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.

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 in clinical practice: from wire-based invasive measurement to image-based computation

2019 ◽  
Vol 41 (34) ◽  
pp. 3271-3279 ◽  
Author(s):  
Shengxian Tu ◽  
Jelmer Westra ◽  
Julien Adjedj ◽  
Daixin Ding ◽  
Fuyou Liang ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Diagnostic Methods ◽  
Functional Evaluation ◽  
Fractional Flow ◽  
Catheterization Laboratory ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Stenosis Severity ◽  
Procedural Guidance ◽  
Invasive Measurement

Abstract Fractional flow reserve (FFR) and instantaneous wave-free ratio are the present standard diagnostic methods for invasive assessment of the functional significance of epicardial coronary stenosis. Despite the overall trend towards more physiology-guided revascularization, there remains a gap between guideline recommendations and the clinical adoption of functional evaluation of stenosis severity. A number of image-based approaches have been proposed to compute FFR without the use of pressure wire and induced hyperaemia. In order to better understand these emerging technologies, we sought to highlight the principles, diagnostic performance, clinical applications, practical aspects, and current challenges of computational physiology in the catheterization laboratory. Computational FFR has the potential to expand and facilitate the use of physiology for diagnosis, procedural guidance, and evaluation of therapies, with anticipated impact on resource utilization and patient outcomes.

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