Validation Study of Image-Based Fractional Flow Reserve During Coronary Angiography

Abstract

Background— Fractional flow reserve (FFR), an index of the hemodynamic severity of coronary stenoses, is derived from invasive measurements and requires a pressure-monitoring guidewire and hyperemic stimulus. Angiography-derived FFR measurements (FFR angio ) may have several advantages. The aim of this study is to assess the diagnostic performance and interobserver reproducibility of FFR angio in patients with stable coronary artery disease. Methods and Results— FFR angio is a computational method based on rapid flow analysis for the assessment of FFR. FFR angio uses the patient’s hemodynamic data and routine angiograms to generate a complete 3-dimensional coronary tree with color-coded FFR values at any epicardial location. Hyperemic flow ratio is derived from an automatic resistance-based lumped model of the entire coronary tree. A total of 203 lesions were analyzed in 184 patients from 4 centers. Values derived using FFR angio ranged from 0.5 to 0.97 (median 0.85) and correlated closely (Spearman ρ=0.90; P <0.001) with the invasive FFR measurements, which ranged from 0.5 to 1 (median 0.84). In Bland–Altman analyses, the 95% limits of agreement between these methods ranged from −0.096 to 0.112. Using an FFR cutoff value of 0.80, the sensitivity, specificity, and diagnostic accuracy of FFR angio were 88%, 95%, and 93%, respectively. The intraclass coefficient between 2 blinded operators was 0.962 with a 95% confidence interval from 0.950 to 0.971, P <0.001. Conclusions— There is a high concordance between FFR angio and invasive FFR. The color-coded display of FFR values during coronary angiography facilitates the integration of physiology and anatomy for decision making on revascularization in patients with stable coronary artery disease. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT03005028.

Diagnostic Performance of In‐Procedure Angiography‐Derived Quantitative Flow Reserve Compared to Pressure‐Derived Fractional Flow Reserve: The FAVOR II Europe‐Japan Study

“…Most existing FFR computation methods for invasive coronary angiography predominantly rely on computational fluid dynamics 5, 6, 16. Inherited limitations of these methods may exist related to generating theoretical boundary conditions to create a “one‐size‐fits‐all”, and to long computation time for blood flow simulations.…”

Planning percutaneous coronary interventions using computed tomography angiography and fractional flow reserve‐derived from computed tomography: A state‐of‐the‐art review

“…In recent years, coronary CTA has been used to provide precise anatomic information regarding the presence, extent and composition of coronary artery disease (CAD) , but has similar limitations to ICA regarding the lack of physiological information . There are numerous invasive and noninvasive techniques for measuring FFR, but among the noninvasive techniques, FFR‐derived by CTA (FFRCT) (HeartFlow, Inc., Redwood City, California) is the only method approved by the Food and Drug Administration in the United States and by the Conformité Européene in Europe. FFRCT is an accurate method for determining the hemodynamic significance of CAD compared with FFRINV .…”

Non-invasive detection and assessment of coronary stenosis from blood mean residence times.

“…FFRangio had a good correlation (P=0.90) with the FFR. Optimal cutoff value was 0.80, with sensitivity, specificity, and accuracy of 88%, 95%, and 93%, respectively [55].…”

“…The overall QFR accuracy was 85%. Pellicano et al [55] introduced another vFFR model named angiography-derived FFR measurement (FFRangio). A total of 203 lesions in 184 patients were studied.…”

“…Alternate approaches have been used for defining volume flow rate as a boundary condition. Papafaklis et al [14] and Pellicano et al [55] used a fix number of 1ml/min or 3 ml/min for all patients depending on whether they modeled baseline or hyperemic conditions. This is not a realistic approach since every patient and each coronary artery segment type have different volume flow rates.…”