Abstract： Objective To investigate the value of microRNA-351(miR-351)and microRNA-29b(miR-29b)in evaluating the prognosis of patients with type 2 diabetes mellitus(T2DM)complicated with heart failure(HF).Methods A total of 145 patients with T2DM and HF treated from February 2020 to January 2022 were enrolled as the observation group.Concurrently,141 healthy individuals were selected as the control group.After 3 months of treatment,patients were followed up and categorized into two groups based on prognosis:the good prognosis group(n=90)and the poor prognosis group(n=55).Levels of miR-351,miR-29b,N-terminal precursor B-type natriuretic peptide(NT-proBNP),glycosylated hemoglobin(HbA1c),left ventricular ejection fraction(LVEF),and left ventricular end-diastolic dimension(LVEDD)were compared between the observation group and the control group.Clinical data,cardiac function indicators,and levels of HbA1C,NT-proBNP,miR-351,and miR-29b were compared between the good and poor prognosis groups.The correlation of these factors with prognosis and their predictive value for poor prognosis were an-alyzed.Results HbA1C,NT-proBNP,miR-351,and LVEDD levels in the observation group were significantly high-er,while miR-29b and LVEF levels were significantly lower than those in the control group(P＜0.05).HbA1C,NT-proBNP,miR-351,and LVEDD levels in the poor prognosis group were significantly higher,while miR-29b and LVEF levels were significantly lower than those in the good prognosis group(P＜0.05).There were no statistically significant differences in medication usage and comorbid conditions between the two prognosis groups(P＞0.05).Logistic regression analysis showed that miR-351 and miR-29b were significantly associated with prognosis in T2DM patients with HF(P＜0.05).Receiver operating characteristic(ROC)curve analysis revealed that the area under the curve(AUC)for miR-351 and miR-29b in predicting prognosis were 0.632 and 0.642,respectively,with the combined AUC being the highest at 0.829.Conclusion The levels of miR-351 and miR-29b are abnormally expressed in patients with T2DM and HF and are correlated with patient prognosis.Combined detection of these factors is valuable for prognosis assessment,suggesting that clinical management should focus on controlling these factors to improve patient outcomes.