DETECTION OF ISCHEMIC MYOCARDIAL SEGMENTS CONFIRMED ON INVASIVE FRACTIONAL FLOW RESERVE USING THE TIME INTERVAL THRESHOLD BETWEEN AORTIC VALVE CLOSURE AND REGIONAL PEAK LONGITUDINAL STRAIN

Abstract Background It has been reported that discordance between fractional flow reserve (FFR) and Instantaneous Wave-Free Ratio (iFR) could occur in up to 20% of cases. However, there are no reports regarding discordance between FFR and iFR in patients with severe aortic valve stenosis (AS). Purpose We aimed to investigate the discordance between FFR and iFR in patients with severe AS. Methods Severe AS was defined as an aortic-valve area of ≤1.0 cm2, a mean aortic-valve gradient of 40mmHg or more, or a peak aortic-jet velocity of 4.0 m/s or more. Intermediate coronary artery stenosis was defined as 30% to 70% stenosis (visual estimation). FFR and iFR were calculated in 4 quadrants based on values of FFR ≤0.8 and iFR ≤0.89 (positive discordance; low FFR and high iFR, negative discordance; high FFR and low iFR). Results We examined consecutive 140 patients (164 intermediate coronary artery stenosis vessels). Mean FFR and iFR ± standard deviation was 0.82±0.09 and 0.82±0.14, respectively. The discordance was observed in 48 vessels (29.3%). In the discordant group, most of cases were negative discordance (45 cases, 93.6%). Binary logistic regression analysis showed that left anterior descending artery (Hazard Ratio 3.80; 1.55 to 9.31, p=0.0036) was independently associated with negative discordance. Conclusions In patients with severe AS, the discordance between FFR and iFR could be observed in 29.3% of the vessels, mostly negative discordance. The left anterior descending artery is an independent predictor for negative discordance. Funding Acknowledgement Type of funding source: None

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Coronary CT Fractional Flow Reserve before Transcatheter Aortic Valve Replacement: Clinical Outcomes

Radiology ◽

10.1148/radiol.2021210160 ◽

2021 ◽

Author(s):

Gilberto J. Aquino ◽

Andres F. Abadia ◽

U. Joseph Schoepf ◽

Tilman Emrich ◽

Basel Yacoub ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Valve Replacement ◽

Clinical Outcomes ◽

Valve Replacement ◽

Fractional Flow Reserve ◽

Transcatheter Aortic Valve Replacement ◽

Fractional Flow ◽

Coronary Ct ◽

Transcatheter Aortic Valve ◽

Flow Reserve

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Influence of caffeine intake on intravenous adenosine-induced fractional flow reserve

European Heart Journal ◽

10.1093/ehjci/ehaa946.1394 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

K Ishibuchi ◽

K Fujii ◽

S Otsuji ◽

S Takiuchi ◽

K Hasegawa ◽

...

Keyword(s):

Clinical Practice ◽

Adenosine Triphosphate ◽

Fractional Flow Reserve ◽

Japanese Patients ◽

Caffeine Intake ◽

Time Interval ◽

Funding Source ◽

Reference Standard ◽

Fractional Flow ◽

Flow Reserve

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

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Comparison of Instantaneous Wave-Free Ratio (iFR) and Fractional Flow Reserve (FFR) with respect to Their Sensitivities to Cardiovascular Factors: A Computational Model-Based Study

Journal of Interventional Cardiology ◽

10.1155/2020/4094121 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Xinyang Ge ◽

Youjun Liu ◽

Zhaofang Yin ◽

Shengxian Tu ◽

Yuqi Fan ◽

...

Keyword(s):

Aortic Valve ◽

Fractional Flow Reserve ◽

Aortic Valve Disease ◽

Computational Method ◽

Valve Disease ◽

Fractional Flow ◽

Coronary Syndrome ◽

Flow Reserve ◽

Large Patient ◽

Discordant Diagnosis

While coronary revascularization strategies guided by instantaneous wave-free ratio (iFR) are, in general, noninferior to those guided by fractional flow reserve (FFR) with respect to the rate of major adverse cardiac events at one-year follow-up in patients with stable angina or an acute coronary syndrome, the overall accuracy of diagnosis with iFR in large patient cohorts is about 80% compared with the diagnosis with FFR. So far, it remains incompletely understood what factors contribute to the discordant diagnosis between iFR and FFR. In this study, a computational method was used to systemically investigate the respective effects of various cardiovascular factors on FFR and iFR. The results showed that deterioration in aortic valve disease (e.g., regurgitation or stenosis) led to a marked decrease in iFR and a mild increase in FFR given fixed severity of coronary artery stenosis and that increasing coronary microvascular resistance caused a considerable increase in both iFR and FFR, but the degree of increase in iFR was lower than that in FFR. These findings suggest that there is a high probability of discordant diagnosis between iFR and FFR in patients with severe aortic valve disease or coronary microcirculation dysfunction.

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

European Heart Journal ◽

10.1093/eurheartj/ehz746.0561 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

T Horie ◽

M Hoshino ◽

H Hirano ◽

Y Kanno ◽

H Ohya ◽

...

Keyword(s):

Confidence Interval ◽

Fractional Flow Reserve ◽

Repeated Measurements ◽

Mean Difference ◽

Time Interval ◽

Rater Agreement ◽

Fractional Flow ◽

Flow Reserve ◽

Significant Difference ◽

Two Indices

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.

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