[Relationship between plasma miR-126 and coronary slow flow phenomenon]

Objective: To investigate the relationship between miR-126 in plasma and coronary slow flow (CSF) phenomenon. Methods: A total of 109 patients without coronary artery disease who underwent coronary angiography at Beijing Anzhen Hospital Affiliated to Capital Medical University from August 2016 to March 2018 were enrolled. The patients were divided into CSF groups (53 cases) and the control group (56 cases) according to CSF existing or not. Clinical data and blood samples of the participants in two groups were collected. Real-time quantitative PCR (RT-qPCR) was used to determine the expression of miR-126 in plasma, and the relationship between miR-126 and CSF and its predictive effect were analyzed. Results: Mean TIMI frame counts (34±4 vs 20±3), left anterior descending TIMI frame counts (35±5 vs 21±3), left gyroscopic TIMI frame counts (36±5 vs 20±3), right coronary TIMI frame counts (34±5 vs 20±35) and expression level of hypersensitive C-reactive protein (hs-CRP, (3.0±1.2) mg/L vs (2.1±0.9) mg/L) and plasma miR-126 (0.25±0.09 vs 0.19±0.10) of the CSF group were significantly higher than those of the control group (P<0.05). Correlation analysis showed that miR-126 and hs-CRP levels were significantly correlated with mean TIMI frame count (r=0.367, P<0.05), and miR-126 was also significantly associated with the hs-CRP level (r=0.388, P<0.05). Logistic regression analysis showed that miR-126 (OR=2.513) and hs-CRP (OR=1.568) were independent risk factors for coronary slow flow. The area under the ROC curve of miR-126 predicting for CSF was 0.661. When the cutoff value was set at 0.225, the Youden index reached the maximum with a sensitivity of 0.660 and a specificity of 0.714. Conclusion: The expression level of miR-126 in plasma is significantly correlated with CSF, and miR-126 can be used as a predictor of coronary slow flow phenomenon.