The predictive value of postoperative blood urea nitrogen for in-hospital and 1-year mortality in elderly patients un-dergoing valve replacement surgery
DU Su-ling
CHE Shuai-zheng
CHEN Yan-li
Abstract：Background: Previous studies have shown a relationship between elevated blood urea nitrogen (BUN) level and poor outcomes in several diseases, but data on the prognostic significance of postoperative BUN in elderly patients undergoing valve replacement surgery (VRS) remained sparse. Methods: BUN was measured immediately after VRS. A total of 3118 elderly patients were enrolled and divided into four groups according to the quartiles of postoperative BUN: Q1, <5.6 mmol/L; Q2, 5.6-6.8 mmol/L; Q3, 6.8-8.4 mmol/L and Q4, ≥8.4 mmol/L. The associations of postoperative BUN with in-hospital and 1-year mortality were evaluated. Results: The incidence of in-hospital death (1.0% vs. 3.3% vs. 3.3% vs. 8.4%, P<0.001) and major adverse clinical events (5.1% vs. 7.8% vs. 9.9% vs. 19.1%, P<0.001) was significantly higher in patients with a high BUN level. BUN was independently associated with all-cause in-hospital mortality [odds ratio (OR): 1.11, 95% confidential interval (CI): 1.07-1.16, P<0.001]. The receiver operating characteristic (ROC) curve showed that BUN>9 mmol/L had a sensitivity of 48.4% and specificity of 81.8% for predicting in-hospital death [area under curve (AUC): 0.705, 95% CI: 0.658-0.753, P<0.001]. Kaplan-Meier survival curves showed that patients with BUN>9 mmol/L had a higher one-year mortality than those without (log-rank test: 91.7, P<0.001). Multivariate analysis showed that BUN>9 mmol/L was an independent predictor for one-year mortality [hazard ratio (HR): 1.67, 95% CI: 1.23-2.28, P=0.001]. Conclusions: This study provided strong evidence that increased postoperative BUN level was associated with poor prognosis in elderly patients undergoing VRS. [S Chin J Cardiol 2025;26(2):107-113]
Keywords：Valve replacement surgeryBlood urea nitrogenPostoperativePrognosisElderly
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 107-113,120 )