Abstract 4344198: Diagnostic efficacy of CT-FFR in coronary artery stenosis of varying severity

Background: Although fractional flow reserve (FFR) remains the gold standard for evaluating myocardial ischemia, its invasive nature limits widespread clinical adoption. CT-derived FFR (CT-FFR) offers a noninvasive alternative, yet its diagnostic consistency across different stenosis severity levels remains unclear. This study aims to evaluate the diagnostic accuracy and correlation of CT-FFR compared to invasive FFR, stratified by stenosis severity, to enhance precision in ischemia assessment. Methods: In this prospective study, 138 patients (mean age 62.4 ± 9.7 years; 64.5% male) with suspected or confirmed coronary artery disease (CAD) and stenosis ranging from 30% to 90% in major coronary arteries (≥2.0 mm diameter) underwent coronary CT angiography (CCTA) followed by CT-FFR analysis (Coronary Scope, Shenzhen Yueying Technology Co., Ltd., China). Invasive FFR (St. Jude Medical, Inc., USA) was performed within 15 days post-CCTA as the reference standard. Both CT-FFR and FFR assessments focused on a single target vessel per patient. Ischemia was defined as FFR ≤0.80, with the same threshold applied to CT-FFR. Stenosis severity was categorized into three groups: 30%–49%, 50%–69%, and 70%–90%. Diagnostic performance metrics (sensitivity, specificity) and correlation coefficients (r) were analyzed. Results: CT-FFR demonstrated outstanding diagnostic efficacy, with sensitivity, specificity, and accuracy of 96.2%, 97.7%, and 97.1%, respectively. A robust overall correlation was observed between CT-FFR and invasive FFR (r = 0.832, 95% CI: 0.773–0.877; p < 0.001). Subgroup analysis revealed progressively stronger correlations with increasing stenosis severity: moderate for 30%–49% stenosis (r = 0.700, 95% CI: 0.483–0.836; p < 0.0001), strong for 50%–69% stenosis (r = 0.755, 95% CI: 0.625–0.844; p < 0.0001), and nearly perfect for 70%–90% stenosis (r = 0.914, 95% CI: 0.840–0.955; p < 0.0001). The correlation in the 70%–90% group was significantly superior to the other groups (p < 0.05). Conclusions: CT-FFR exhibits high diagnostic accuracy across a wide spectrum of coronary stenosis (30%–90%), with exceptional performance in severe stenosis (70%–90%). These results underscore the potential of CT-FFR as a frontline noninvasive modality for guiding revascularization strategies, particularly in cases of high-grade stenosis, and advocate for its integration into precision-driven CAD management protocols.