Abstract:Objective To evaluate the clinical value of plasma microRNA in the early diagnosis of ventricular septal defect (VSD) and its feasibility as a molecular diagnostic marker for VSD, and to establish a clinical early diagnosis model. Methods This study was conducted using a Jinan Children's Hospital and Taian Maternal and Child Health Hospital-based case-control study. A total of 85 cases were collected for the VSD group and 80 cases for the control group. The test was performed in three stages. At first, 3 cases of ventricular septal defect (VSD) and 3 matched controls were selected, and the microRNA whole genome expression profile chip was used for primary screening. Then, the sample size was expanded (20 VSD cases VS 15 controls). The selected 8 differential microRNAs were verified by real-time quantitative PCR (qRT-PCR). Finally, further expanding samples (62 VSD cases VS 62 controls) were selected for qRT-PCR to screen biomarkers for early diagnosis of congenital heart disease and to establish a multi-index logistic regression model, and using MedCalc software for ROC (Receiver-Operator Characteristic curve)curve to analyze the value of the diagnostic model. Results Compared with control group, the results of microarray screening showed that there were 36 differential-expressed microRNAs (P?0.05), two-stage large samples detected by qRT-PCR (P?0.05) and significantly different expression among five plasma microRNAs (let-7e-5p, miR-155-5p, miR-222-3p, miR-433-3p and miR-487b-5p) in VSD (P?0.05), which proved plasma microRNAs can be biomarkers for early diagnostic significance of VSD. The area under the ROC curve of five plasma microRNAs ranged from 0.678 to 0.832, and the largest area under the ROC curve was 0.832 in miR-222-3p. A multi-index logistic regression analysis model was established. Five plasma microRNAs combined models could improve the diagnostic efficiency of VSD. The area under the ROC curve reached 0.955, and the sensitivity and specificity were 83.87% and 95.16%, respectively. In the combined diagnostic model of three plasma microRNAs (let-7e-5p, miR-155-5p, miR-222-3p), the area under the ROC curve reached 0.910, sensitivity and specificity were 82.30% and 90.30%, respectively, which was closed to the diagnosis effectiveness of five miRNAs. Conclusions Five kinds of plasma microRNAs have certain credibility as early diagnostic markers of VSD. After integration, a joint diagnostic model with multiple indicators can be established. Combining three kinds of plasma microRNA to construct a diagnostic model can significantly improve the diagnostic efficiency of VSD, and has more clinical application value.