Association of Ferritin, Transferrin, and TSAT with 1-Year Mortality in AMI Patients Admitted to the ICU: A MIMIC-IV Database Study

Background The prognostic value of iron homeostasis markers—ferritin, transferrin, and transferrin saturation (TSAT)—in patients with acute myocardial infarction (AMI) remains poorly defined, particularly in critically ill populations requiring admission to the intensive care unit (ICU). Methods Patients with acute myocardial infarction (AMI) who underwent testing for iron homeostasis markers (ferritin, transferrin, and transferrin saturation [TSAT]) within 24 hours of ICU admission were included from the MIMIC-IV database. The primary outcome was one-year all-cause mortality. Multivariable Cox regression, Kaplan-Meier analysis, and restricted cubic spline models were employed to assess the associations of these three markers with mortality risk, with patients categorized into tertiles for grouped analyses. Receiver operating characteristic (ROC) curve analysis was performed to compare the predictive performance of the three markers for mortality and to evaluate their incremental predictive value beyond a baseline risk model. Results A total of 416 patients with AMI were included in the analysis. Using the lowest tertile as reference, the highest tertiles of ferritin (HR = 1.88) and TSAT (HR = 1.60) were independently associated with an increased risk of 1-year mortality, while the middle tertile of transferrin was associated with a reduced risk (HR = 0.64). Restricted cubic spline models suggested nonlinear associations. The predictive performance of each marker was limited (AUC range: 0.57–0.63), and none significantly improved the predictive ability of the baseline model. Conclusion Ferritin and TSAT measured within 24 hours of ICU admission, as well as decreased transferrin, are independent predictors of 1-year all-cause mortality in ICU-admitted patients with AMI. However, their incremental predictive value beyond traditional risk models is limited. Subgroup analyses suggest that the prognostic value of these markers may be heterogeneous in patients with specific comorbidities (e.g., COPD, AF, diabetes, and CKD), a finding that warrants further investigation.