Introduction

Optical coherence tomography–derived fractional flow reserve (FFR-OCT), computed as virtual flow reserve, combines anatomical and functional lesion assessment without pressure-wire manipulation or pharmacological hyperemia. Its output may depend on accurate lumen delineation and side-branch recognition.

Aim

To assess the agreement between operator-reviewed FFR-OCT and wire-based FFR in routine practice, and the effect of manual segmentation correction.

Material and methods

We analyzed 14 consecutive patients (19 vessels) undergoing wire-based FFR followed by OCT-guided percutaneous coronary intervention (PCI). OCT pullbacks were processed with Ultreon 3.0 software; automated FFR-OCT values were reviewed by an experienced operator with manual correction of lumen and side-branch segmentation. Comparison used Pearson’s correlation, Bland–Altman analysis, and concordance in ischemia classification at the 0.80 threshold.

Results

Wire-based FFR was 0.79 ±0.10. In 13 vessels with both values, automated FFR-OCT increased from 0.68 ±0.16 to 0.75 ±0.11 after operator review (mean paired difference +0.064; Wilcoxon p = 0.016). Across 19 vessels, operator-reviewed FFR-OCT (0.76 ±0.10) correlated moderately with wire-based FFR (r = 0.614, 95% CI: 0.222–0.835; p = 0.005; bias +0.025, 95% limits of agreement −0.153 to +0.203). Classification was concordant in 15 of 19 vessels; 4 were discordant (21.1%, 95% CI: 6.1–45.6%).

Conclusions

Manual review of segmentation substantially changed the automated FFR-OCT result. Although operator-reviewed FFR-OCT was associated with wire-based FFR, agreement near the 0.80 threshold was imperfect. FFR-OCT may aid PCI planning but does not yet appear interchangeable with pressure-wire physiology. Larger prospective studies with prespecified, blinded image analysis are warranted.