At present, FFR is the ＂gold standard＂ index for evaluating the function and physiology of coronary blood flow. CT-fractional flow reserve (CT-FFR) reflects the hemodynamic changes of coronary artery lesions, it has higher diagnostic and differential ability in distinguishing lesion-specific ischemia compare with FFR.

To evaluate the value of CT-FFR in predicting the incidence of MACE in patients with stable chest pain caused by coronary artery obstruction.

This study included 116 patients who underwent coronary CT angiography (CCTA) examination for stable chest pain in the General Hospital of Ningxia Medical University from January 2017 to June 2021, and were followed up for a median of 2 (0, 25) months. The subjects were divided into MACE group (n=55) and non-MACE group (n=61) according to whether occurred major adverse cardiovascular events (MACE) during the follow-up period. The differences of the degree of coronary artery stenosis and CT-FFR between the two groups were compared, and the patients were classified according to the median of degree of coronary artery stenosis and CT-FFR, and compared the total incidence of MACE and the incidence of MACE within 3 months, 3 to 6 months and after 6 months. Spearman rank correlation analysis was used to analyze the correlation between the degree of coronary artery stenosis and CT-FFR, and multivariate Logistic regression analysis was used to explore the influencing factors of MACE. The ROC curves of stenosis degree, CT-FFR and the combination of the two index on the occurrence of MACE in patients with stable chest pain caused by coronary artery obstruction were drawn, and compared the predictive performance of different indexes according to the area under ROC curve (AUC) .

The median degree of coronary lumen stenosis in 116 patients was 70% (60%, 80%), and the median CT-FFR was 0.79 (0.74, 0.85). The degree of coronary lumen stenosis in the MACE group was higher than that in the non-MACE group (Z=-4.41, P<0.001), and CT-FFR was lower (Z=-5.54, P<0.001). The incidence of MACE in patients with coronary artery stenosis between 70% and 90% was higher than that in patients with coronary artery stenosis between 50% and 69% (χ²=19.221, P<0.001). The incidence of MACE in CT-FFR≤0.8 patients was higher than that in CT-FFR>0.8 (χ²=30.025, P<0.001). The incidence of MACE in patients with different degrees of coronary artery stenosis combined with different CT-FFR was significantly different (χ²=37.789, P<0.001). The incidence of MACE was higher in patients with stenosis between 70% and 90% within 3 months than that in patients with stenosis between 50% and 69%, and the incidence of MACE in patients with CT-FFR≤0.8 within 3 months was higher than that in patients with CT-FFR>0.8. The incidence of MACE in patients with stenosis between 70% and 90% and CT-FFR≤0.8 within 3 months of follow-up was higher than that in other categories (P<0.05). Spearman rank correlation analysis showed that the degree of coronary lumen stenosis was negatively correlated with CT-FFR (r_s=-0.532 6, P<0.001). Multivariate Logistic regression analysis showed that the degree of coronary lumen stenosis between 70% and 90% (OR=3.085, 95%CI=1.147-8.298, P=0.026), CT-FFR≤0.8 (OR=6.527, 95%CI=2.560-16.641, P<0.001) were risk factors for MACE. The value of coronary lumen stenosis combined with CT-FFR in predicting MACE was higher (AUC=0.812, 95%CI=0.731-0.892, P<0.001) .

The degree of coronary artery stenosis between 70% and 90%, CT-FFR≤0.8 may be the risk factors of MACE in patients. Compared with the degree of stenosis, CT-FFR has a beneficial value in predicting the incidence of MACE in patients with stable chest pain caused by coronary artery obstruction, and the prediction performance is better when the degree of stenosis is combined with CT-FFR.