Global trans-lesional computed tomography-derived fractional flow reserve gradient is associated with clinical outcomes in diabetic patients with non-obstructive coronary artery disease

BackgroundCoronary computed tomography angiography (CCTA)-derived fractional flow reserve (CT-FFR) enables physiological assessment and risk stratification, which is of significance in diabetic patients with nonobstructive coronary artery disease (CAD). We aim to evaluate prognostic value of the global trans-lesional CT-FFR gradient (G & UDelta;CT-FFR), a novel metric, in patients with diabetes without flow-limiting stenosis.MethodsPatients with diabetes suspected of having CAD were prospectively enrolled. G & UDelta;CT-FFR was calculated as the sum of trans-lesional CT-FFR gradient in all epicardial vessels greater than 2 mm. Patients were stratified into low-gradient without flow-limiting group (CT-FFR > 0.75 and G & UDelta;CT-FFR < 0.20), high-gradient without flow-limiting group (CT-FFR > 0.75 and G & UDelta;CT-FFR & GE; 0.20), and flow-limiting group (CT-FFR & LE; 0.75). Discriminant ability for major adverse cardiovascular events (MACE) prediction was compared among 4 models [model 1: Framingham risk score; model 2: model 1 + Leiden score; model 3: model 2 + high-risk plaques (HRP); model 4: model 3 + G & UDelta;CT-FFR] to determine incremental prognostic value of G & UDelta;CT-FFR.ResultsOf 1215 patients (60.1 & PLUSMN; 10.3 years, 53.7% male), 11.3% suffered from MACE after a median follow-up of 57.3 months. G & UDelta;CT-FFR (HR: 2.88, 95% CI 1.76-4.70, P < 0.001) remained independent risk factors of MACE in multivariable analysis. Compared with the low-gradient without flow-limiting group, the high-gradient without flow-limiting group (HR: 2.86, 95% CI 1.75-4.68, P < 0.001) was associated with higher risk of MACE. Among the 4 risk models, model 4, which included G & UDelta;CT-FFR, showed the highest C-statistics (C-statistics: 0.75, P = 0.002) as well as a significant net reclassification improvement (NRI) beyond model 3 (NRI: 0.605, P < 0.001).ConclusionsIn diabetic patients with non-obstructive CAD, G & UDelta;CT-FFR was associated with clinical outcomes at 5 year follow-up, which illuminates a novel and feasible approach to improved risk stratification for a global hemodynamic assessment of coronary artery in diabetic patients.

Automated summary

The prognostic value of a novel metric, the global trans-lesional CT-FFR gradient (G & UDelta;CT-FFR), was evaluated in diabetic patients with nonobstructive coronary artery disease (CAD). The results showed that G & UDelta;CT-FFR was an independent risk factor for clinical outcomes in diabetic patients with non-obstructive CAD and had a high predictive ability.