Objective To explore the correlation between the level of plasma microRNA-34a(miR-34a) and the degree of coronary artery disease in patients with coronary atherosclerotic heart disease (CHD).

Methods The venous blood samples of 93 hospitalized patients in cardiovascular department were collected, and the level of plasma miR-34a was detected by ultraviolet spectrophotometry. According to the results of coronary angiography, 93 patients were divided into control group (non-CHD patients, 20 cases) and experimental group (CHD patients, 73 cases). According to whether the lesions were chronic total occlusion of coronary artery (CTO) or not, the patients in the experimental group were divided into CTO group(18 cases) and non-CTO group(55 cases). The difference of plasma miR-34a level in each group was compared. The diagnostic value of plasma miR-34a level in coronary artery disease was analyzed by receiver operating characteristic (ROC) curve, and the correlations of plasma miR-34a level with SYNTAX score and Gensini score in patients with CHD were analyzed.

Results Plasma miR-34A levels in the CTO group and non-CTO group were (4.21±1.37) and (2.19±1.05), respectively, which were higher than (1.10±0.27) in the control group (P < 0.05). The level of plasma miR-34a in the CTO group was higher than that in the non-CTO group (P < 0.05). The expression level of plasma miR-34a in CHD patients showed a gradient upward trend with the increase of SYNTAX score and Gensini score, and the differences among subgroups were statistically significant (P < 0.05). ROC curve showed that the area under curve (AUC) of plasma miR-34A level for diagnosing coronary artery lesions (SYNTAX score) was 0.786, with 95%CI of 0.739 to 0.829, sensitivity of 0.533, and specificity was 0.892. AUC of plasma miR-34a level for diagnosis of coronary artery disease (Gensini score) was 0.793, with 95% CI of 0.745 to 0.835, sensitivity of 0.739, and specificity of 0.746. Correlation analysis showed that plasma miR-34a expression level was significantly positively correlated with SYNTAX score and Gensini score in CHD patients (r=0.084, 0.076, P < 0.001).

Conclusion The level of plasma miR-34a is positively correlated with the degree of coronary artery lesions in patients with CHD, which can be probably used as a new biological index to evaluate the degree of coronary artery lesions in these patients.