Assessment of Invasive Fractional Flow Reserve Procedures Using Computational Fluid Dynamics

2020 ◽  
Author(s):  
Yasser Abuouf ◽  
Muhamed Albadawi ◽  
Shinichi Ookawara ◽  
Mahmoud Ahmed
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Pressure Drop ◽  
Fractional Flow Reserve ◽  
Treatment Plan ◽  
Three Dimensional ◽  
Patient Specific ◽  
Concomitant Treatment ◽  
Fractional Flow ◽  
Flow Reserve

Abstract Coronary artery disease is the abnormal contraction of heart supply blood vessel. It may lead to major consequences such as heart attack and death. This narrowing in the coronary artery limits the oxygenated blood flow to the heart. Thus, diagnosing its severity helps physicians to select the appropriate treatment plan. Fractional Flow Reserve (FFR) is one of the most accurate methods to pinpoint the stenosis severity. The advantages of FFR are high accuracy, immediate estimation of the severity of the stenosis, and concomitant treatment using balloon or stent. Nevertheless, the main disadvantage of the FFR is being an invasive procedure that requires an incision under anesthesia. Moreover, inserting the guidewire across the stenosis may result in a ‘tight-fit’ between the vessel lumen and the guidewire. This may cause an increase in the measured pressure drop, leading to a false estimation of the blood flow parameters. To estimate the errors in diagnosis procedures, a comprehensive three-dimensional model blood flow along with guidewire is developed. Reconstructed three-dimensional coronary artery geometry from a patient-specific scan is used. Blood is considered non-Newtonian and the flow is pulsatile. The comprehensive model is numerically simulated using boundary conditions. Based on the predicted results, the ratio between pressure drop and distal dynamic pressure (CDP) is studied. The predicted results for each case are compared with the control case (the case without guidewire) and analyzed. It was found that simulating the model by placing the guidewire at a full position prior to the simulation leads to an overestimation of the CDP as it increases by 34.3%. However, simulating the procedure of guidewire insertion is more accurate. It shows that the CDP value increases by 7%.

scholarly journals Effect of guidewire insertion in fractional flow reserve procedure for real geometry using computational fluid dynamics

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yasser Abuouf ◽  
Muhamed AlBadawi ◽  
Shinichi Ookawara ◽  
Mahmoud Ahmed
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Treatment Plan ◽  
Three Dimensional ◽  
Patient Specific ◽  
Flow Ratio ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Actual Flow

Abstract Background Coronary artery disease is an abnormal contraction of the heart supply blood vessel. It limits the oxygenated blood flow to the heart. Thus, diagnosing its severity helps physicians to select the appropriate treatment plan. Fractional flow reserve (FFR) is the most accurate method to pinpoint the stenosis severity. However, inserting the guidewire across stenosis may cause a false overestimation of severity. Methods To estimate the errors due to guidewire insertion, reconstructed three-dimensional coronary artery geometry from a patient-specific scan is used. A comprehensive three-dimensional blood flow model is developed. Blood is considered non-Newtonian and the flow is pulsatile. The model is numerically simulated using realistic boundary conditions. Results The FFR value is calculated and compared with the actual flow ratio. Additionally, the ratio between pressure drop and distal dynamic pressure (CDP) is studied. The obtained results for each case are compared and analyzed with the case without a guidewire. It was found that placing the guidewire leads to overestimating the severity of moderate stenosis. It reduces the FFR value from 0.43 to 0.33 with a 23.26% error compared to 0.44 actual flow ratio and the CDP increases from 5.31 to 7.2 with a 35.6% error. FFR value in mild stenosis does not have a significant change due to placing the guidewire. The FFR value decreases from 0.83 to 0.82 compared to the 0.83 actual flow ratio. Conclusion Consequently, physicians should consider these errors while deciding the treatment plan.

scholarly journals Coronary Tortuosity Overestimate The FFR Measurement In Stenotic Coronary Artery Model

2021 ◽  
Author(s):  
Jiatong Liu ◽  
Libo Zhang ◽  
Hongzeng Xu
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Three Dimensional ◽  
Pressure Profile ◽  
Measurement Procedure ◽  
Fractional Flow ◽  
Load Effect ◽  
Flow Reserve ◽  
Coronary Tortuosity

Abstract Background: The object of the study is to investigate the effect of coronary tortuosity (CT) on fractional flow reserve (FFR) in stenotic coronary artery.Methods: A three dimensional computational model of simulation of blood flow in stenotic coronary artery with multi-bend CT was constructed with Fluent 16.0 software. Blood was simulated as non-Newtonian fluid with the Carreau model. The simulation of blood flow in coronary artery stenotic model was used by the finite element methods with the condition of CT and no coronary tortuosity (NCT). Coronary artery hemodynamic parameters such as pressure, velocity and physiological diagnostic parameter fractional flow reserve (FFR) were studied in the model with the coronary tortuosity condition.Results: The results showed that the downstream CT impedance condition has significant impacts on numerical simulation. The pressure profile of pre-stenotic is almost identical in the two models. However the pressure in the pre-stenotic and post-stenotic artery domain is much higher in the CT model. The pressure fluctuation range in CT model was much higher than that in the NCT model. In the coronary artey model with 75% stenosis for the CT condition, the FFR was 0.823 while the FFR was 0.767 in the same model with NCT condition.Conclusions: This study provides evidence that FFR value was increased in coronary stenotic artery with the presence of CT. Therefore, it should be taking into account the influence of CT load effect in FFR measurement procedure, otherwise the CAD risk will be underestimated.

13N-ammonia PET/CT stress myocardial blood flow compared to fractional flow reserve in coronary artery disease

2020 ◽  
Vol 41 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Jouke J. Boer ◽  
Johan J.J.S. Kappelhof ◽  
Friso M. van der Zant ◽  
Maurits Wondergem ◽  
Hans(J) B.R.M. de Swart ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Blood Flow ◽  
Coronary Artery ◽  
Myocardial Blood Flow ◽  
Fractional Flow Reserve ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Stress Myocardial Blood Flow ◽  
Pet Ct ◽  
Artery Disease

scholarly journals The Accuracy of Virtual Fractional Flow Reserve From Invasive Angiography: Importance of the Method of Reconstructing Three-dimensional Coronary Artery Anatomy

2021 ◽  
Author(s):  
Roshni Solanki ◽  
Rebecca Gosling ◽  
Vignesh Rammohan ◽  
Giulia Pederzani ◽  
Pankaj Garg ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Three Dimensional ◽  
Epipolar Line ◽  
Fractional Flow ◽  
Coronary Anatomy ◽  
Flow Reserve ◽  
3D Printed ◽  
Surface Similarity ◽  
Line Projection

Abstract Background Three dimensional (3D) coronary anatomy, reconstructed from coronary angiography (CA), is now being used as the basis to compute ‘virtual’ fractional flow reserve (vFFR), and thereby guide treatment decisions in patients with coronary artery disease (CAD). Reconstruction accuracy is therefore important. Yet these methods remain poorly validated. Furthermore, the magnitude of vFFR error arising from reconstruction is unkown. We aimed to validate a new method for 3D CA reconstruction and determine the effect this had upon the accuracy of vFFR.Methods Clinically realistic coronary phantom models were created (seven standard stenoses in aluminium and 15 patient-based 3D-printed) and imaged with CA, three times, according to clinical protocols, yielding 66 datasets. Each was reconstructed using epipolar line projection and intersection. All reconstructions were compared against the phantom models in terms of minimal lumen diameter, centreline and surface similarity. 3D-printed reconstructions (n=45) and the reference files from which they were printed underwent vFFR computation, and the results were compared. Results The average error in reconstructing minimum lumen diameter (MLD) was 0.05 (±0.03 mm) which was <1% (95%CI 0.13-1.61%) compared with caliper measurement. Overall surface similarity was excellent (Hausdorff distance 0.65 mm). Errors in 3D CA reconstruction accounted for an error in vFFR of ±0.06 (95% limits of agreement).Conclusions Errors arising from the epipolar line projection method used to reconstruct 3D coronary anatomy from CA are small but result in clinically relevant errors in vFFR simulation, amounting to approximately 40% of the total error associated with vFFR.

P6181The association of coronary lumen volume to left ventricle mass ratio with myocardial blood flow and fractional flow reserve

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
P A Van Diemen ◽  
S P Schumacher ◽  
M J Bom ◽  
R S Driessen ◽  
H Everaars ◽  
...  
Keyword(s):  
Blood Flow ◽  
Left Ventricle ◽  
Myocardial Blood Flow ◽  
Fractional Flow Reserve ◽  
Patient Specific ◽  
Mass Ratio ◽  
Fractional Flow ◽  
Left Ventricle Mass ◽  
Lumen Volume ◽  
Flow Reserve

Abstract Background A low coronary lumen volume to left ventricle mass ratio (V/M) derived from coronary computed tomography angiography (CCTA) has been proposed as a factor contributing to impaired myocardial blood flow (MBF) even in the absence of obstructive coronary artery disease (CAD). Objective To elucidate the association of V/M with non-invasively obtained MBF parameters by means of [15O]H2O positron emission tomography (PET), as well as its correlations with invasively measured fractional flow reserve (FFR), overall and specifically in vessel with non-obstructive CAD. Methods This is a substudy of the PACIFIC trial, in which 208 patients underwent CCTA, and [15O]H2O PET prior to invasive coronary angiography (ICA) in conjunction with 3 vessel FFR measurements. Patient specific V/M was calculated for 152 patients. Matched vessel specific hyperemic MBF (hMBF), coronary flow reserve (CFR), FFR, and patient specific V/M were available for 431 vessels. The median V/M (20.71 mm3/g) was used to divide the study population into a group with a low V/M (<20.71 mm3/g) and a high V/M (≥20.71 mm3/g). Non-obstructive CAD was defined as a ≤50% stenosis grade on ICA. Results Overall, a higher percentage of vessels with an abnormal hMBF (34% vs. 19%, p=0.009), lower FFR values (0.93 [interquartile range: 0.85–0.97] vs. 0.95 [0.89–0.98], p=0.016), and a higher number of positive FFR values (20% vs. 9%, p=0.004) were observed among vessels in the low V/M group. Furthermore, a weak correlation between V/M, global hMBF (R=0.179, p=0.027), and global CFR (R=0.163, p=0.045) as well as a weak significant association with vessel specific hMBF (p=0.027), and FFR (p<0.001) was observed (figure 1). V/M was not independently predictive of vessels specific MBF parameters or FFR. Among vessels with non-obstructive CAD (361 vessels), an abnormal hMBF tended to be more frequently observed in vessels with a low patient specific V/M (21% vs. 13%, p=0.056). Globally, there was no correlation between V/M and hMBF nor CFR. Patient specific V/M tended to be weakly associated with vessel specific hMBF (p=0.083) and was associated with FFR (p=0.027) (figure 1). Lastly, patient specific V/M tended to be independently predictive of FFR in this specific group. Conclusion Overall, vessels with an abnormal hMBF, and positive FFR measurements were more frequently observed in patients with a low V/M compared to those with a high V/M. Furthermore, V/M weakly correlated with global hMBF as well as with CFR and was associated with vessel specific hMBF and FFR. However, there was no correlation between V/M and global nor vessel specific blood flow parameters in the absence of obstructive CAD, notwithstanding a weak association of V/M with FFR within this group was noted.

scholarly journals Numerical and experimental investigations of Fractional Flow Reserve (FFR) in a stenosed coronary artery

2019 ◽  
Vol 128 ◽  
pp. 02006 ◽  
Author(s):  
Supratim Saha ◽  
T. Purushotham ◽  
K. Arul Prakash
Keyword(s):  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Surgical Intervention ◽  
Patient Specific ◽  
Experimental Investigations ◽  
Lesion Length ◽  
Fractional Flow ◽  
Specific Data ◽  
Flow Reserve ◽  
Stenosed Coronary Artery

The coronary artery is numerically investigated based on CFD techniques for measuring the severity of stenosis. In mild cases, medication is often preferred whereas for severe cases surgical intervention is `required but most of the cases fall in between. Thus, it poses a problem for clinicians in choosing an appropriate action. The Fractional Flow Reserve (FFR) is a number which helps to predict the functional significance of stenosis in this scenario. In this study, various cases of occlusion percentranging between 40 to 70 are considered using different models for predicting FFR in the stenosed coronary artery. The lesion length is also varied between 1 cm and 5 cm based on patient–specific data. The experimental investigation of FFR in the coronary stenosis using silicon model is also carried out in this study and compared with numerical results. The effect of occlusion percentage and lesionlengthon the FFR value are quantified.

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