White Blood Cell-to-Haemoglobin Ratio as a Predictor of 30-Day Mortality in ICU Patients with Pulmonary Hypertension: Analysis of the MIMIC-IV Database

The white blood cell-to-haemoglobin ratio (WHR) is a comprehensive indicator of inflammation and anaemia status. However, the relationship between the WHR and the risk of 30-day mortality among intensive care unit (ICU) patients with pulmonary hypertension (PH) remains unclear. The purpose of this study was to investigate the association between the WHR and 30-day mortality in critically ill patients with PH. Clinical data of patients with PH were extracted from the MIMIC-IV (2.2) database. Restricted cubic splines and logistic regression analysis were used to investigate the relationship between the WHR and 30-day mortality. Subgroup analysis was used to assess the robustness of the results. The predictive model was constructed based on the logistic regression results. A total of 451 patients with PH were enrolled, with 78 (17.3%) dying within 30 days. Restricted cubic spline analysis revealed a linear relationship between the WHR and 30-day mortality. The WHR was an independent predictor for 30-day mortality in PH patients (OR, 1.58; 95% CI, 1.05–2.37; P = 0.028). The AUC of the WHR was 0.646 (95% CI: 0.60–0.69). Subgroup analyses revealed no significant interaction effect of the WHR on each subgroup (P for interaction: 0.134–0.942). A predictive model including the WHR, sepsis status, age, anion gap, respiratory rate and Charlson Comorbidity score had high predictive value for 30-day mortality in PH patients [AUC 0.8 (95% CI: 0.74–0.86)].