Quantitative flow reserve (QFR) is a computation of fractional flow reserve (FFR) based on angiography without use of a pressure wire. The ability to predict 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. 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.

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 84pre-PCI residual QFR measurements were compared to post-PCI FFR measurements. Mean post-PCI FFR value of 0.92±0.05 compared to mean residual QFR and compared to mean post-PCI QFR values were 0.93±0.05 for both (P>0.05). Correlation coefficients of residual QFR and post-PCI-QFR were respectively 0.68, (95% CI: 0.53–0.78) and 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.