Abstract: This article investigated the clinical value and risk factors of spiral CT coronary angiography (CCTA) in the diagnosis of left coronary bifurcation lesions. Selected 200 patients with coronary heart disease who received CCTA and coronary angiography for analysis. Taking coronary angiography results as the diagnostic gold standard, the patients were divided into the left coronary angle proximal lumen stenosis group (93 cases) and non-stenosis group (107 cases). In the stenosis group, the included angle of the left coronary artery was negatively correlated with the lumen diameter and the measured value of the lumen cross-sectional area (P<0.05). The area under the ROC curve (AUC) of the left coronary angle in the diagnosis of the proximal lumen stenosis of the left coronary angle was 0.894, the diagnostic sensitivity was 81.36%, the specificity was 83.55%, and the critical value of the left coronary angle was 81.3°. Smoking, combined hypertension, family history of coronary heart disease, increased serum TG, increased HDL-C, increased hs-CRP, increased FPG, and left coronary angle > 81.3° were the independent risk factors (P<0.05) for the occurrence of proximal lumen stenosis in the left coronary angle. Increased serum HDL-C level can reduce the risk of stenosis in the proximal segment of the left coronary angle (P<0.05). The use of CCTA to examine the included angle of the left coronary artery has a high clinical value in predicting and diagnosing the proximal lumen stenosis of the left coronary angle. The proximal lumen stenosis of the left coronary angle in patients with coronary heart disease is affected by many factors, among them the increased included angle of arteries (>81.3°) can significantly increase its risk.

Key words: spiral CT coronary angiography, left coronary artery, included angle, risk factors