Abstract
BACKGROUND: Coronary computed tomography angiography-derived fractional flow reserve (FFR(CT)) is a per-vessel index reflecting cumulative hemodynamic burden while coronary events occur in focal lesions. OBJECTIVES: The authors sought to evaluate the additive prognostic value of the local gradient of FFR(CT) (FFR(CT) gradient) in addition to FFR(CT) to predict future coronary events. METHODS: The current study included 245 patients (634 vessels) who underwent coronary computed tomography angiography within 6 to 36 months before the index angiography, of which 209 vessels had future coronary events and 425 vessels did not. Future coronary events were defined as a composite of vessel-specific myocardial infarction or urgent revascularization during a mean interval of 1.5 years. Pre-existing disease patterns were classified according to FFR(CT) of ≤0.80 and FFR(CT) gradient of ≥0.025/mm. RESULTS: Both FFR(CT) (per 0.01 decrease; adjusted HR: 1.040; 95% CI: 1.029-1.051; P < 0.001) and FFR(CT) gradient (per 0.01 increase; adjusted HR: 1.144; 95% CI: 1.101-1.190; P < 0.001) were significantly associated with the risk of future coronary events. Lesions with FFR(CT) gradient of ≥0.025/mm showed significantly higher risk of future coronary events than those with FFR(CT) gradient of <0.025/mm in both the FFR(CT) >0.80 (49.2% vs 30.1%; HR: 2.069; 95% CI: 1.265-3.385; P = 0.004) and FFR(CT) ≤0.80 groups (60.9% vs 38.3%; HR: 1.988; 95% CI: 1.317-2.999; P =0 .001). Adding FFR(CT) gradient into the model with FFR(CT) alone showed significantly increased predictability of future coronary events (global chi-square: 45.8 vs 39.9; P = 0.015). CONCLUSIONS: Patients with high FFR(CT) gradient showed increased risk of future coronary events irrespective of FFR(CT). Integrating both FFR(CT) and FFR(CT) gradient showed incremental predictability of future coronary events compared with FFR(CT) alone. (Prediction and Validation of Clinical Course of Coronary Artery Disease With CT-Derived Non-Invasive Hemodynamic Phenotyping and Plaque Characterization [DESTINY Study]; NCT04794868).