Objective To explore the association between plasma Leukotriene B4 (LT-B4) and the severity of coronary artery lesions in coronary heart disease (CHD) patients.

Methods 400 patients were divided into CHD group (n=310) and control group (n=90)according to the Coronary Angiography (CAG). 310 patients in CHD group divided into Acute Coronary Syndrome (ACS) group (n=217) and Stable Angina Pectoris (SAP) group (n=93) according to clinical information.The severity and extent of coronary lesions was analysed by CAG and typified by means of Gensini coronary score system.LT-B4 level in plasma of all patients were tested by Enzyme linked immunosorbent assay. And blood pressure, height, weight, body mass index (BMI)=kg/m2 were measured at the same time. 85 cases of coronary heart disease patients were underwent 64-slice spiral CT coronary artery imaging. Then, we evaluate the main plaque in Coronary artery.

Results HDL-C in CHD group was significantly lower than that in control group, but BMI, TC, TG, LDL-C, GLu and uric acid increased significantly compared with the control group. LT-B4 level in CHD patients increased significantly compared with the control group (p<0.05).The concentrations of LT-B4, LDL- C and GLu in ACS group were increased significantly compared with SAP group, HDL-C in ACS group was significantly lower than that in the SAP group (p<0.05). As the the change of lesion type and the increasing of the severity of coronary artery disease, LT-B4 concentration increased gradually (p <0.05). The plasma LT-B4 levels in soft plaque group and fibrous plaque group were much higher than that in calcified plaque group in CHD patients, and the difference was statistically significant (p <0.05). Stepwise regression analysis showed that the concentration of LT-B4 was significantly correlated with Gensini score of coronary lesions.

Conclusion The LT-B4 level in ACS patients elevated significantly which might be positive correlated with the severity of coronary artery disease, and could promote the formation of vulnerable plaque. Plasma Leukotriene-B4 testing can improve the accuracy of detection of coronary artery plaque by 64-slice spiral CT in patients with ACS, and have certain prediction effect of the diagnosis of the ACS and the judgements of coronary lesions. Currently, leukotriene receptor antagonist have been widely used in allergic inflammation in the respiratory system, but the clinical application in atherosclerotic disease is still being studied. Therefore, in-depth study the molecular mechanisms of 5-lipoxygenase /leukotriene pathway in the process of acute coronary syndrome may play an important role in the prediction and control of ACS and the vulnerable plaque.