29% at a 1D-vFFR of 0.7). Conclusions 1D-vFFR improves the determination of functionally significant coronary lesions compared with conventional angiography without requiring a pressure-wire or hyperaemia induction. It is fast enough to influence immediate clinical decision-making but requires further clinical evaluation.

P6187Multicentre diagnostic performance of on-site workstation CT derived fractional flow reserve

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A R Ihdayhid ◽  
S Fujimoto ◽  
S Motoyama ◽  
A Comella ◽  
E Kato ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Diagnostic Performance ◽  
Pearson Correlation ◽  
Pooled Analysis ◽  
Fractional Flow ◽  
Desktop Computer ◽  
Reduced Order ◽  
Flow Reserve ◽  
Artery Disease ◽  
Global Data

Abstract Background On-site workstation based computed tomography derived fractional flow reserve (CT-FFR) is an emerging method to assess vessel specific ischaemia in coronary artery disease (CAD). Global data on its diagnostic performance when compared with CT coronary angiography (CTA) is limited. Purpose To evaluate the on-site multicentre diagnostic performance of reduced-order CT-FFR at detecting vessel specific ischaemia. Method This is a retrospective pooled analysis of 141 patients (204 vessels) with suspected CAD enrolled from 3 global centres who underwent CTA, onsite CT-FFR and invasive FFR. On-site CT-FFR was performed using a reduced order model on a standard desktop computer with dedicated software. The per vessel diagnostic performance of CT-FFR (≤0.8) for vessel specific ischemia (FFR≤0.8) was compared with CTA (≥50% stenosis). Results Mean age was 65.8±9.9, 70.7% were male. FFR significant stenosis was present in 34.3% (70/204) of vessels. Pearson correlation of CT-FFR for invasive FFR was 0.52, P<0.001. Bland Altman analysis demonstrated a mean difference of 0.06±0.15 (95% limits of agreement −0.22 to 0.35). Per vessel diagnostic accuracy, sensitivity and specificity of CT-FFR and CTA were 79.9% vs 53.5%; 78.6% vs 85.7%; 80.6% vs 35.9% respectively. Diagnostic performance as assessed by area under the receiver operator curve (AUC) for CT FFR was superior to CTA (0.82 [95% CI 0.76–0.88] vs 0.61 [0.55–0.67]; P<0.001). Conclusion On-site workstation CT-FFR demonstrated high per vessel diagnostic performance and was superior when compared with CTA in assessment of vessel specific ischaemia as assessed by invasive FFR in a multicentre setting.

Fractional Flow Reserve: Does a Cut-off Value add Value?

2016 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Shah R Mohdnazri ◽  
◽  
◽  
◽  
Thomas R Keeble ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Coronary Intervention ◽  
Grey Zone ◽  
Fractional Flow ◽  
Non Invasive ◽  
Invasive Test ◽  
Flow Reserve ◽  
A Value ◽  
Percutaneous Coronary ◽  
Value Add

Fractional flow reserve (FFR) has been shown to improve outcomes when used to guide percutaneous coronary intervention (PCI). There have been two proposed cut-off points for FFR. The first was derived by comparing FFR against a series of non-invasive tests, with a value of ≤0.75 shown to predict a positive ischaemia test. It was then shown in the DEFER study that a vessel FFR value of ≥0.75 was associated with safe deferral of PCI. During the validation phase, a ‘grey zone’ for FFR values of between 0.76 and 0.80 was demonstrated, where a positive non-invasive test may still occur, but sensitivity and specificity were sub-optimal. Clinical judgement was therefore advised for values in this range. The FAME studies then moved the FFR cut-off point to ≤0.80, with a view to predicting outcomes. The ≤0.80 cut-off point has been adopted into clinical practice guidelines, whereas the lower value of ≤0.75 is no longer widely used. Here, the authors discuss the data underpinning these cut-off values and the practical implications for their use when using FFR guidance in PCI.

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