Red Cell Distribution Width/Albumin Ratio: A Predictor of In-Hospital All-Cause Mortality in Patients with Acute Myocardial Infarction in the ICU

Purpose: Red cell distribution width (RDW) and albumin level are linked to adverse outcomes in patients with acute myocardial infarction (AMI). Nonetheless, it remains unknown whether the RDW/albumin ratio (RAR) is associated with the short-term prognosis of AMI. Using a large cohort, we aimed to explore the association between RAR and in-hospital all-cause mortality in intensive care unit (ICU) patients with AMI.

Patients and methods: The patients' data analyzed in this retrospective cohort investigation were obtained from the eICU Collaborative Research Data Resource. RAR was calculated based on the serum albumin level and RDW. The primary outcome was in-hospital all-cause mortality. Receiver operating characteristic curve, multiple logistic regression model, and Kaplan-Meier survival analysis were performed to explore the prognostic value of RAR.

Results: We enrolled 2594 patients in this study. After correcting for confounding factors, the RAR was an independent predictor for in-hospital mortality in our model (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.12, 1.43). A similar relationship was observed with mechanical ventilation use. RAR showed a better predictive value with an area under the curve (AUC) of 0.738 (cutoff, 4.776) for in-hospital all-cause mortality compared to RDW or albumin alone. Kaplan-Meier estimator curve analyses for RAR demonstrated that the group with RAR ≥4.776%/g/dL had poorer survival than the group with RAR <4.776%/g/dL (p< 0.0001). The subgroup analysis revealed no significant interaction between RAR and in-hospital all-cause mortality in all strata.

Conclusion: RAR was an independent risk factor for in-hospital all-cause mortality in ICU patients with AMI. Higher RAR values corresponded to higher mortality rates. RAR is a more accurate predictor of in-hospital all-cause mortality in patients with AMI in the ICU than albumin or RDW. Thus, RAR may be a potential biomarker of AMI.