P5617Repeatability of instantaneous wave-free ratio in comparison with fractional flow reserve

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Horie ◽  
M Hoshino ◽  
H Hirano ◽  
Y Kanno ◽  
H Ohya ◽  
...  

Abstract Background Instantaneous wave-free ratio (iFR) has been recently introduced as an adenosine free alternative for fractional flow reserve (FFR) to assess the functional significance of epicardial coronary stenosis. Little is known, however, regarding the repeatability and stability of iFR in comparison with FFR. Purpose The aim of this study was to evaluate the repeatability of iFR and compare it to that of FFR. Methods Patients with stable coronary artery disease who underwent physiological assessment twice within 90 days were enrolled. Repeated measurements were performed at diagnostic and therapeutic catheterization in about 70% of studied population. The remaining patients were measured twice for non-culprit lesion assessment at primary PCI and subsequent non-culprit and ischemia-documented lesion PCI. The calculation of iFRmatlab from DICOM pressure tracing data of resting state was performed using a fully automated off-line software algorithm in a blind fashion. FFR values were also measured by a fully automated algorithm in the same core laboratory by using hyperemic pressure tracing data. The repeatability of the two indices were evaluated and compared. The inter-rater agreement between iFRmatlab and FFR values of two measurements was assessed by κ coefficient. The pressure rate product during each assessment was also documented and evaluated. Results Ninety-three lesions from 92 patients were included in the study. The time interval between the two assessments was 38.4±19.0 days. iFRmatlab and FFR both showed significant correlation within the two assessments (iFRmatlab: r=0.75, 95% confidence interval, 0.64 to 0.83; mean difference, −0.006 [−0.18 to −0.01], FFR: r=0.86, 95% confidence interval, 0.79 to 0.90; mean difference, 0.004 [−0.07 to 0.03]). The inter-rater agreement of functional ischemia for iFRmatlab and FFR were κ=0.449 and κ=0.732, respectively. Although the prevalence of functional ischemia during the first and second assessment were consistent for both indices (iFRmatlab: 70.0%/67.7%, FFR: 86.0%/ 86.0%), significant difference was observed in the prevalence of clinical disagreement on the diagnosis of functional ischemia (FFR=0.80, iFR=0.89 used as cut-off values, respectively) between the first and second assessment among the two indices (iFRmatlab: 6.5%, FFR: 23.7%, p=0.002). iFRmatlab was significantly associated with pressure rate product during the examination compared to FFR (iFRmatlab: r= −0.25, 95% confidence interval, −0.43 to −0.04, P=0.018, FFR: r=−0.08, 95% confidence interval, −0.28 to −0.13, p=0.467). Conclusion Our results suggested that iFRmatlab showed lower repeatability and reliability for decision making compared to FFR. The instability of iFRmatlab potentially derives at least in part from its association with heart rate and blood pressure product.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Ishibuchi ◽  
K Fujii ◽  
S Otsuji ◽  
S Takiuchi ◽  
K Hasegawa ◽  
...  

Abstract Background This study evaluated whether caffeine abstention is required before fractional flow reserve (FFR) measurement by intravenous adenosine triphosphate (ATP) administration in Japanese patients. Methods and results This study was a subanalysis of a previously published study and a total of 208 intermediate lesions that underwent FFR measurements were enrolled for this analysis. Hyperemia was induced by continuous intravenous ATP infusion at 150μg/kg/min (IVATP150) and 210μg/kg/min (IVATP210), and by intracoronary administration of nicorandil 2mg (ICNIC2mg) as a reference standard. The degree of change in the FFR value both after IVATP150 and after IVATP210, as compared with the FFR value after ICNIC2mg was similar between the caffeine and non-caffeine groups (−0.04±0.05 vs. −0.04±0.07, and 0.00±0.02 vs. 0.01±0.02, respectively). In patients who consumed caffeine before the FFR measurement, the degree of FFR change was independent of the time interval (<12 hours, 12–24 hours, and 24–48 hours) between caffeine intake and catheterization both after IVATP150 and ICNIC2mg and after IVATP210 and ICNIC2mg. Conclusion When compared with the FFR value after ICNIC2mg, the degree of change in the FFR value both after IVATP150 and after IVATP210 remained similar regardless of caffeine intake. Strict caffeine abstention before intravenous ATP-induced FFR measurement may not be required in clinical practice. Funding Acknowledgement Type of funding source: None


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Tomoyuki Ikeda ◽  
Masafumi Ueno ◽  
Shinichiro Ikuta ◽  
Kosuke Fujita ◽  
Masakazu Yasuda ◽  
...  

Background: Fractional flow reserve (FFR) is calculated as the ratio between distal coronary pressure(Pd)and aortic pressure(Pa)during whole cardiac cycle at stable hyperemia. In clinical practice, we experience various Pd wave pattern during hyperemia, such as decreasing equally in systolic and diastolic phase, or mainly decreasing in diastolic phase. Purpose: The aim of the study was to evaluate the impact of systolic and diastolic pressure response during hyperemia in patients with coronary stenosis and an FFR of less than 0.8. Methods: A total of 35 patients (40 stenosis)had FFR of less than 0.8 were enrolled. FFR measurements were performed using a standard technique. Based on Pa and Pd wave forms, the decreasing area in systolic and diastolic were calculated by integrating Pa-Pd pressure gradient during hyperemia using the RadiView2.2 software. %Sys value was defined as the percentage of delta systolic area during the whole cardiac cycle (Figure). The results of %Sys values were divided into tertiles to evaluate the most significant factors for systolic pressure response. Results: Vessel distribution was as follows: LAD (60%), CX (20%) and RCA (20%). There was a significant difference of vessel distribution in coronary arteries in the upper tertile compared with the other two tertiles of %Sys values (p=0.028). However, the other factors such as FFR value, lesion length and severity, history of diabetes mellitus and previous myocardial infraction were not affected by the %Sys values. In addition, there was a significant difference of %Sys values among three major coronary arteries (LAD 49.4±18.5%, CX 81.5±38.7%, RCA 67.5±20.2%, p=0.006). %Sys values were significantly higher in non-LAD lesions compared with LAD lesions (74.5±30.7% vs 49.4±18.5%, p=0.003). Conclusions: There was a significant difference of decreasing pattern of Pd wave during hyperemia among the three coronary arteries. These findings suggest that iFR might not be accurate in non-LAD lesion.


Author(s):  
Ishan Goswami ◽  
Srikara V. Peelukhana ◽  
Marwan Al-Rjoub ◽  
Lloyd H. Back ◽  
Rupak K. Banerjee

Fractional flow reserve (FFR), the ratio of the pressures distal (Pd) and proximal (Pa) to a stenosis, and coronary flow reserve (CFR), the ratio of flows at maximal vasodilation to the resting condition, are widely used for determining the functional severity of a coronary artery stenosis. However, the diameter of the native artery might influence the FFR values. Therefore, using an in-vitro experimental study, we tested the variation of FFR for two arterial diameters, 2.5 mm (N1) and 3 mm (N2). We hypothesize that FFR is not influenced by native arterial diameter. For both N1 and N2, vasodilation-distal perfusion pressure (CFR-Prh) curves were obtained using a 0.35 mm guidewire by simulating physiologic flows under different blockage conditions: mild (64% area stenosis (AS)), intermediate (80% AS) and severe (90% AS). The FFR values for the two arterial models differed insignificantly, within 3%, for mild and intermediate stenoses but differed appreciably for severe stenosis (∼25%). This significant difference in FFR values for severe stenosis can be attributed to relatively larger difference in guidewire obstruction effect at the stenotic throat region of the two native arterial models. These findings confirm that FFR will not differ for the clinically relevant cases of mild and intermediate stenosis for different arterial diameters.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Doosup Shin ◽  
Joo Myung Lee ◽  
Seung Hun Lee ◽  
Doyeon Hwang ◽  
Ki Hong Choi ◽  
...  

AbstractLimited data are available regarding comparative prognosis after percutaneous coronary intervention (PCI) versus deferral of revascularization in patients with intermediate stenosis with abnormal fractional flow reserve (FFR) but preserved coronary flow reserve (CFR). From the International Collaboration of Comprehensive Physiologic Assessment Registry (NCT03690713), a total of 330 patients (338 vessels) who had coronary stenosis with FFR ≤ 0.80 but CFR > 2.0 were selected for the current analysis. Patient-level clinical outcome was assessed by major adverse cardiac events (MACE) at 5 years, a composite of all-cause death, target-vessel myocardial infarction (MI), or target-vessel revascularization. Among the study population, 231 patients (233 vessels) underwent PCI and 99 patients (105 vessels) were deferred. During 5 years of follow-up, cumulative incidence of MACE was 13.0% (31 patients) without significant difference between PCI and deferred groups (12.7% vs. 14.0%, adjusted HR 1.301, 95% CI 0.611–2.769, P = 0.495). Multiple sensitivity analyses by propensity score matching and inverse probability weighting also showed no significant difference in patient-level MACE and vessel-specific MI or revascularization. In this hypothesis-generating study, there was no significant difference in clinical outcomes between PCI and deferred groups among patients with intermediate stenosis with FFR ≤ 0.80 but CFR > 2.0. Further study is needed to confirm this finding.Clinical Trial Registration: International Collaboration of Comprehensive Physiologic Assessment Registry (NCT03690713; registration date: 10/01/2018).


2016 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Shah R Mohdnazri ◽  
◽  
◽  
◽  
Thomas R Keeble ◽  
...  

Fractional flow reserve (FFR) has been shown to improve outcomes when used to guide percutaneous coronary intervention (PCI). There have been two proposed cut-off points for FFR. The first was derived by comparing FFR against a series of non-invasive tests, with a value of ≤0.75 shown to predict a positive ischaemia test. It was then shown in the DEFER study that a vessel FFR value of ≥0.75 was associated with safe deferral of PCI. During the validation phase, a ‘grey zone’ for FFR values of between 0.76 and 0.80 was demonstrated, where a positive non-invasive test may still occur, but sensitivity and specificity were sub-optimal. Clinical judgement was therefore advised for values in this range. The FAME studies then moved the FFR cut-off point to ≤0.80, with a view to predicting outcomes. The ≤0.80 cut-off point has been adopted into clinical practice guidelines, whereas the lower value of ≤0.75 is no longer widely used. Here, the authors discuss the data underpinning these cut-off values and the practical implications for their use when using FFR guidance in PCI.


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