Prognostic value of hemoglobin to red cell distribution width ratio in patients with pulmonary embolism

Background his study investigates the prognostic value of the hemoglobin to red cell distribution width ratio (HRR) in pulmonary embolism (PE), a life-threatening cardiovascular disease. While inflammation and hypercoagulability drive PE pathogenesis, the role of HRR remains unexplored. Methods In this retrospective cohort study, data from 1,658 critically ill PE patients (2008–2022) were extracted from the MIMIC-IV database. Patients were stratified by HRR quartiles (Q1–Q4). COX proportional hazards regression analysis, Kaplan- Meier survival curves and restricted cubic spline models were employed to investigate the association of RDW and HRR levels with mortality. Time-dependent receiver operating characteristic curve (ROC) analysis was conducted to evaluate the accuracy of RDW and HRR in predicting mortality in patients with PE. Results Patients with a poor prognosis and mortality had significantly lower HRR levels at admission. When HHR was considered as a continuous variable, HRR was inversely associated with 28-day mortality (HR = 0.44, 95% CI = 0.22–0.86, p < 0.017) and 90-day mortality (HR = 0.29, 95% CI = 0.16–0.52, p < 0.001) after adjusting for various potential confounders. The Kaplan-Meier survival curve showed that the survival rate for 28-day increased for the higher HRR groups compared to the lower HRR groups (log-rank test p < 0.001). Moreover, the 90-day survival curve demonstrated similar results. Receiver-operating characteristic curve analysis demonstrated that HRR appears to be a more reliable predictor for both 28-day mortality ( The AUC is 0.610) and 90-day mortality ( The AUC is 0.641) than RDW and hemoglobin. Conclusions HRR levels as a simple, novel, cost-effective, and valuable biomarker, are an independent predictor of poor prognosis for patients with pulmonary embolism. However, further research is necessary to elucidate the underlying biological mechanisms and confirm the clinical utility of HRR.