Diagnostic accuracy of delta FFRCT for predicting revascularization

Background The optimal CT-derived fractional flow reserve (FFRCT) measurement method and lesion type for predicting revascularization remain controversial. Purpose To assess the diagnostic performance of different FFRCT measurement methods across lesion types. Methods A total of 382 vessels showing ≥50% diameter stenosis (DS) by conventional coronary angiography and evaluated by coronary CT angiography (CCTA) were enrolled. Lesions were categorized as focal (<40 mm) or diffuse (≥40 mm) and as moderate (50–69%) or severe (70–99%) stenoses. FFRCT was measured (1) at the distal end of the vessel (vessel-distal FFRCT), (2) just distal to the stenotic lesion (lesion-specific FFRCT), and (3) across the lesion (ΔFFRCT). Each was compared with DS for its ability to predict revascularization. Results For focal lesions, ΔFFRCT showed similar predictive performance to DS (AUC = 0.71 vs 0.76, P = 0.166) and outperformed lesion-specific FFRCT (AUC = 0.67, P < 0.001) and vessel-distal FFRCT (AUC = 0.63, P < 0.001). Multivariable regression revealed lesion length as the strongest predictor of ΔFFRCT (β = 0.42, P = 0.006). In diffuse lesions, ΔFFRCT (AUC = 0.73) demonstrated comparable performance to DS (AUC = 0.77, P = 0.67), lesion-specific FFRCT (AUC = 0.72, P = 0.65), and vessel-distal FFRCT (AUC = 0.69, P = 0.24). Lesion length was again the strongest predictor of ΔFFRCT (β = 0.99, P < 0.001). Conclusion ΔFFRCT demonstrated diagnostic performance comparable to DS for predicting revascularization in both focal and diffuse lesions. These findings suggest ΔFFRCT may be a clinically useful metric for FFRCT evaluation across lesion types.