Abstract
PURPOSE: Hemoglobin (Hb) levels and red cell distribution width (RDW) are standard and widely used parameters that predict clinical outcomes in patients with chronic heart failure (CHF). The Hb to RDW ratio (HRR) provides an incremental clinical prediction, as it reflects the various clinical characteristics of patients. No published data exists in the Medical Information Mart for Intensive Care (MIMIC-IV) and eICU Collaborative Research Database (eICU-CRD) databases on HRR and its association with in-hospital mortality among patients with CHF. The aim of this study was to evaluate the relationship between the HRR and in-hospital mortality in two large real-world cohorts of patients with chronic CHF. PATIENTS AND METHODS: Data from the MIMIC-IV and eICU-CRD databases were used to explore the association between HRR and in-hospital mortality. Multivariate logistic regression, stratified analysis with interaction, and restricted cubic splines were used to investigate the association between HRR and in-hospital mortality. RESULTS: A total of 30,411 patients with CHF were enrolled based on the MIMIC-IV and multicenter eICU-CRD databases (15,983 and 14,428, respectively), including 16,295 men and 14,116 women with a median age of 73 years. The mean HRR was 0.69 ± 0.20. The overall in-hospital mortality rate was 12.63%. Increasing quantiles of HRR were associated with reduced in-hospital mortality rates. After adjusting for significant predictors, multivariate logistic regression analysis demonstrated that a low HRR was a significant predictor of in-hospital mortality, with a graded reduction in risk as HRR increased. Sensitivity analysis using restricted cubic splines demonstrated a continuous increase in in-hospital mortality risk with decreasing HRR (P = 0.262 for the non-linear model). CONCLUSION: A linear relationship was observed between baseline HRR levels and in-hospital mortality. Lower HRR levels were associated with higher in-hospital mortality in patients with CHF. HRR could be a reliable clinical metric for assessing in-hospital mortality risk.