Prepared by: Dr. Özkan Karaca

Study Title: Optical Coherence Tomography-Based Post-PCI Physiology Assessment: An ILUMIEN-IV Substudy

Conference: EuroPCR 2025

Link: https://media.pcronline.com/diapos/EuroPCR2025.pdf

Introduction:
Post-PCI imaging using optical coherence tomography (OCT) provides precise assessment of stent deployment quality. Virtual Flow Reserve (VFR), derived from OCT data, estimates hemodynamic loss through coronary lesions and may enhance post-PCI physiologic assessment. However, the association of VFR with long-term clinical outcomes remains to be fully established.

Objective:
To evaluate whether post-PCI OCT-derived VFR and minimal stent area (MSA) predict 2-year clinical outcomes including target vessel failure (TVF), target lesion failure (TLF), cardiac death, myocardial infarction, and repeat revascularization in the ILUMIEN-IV trial population.

Methods:
The study retrospectively analyzed OCT images from 2057 patients enrolled in ILUMIEN-IV. VFR and MSA were calculated, with thresholds of ?0.90 and ?5.26 mm² respectively. Patients were followed for two years, and outcomes were analyzed using Kaplan-Meier survival curves and multivariable Cox regression models.

Results:
- Patients with MSA >5.26 mm² had significantly lower TVF rates (5.7% vs 8.2%, HR 0.69, p=0.030).
- VFR >0.90 was associated with numerically lower TVF but did not reach statistical significance (p=0.122).
- Multivariate analysis confirmed MSA and VFR as independent predictors of TVF and TLF.
- The group with both high MSA and high VFR had the lowest 2-year TVF (5.5%).
- OCT-identified factors such as proximal reference disease and dissection also influenced outcomes.

Conclusions:
OCT-derived VFR and MSA are valuable indicators for predicting clinical outcomes after PCI. Their combined use provides complementary information on anatomical and physiological optimization. Incorporating VFR into routine post-PCI imaging may enhance patient risk stratification and procedural success.

Comment:
This substudy provides compelling evidence that post-PCI OCT-derived metrics such as MSA and VFR are independent predictors of long-term outcomes. The synergistic prognostic value of combining anatomical and physiological assessments post-intervention suggests a paradigm shift in how we approach procedural optimization. As a cardiologist, I find the integration of VFR into routine imaging workflows particularly promising, though real-time computation and clinical accessibility remain challenges to be addressed.