Abstract
BACKGROUND AND OBJECTIVES: Quantitative flow ratio (QFR) offers a non-interventional alternative for evaluating ischemia, yet its concordance with real-world treatment and clinical outcomes remains unclear. This study aimed to assess the alignment between Murray law-based QFR (μQFR) physiological assessment and treatment strategies, evaluate the association between treatment concordance and clinical outcomes, and explore factors influencing concordance. METHODS: In this retrospective cohort, 242 patients with angiographically intermediate coronary stenosis and μQFR values adjacent to the grey-zone (low: 0.70-0.74; high: 0.86-0.90) were included. Treatment concordance was defined as PCI for low μQFR and medication for high μQFR. The primary endpoint was target vessel failure (TVF), comprising cardiac death, target vessel myocardial infarction, and ischemia-driven target vessel revascularization (ID-TVR). Median follow-up was 18 months. Kaplan-Meier analysis was used to evaluate outcomes, and logistic regression identified determinants of operator decision-making. RESULTS: Among 242 patients, 177 (73.1%) received μQFR-concordant and 65 (26.9%) discordant treatment. TVF occurred less frequently in μQFR-concordant group (2.3% vs. 7.9%, P = 0.043), mainly due to reduced ID-TVR (1.1% vs. 6.4%, P = 0.024) and mainly driven by differences between the high- and low-μQFR medication subgroups. Operator decisions were influenced by lesion severity and overall coronary complexity, with more severe lesions favoring PCI and higher complexity favoring conservative management. CONCLUSIONS: Approximately one-fifth of treatment for intermediate coronary stenoses was discordant with μQFR assessment. μQFR-concordant treatment was associated with lower TVF, primarily due to fewer ID-TVR. Integrating μQFR into clinical decision-making may help optimize revascularization strategies and improve outcomes in real-world practice.