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.

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.

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.

scholarly journals Extremely tortuous coronary arteries - when optical coherence tomography and fractional flow reserve did not help us much

2018 ◽  
Vol 75 (1) ◽  
pp. 100-103
Author(s):  
Vladimir Miloradovic ◽  
Dusan Nikolic ◽  
Miodrag Sreckovic ◽  
Ivana Djokic-Nikolic
Keyword(s):  
Optical Coherence Tomography ◽  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Stable Angina ◽  
Stress Test ◽  
Optical Coherence ◽  
Fractional Flow ◽  
Coronary Pressure ◽  
Flow Reserve ◽  
Coronary Tortuosity

Introduction. Extreme coronary tortuosity may lead to flow alteration resulting in a reduction in coronary pressure distal to the tortuous segment, subsequently leading to ischemia. Therefore the detection of a true cause of ischemia, i.e. whether a fixed stenosis or tortuosity by itself is responsible for its creation, with non-invasive and invasive methods is a real challenge. Case report. We presented a case of a patient with a history of stable angina [Canadian Cardiovascular Society (CCS class II)], an abnormal stress test and coronary tortuosity without hemodynamically significant stenosis. Due to suspected linear lesion between the two bends in proximal segment of Right coronary artery (RCA) we performed optical coherence tomography (OCT), minimum lumen area (MLA)-13.19 mm2) and fractional flow reserve (FFR) RCA (0.94). We opted for conservative treatment for stable angina. Conclusion. When tortuosities are associated with atherosclerosis in coronary artery for determination of true cause of ischemia invasive methods can be used, such as OCT and FFR. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/VSP1912304E">10.2298/VSP1912304E</a><u></b></font>

scholarly journals Resistance to Flow of Arterial Y-Grafts 6 Months After Coronary Artery Bypass Surgery

Circulation ◽  
2005 ◽  
Vol 112 (9_supplement) ◽  
Author(s):  
David Glineur ◽  
Philippe Noirhomme ◽  
Jim Reisch ◽  
Gebrine El Khoury ◽  
Parla Astarci ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Pressure Gradient ◽  
Fractional Flow Reserve ◽  
Artery Bypass ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Flow Demand ◽  
Minimal Resistance

Background— The use of both internal thoracic arteries (ITAs) as a Y-graft configuration has been proposed as a technique allowing complete arterial revascularization. Controversy remains, however, about the capacity of this Y-graft configuration to provide sufficient blood flow to the whole left coronary system and about possible steal phenomenon occurring during periods of maximal myocardial blood flow demand. Methods and Results— To evaluate graft conductance 6 months after Y-graft revascularization of the left coronary system with both ITAs, 11 consecutive patients were studied during cardiac catheterization. In all of the cases, the left ITA had been connected to the left anterior descending coronary artery (LAD) territory (mean, 1.3 anastomoses), and the free right ITA was anastomosed proximally to the left ITA and distally to the left circumflex (LCX) territory (mean, 1.9 anastomoses). Pressure and fractional flow reserve (FFR) were recorded using a 0.014-inch pressure wire advanced distally in the left ITA main stem close to the proximal anastomosis of the free right ITA (ITA-stem) and in the distal part of each ITA branch at the site of their implantation to the LAD (ITA-LAD) or LCX (ITA-LCX) system. At each of these sites, the pressure gradient between aorta and the graft was measured in basal condition and during maximal hyperemia induced by intragraft bolus injection of 40 μg of adenosine. In basal conditions, the pressure gradient was minimal between the aorta and the ITA-stem (2±2 mm Hg), the ITA-LAD (3±3 mm Hg), and the ITA-LCX (3±2 mm Hg; P value was not significant versus ITA-LAD). During maximal hyperemia, the pressure gradient increased to 7±2 mm Hg in the ITA-stem, to 9±5 mm Hg in the ITA-LAD, and to 9±3 in the ITA-LCX ( P value not significant versus ITA-LAD). The fractional flow reserve was 0.93±0.03 in the ITA-stem, 0.91±0.04 in the ITA-LAD, and 0.91±0.03 in the ITA-LCX. Conclusions— A Y-graft configuration with a free right ITA attached to a pedicled left ITA allows an adequate revascularization of the whole left coronary system with an even distribution of perfusion pressure in both distal branches and minimal resistance to maximal blood flow.

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