scholarly journals Effect of Patient-Specific Coronary Flow Reserve Values on the Accuracy of MRI-Based Virtual Fractional Flow Reserve

2021 ◽  
Vol 8 ◽  
Author(s):  
Jackson Hair ◽  
Lucas Timmins ◽  
Retta El Sayed ◽  
Habib Samady ◽  
John Oshinski
Keyword(s):  
Magnetic Resonance ◽  
Functional Significance ◽  
Coronary Flow ◽  
Patient Specific ◽  
Flow Waveform ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Epicardial Stenosis ◽  
Flow Waveforms ◽  
Hyperemic Flow

The purpose of this study is to investigate the effect of varying coronary flow reserve (CFR) values on the calculation of computationally-derived fractional flow reserve (FFR). CFR reflects both vessel resistance due to an epicardial stenosis, and resistance in the distal microvascular tissue. Patients may have a wide range of CFR related to the tissue substrate that is independent of epicardial stenosis levels. Most computationally based virtual FFR values such as FFRCT do not measure patient specific CFR values but use a population-average value to create hyperemic flow conditions. In this study, a coronary arterial computational geometry was constructed using magnetic resonance angiography (MRA) data acquired in a patient with moderate CAD. Coronary flow waveforms under rest and stress conditions were acquired in 13 patients with phase-contrast magnetic resonance (PCMR) to calculate CFR, and these flow waveforms and CFR values were applied as inlet flow boundary conditions to determine FFR based on computational fluid dynamics (CFD) simulations. The stress flow waveform gave a measure of the functional significance of the vessel when evaluated with the physiologically-accurate behavior with the patient-specific CFR. The resting flow waveform was then scaled by a series of CFR values determined in the 13 patients to simulate how hyperemic flow and CFR affects FFR values. We found that FFR values calculated using non–patient-specific CFR values did not accurately predict those calculated with the true hyperemic flow waveform. This indicates that both patient-specific anatomic and flow information are required to accurately non-invasively assess the functional significance of coronary lesions.

scholarly journals Diagnostic value of myocardial perfusion CT to detect coexisting microvascular dysfunction in patients with obstructive epicardial coronary disease

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Hada ◽  
Y Kanaji ◽  
H Ueno ◽  
K Nogami ◽  
T Misawa ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Coronary Flow ◽  
Microvascular Dysfunction ◽  
Diagnostic Value ◽  
Regional Myocardial Blood Flow ◽  
Fractional Flow ◽  
Coronary Syndrome ◽  
Flow Reserve ◽  
Significant Difference ◽  
Epicardial Stenosis

Abstract Background The usefulness of computed tomography myocardial perfusion (CTP) to assess hemodynamically significant coronary artery lesions has been previously reported. However, the diagnostic value of quantitative evaluation of regional absolute coronary flow by CTP to detect microvascular dysfunction remains unknown. Purpose The aim of study is to assess the diagnostic value of preprocedural CTP to detect coexisting microvascular dysfunction with functionally significant epicardial stenosis in patients with chronic coronary syndromes. Methods and results Thirty-three chronic coronary syndrome patients with de novo single functionally significant stenosis (Fractional flow reserve [FFR]<0.80) who underwent noncomplicated PCI were investigated. In CTP analysis, regional myocardial blood flow (MBF) at rest (rest-MBF) and hyperemia (hyperemic-MBF) were evaluated semi-automatically. Clinical characteristics, pressure-temperature sensor-chipped wire-based information and CTP findings were compared between groups with and without microvascular dysfunction defined by the index of microcirculatory resistance (IMR) (IMR≥25, n=17, IMR<25, n=16, respectively). The determinants of coexistence of microvascular dysfunction and functional epicardial stenosis were determined. In invasive wire-based analysis, FFR, coronary flow reserve (CFRwire) and IMR were 0.68 (0.57–0.72), 1.61 (1.00–1.98), and 26.7 (19.3–39.4) respectively. In CTP analysis, rest and hyperemic-MBF and CFR derived from CTP (CFRCTP; calculated as hyperemic-MBF/rest-MBF) were 2.00 (1.31–2.35) ml/min/g, 4.03 (2.11–5.44) ml/min/g, and 2.09 (1.49–2.09) respectively. In the lesions with IMR>25, hyperemic-MBF was significantly lower than that in IMR<25 (3.42 [1.89–4.34] vs 4.50 [3.44–5.99], p=0.031), although there was no significant difference in regional rest-MBF and CFRCTP (1.75 [1.31–2.24] vs 2.05 [1.35–2.46], p=0.439, and 1.83 [1.21–2.11] vs 2.61 [1.91–2.91], p=0.101 respectively). Receiver operating characteristic curve analysis of hyperemic-MBF detecting IMR>25 showed area under the curve of 0.72 (0.54–0.90), sensitivity of 47% and specificity of 94%. Conclusion Quantitative assessment of absolute coronary flow by CTP may help detect coexisting microvascular dysfunction in patients with significant epicardial stenotic lesions. Funding Acknowledgement Type of funding source: None

scholarly journals Impact of Elective Percutaneous Coronary Intervention on Global Absolute Coronary Flow and Flow Reserve Evaluated by Phase-Contrast Cine-Magnetic Resonance Imaging in Relation to Regional Invasive Physiological Indices

2018 ◽  
Vol 11 (7) ◽  
Author(s):  
Yoshihisa Kanaji ◽  
Taishi Yonetsu ◽  
Rikuta Hamaya ◽  
Tadashi Murai ◽  
Eisuke Usui ◽  
...  
Keyword(s):  
Blood Flow ◽  
Magnetic Resonance ◽  
Coronary Blood Flow ◽  
Fractional Flow Reserve ◽  
Coronary Flow ◽  
Phase Contrast ◽  
Coronary Intervention ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Physiological Indices

Background: Few studies have documented changes in global absolute coronary blood flow and global coronary flow reserve after percutaneous coronary intervention (PCI) in relation to regional physiological measures. Phase-contrast cine-magnetic resonance of the coronary sinus is a promising approach to quantify global absolute coronary blood flow. We aimed to assess the impact of elective PCI on global absolute coronary blood flow and global coronary flow reserve by quantifying coronary sinus flow (CSF) using phase-contrast cine-magnetic resonance in relation to regional physiological indices. Methods and Results: We prospectively studied 54 patients with stable angina undergoing elective PCI for a single proximal lesion. Phase-contrast cine-magnetic resonance was used to assess CSF and CSF reserve at rest and during maximum hyperemia, before and after PCI. Regional physiological indices were obtained during PCI. A complete data set was obtained in 50 patients. Hyperemic CSF increased significantly after PCI (pre-PCI, 230.2 [167.4–282.8] mL/min; post-PCI, 267.4 [224.1–346.2] mL/min; P <0.01), although 12 patients (24.0%) showed a decrease, despite successful PCI and improved fractional flow reserve. CSF reserve numerically, albeit not statistically significant ( P =0.19), increased from 2.65 (1.95–3.96) to 2.98 (2.13–4.32). Patients with decreased CSF after PCI were associated with significantly greater pre-PCI hyperemic CSF, lower global coronary vascular resistance, lower regional microcirculatory resistance, and higher fractional flow reserve (all P <0.01). Conclusions: Fractional flow reserve–guided PCI in patients with single de novo lesions was associated with increased absolute hyperemic CSF, although 24% of patients showed decreased hyperemic CSF, despite successful and uncomplicated PCI. The present approach combining regional and global physiological assessments may provide a novel insight into the dynamic behavior of the coronary hemodynamics and microvascular function after PCI.

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.

scholarly journals Discordance Between Fractional Flow Reserve and Coronary Flow Reserve

2017 ◽  
Vol 10 (10) ◽  
pp. 999-1007 ◽  
Author(s):  
Sung Gyun Ahn ◽  
Jon Suh ◽  
Olivia Y. Hung ◽  
Hee Su Lee ◽  
Yasir H. Bouchi ◽  
...  
Keyword(s):  
Coronary Flow Reserve ◽  
Fractional Flow Reserve ◽  
Coronary Flow ◽  
Fractional Flow ◽  
Flow Reserve
Sign in / Sign up

Export Citation Format

Share Document