scholarly journals Complex Coronary Hemodynamics - Simple Analog Modelling as an Educational Tool

2017 ◽  
Vol 11 (1) ◽  
pp. 12-19
Author(s):  
Gaurav R. Parikh ◽  
Elvis Peter ◽  
Nikolaos Kakouros
Keyword(s):  
Invasive Coronary Angiography ◽  
Computational Modelling ◽  
Poor Correlation ◽  
Educational Tool ◽  
Loss Assessment ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Complex Anatomy ◽  
Coronary Stenoses ◽  
Coronary Lesions

Objective: Invasive coronary angiography remains the cornerstone for evaluation of coronary stenoses despite there being a poor correlation between luminal loss assessment by coronary luminography and myocardial ischemia. This is especially true for coronary lesions deemed moderate by visual assessment. Coronary pressure-derived fractional flow reserve (FFR) has emerged as the gold standard for the evaluation of hemodynamic significance of coronary artery stenosis, which is cost effective and leads to improved patient outcomes. There are, however, several limitations to the use of FFR including the evaluation of serial stenoses. Method: In this article, we discuss the electronic-hydraulic analogy and the utility of simple electrical modelling to mimic the coronary circulation and coronary stenoses. We exemplify the effect of tandem coronary lesions on the FFR by modelling of a patient with sequential disease segments and complex anatomy. Results: We believe that such computational modelling can serve as a powerful educational tool to help clinicians better understand the complexity of coronary hemodynamics and improve patient care.

Abstract 20015: Value of Quantitative Atherosclerotic Plaque Assessment Using CCTA to Predict Lesion-specific Ischemia, Data from 407 Coronary Lesions

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Ran Heo ◽  
Hyung-Bok Park ◽  
Nakazato Ryo ◽  
Iksung Cho ◽  
Heidi Gransar ◽  
...  
Keyword(s):  
Invasive Coronary Angiography ◽  
Computed Tomographic Angiography ◽  
Plaque Burden ◽  
Fractional Flow ◽  
Luminal Diameter ◽  
Computed Tomographic ◽  
Flow Reserve ◽  
Significant Difference ◽  
Coronary Lesions ◽  
Tomographic Angiography

Introduction: While coronary computed tomographic angiography (CCTA) demonstrates high diagnostic performance for identification and exclusion of high-grade anatomic stenosis, it is unable to effectively discriminate coronary lesions that causes ischemia. Hypothesis: To study whether quantitative assessment of CCTA offer incremental information for discrimination of lesion ischemia beyond stenosis measures. Methods: 252 consecutive patients with suspected or known coronary artery disease (CAD) from 17 centers in 5 countries were enrolled (mean age 63±9 years, 71% male). Patients underwent CCTA and invasive coronary angiography (ICA), with 407 coronary lesions interrogated by invasive fractional flow reserve (FFR) at the time of maximum hyperemia. For these coronary lesions, we evaluated % diameter stenosis (%DS), % area stenosis (%AS), minimal luminal diameter (MLD, mm), minimal luminal area (MLA, mm 2 ), and plaque burden at MLA by CCTA. Plaque burden (PB, %) was defined as (vessel area–lumen area)/vessel areaх100. Lesion-specific ischemia by FFR was defined as a value ≤0.8. Results: In quantitative analysis area under the receiver operating characteristic curves (AUC) value of %DS, %AS, MLD, MLA, and PB for prediction of ischemia were 0.72 (95% confidence interval (CI) 0.68-0.77, p<0.001), 0.73 (95% CI 0.68-0.77, p<0.001), 0.75 (95% CI 0.70-0.79, p<0.001), 0.75 (95% CI 0.70-0.79, p<0.001), and 0.77 (95% CI 0.73-0.81, p<0.001), respectively. PB showed significantly improved AUC when compared to % area stenosis (p=0.002). However, PB didn’t show incremental power over MLA (p=0.213). There also was no significant difference in AUC between MLA and % area stenosis (p=0.330) Conclusions: Quantitative plaque assessment using CCTA could predict lesion-specific ischemia with good discrimination. Plaque burden showed incremental value over % area stenosis for ischemia prediction.

Functional assessment of myocardial ischemia by intracoronary electrocardiogram

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M.R Bigler ◽  
F Praz ◽  
G.C.M Siontis ◽  
M Stoller ◽  
R Grossenbacher ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Primary Study ◽  
Coronary Perfusion ◽  
Funding Source ◽  
Maximal Heart Rate ◽  
Fractional Flow ◽  
Coronary Syndrome ◽  
Flow Reserve ◽  
St Segment ◽  
Coronary Lesions

Abstract Background In patients with chronic coronary syndrome (CCS), percutaneous coronary intervention (PCI) targets hemodynamically significant stenoses, i.e., those thought to cause ischemia. The hemodynamic severity of a coronary stenosis increases with its tightness and with the myocardial mass of viable myocardium downstream of the stenosis. Besides the structural angiographic approach, assessment of functional relevance by pressure measurements (fractional flow reserve, FFR; instantaneous wave-free ratio, iFR) is recommended. However, visual angiographic assessment continues to dominate the treatment decisions for intermediate coronary lesions. Conversely, intracoronary ECG (icECG) potentially provides an inexpensive, sensitive and direct measure of myocardial ischemia. Purpose The goal of this study was to test the accuracy of intracoronary ECG during pharmacologic inotropic stress to determine coronary lesion severity in comparison to established physiologic indices (FFR/iFR) as well as with quantitatively determined percent diameter stenosis (%S) using biplane coronary angiography. Method This was a prospective, open-label study in patients with CCS. The primary study end point was the maximal change in icECG ST-segment shift during pharmacologic inotropic stress induced by dobutamine plus atropine obtained within 1 minute after the point of maximal heart rate (estimated by the formula 220 - age). IcECG was acquired by attaching an alligator clamp to the angioplasty guidewire positioned downstream of a stenosis. For the pressure-derived ratios, i.e. FFR and iFR, the coronary perfusion pressure downstream of a lesion as well as the aortic pressure were continuously recorded. Results One hundred patients were included in the study. Pearson-Correlation coefficient was significant between icECG and all three comparators (%S p&lt;0.001, iFR p&lt;0.001, FFR p&lt;0.001). Using the FFR threshold of 0.80 defining coronary hemodynamic significance, ROC-analysis of the absolute icECG ST-segment shift showed an area under the curve (AUC) of 0.708±0.053 (p=0.0001, n=100, FFR&lt;0.80 n=41). AUC for iFR was 0.919±0.030 (p&lt;0.0001), for percent diameter stenosis it was 0.867±0.036 (p&lt;0.0001). Conclusions During pharmacologic inotropic stress, intracoronary ECG ST-segment shift provides specific evidence for regional myocardial ischemia irrespective of the etiology and thus, provides an additional (patho-)physiologic information for decision making in borderline coronary lesions. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Swiss Heart Foundation

The Clinical Outcomes of Fractional Flow Reserve–Based Deferred Revascularization of Coronary Lesions in Patients on Hemodialysis

2021 ◽  
Vol 14 (4) ◽  
pp. 486-488
Author(s):  
Hisao Otsuki ◽  
Junichi Yamaguchi ◽  
Junya Matsuura ◽  
Yusuke Inagaki ◽  
Kazuki Tanaka ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Fractional Flow Reserve ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Coronary Lesions

scholarly journals Diagnostic performance and clinical implications for enhancing a hybrid quantitative flow ratio–FFR revascularization decision-making strategy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joyce Peper ◽  
Robbert W. van Hamersvelt ◽  
Benno J. W. M. Rensing ◽  
Jan-Peter van Kuijk ◽  
Michiel Voskuil ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Invasive Coronary Angiography ◽  
Hybrid Approach ◽  
Intermediate Zone ◽  
Flow Ratio ◽  
Fractional Flow ◽  
Hybrid Strategy ◽  
Flow Reserve ◽  
Quantitative Flow Ratio ◽  
Quantitative Flow

AbstractInvasive fractional flow reserve (FFR) adoption remains low mainly due to procedural and operator related factors as well as costs. Alternatively, quantitative flow ratio (QFR) achieves a high accuracy mainly outside the intermediate zone without the need for hyperaemia and wire-use. We aimed to determine the diagnostic performance of QFR and to evaluate a QFR–FFR hybrid strategy in which FFR is measured only in the intermediate zone. This retrospective study included 289 consecutive patients who underwent invasive coronary angiography and FFR. QFR was calculated for all vessels in which FFR was measured. The QFR–FFR hybrid approach was modelled using the intermediate zone of 0.77–0.87 in which FFR-measurements are recommended. The sensitivity, specificity, and accuracy on a per vessel-based analysis were 84.6%, 86.3% and 85.6% for QFR and 88.0%, 92.9% and 90.3% for the QFR–FFR hybrid approach. The diagnostic accuracy of QFR–FFR hybrid strategy with invasive FFR measurement was 93.4% and resulted in a 56.7% reduction in the need for FFR. QFR has a good correlation and agreement with invasive FFR. A hybrid QFR–FFR approach could extend the use of QFR and reduces the proportion of invasive FFR-measurements needed while improving accuracy.

scholarly journals CT Determination of Fractional Flow Reserve in Coronary Lesions

2016 ◽  
Vol 1 (3) ◽  
pp. 237-241 ◽  
Author(s):  
András Mester ◽  
Monica Chiţu ◽  
Nora Rat ◽  
Diana Opincariu ◽  
Lehel Bordi ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Computational Techniques ◽  
Functional Evaluation ◽  
Fractional Flow ◽  
Gold Standard Method ◽  
Flow Reserve ◽  
Ct Evaluation ◽  
Coronary Lesions

Abstract Invasively determined fractional flow reserve (FFR) represents the gold-standard method for the functional evaluation of coronary lesions. Coronary computed tomography angiography (CCTA) provides characterization of the coronary anatomy, with important morphological information on the atherosclerotic plaques, but does not offer a hemodynamic evaluation of coronary artery lesions. CT evaluation of FFR (FFRCT) is a new noninvasive diagnostic method, which provides anatomical and functional assessment of the whole coronary tree, based on computational techniques, with no more radiation or hyperemic agent administration compared with routine CCTA. Recent studies demonstrated the safety and accuracy of FFRCT and its therapeutic use and cost benefits in real-world clinical use.

Abstract 4471: Long-Term Follow-Up After Deferral of Percutaneous Coronary Intervention (PCI) in Patients With Moderate Coronary Lesions and Borderline Fractional Flow Reserve Measurements

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Takafumi Yamane ◽  
Koichi Tamita ◽  
Noriomi Kimura ◽  
Shunsuke Funakoshi ◽  
Kite Kim ◽  
...  
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Coronary Intervention ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Percutaneous Coronary ◽  
Coronary Lesions ◽  
Group 2 ◽  
Group 1

Background: Many studies have demonstrated that deferral of percutaneous coronary intervention (PCI) on the basis of a myocardial fractional flow reserve (FFR) ≥0.75 is associated with a very low coronary event rate. However, some groups have empirically chosen the cut-off value of 0.80 rather than 0.75 for decision to defer PCI and the FFR measurement between 0.75 and 0.80 has been established as a grey zone. The aim of this study was to evaluate the long-term clinical outcomes of patients with moderate coronary lesions and FFR measurements between 0.75 and 0.80. Methods: The study included 125 anigiographically moderate coronary lesions (>50% diameter stenosis by visual assessment) in 125 patients but in whom the PCI was deferred on the basis of an FFR ≥ 0.75. The FFR was calculated as the ratio of mean distal pressure divided by the proximal pressure during hyperemia. Patients were divided into two groups according to the result of FFR: ≥ 0.80 (n=99, group 1) and between 0.75 and 0.79 (n=26, group 2). We evaluated the long-term major adverse cardiovascular events (MACE) related and unrelated to the FFR-evaluated lesion. Results: During a follow-up period of 82 ± 29 months (mean ± SD), The Kaplan-Meier event-free survival curves showed that group 2 was poorer than group 1 in prognosis (p=0.0148). The incidence of MACE unrelated FFR-evaluated lesion in group 1 was equivalent to that in group 2 (p=0.96). Conclusions: In patients with moderate coronary lesions and borderline FFR measurements, deferral of PCI was associated with a higher rate of MACE related to the FFR-evaluated lesion. FFR cut-off point of 0.80 instead of 0.75 may be more appropriate for deferring PCI.

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