To investigate the relationship between peripheral blood microRNA-125a-5p (miR-125a-5p) and miR-483-3p expression and cardiac function, ischemia-reperfusion injury (IRI), and prognosis in patients with acute myocardial infarction (AMI).

A prospective cohort study was conducted; 136 patients with AMI (AMI group) and 136 healthy volunteers (control group) admitted to Yangling Demonstration Zone Hospital from September 2020 to September 2023 were selected. Patients with AMI were divided into a group Ⅰ-Ⅱ (n = 85) and a group Ⅲ-Ⅳ (n = 51) by Killip class, and also divided into an IRI group (n = 63) and a non-IRI group (n = 73) by IRI occurrence. Patients with AMI were followed up for one year after discharge, with two patients lost. The remaining patients were divided into a good prognosis group (n = 89) and a poor prognosis group (n = 45) according to the prognosis. Peripheral blood miR-125a-5p and miR-483-3p expression levels in all subjects were detected within 24 hours after enrollment, and the differences between groups were compared. Multivariate logistic regression analysis was applied to discover the factors influencing the prognosis of patients with AMI. Based on the analysis results, a combined prediction model was constructed, and a receiver operating characteristic (ROC) curve was used to analyze the predictive value of each indicator individually and jointly in predicting the prognosis of patients with AMI, followed by internal validation.

Peripheral blood miR-125a-5p expression was significantly higher and miR-483-3p expression was significantly lower in the AMI group than in the control group (both P < 0.05), in the group Ⅲ-Ⅳ than in the group Ⅰ-Ⅱ (both P < 0.05), and in the IRI group than in the non-IRI group (both P < 0.05). Killip class Ⅲ-Ⅳ, IRI, and high miR-125a-5p expression were independent risk factors for poor prognosis in patients with AMI, while high miR-483-3p expression was a protective factor (all P < 0.05). The area under the curve (AUC) of peripheral blood miR-125a-5p, miR-483-3p, Killip class Ⅲ-Ⅳ, and IRI for predicting poor prognosis in patients with AMI was 0.785, 0.804, 0.670, and 0.664, and the AUC of the combined prediction model was 0.897. The Delong test demonstrated that the AUC of the combined prediction model was higher than that of peripheral blood miR-125a-5p, miR-483-3p, Killip class Ⅲ-Ⅳ, and IRI alone (Z = 2.637, 2.497, 2.917, 3.017; P = 0.010, 0.014, 0.004, 0.003). The concordance index was 0.684, indicating that the model's predicted results were highly consistent with the actual situation.

High miR-125a-5p and low miR-483-3p expression in peripheral blood are associated with impaired cardiac function, IRI, and poor prognosis in patients with AMI; combining miR-125a-5p, miR-483-3p, Killip class, and IRI can effectively predicting the risk of poor prognosis in these patients.