Objective:To investigate the diagnostic value of CT myocardial perfusion combined with serum cystatin C (CysC) and galectin-3 (Gal-3) for coronary heart disease (CHD) and its correlation with coronary artery disease.Methods:The clinical data of 126 patients with CHD (CHD group) and 126 patients with suspected CHD but excluded CHD by coronary angiography (control group) in Shanxi Provincial General Hospital of Armed Police Force from May 2018 to May 2020 were retrospectively analyzed. CT myocardial perfusion myocardial imaging was performed in both groups, and blood perfusion (BF) and mean transit time (MTT) were calculated. The serum Gal-3 was detected by enzyme-linked immunosorbent method, and the serum CysC was detected by immunoturbidimetric method. The changes of indexes in 2 groups and in CHD patients with different degrees of coronary artery stenosis and number of diseased branches were compared. Logistic regression was used to analyze the influencing factors of CHD; Pearson correlation was used to analyze the relationship between BF, MTT, CysC, Gal-3 and the degree of coronary artery stenosis and the number of diseased branches in patients with CHD; the receiver operating characteristic (ROC) curve was drawn, and the effectiveness of each index in diagnosing CHD was analyzed. The area under curve (AUC) was compared by DeLong test, and the combined diagnosis was performed by Logistic binary regression fitting.Results:The BF in CHD group was significantly lower than that in control group: (102.30 ± 9.25) ml/(100 g·min) vs. (119.97 ± 12.08) ml/(100 g·min), the MTT, CysC and Gal-3 were significantly higher than those in control group: (17.23 ± 3.04) s vs. (5.38 ± 1.29) s, (0.98 ± 0.24) mg/L vs. (0.73 ± 0.18) mg/L and (55.27 ± 16.42) ng/L vs. (16.93 ± 5.75) ng/L, and there were statistical differences ( P<0.01). Logistic regression analysis result showed that BF, MTT, CysC and Gal-3 were the influencing factors of CHD ( P<0.01). ROC curve analysis result showed that the AUC of BF, MTT, CysC combined with Gal-3 in the diagnosis of CHD was the largest (0.879), with a specificity of 84.92% and a sensitivity of 80.95%. In patients with CHD, with the aggravation of coronary artery stenosis and the increase of the number of diseased branches, the BF decreased gradually, the MTT, CysC and Gal-3 increased gradually, and there were statistical differences ( P<0.05). Pearson correlation analysis result showed that the BF had negative correlation with the degree of coronary artery stenosis and the number of diseased branches in patients with CHD ( r=-0.592 and -0.573, P<0.01), and the MTT, CysC and Gal-3 had positive correlation with the degree of coronary artery stenosis and the number of diseased branches (MTT: r = 0.695 and 0.674, P<0.01; CysC: r = 0.546 and 0.519, P<0.01; Gal-3: r = 0.628 and 0.609, P<0.01). Conclusions:CT myocardial perfusion imaging indexes (BF and MTT), serum CysC and Gal-3 levels are related to the degree of coronary artery stenosis and the number of diseased branches in patients with CHD. The combined detection of various indicators can improve the diagnostic value and provide a certain basis for clinical diagnosis and treatment and disease monitoring.