Distinguishing Epicardial and Microvascular Disease Using Combined Functional and Anatomical Endpoints in a Porcine Model

2012 ◽  
Author(s):  
Srikara V. Peelukhana ◽  
Kranthi K. Kolli ◽  
Massoud Leesar ◽  
Mohamed Effat ◽  
Tarek Helmy ◽  
...  
Keyword(s):  
Resistance Index ◽  
Microvascular Disease ◽  
Flow Coefficient ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Artery Disease ◽  
Lesion Flow Coefficient ◽  
Epicardial Stenosis ◽  
The Individual ◽  
Concurrent Assessment

For a better treatment of coronary artery disease in a catheterization lab, detection of the relative contributions of the epicardial stenosis (ES) and concomitant microvascular disease (MVD) is important. To diagnose ES, fractional flow reserve (FFR), the hyperemic stenosis resistance index (hSRv) and to diagnose MVD, hyperemic microvascular resistance index (hMRv) have been tested in cath labs. However, for concurrent assessment of ES and MVD, functional parameter utilizing flow and pressure values, pressure drop coefficient (CDP) and combined functional and anatomical parameter, lesion flow coefficient (LFC) are defined. To test the ability of CDP and LFC to account for ES and MVD, they were correlated with the hSRv and hMRv. We hypothesize that CDP and LFC will have a better combined correlation with hSRv and hMRv. Simultaneous pressure and flow readings were obtained in 11 Yorkshire swine. Single and multiple linear regression analyses were conducted between the FFR, CDP and LFC vs hSRv and hMRv. The correlation coefficient (r) was used to check the strength of correlation. The individual correlation between hSRv and hMRV with CDP (r = 0.90; r = 0.78) and LFC (r = 0.89; r = 0.95) was stronger compared to FFR (r = 0.63; r = 0.32). The combined correlation between hSRv and hMRv with CDP (r = 0.95) and LFC (r = 0.95) increased from the individual correlation. Therefore, we conclude that CDP and LFC can diagnose ES and MVD concurrently and might prove to be improved diagnostic parameters than FFR.

Functional and Anatomical Diagnosis of Coronary Artery Stenoses: A Retrospective Study in Humans

2012 ◽  
Author(s):  
Kranthi K. Kolli ◽  
Mohamed Effat ◽  
Imran Arif ◽  
Tarek Helmy ◽  
Massoud Leesar ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Dynamic Pressure ◽  
Microvascular Disease ◽  
Flow Coefficient ◽  
Fractional Flow ◽  
Throat Region ◽  
Flow Reserve ◽  
Stenosis Severity ◽  
Lesion Flow Coefficient ◽  
Hemodynamic Information

Fractional flow reserve (FFR: ratio of distal to proximal pressure of a stenotic section) is used to evaluate hemodynamic significance of epicardial stenosis. However, FFR and coronary flow reserve (CFR: ratio of hyperemic blood velocity to that of resting condition) are used in conjunction to evaluate combination of both epicardial and microvascular disease. It has been proposed that optimization of cutoff values for diagnostic parameters in determining stenosis severity depends on coupling functional (pressure and velocity) and anatomical data (% area stenosis). We hypothesize that, pressure drop coefficient (CDP: the ratio of trans-stenotic pressure drop to distal dynamic pressure) which has the functional information of pressure and velocity in its formulation correlates significantly with FFR and CFR, and lesion flow coefficient (LFC: ratio of % area stenoses to CDP at throat region) which combines both functional and anatomical (% area stenoses) information in its formulation correlates significantly with FFR, CFR and % area stenosis. We retrospectively analyzed the hemodynamic information from Meuwissen et al [3] to test this hypothesis. It was observed that, CDP, a functional index based on pressure drop and velocity, correlated linearly and significantly with FFR and CFR. And, LFC (combined functional and anatomic parameter) also correlated significantly with FFR, CFR (both hemodynamic endpoints) and % area stenosis (anatomic endpoint).

Effects of Microvascular Integrity on the Evaluation of Fractional Flow Reserve and Epicardial Stenosis Resistance Index

2005 ◽  
Vol 35 (10) ◽  
pp. 742
Author(s):  
Myeong Ho Yoon ◽  
Seung Jea Tahk ◽  
So Yeon Choi ◽  
Sung Gyun Ahn ◽  
Sang Yong Yoo ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Resistance Index ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Epicardial Stenosis

FFR-gesteuerte Revaskularisation – wann indiziert, wann überflüssig?

2017 ◽  
Vol 142 (21) ◽  
pp. 1595-1603
Author(s):  
Hannes Reuter ◽  
Stephan Baldus
Keyword(s):  
Inverse Correlation ◽  
Individual Risk ◽  
Fractional Flow ◽  
Rapid Disease Progression ◽  
Flow Reserve ◽  
Patients With Diabetes ◽  
Artery Disease ◽  
The Individual ◽  
Ischemic Events ◽  
Invasive Measurement

AbstractAn invasive measurement of the fractional flow reserve (FFR) allows the valuation of the individual risk for ischemic events in patients with coronary artery disease. Therefore, FFR has become a valuable tool to guide coronary revascularisations. The cut-off value ≤ 0.80 has been validated in many different subsets of patients. However, FFR values describe a risk continuum with an inverse correlation between FFR value and the risk of events. So FFR should always be interpreted regarding the patient’s clinical context, especially in patients with a high risk for rapid disease progression. As such, patients with diabetes mellitus and deferred revascularisation based on FFR > 0.80 had worse clinical outcomes compared to patients without diabetes. In addition, FFR shows methodical deficiencies concerning the quantification of serial stenoses as well as the valuation of residual ischemia of the culprit vessel early after myocardial infarction. This article highlights both the strengths and the pitfalls in the use and interpretation of FFR.

Effect of heart rate on hemodynamic endpoints under concomitant microvascular disease in a porcine model

2012 ◽  
Vol 302 (8) ◽  
pp. H1563-H1573 ◽  
Author(s):  
S. V. Peelukhana ◽  
R. K. Banerjee ◽  
K. K. Kolli ◽  
M. A. Effat ◽  
T. A. Helmy ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pressure Drop ◽  
Dynamic Pressure ◽  
Microvascular Disease ◽  
Flow Coefficient ◽  
Fractional Flow ◽  
Anova Analysis ◽  
Throat Region ◽  
Flow Reserve ◽  
Yorkshire Pigs

Diagnosis of the ischemic power of epicardial stenosis with concomitant microvascular disease (MVD) is challenging during coronary interventions, especially under variable hemodynamic factors like heart rate (HR). The goal of this study is to assess the influence of variable HR and percent area stenosis (%AS) in the presence of MVD on pressure drop coefficient (CDP; ratio of transstenotic pressure drop to the distal dynamic pressure) and lesion flow coefficient (LFC; ratio of %AS to the CDP at the throat region). We hypothesize that CDP and LFC are independent of HR. %AS and MVD were created using angioplasty balloons and 90-μm microspheres, respectively. Simultaneous measurements of pressure drop (DP) and velocity were done in 11 Yorkshire pigs. Fractional flow reserve (FFR), CDP, and LFC were calculated for the groups HR < 120 and HR > 120 beats/min, %AS < 50 and %AS > 50, and additionally for DP < 14 and DP > 14 mmHg, and analyzed using regression and ANOVA analysis. Regression analysis showed independence between HR and the FFR, CDP, and LFC while it showed dependence between %AS and the FFR, CDP, and LFC. In the ANOVA analysis, for the HR < 120 beats/min and HR > 120 beats/min groups, the values of FFR (0.82 ± 0.02 and 0.82 ± 0.02), CDP (83.15 ± 26.19 and 98.62 ± 26.04), and LFC (0.16 ± 0.03 and 0.15 ± 0.03) were not significantly different ( P > 0.05). However, for %AS < 50 and %AS > 50, the FFR (0.89 ± 0.02 and 0.75 ± 0.02), CDP (35.97 ± 25.79.10 and 143.80 ± 25.41), and LFC (0.09 ± 0.03 and 0.22 ± 0.03) were significantly different ( P < 0.05). A similar trend was observed between the DP groups. Under MVD conditions, FFR, CDP, and LFC were not significantly influenced by changes in HR, while they can significantly distinguish %AS and DP groups.

Influence of heart rate on fractional flow reserve, pressure drop coefficient, and lesion flow coefficient for epicardial coronary stenosis in a porcine model

2011 ◽  
Vol 300 (1) ◽  
pp. H382-H387 ◽  
Author(s):  
Kranthi K. Kolli ◽  
R. K. Banerjee ◽  
Srikara V. Peelukhana ◽  
T. A. Helmy ◽  
M. A. Leesar ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pressure Drop ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Flow Coefficient ◽  
Fractional Flow ◽  
Mean Values ◽  
Flow Reserve ◽  
The Mean ◽  
Lesion Flow Coefficient

A limitation in the use of invasive coronary diagnostic indexes is that fluctuations in hemodynamic factors such as heart rate (HR), blood pressure, and contractility may alter resting or hyperemic flow measurements and may introduce uncertainties in the interpretation of these indexes. In this study, we focused on the effect of fluctuations in HR and area stenosis (AS) on diagnostic indexes. We hypothesized that the pressure drop coefficient (CDPe, ratio of transstenotic pressure drop and distal dynamic pressure), lesion flow coefficient (LFC, square root of ratio of limiting value CDP and CDP at site of stenosis) derived from fluid dynamics principles, and fractional flow reserve (FFR, ratio of average distal and proximal pressures) are independent of HR and can significantly differentiate between the severity of stenosis. Cardiac catheterization was performed on 11 Yorkshire pigs. Simultaneous measurements of distal coronary arterial pressure and flow were performed using a dual sensor-tipped guidewire for HR < 120 and HR > 120 beats/min, in the presence of epicardial coronary lesions of <50% AS and >50% AS. The mean values of FFR, CDPe, and LFC were significantly different ( P < 0.05) for lesions of <50% AS and >50% AS (0.88 ± 0.04, 0.76 ± 0.04; 62 ± 30, 151 ± 35, and 0.10 ± 0.02 and 0.16 ± 0.01, respectively). The mean values of FFR and CDPe were not significantly different ( P > 0.05) for variable HR conditions of HR < 120 and HR > 120 beats/min (FFR, 0.81 ± 0.04 and 0.82 ± 0.04; and CDPe, 95 ± 33 and 118 ± 36). The mean values of LFC do somewhat vary with HR (0.14 ± 0.01 and 0.12 ± 0.02). In conclusion, fluctuations in HR have no significant influence on the measured values of CDPe and FFR but have a marginal influence on the measured values of LFC. However, all three parameters can significantly differentiate between stenosis severities. These results suggest that the diagnostic parameters can be potentially used in a better assessment of coronary stenosis severity under a clinical setting.

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