In-Vivo Evaluation of Severity of Microvascular Impairments and Epicardial Coronary Stenoses Using Fundamental Fluid Dynamics Endpoints

2008 ◽  
Author(s):  
Koustubh D. Ashtekar ◽  
Edward Kim ◽  
Abhijit S. Roy ◽  
Tarek A. Helmy ◽  
Mohamed A. Effat ◽  
...  
Keyword(s):  
Clinical Decision Making ◽  
Clinical Decision ◽  
Fractional Flow ◽  
In Vivo Evaluation ◽  
Flow Reserve ◽  
Coronary Stenoses ◽  
Decision Making Processes ◽  
Epicardial Stenosis ◽  
Treatment Procedures

Coronary circulation is mainly regulated by two serial resistances, namely, epicardial stenosis and microvascular impairments, both causing abnormal coronary blood circulation [1]. Delineation of the true severities of these diseases is important to guide clinical decision-making processes for the selection of appropriate treatment procedures [2]. The presently used diagnostic parameters: FFR (fractional flow reserve defined as the ratio of distal to proximal hyperemic pressure) and CFR (coronary flow reserve defined as ratio of basal to hyperemic flow) [1], for the evaluation of severity of epicardial coronary stenosis are well established in clinical practice. On the other hand, current methods to evaluate the microcirculatory status are limited [3].

Influence of Variable Native Arterial Diameter and Vasculature Status on Coronary Diagnostic Parameters

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Ishan Goswami ◽  
Srikara V. Peelukhana ◽  
Marwan F. Al-Rjoub ◽  
Lloyd H. Back ◽  
Rupak K. Banerjee
Keyword(s):  
Pressure Drop ◽  
Clinical Decision Making ◽  
Dynamic Pressure ◽  
Clinical Intervention ◽  
Clinical Decision ◽  
Fractional Flow ◽  
Arterial Diameter ◽  
Diagnostic Parameters ◽  
Flow Reserve

In current practice, diagnostic parameters, such as fractional flow reserve (FFR) and coronary flow reserve (CFR), are used to determine the severity of a coronary artery stenosis. FFR is defined as the ratio of hyperemic pressures distal (p˜rh) and proximal (p˜ah) to a stenosis. CFR is the ratio of flow at hyperemic and basal condition. Another diagnostic parameter suggested by our group is the pressure drop coefficient (CDP). CDP is defined as the ratio of the pressure drop across the stenosis to the upstream dynamic pressure. These parameters are evaluated by invasively measuring flow (CFR), pressure (FFR), or both (CDP) in a diseased artery using guidewire tipped with a sensor. Pathologic state of artery is indicated by lower CFR (<2). Similarly, FFR lower than 0.75 leads to clinical intervention. Cutoff for CDP is under investigation. Diameter and vascular condition influence both flow and pressure drop, and thus, their effect on FFR and CDP was studied. In vitro experiment coupled with pressure-flow relationships from human clinical data was used to simulate pathophysiologic conditions in two representative arterial diameters, 2.5 mm (N1) and 3 mm (N2). With a 0.014 in. (0.35 mm) guidewire inserted, diagnostic parameters were evaluated for mild (∼64% area stenosis (AS)), intermediate (∼80% AS), and severe (∼90% AS) stenosis for both N1 and N2 arteries, and between two conditions, with and without myocardial infarction (MI). Arterial diameter did not influence FFR for clinically relevant cases of mild and intermediate stenosis (difference < 5%). Stenosis severity was underestimated due to higher FFR (mild: ∼9%, intermediate: ∼ 20%, severe: ∼ 30%) for MI condition because of lower pressure drops, and this may affect clinical decision making. CDP varied with diameter (mild: ∼20%, intermediate: ∼24%, severe: by 2.5 times), and vascular condition (mild: ∼35%, intermediate: ∼14%, severe: ∼ 9%). However, nonoverlapping range of CDP allowed better delineation of stenosis severities irrespective of diameter and vascular condition.

scholarly journals The FAME Trials: Impact on Clinical Decision Making

2016 ◽  
Vol 11 (2) ◽  
pp. 116 ◽  
Author(s):  
Guy R Heyndrickx ◽  
Gábor G Tóth ◽  
◽  
Keyword(s):  
Medical Treatment ◽  
Fractional Flow Reserve ◽  
Clinical Decision Making ◽  
Stable Coronary Artery Disease ◽  
Coronary Intervention ◽  
Clinical Decision ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Stenosis Severity ◽  
Artery Disease

Careful and stepwise evaluation of the fractional flow reserve (FFR) index has been performed over the years, culminating in the landmark Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) and Fractional Flow Reserve-Guided Percutaneous Coronary Intervention Plus Optimal Medical Treatment Versus Optimal Medical Treatment Alone in Patients with Stable Coronary Artery Disease (FAME II) trials. Findings from these studies demonstrated unequivocally the overall inadequacy of angiography versus FFR to correctly assess stenosis severity. Thus, proof of concept and clinical applicability was established beyond debate and will be discussed here.

scholarly journals Case Report of First Angiography-Based On-Line FFR Assessment during Coronary Catheterization

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Ran Kornowski ◽  
Hana Vaknin-Assa
Keyword(s):  
Decision Making ◽  
Case Report ◽  
Clinical Decision Making ◽  
Guide Wire ◽  
Coronary Revascularization ◽  
Three Dimensional ◽  
Clinical Decision ◽  
Fractional Flow ◽  
Flow Reserve ◽  
On Line

Fractional flow reserve (FFR), an index of the hemodynamic severity of coronary stenoses, is derived from hyperemic pressure measurements and requires a pressure-monitoring guide wire and hyperemic stimulus. Although it has become the standard of reference for decision-making regarding coronary revascularization, the procedure remains underutilized due to its invasive nature. FFRangio is a novel technology that uses the patient’s hemodynamic data and routine angiograms to generate a complete three-dimensional coronary tree, with color-coded display of the FFR values at each point along the vessels. After being proven to be as accurate as invasive FFR measurements in an off-line study, this case report presents the first on-line application of the system in the catheterization lab. Here too, a high concordance between FFRangio and invasive FFR was observed. In light of the demonstrated capabilities of the FFRangio system, it should emerge as an important tool for clinical decision-making regarding revascularization in patients with coronary artery disease.

scholarly journals DISENGAGE Registry

2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Mariano Pellicano ◽  
Giovanni Ciccarelli ◽  
Panagiotis Xaplanteris ◽  
Giuseppe Di Gioia ◽  
Anastasios Milkas ◽  
...  
Keyword(s):  
Decision Making ◽  
Fractional Flow Reserve ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Coronary Ostium ◽  
Fractional Flow ◽  
Flow Reserve ◽  
The Impact ◽  
Guiding Catheter ◽  
Hyperemic Flow

Background: During fractional flow reserve (FFR) measurement, the simple presence of the guiding catheter (GC) within the coronary ostium might create artificial ostial stenosis, affecting the hyperemic flow. We aimed to investigate whether selective GC engagement of the coronary ostium might impede hyperemic flow, and therefore impact FFR measurements and related clinical decision-making. Methods: In the DISENGAGE (Determination of Fractional Flow Reserve in Intermediate Coronary Stenosis With Guiding Catheter Disengagement) registry, FFR was prospectively measured twice (with GC engaged [FFR eng ] and disengaged [FFR dis ]) in 202 intermediate stenoses of 173 patients. We assessed (1) whether ΔFFR eng –FFR dis was significantly different from the intrinsic variability of repeated FFR measurements (test-retest repeatability); (2) whether the extent of ΔFFR eng –FFR dis could be clinically significant and therefore able to impact clinical decision-making; and (3) whether ΔFFR eng –FFR dis related to the stenosis location, that is, proximal and middle versus distal coronary segments. Results: Overall, FFR significantly changed after GC disengagement: FFR eng 0.84±0.08 versus FFR dis 0.80±0.09, P <0.001. Particularly, in 38 stenoses (19%) with FFR values in the 0.81 to 0.85 range, GC disengagement was associated with a shift from above to below the 0.80 clinical cutoff, resulting into a change of the treatment strategy from medical therapy to percutaneous coronary intervention. The impact of GC disengagement was significantly more pronounced with stenoses located in proximal and middle as compared with distal coronary segments (ΔFFR eng –FFR dis , proximal and middle 0.04±0.03 versus distal segments 0.03±0.03; P =0.042). Conclusions: GC disengagement results in a shift of FFR values from above to below the clinical cutoff FFR value of 0.80 in 1 out of 5 measurements. This occurs mostly when the stenosis is located in proximal and middle coronary segments and the FFR value is close to the cutoff value.

scholarly journals Non-hyperaemic pressure ratios to guide percutaneous coronary intervention

Open Heart ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. e001308
Author(s):  
Michael Michail ◽  
Udit Thakur ◽  
Ojas Mehta ◽  
John M Ramzy ◽  
Andrea Comella ◽  
...  
Keyword(s):  
Clinical Decision Making ◽  
Pressure Ratio ◽  
Coronary Intervention ◽  
Clinical Decision ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Pressure Wire ◽  
Procedural Time ◽  
Catheter Laboratory

The use of fractional flow reserve (FFR) in guiding revascularisation improves patient outcomes and has been well-established in clinical guidelines. Despite this, the uptake of FFR has been limited, likely attributable to the perceived increase in procedural time and use of hyperaemic agents that can cause patient discomfort. This has led to the development of instantaneous wave-free ratio (iFR), an alternative non-hyperaemic pressure ratio (NHPR). Since its inception, the use of iFR has been supported by an increasing body of evidence and is now guideline recommended. More recently, other commercially available NHPRs including diastolic hyperaemia-free ratio and resting full-cycle ratio have emerged. Studies have demonstrated that these indices, in addition to mean distal coronary artery pressure to mean aortic pressure ratio, are mathematically analogous (with specific nuances) to iFR. Additionally, there is increasing data demonstrating the equivalent diagnostic performance of alternative NHPRs in comparison with iFR and FFR. These NHPRs are now integral within most current pressure wire systems and are commonly available in the catheter laboratory. It is therefore key to understand the fundamental differences and evidence for NHPRs to guide appropriate clinical decision-making.

scholarly journals Opportunities and challenges of implementing computed tomography fractional flow reserve into clinical practice

Heart ◽  
2020 ◽  
Vol 106 (18) ◽  
pp. 1387-1393 ◽  
Author(s):  
Muhummad Sohaib Nazir ◽  
Tarun K Mittal ◽  
Jonathan Weir-McCall ◽  
Koen Nieman ◽  
Keith Channon ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Fractional Flow Reserve ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Outcome Data ◽  
Resource Utilisation ◽  
Clinical Implementation ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Pre Treatment

CT-derived fractional flow reserve (CT-FFR) uses computational fluid dynamics to derive non-invasive FFR to determine the haemodynamic significance of coronary artery lesions. Studies have demonstrated good diagnostic accuracy of CT-FFR and reassuring short-term clinical outcome data.As a prerequisite, high-quality CT coronary angiography (CTCA) images are required with good heart rate control and pre-treatment with glyceryl trinitrate, which would otherwise render CTCA as unsuitable for CT-FFR. CT-FFR can determine the functional significance of CAD lesions, and there are supportive data for its use in clinical decision-making. However, the downstream impact on myocardial ischaemic burden or viability cannot be obtained.Several challenges remain with implementation of CT-FFR, including interpretation, training, availability, resource utilisation and funding. Further research is required to determine which cases should be considered for clinical CT-FFR analysis, with additional practical guidance on how to implement this emerging technique in clinical practice. Furthermore, long-term prognostic data are required before widespread clinical implementation of CT-FFR can be recommended.While there are several potential opportunities for CT-FFR, at present there remain important systemic and technical limitations and challenges that need to be overcome prior to routine integration of CT-FFR into clinical practice.

P2736Hemodynamic and clinical impact in adult patients with anomalous aortic origin of the coronary artery evaluated with quantitative flow reserve

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J Adjedj ◽  
F Hyafil ◽  
F Aminfar ◽  
A Farnoud ◽  
V Rubimbura ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Clinical Decision Making ◽  
Quantitative Coronary Angiography ◽  
Proximal Part ◽  
Clinical Impact ◽  
Adult Patients ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Quantitative Flow

Abstract Background Anomalous origin of the right coronary artery (ARCA) represents the most frequent form of abnormal coronary origin and may potentially increase the risk for sudden cardiac death. Evaluation of ARCA in adult patients referred for invasive coronary angiograms (ICA) is difficult, and clinical impact is unknown. Quantitative flow reserve (QFR) is an available method able to virtually calculate fractional flow reserve using 3-dimensional quantitative coronary angiography (3D-QCA) based on ICA. Objectives To evaluate the feasibility of QFR analysis in patients with ARCA and its clinical impact. Methods Using the registry of proximal anomalous connections of coronary arteries (ANOCOR registry), a multicentric observational registry including 472 adult patients with ANOCOR between 2010 and 2013, we retrospectively performed QFR analysis from ICA and evaluated the rate of death, myocardial infarction, unplanned revascularization and hospitalization in cardiology at 5 years. Results Among 128 patients with ARCA, 41 (32%) could have QFR analysis with median clinical follow-up of 8.3 years. The mean QFR value was 0.90±0.10, and 3D-QCA analysis showed preserved lumen area despite the elliptical shape of the proximal part of the ARCA which in the worst cases appeared on ICA as a significant narrowing. The event rate was 14.6% (n=6), including three deaths (one due to cancer, one due to stroke, and one cause remains unknown), two unplanned revascularizations, and one hospitalization for heart failure at 5 years. No myocardial infarction was reported. Conclusions QFR analysis of ARCA is feasible and non-significant QFR values are associated with good clinical outcome at 5 years. QFR of ARCA could be the evaluation of choice to help in clinical decision-making during ICA, when applicable.

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