RESUMEN
Objective:To investigate the value of serum urea nitrogen on in-hospital death in patients with heart failure.Methods:The clinical data of 9 459 patients with heart failure from January 2013 to December 2018 in Shengjing Hospital of China Medical University were retrospectively analyzed. Among them, 296 cases died in hospital (death group) and 9 163 cases survived (survival group). The clinical data of patients were collected, including general condition, disease history, physical examination, laboratory indicators and relevant physical examination, etc. Correlation was finished with Pearson correlation analysis. Multivariate Logistic regression analysis was used to determine independent risk factors for in-hospital death in patients with heart failure. Receiver operating characteristic (ROC) curve was used to determine the optimal predictive threshold of urea nitrogen for in-hospital death.Results:The in-hospital mortality in patients with heart failure was 3.1% (296/9 459). There were statistical differences in age, hypertension rate, diabetes rate, a history of atrial fibrillation rate, smoking history rate, hemoglobin, albumin, glycosylated hemoglobin, urea nitrogen, creatinine, uric acid, serum potassium, serum sodium, troponin I, N terminal brain natriuretic peptide precursor (NT-proBNP), left ventricular ejection fraction (LVEF) between death group and survival group ( P<0.01 or <0.05), and there were no statistical difference in gender composition, coronary heart disease rate, platelet, total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglyceride, left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) between 2 groups ( P>0.05). Pearson correlation analysis result showed that the urea nitrogen was positively correlated with age, coronary heart disease, hypertension, diabetes, glycosylated hemoglobin, creatinine, uric acid, serum potassium, troponin I, NT-proBNP, LVEDV and LVESV ( r = 0.130, 0.024, 0.053, 0.128, 0.033, 0.739, 0.468, 0.377, 0.065, 0.432, 0.084 and 0.101; P<0.01 or <0.05); and the urea nitrogen was negatively correlated with gender, history of atrial fibrillation, hemoglobin, platelet, albumin, total cholesterol, LDL-C, serum sodium and LVEF ( r = -0.033, -0.063, -0.272, -0.077, -0.188, -0.070, -0.071, -0.199 and -0.113, P<0.01); and there were no correlation between urea nitrogen and smoking history or triglyceride ( P>0.05). Multivariate Logistic regression analysis result showed that age, hypertension, albumin, urea nitrogen, troponin I and NT-proBNP were independent risk factors for in-hospital death in patients with heart failure ( OR = 1.018, 0.613, 0.924, 1.082, 1.340 and 1.005; 95% CI 1.002 to 1.033, 0.427 to 0.881, 0.889 to 0.961, 1.040 to 1.126, 1.111 to 1.617 and 1.003 to 1.007; P<0.05 or <0.01). ROC curve analysis result showed that the area under the curve (AUC) of urea nitrogen for prediction of in-hospital death in patients with heart failure was 0.737 (95% CI 0.728 to 0.748), and the optimal threshold value was 11.41 mmol/L, with a sensitivity of 60.16% and a specificity of 77.01%; the AUC of NT-proBNP for prediction of in-hospital death in patients with heart failure was 0.726 (95% CI 0.712 to 0.740), and there was no statistical difference in the AUC between urea nitrogen and NT-proBNP ( Z=1.055, P=0.291). Conclusions:Elevated urea nitrogen level is independently associated with an increase in in-hospital mortality in patients with heart failure, and the optimal threshold for predicting in-hospital death is 11.41 mmol/L.