Agreement between Murray law-based quantitative flow ratio (μQFR) and three-dimensional quantitative flow ratio (3D-QFR) in non-selected angiographic stenosis: A multicenter study

Abstract

Background The agreement between single-projection Murray-based quantitative flow ratio ( μ QFR) and conventional three-dimensional quantitative flow ratio (3D-QFR) has not been reported hitherto. Methods Patients from a multinational database were randomly selected for the study of agreement, according to sample size calculation. Both conventional 3D-QFR and μ QFR were analyzed for all available arteries at a central corelab by independent analysts, blinded to each other’s results. Results Ninety-eight coronary arteries from 35 patients were finally analyzed. Median 3D-QFR was 0.82 (interquartile range 0.78–0.87). The intraclass correlation coefficient for the absolute agreement between 3D-QFR and μ QFR was 0.996 (95% confidence interval [CI]: 0.993–0.997); Lin’s coefficient 0.996 (95% CI: 0.993–0.997), without constant or proportional bias (intercept = 0 and slope = 1 in orthogonal regression). As dichotomous variable, there was absolute agreement between μ QFR and 3D-QFR, resulting in no single false positive or negative. Kappa index was 1 and the diagnostic accuracy 100%. Conclusions μ QFR using a single angiographic projection showed almost perfect agreement with standard 3D-QFR. These results encourage the interchangeable use of μ QFR and 3D-QFR, which can be interesting to improve QFR feasibility in retrospective studies, wherein appropriate double angiographic projections might be challenging to obtain.

Rationale and design of a comparison of angiography-derived fractional flow reserve-guided and intravascular ultrasound-guided intervention strategy for clinical outcomes in patients with coronary artery disease: a randomised controlled trial (FLAVOUR II)

“…Briefly, μQFR, an upgraded technique, is able to compute FFR from a single angiographic view with incorporating Murray bifurcation fractal law. Its diagnostic performance and clinical implications were demonstrated previously 19–22. In the catheterisation laboratory, one single operator will perform angiography-derived FFR measurement.…”

“…For the angiography-derived FFR-guided strategy arm, an imaging-based FFR (QFR or Murray law-based QFR (μQFR)) will be used, and the criterion for PCI is QFR or μQFR≤0.8 9 19 20. Briefly, μQFR, an upgraded technique, is able to compute FFR from a single angiographic view with incorporating Murray bifurcation fractal law.…”

“…Its diagnostic performance and clinical implications were demonstrated previously. [19][20][21][22] In the catheterisation laboratory, one single operator will perform angiography-derived FFR measurement.…”

Post-procedural and long-term functional outcomes of jailed side branches in stented coronary bifurcation lesions assessed with side branch Murray law–based quantitative flow ratio

“…μQFR had a high diagnostic accuracy to estimate FFR even using suboptimal angiographic image projection (13). It was recently shown that single view μQFR had a similar diagnostic accuracy as three-dimensional (3D) QFR (14,15). Thus, μQFR could be used for SB functional assessment.…”