OCT‐Derived Virtual Fractional Flow Reserve Associated With 1‐Year Outcomes After PCI in ACS Patients

ABSTRACT Background Despite PCI, many acute coronary syndrome (ACS) patients experience major adverse cardiovascular events (MACE). Angiography is limited, and fractional flow reserve (FFR) is restricted by cost and specialized resource requirements. Optical coherence tomography (OCT)‐derived FFR (OFR) allows functional assessment without hyperemia, but its prognostic role after PCI is unclear. Aims To investigate the association between post‐PCI OFR and 1‐year target vessel‐related MACE in ACS patients and to develop machine learning‐based models to explore risk stratification. Methods This single‐center retrospective study included 719 ACS patients undergoing OCT‐guided PCI at the Affiliated Hospital of Zunyi Medical University (May 2022 to December 2023). The primary endpoint was target vessel‐related MACE (cardiac death, revascularization, myocardial infarction, or angina rehospitalization). Imaging features were selected by LASSO and Boruta, and machine learning–based classification models were built with XGBoost, random forest, support vector machine, logistic regression, and light gradient boosting. Performance was assessed using ROC curves and feature importance via GINI index.