We sought to evaluate the correlations of pre-PCI QFR analysis with virtual PCI called residual QFR and post-PCI QFR compared to post-PCI FFR.
Quantitative flow ratio (QFR) is a computation of fractional flow reserve (FFR) based on angiography without use of a pressure wire. The ability to evaluate post-PCI FFR using pre-PCI QFR analysis with a virtual PCI and the correlation between post-PCI QFR compared to post-PCI FFR remains unknown.
From the DOCTORS (Does Optical Coherence Tomography Optimize Results of Stenting) study population, we blindly analyzed residual QFR and post-PCI QFR from angiographies and compared them to post-PCI FFR.
Ninety-three post-PCI QFR measurements and 84 pre-PCI residual QFR measurements were compared to post-PCI FFR measurements. No significant difference were observed between mean post-PCI FFR value (0.92 ± 0.05) compared to mean residual (0.93 ± 0.05) QFR and between mean post-PCI FFR value compared to mean post-PCI QFR values were (0.93 ± 0.05) (p > .05 for both). The correlation coefficient of residual QFR with post-PCI FFR was 0.68 (95% CI: 0.53-0.78) and the correlation coefficient of post-PCI-QFR with post-PCI FFR was 0.79 (95% CI: 0.70-0.86).
Residual QFR corresponding to pre-PCI QFR analysis with virtual PCI, and post-PCI QFR analysis, correlated well with post-PCI FFR. Further studies are needed to prospectively validate a QFR-guided PCI strategy.