P5511Improving the diagnostic accuracy of quantitative flow ratio (QFR): a proposal of QFR-fractional flow reserve (FFR) hybrid approach

BackgroundMeasurement of the contrast-flow quantitative flow ratio (cQFR) is a novel method for rapid computational estimation of fractional flow reserve (FFR). Discordance between FFR and cQFR has not been completely characterised.MethodsWe performed a post-hoc analysis of 504 vessels with angiographically intermediate stenosis in 504 patients who underwent measurement of FFR, coronary flow reserve (CFR), the index of microcirculatory resistance (IMR) and Duke jeopardy score.ResultsIn total, 396 (78.6%) and 108 (21.4%) lesions showed concordant and discordant FFR and cQFR functional classifications, respectively. Among lesions with a reduced FFR (FFR+), those with a preserved cQFR (cQFR−) showed significantly lower IMR, shorter mean transit time (Tmn), shorter lesion length (all, p<0.01) and similar CFR and Duke jeopardy scores compared with lesions showing a reduced cQFR (cQFR+). Furthermore, lesions with FFR+ and cQFR− had significantly lower IMR and shorter Tmn compared with lesions showing a preserved FFR (FFR−) and cQFR+. Of note, in cQFR+ lesions, higher IMR lesions were associated with decreased diagnostic accuracy (high-IMR; 63.0% and low-IMR; 75.8%, p<0.01). In contrast, in cQFR− lesions, lower IMR lesions was associated with decreased diagnostic accuracy (high-IMR group; 96.8% and low-IMR group; 80.0%, p<0.01). Notably, in total, 31 territories (6.2%; ‘jump out’ group) had an FFR above the upper limit of the grey zone (>0.80) and a cQFR below the lower limit (≤0.75). In contrast, five territories (1.0%; ‘jump in’ group) exhibited opposite results (FFR of ≤0.75 and cQFR of >0.80). The ‘jump out’ territories showed significantly higher IMR values than ‘jump in’ territories (p<0.01).ConclusionsFFR− with cQFR+ is associated with increased microvascular resistance, and FFR+ with cQFR− showed preservation of microvascular function with high coronary flow. Microvascular function affected diagnostic performance of cQFR in relation to functional stenosis significance.

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TCT-333 Comparison of Diagnostic Accuracy Between Quantitative Flow Ratio, Instantaneous Wave-Free Ratio and DILEMMA Score Against Fractional Flow Reserve

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2019.08.414 ◽

2019 ◽

Vol 74 (13) ◽

pp. B331

Author(s):

Ojas Mehta ◽

Michael Hay ◽

Abdul Rahman Ihdayhid ◽

James Cameron ◽

Dennis Wong

Keyword(s):

Diagnostic Accuracy ◽

Fractional Flow Reserve ◽

Flow Ratio ◽

Fractional Flow ◽

Flow Reserve ◽

Quantitative Flow Ratio ◽

Quantitative Flow

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Non-invasive imaging software to assess the functional significance of coronary stenoses: a systematic review and economic evaluation

Health Technology Assessment ◽

10.3310/hta25560 ◽

2021 ◽

Vol 25 (56) ◽

pp. 1-230

Author(s):

Ana Duarte ◽

Alexis Llewellyn ◽

Ruth Walker ◽

Laetitia Schmitt ◽

Kath Wright ◽

...

Keyword(s):

Cost Effectiveness ◽

Diagnostic Accuracy ◽

Fractional Flow Reserve ◽

Invasive Coronary Angiography ◽

Clinical Effectiveness ◽

Flow Ratio ◽

Fractional Flow ◽

Flow Reserve ◽

Quantitative Flow Ratio ◽

Quantitative Flow

Background QAngio® XA 3D/QFR® (three-dimensional/quantitative flow ratio) imaging software (Medis Medical Imaging Systems BV, Leiden, the Netherlands) and CAAS® vFFR® (vessel fractional flow reserve) imaging software (Pie Medical Imaging BV, Maastricht, the Netherlands) are non-invasive technologies to assess the functional significance of coronary stenoses, which can be alternatives to invasive fractional flow reserve assessment. Objectives The objectives were to determine the clinical effectiveness and cost-effectiveness of QAngio XA 3D/QFR and CAAS vFFR. Methods We performed a systematic review of all evidence on QAngio XA 3D/QFR and CAAS vFFR, including diagnostic accuracy, clinical effectiveness, implementation and economic analyses. We searched MEDLINE and other databases to January 2020 for studies where either technology was used and compared with fractional flow reserve in patients with intermediate stenosis. The risk of bias was assessed with quality assessment of diagnostic accuracy studies. Meta-analyses of diagnostic accuracy were performed. Clinical and implementation outcomes were synthesised narratively. A simulation study investigated the clinical impact of using QAngio XA 3D/QFR. We developed a de novo decision-analytic model to estimate the cost-effectiveness of QAngio XA 3D/QFR and CAAS vFFR relative to invasive fractional flow reserve or invasive coronary angiography alone. Scenario analyses were undertaken to explore the robustness of the results to variation in the sources of data used to populate the model and alternative assumptions. Results Thirty-nine studies (5440 patients) of QAngio XA 3D/QFR and three studies (500 patients) of CAAS vFFR were included. QAngio XA 3D/QFR had good diagnostic accuracy to predict functionally significant fractional flow reserve (≤ 0.80 cut-off point); contrast-flow quantitative flow ratio had a sensitivity of 85% (95% confidence interval 78% to 90%) and a specificity of 91% (95% confidence interval 85% to 95%). A total of 95% of quantitative flow ratio measurements were within 0.14 of the fractional flow reserve. Data on the diagnostic accuracy of CAAS vFFR were limited and a full meta-analysis was not feasible. There were very few data on clinical and implementation outcomes. The simulation found that quantitative flow ratio slightly increased the revascularisation rate when compared with fractional flow reserve, from 40.2% to 42.0%. Quantitative flow ratio and fractional flow reserve resulted in similar numbers of subsequent coronary events. The base-case cost-effectiveness results showed that the test strategy with the highest net benefit was invasive coronary angiography with confirmatory fractional flow reserve. The next best strategies were QAngio XA 3D/QFR and CAAS vFFR (without fractional flow reserve). However, the difference in net benefit between this best strategy and the next best was small, ranging from 0.007 to 0.012 quality-adjusted life-years (or equivalently £140–240) per patient diagnosed at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year. Limitations Diagnostic accuracy evidence on CAAS vFFR, and evidence on the clinical impact of QAngio XA 3D/QFR, were limited. Conclusions Quantitative flow ratio as measured by QAngio XA 3D/QFR has good agreement and diagnostic accuracy compared with fractional flow reserve and is preferable to standard invasive coronary angiography alone. It appears to have very similar cost-effectiveness to fractional flow reserve and, therefore, pending further evidence on general clinical benefits and specific subgroups, could be a reasonable alternative. The clinical effectiveness and cost-effectiveness of CAAS vFFR are uncertain. Randomised controlled trial evidence evaluating the effect of quantitative flow ratio on clinical and patient-centred outcomes is needed. Future work Studies are required to assess the diagnostic accuracy and clinical feasibility of CAAS vFFR. Large ongoing randomised trials will hopefully inform the clinical value of QAngio XA 3D/QFR. Study registration This study is registered as PROSPERO CRD42019154575. Funding This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 56. See the NIHR Journals Library website for further project information.

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Diagnostic Accuracy of Quantitative Flow Ratio (QFR) Compared to Instantaneous Flow Wave Free Ratio (iFR) and DILEMMA Score to Predict Fractional Flow Reserve (FFR)

Heart Lung and Circulation ◽

10.1016/j.hlc.2019.06.607 ◽

2019 ◽

Vol 28 ◽

pp. S394

Author(s):

O. Mehta ◽

R. Lim ◽

M. Hay ◽

A. Ildayhid ◽

M. Zhang ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Fractional Flow Reserve ◽

Flow Ratio ◽

Fractional Flow ◽

Instantaneous Flow ◽

Flow Reserve ◽

Quantitative Flow Ratio ◽

Quantitative Flow

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Diagnostic performance and clinical implications for enhancing a hybrid quantitative flow ratio and fractional flow reserve revascularization decision making strategy

European Heart Journal ◽

10.1093/ehjci/ehaa946.1382 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

J Peper ◽

R.W Van Hamersvelt ◽

B.J.M.W Rensing ◽

J.P Van Kuijk ◽

M Voskuil ◽

...

Keyword(s):

Diagnostic Performance ◽

Hybrid Approach ◽

High Accuracy ◽

Intermediate Zone ◽

Flow Ratio ◽

Fractional Flow ◽

Hybrid Strategy ◽

Flow Reserve ◽

Quantitative Flow Ratio ◽

Quantitative Flow

Abstract Background Fractional flow reserve (FFR) adoption persists low mainly due to procedural and operator related factors as well as costs. An alternative for FFR, quantitative flow ratio (QFR) achieves a high accuracy mainly outside the intermediate zone without the need for hyperemia and wire-use. Currently, no outcome trials assess the role of QFR in the guidance of revascularization. Therefore, we evaluate a QFR-FFR hybrid strategy in which FFR is measured inside of the intermediate zone. Methods This retrospective multi-center study included consecutive patients who underwent both invasive coronary angiography and FFR in the participating centers. QFR was calculated for all vessels in which FFR was measured. Diagnostic performance of QFR was assessed using an FFR cut-off of 0.80 as reference standard. The QFR-FFR hybrid approach was modeled using the intermediate zone of 0.77 to 0.87 assuming that lesions within the intermediate zone follow the FFR binary cutoff. Results In total, 381 vessels in 289 patients were analyzed. The sensitivity, specificity and accuracy on a per vessel-based analysis were 84.6%, 86.3% and 85.6% for QFR and 91.1%, 95.3% and 93.4% for the QFR-FFR hybrid approach. The diagnostic accuracy of QFR-FFR hybrid strategy with invasive FFR measurement is 93.4% and results in a FFR reduction of 56.7%. Conclusion QFR has a good correlation and agreement with invasive FFR and a high diagnostic accuracy. A hybrid QFR-FFR approach could extend the use of QFR and reduces the proportion of invasive FFR-measurements needed while maintaining a high accuracy. Hybrid QFR-FFR strategy Funding Acknowledgement Type of funding source: None

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Diagnostic performance and clinical implications for enhancing a hybrid quantitative flow ratio–FFR revascularization decision-making strategy

Scientific Reports ◽

10.1038/s41598-021-85933-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Joyce Peper ◽

Robbert W. van Hamersvelt ◽

Benno J. W. M. Rensing ◽

Jan-Peter van Kuijk ◽

Michiel Voskuil ◽

...

Keyword(s):

Diagnostic Performance ◽

Invasive Coronary Angiography ◽

Hybrid Approach ◽

Intermediate Zone ◽

Flow Ratio ◽

Fractional Flow ◽

Hybrid Strategy ◽

Flow Reserve ◽

Quantitative Flow Ratio ◽

Quantitative Flow

AbstractInvasive fractional flow reserve (FFR) adoption remains low mainly due to procedural and operator related factors as well as costs. Alternatively, quantitative flow ratio (QFR) achieves a high accuracy mainly outside the intermediate zone without the need for hyperaemia and wire-use. We aimed to determine the diagnostic performance of QFR and to evaluate a QFR–FFR hybrid strategy in which FFR is measured only in the intermediate zone. This retrospective study included 289 consecutive patients who underwent invasive coronary angiography and FFR. QFR was calculated for all vessels in which FFR was measured. The QFR–FFR hybrid approach was modelled using the intermediate zone of 0.77–0.87 in which FFR-measurements are recommended. The sensitivity, specificity, and accuracy on a per vessel-based analysis were 84.6%, 86.3% and 85.6% for QFR and 88.0%, 92.9% and 90.3% for the QFR–FFR hybrid approach. The diagnostic accuracy of QFR–FFR hybrid strategy with invasive FFR measurement was 93.4% and resulted in a 56.7% reduction in the need for FFR. QFR has a good correlation and agreement with invasive FFR. A hybrid QFR–FFR approach could extend the use of QFR and reduces the proportion of invasive FFR-measurements needed while improving accuracy.

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