Abstract: Objective  To explore the correlation between quantitative coronary computed tomography angiography(CTA) parameters and peripheral blood platelet function indexes, and to analyze its diagnostic value in coronary artery stenosis and its relationship with disease severity.
Methods  A total of 183 patients with suspected CAS were selected as the research subjects. According to the results of coronary CTA, patients with confirmed CAS were enrolled as the observation group(n=125), and those without CAS were enrolled as the control group(n=58). The parameters of quantitative coronary CTA［minimum lumen diameter(MLD), percentage of area stenosis(%AS), percentage of diameter stenosis(%DS), minimum lumen area(MLA)］ between two groups and the observation group of patients with different conditions were compared. The platelet function indexes in peripheral blood of patients with different conditions in the observation group［mean platelet volume(MPV), thrombelastography maximum(TEG-MA), platelet-derived growth factor BB(PDGF-BB)］ were compared. The correlation between parameters of quantitative coronary CTA and platelet function indexes in peripheral blood and their diagnostic value for CAS were analyzed.
Results  MLA and MLD in the observation group were smaller than those in the control group, and %AS and %DS were larger than those in the control group(P＜0.05). MLA and MLD were negatively correlated with the degree of stenosis and positively correlated with the plaque properties. %AS, %DS were positively correlated with the degree of stenosis and negatively correlated with the plaque properties. MPV, TEG-MA and PDGF-BB were positively correlated with the degree of stenosis and negatively correlated with the plaque properties(P＜0.05). MLA and MLD were negatively correlated with MPV, TEG-MA and PDGF-BB, and %AS and %DS were positively correlated with MPV, TEG-MA and PDGF-BB(P＜0.05). The area under the curve(AUC) of MLA and MLD in the diagnosis of CAS was 0.901, the sensitivity was 76.80%, and the specificity was 94.83%.
Conclusion  There is a certain correlation between CTA parameters and peripheral blood platelet function. Quantitative coronary CTA examination can help improve the diagnostic value in coronary artery stenosis, and assess the properties of coronary atherosclerotic plaque, which can be used as a reliable non-invasive means to assess and judge the severity of the disease.

Key words: coronary stenosis, angiocardiography, platelets