Prognostic value of hemoglobin-to-red cell distribution width ratio in patients with thoracoabdominal aortic aneurysm: a MIMIC-IV database-based retrospective study.

BACKGROUND

In recent years, the role of hemoglobin-to-red blood cell distribution width ratio (HRR) in risk stratification of cardiovascular and cancer diseases has attracted much attention, but its prognostic significance in thoracoabdominal aortic aneurysm (TAAA) patients is not clear. This study aimed to explore the correlation between the HRR and the mortality of patients with TAAA, as well as its value for prognosis of these patients.

METHODS

This retrospective study utilized data from patients diagnosed with TAAA from the MIMIC-IV database (v2.2). hemoglobin (Hb) and red blood cell distribution width (RDW) were measured to determine the HRR. The primary outcome assessed in this study was in-hospital mortality, while secondary outcomes included mortality at 7, 30, and 365 days post-intensive care unit (ICU) discharge. Logistic regression and restricted cubic splines (RCS) were adopted to explore the correlation between HRR and mortality in TAAA patients; the prognostic value of HRR for patients with TAAA was analyzed by the receiver operating characteristic (ROC) curve and decision curve. The robustness of the study results was evaluated through subgroup analysis and interaction testing by the likelihood ratio test.

RESULTS

In the study, a total of 1,824 patients were enrolled and stratified into Q1 (<0.85), Q2 (0.85-1.02), and Q3 (>1.02) groups based on tertiles of HRR. The logistic regression model revealed a negative correlation between HRR and in-hospital mortality in the adjusted Model 3 [odds ratio (OR): 0.151, 95% confidence interval (CI): 0.028-0.838]. The RCS analysis further confirmed a linear correlation between these two. ROC curve analysis of in-hospital mortality showed an area under the curve (AUC) of 0.727, indicating a significant predictive advantage of HRR. The decision curve indicated a relatively large net benefit range of HRR. In subgroup analysis, the correlation between HRR and in-hospital mortality among TAAA patients was stable (P<0.05), with no interaction with other subgroups except for the subgroup treated with furosemide.

CONCLUSIONS

HRR is significantly negatively correlated with the mortality of patients with TAAA and is a relatively independent predictor.