scholarly journals A Computational Analysis of the Influence of a Pressure Wire in Evaluating Coronary Stenosis

Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 165
Author(s):  
Jie Yi ◽  
Fang-Bao Tian ◽  
Anne Simmons ◽  
Tracie Barber
Keyword(s):  
Coronary Stenosis ◽  
Severe Case ◽  
Patient Specific ◽  
Fractional Flow ◽  
Ideal Model ◽  
Coronary Pressure ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Physical Presence ◽  
The Difference

Cardiovascular disease is one of the world’s leading causes of morbidity and mortality. Fractional flow reserve (FFR) was proposed in the 1990s to more accurately evaluate the functional severity of intermediate coronary stenosis, and it is currently the gold standard in cardiac catheterization laboratories where coronary pressure and flow are routinely obtained. The clinical measurement of FFR relies on a pressure wire for the recording of pressures; however, in computational fluid dynamics studies, an FFR is frequently predicted using a wire-absent model. We aim to investigate the influence of the physical presence of a 0.014-inch (≈0.36 mm) pressure wire in the calculation of virtual FFR. Ideal and patient-specific models were simulated with the absence and presence of a pressure wire. The computed FFR reduced from 0.96 to 0.93 after inserting a wire in a 3-mm non-stenosed (pipe) ideal model. In mild stenotic cases, the difference in FFR between the wire-absent and wire-included models was slight. The overestimation in severe case was large but is of less clinical significance because, in practice, this tight lesion does not require sophisticated measurement to be considered critical. However, an absence of the pressure wire in simulations could contribute to an over-evaluation for an intermediate coronary stenosis.

Fractional flow reserve

2021 ◽  
pp. 63-67
Author(s):  
Giovanni Ciccarelli ◽  
Emanuele Barbato ◽  
Bernard De Bruyne
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Coronary Intervention ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Coronary Pressure ◽  
Flow Reserve ◽  
Percutaneous Coronary

Fractional flow reserve is an index of the physiological significance of a coronary stenosis, defined as the ratio of maximal myocardial blood flow in the presence of the stenosis to the theoretically normal maximal myocardial blood flow (i.e. in the absence of the stenosis). This flow ratio can be calculated from the ratio of distal coronary pressure to central aortic pressure during maximal hyperaemia. More practically, fractional flow reserve indicates to what extent the epicardial segment can be responsible for myocardial ischaemia and, accordingly, fractional flow reserve quantifies the expected perfusion benefit from revascularization by percutaneous coronary intervention. Very limited evidence exists on the role on fractional flow reserve for bypass grafts.

scholarly journals Comparison of Machine Learning Computed Tomography-Based Fractional Flow Reserve and Coronary CT Angiography-Derived Plaque Characteristics with Invasive Resting Full-Cycle Ratio

2020 ◽  
Vol 9 (3) ◽  
pp. 714
Author(s):  
Stefan Baumann ◽  
Markus Hirt ◽  
Christina Rott ◽  
Gökce H. Özdemir ◽  
Christian Tesche ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computed Tomography ◽  
Coronary Artery ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Fractional Flow ◽  
Luminal Diameter ◽  
Coronary Computed Tomography ◽  
Flow Reserve ◽  
Pressure Wire

Background: The aim is to compare the machine learning-based coronary-computed tomography fractional flow reserve (CT-FFRML) and coronary-computed tomographic morphological plaque characteristics with the resting full-cycle ratio (RFRTM) as a novel invasive resting pressure-wire index for detecting hemodynamically significant coronary artery stenosis. Methods: In our single center study, patients with coronary artery disease (CAD) who had a clinically indicated coronary computed tomography angiography (cCTA) and subsequent invasive coronary angiography (ICA) with pressure wire-measurement were included. On-site prototype CT-FFRML software and on-site CT-plaque software were used to calculate the hemodynamic relevance of coronary stenosis. Results: We enrolled 33 patients (70% male, mean age 68 ± 12 years). On a per-lesion basis, the area under the receiver operating characteristic curve (AUC) of CT-FFRML (0.90) was higher than the AUCs of the morphological plaque characteristics length/minimal luminal diameter4 (LL/MLD4; 0.80), minimal luminal diameter (MLD; 0.77), remodeling index (RI; 0.76), degree of luminal diameter stenosis (0.75), and minimal luminal area (MLA; 0.75). Conclusion: CT-FFRML and morphological plaque characteristics show a significant correlation to detected hemodynamically significant coronary stenosis. Whole CT-FFRML had the best discriminatory power, using RFRTM as the reference standard.

Fractional Flow Reserve Estimation in Coronary Arteries by Forward Geometrical Modeling

2013 ◽  
Author(s):  
Jelle T. C. Schrauwen ◽  
Jolanda J. Wentzel ◽  
Anton F. W. van der Steen ◽  
Frank J. H. Gijsen
Keyword(s):  
Clinical Practice ◽  
Pressure Drop ◽  
Coronary Arteries ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Fractional Flow ◽  
Reserve Estimation ◽  
Important Indicator ◽  
Flow Reserve ◽  
Pressure Wire

Fractional Flow Reserve (FFR) is an important indicator for the hemodynamic significance of a coronary stenosis [1]. The FFR is defined as the pressure drop over the stenosis under hyperemia. The pressure drop, and thus the FFR, depends on both the geometry and flow. In clinical practice, the FFR is measured with a pressure wire under administration of adenosine and intervention is warranted if the FFR is below 0.8.

scholarly journals The imortance of hyperemic contrast velocity assessment on image-based fractional flow reserve calculation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
B Tar ◽  
A Uveges ◽  
Z Koszegi
Keyword(s):  
Fractional Flow Reserve ◽  
Three Dimensional ◽  
Microvascular Disease ◽  
Simple Calculation ◽  
Fractional Flow ◽  
Roc Curve Analysis ◽  
Flow Reserve ◽  
Myocardial Area ◽  
Pressure Wire ◽  
The Difference

Abstract Aims Image-based fractional flow reserve (FFR) calculations reported good agreement with FFR measured invasively. The purpose of this study was to perform a retrospective analysis of the cases of a previous study on less invasive FFR calculation (simple FFR: FFRsim) as a simple calculation from hyperemic contrast flow data and three-dimensional coronary parameters. Methods and results We aimed to analyze the relations between the pressure wire-based FFR (FFRmeas) and fixed FFRsim: calculated from the fixed hyperemic velocity, rest FFRsim: calculated using the non-hyperemic frame count data to extrapolate the hyperemic velocity (based on the database used in the FAVOR1 study) hyp FFRsim: the hyperemic velocity derived from the frame count assessment during vasodilation.To calculate the frame count reserve (CFRFC) the resting frame count was divided by the hyperemic frame count; this value was then used to determine the CFRFC/FFRmeas ratio as an indicator of microvascular function in the corresponding myocardial area of the measured coronary vessel. A total of 50 lesions with intermediate stenosis were investigated. Correlation between rest FFRsim (from the resting frame count extrapolated to the hyperemic velocity) and FFRmeas was lower than the correlation between hyp FFRsim and FFRmeas (r=0.761 vs. 0.824). Based on ROC curve analysis for predicting the abnormal FFR of ≤0.80 the AUC were significantly higher for the hyperemia-based parameter than those calculated from resting frame counts. Significantly higher AUC were detected by the hyp FFRsim than by the rest FFRsim: 0.936 (95% CI: 0.828 to 0.985) vs. 0.862 (CI: 0.734 to 0.943); p=0.011. Linear regression analyses between the FFRsim (either by fixed FFRsim or by rest FFRsim or by hyp FFRsim methods) and the FFRmeas showed higher intercepts and less steep of the slopes in the subgroups with presence of microvascular disease defined as CFRFC/FFRmeas <2 than in those without microvascular disease (CFRFC/FFRmeas >2); the difference reached significant level (p=0.019) when calculated by rest FFRsim. Conclusions Hyperemic challenge either by adenosine or regadenoson is required for exact image-based FFR calculation especially in cases of suspicion for microvascular coronary disease. Funding Acknowledgement Type of funding source: None

Next Generation FFR Microcatheter Technology

2017 ◽  
Vol 12 (02) ◽  
pp. 2
Author(s):  
Katrina Mountfort ◽  
Keyword(s):  
Fractional Flow Reserve ◽  
Clinical Utility ◽  
Independent Predictor ◽  
Medical Systems ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Percutaneous Coronary ◽  
The Difference ◽  
Standard Techniques

Fractional flow reserve (FFR) is the mainstay of functional haemodynamic assessment of coronary artery lesions, guiding decisions in percutaneous coronary interventions (PCI). The RXi® rapid exchange FFR system, featuring an ultrathin monorail pressure microcatheter (Navvus™) has the potential to simplify PCI procedures. Data from two studies sponsored by ACIST Medical Systems evaluating the clinical utility of the microcatheter system were presented at EuroPCR, which took place over 16–19 May 2017 in Paris. Early data from the FFR-Stent Evaluated at Rotterdam Cardiology Hospital (FFR-SEARCH) registry have indicated that post-PCI, almost half of patients have FFR values below 0.90 even when stent placement appears fine on angiography. This registry is noteworthy for including a high proportion of unstable patients. The Assessment of Catheter-based Interrogation and Standard Techniques for Fractional Flow Reserve measurement (ACIST-FFR) study has shown that the microcatheter system provides a modestly lower FFR value compared with the traditional pressure wire, and an independent predictor of a difference between the two is the physiological severity of the lesion as measured by the Navvus microcatheter, meaning that the clinical impact of the difference is minimal for most measurements. These findings add to the growing body of evidence in support of the microcatheter FFR system and have prompted further research into optimising procedures.

Prognostic implication of CT-FFR based functional SYNTAX score in patients with de novo three-vessel disease

2020 ◽  
Author(s):  
Hong Yan Qiao ◽  
Jian Hua Li ◽  
U Joseph Schoepf ◽  
Richard R Bayer ◽  
Fiona C Tinnefeld ◽  
...  
Keyword(s):  
De Novo ◽  
Predictive Accuracy ◽  
Computed Tomographic Angiography ◽  
Syntax Score ◽  
Cardiac Events ◽  
Fractional Flow ◽  
Computed Tomographic ◽  
Flow Reserve ◽  
The Difference ◽  
Functional Syntax

Abstract Aims This study was aimed at investigating whether a machine learning (ML)-based coronary computed tomographic angiography (CCTA) derived fractional flow reserve (CT-FFR) SYNTAX score (SS), ‘Functional SYNTAX score’ (FSSCTA), would predict clinical outcome in patients with three-vessel coronary artery disease (CAD). Methods and results The SS based on CCTA (SSCTA) and ICA (SSICA) were retrospectively collected in 227 consecutive patients with three-vessel CAD. FSSCTA was calculated by combining the anatomical data with functional data derived from a ML-based CT-FFR assessment. The ability of each score system to predict major adverse cardiac events (MACE) was compared. The difference between revascularization strategies directed by the anatomical SS and FSSCTA was also assessed. Two hundred and twenty-seven patients were divided into two groups according to the SSCTA cut-off value of 22. After determining FSSCTA for each patient, 22.9% of patients (52/227) were reclassified to a low-risk group (FSSCTA ≤ 22). In the low- vs. intermediate-to-high (>22) FSSCTA group, MACE occurred in 3.2% (4/125) vs. 34.3% (35/102), respectively (P < 0.001). The independent predictors of MACE were FSSCTA (OR = 1.21, P = 0.001) and diabetes (OR = 2.35, P = 0.048). FSSCTA demonstrated a better predictive accuracy for MACE compared with SSCTA (AUC: 0.81 vs. 0.75, P = 0.01) and SSICA (0.81 vs. 0.75, P < 0.001). After FSSCTA was revealed, 52 patients initially referred for CABG based on SSCTA would have been changed to PCI. Conclusion Recalculating SS by incorporating lesion-specific ischaemia as determined by ML-based CT-FFR is a better predictor of MACE in patients with three-vessel CAD. Additionally, the use of FSSCTA may alter selected revascularization strategies in these patients.

Abstract 14743: Usefulness of Estimated Coronary Flow Velocity Using Quantitative Flow Ratio for Intermediate Coronary Stenosis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Eiji Ichimoto ◽  
Nao Konagai ◽  
Sawako Horie ◽  
Atsushi Hasegawa ◽  
Hirofumi Miyahara ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Coronary Stenosis ◽  
Coronary Flow ◽  
Flow Ratio ◽  
Operating Characteristics ◽  
Fractional Flow ◽  
Coronary Flow Velocity ◽  
Flow Reserve ◽  
Quantitative Flow Ratio ◽  
Quantitative Flow

Introduction: Quantitative flow ratio (QFR) is a diagnostic modality for functional assessment for intermediate coronary stenosis without the use of pressure wire. QFR is calculated from 3-dimensional quantitative CAG (3D-QCA) using an advanced algorithm that enables fast computation of the pressure drop caused by coronary stenosis. Hypothesis: We assessed the usefulness of QFR and the association with an estimated coronary flow velocity (eCFV) for intermediate coronary stenosis. Methods: A total of 100 lesions in 80 consecutive patients were assessed Fractional Flow Reserve (FFR) for intermediate coronary stenosis between January 2011 and April 2019. Of these, 97 lesions in 77 patients who underwent QFR were included in this study. Patients were classified into two groups (FFR ≤ 0.80 or FFR > 0.80). QFR and eCFV using contrast were measured by Thrombolysis in Myocardial Infarction (TIMI) frame counts. Results: There was no significant differences in target vessels (p = 0.90) and diffuse lesions (p = 0.06) between the two groups (FFR ≤ 0.80 or FFR > 0.80). Mean FFR and QFR values were 0.78 ± 0.12 and 0.77 ± 0.11, respectively. QFR had a good correlation with FFR values (r = 0.86, p < 0.0001). The diagnostic accuracy, sensitivity, and specificity on QFR ≤ 0.80 were 91.8%, 92.7% and 90.5%, respectively. The eCFV of FFR ≤ 0.80 was greater than that of FFR > 0.80 (0.19 ± 0.08 m/s vs. 0.14 ± 0.06 m/s, p<0.001). Figure showed that the eCFV correlated with FFR values (r = -0.29, p < 0.01). Moreover, the eCFV had a high area under the curve (AUC = 0.71, p < 0.01) on Receiver operating characteristics curve (ROC) analysis with FFR ≤ 0.80. Conclusions: QFR was useful for the assessment of functional stenosis severity. As eCFV was faster, FFR was lower for intermediate coronary stenosis. The eCFV had a good correlation with FFR and may become one of the evaluations for ischemia.

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