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.

Differential influence of lesion length on fractional flow reserve in intermediate coronary lesions between each coronary artery

2019 ◽  
Vol 95 (6) ◽  
Author(s):  
Hiroki Shibutani ◽  
Kenichi Fujii ◽  
Koichiro Matsumura ◽  
Munemitsu Otagaki ◽  
Shun Morishita ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Lesion Length ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Coronary Lesions

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.

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.

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