Association between white blood cell-to-haemoglobin ratio and 30 day mortality in heart failure in intensive care unit.

AIMS: The short-term mortality of heart failure (HF) patients admitted to the intensive care unit (ICU) is reported to be high. This study aims to explore the association between white blood cell-to-haemoglobin ratio (WHR) and 30 day mortality from the admission to the ICU. METHODS AND RESULTS: This retrospective cohort study was performed based on the Medical Information Mart for Intensive Care III (MIMIC-III) database (2001-12) and MIMIC-IV database (2008-19). Covariables were selected using the least absolute shrinkage and selection operator regression. Based on the optimal cutoff point selected using the survminer package, WHR was divided into high-ratio group (≥1.6) and low-ratio group (<1.6). The association between WHR and the risk of 30 day mortality was explored using univariate and multivariable Cox regression models. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the prediction performance of WHR. A total of 13 702 patients were included. After adjusting the potential covariates, high WHR was associated with a greater risk of 30 day mortality compared with low WHR [hazard ratio = 1.16, 95% confidence interval (CI): 1.07-1.27, P < 0.001]. WHR also showed a good performance for the prediction of risk of 30 day mortality (AUC = 0.751, 95% CI: 0.746-0.756). CONCLUSIONS: WHR was positively associated with and performed well to predict 30 day mortality, indicating that WHR may be a reliable index to assess the prognosis of HF patients admitted to the ICU.