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The following is a summary of “Association between serum creatinine—to—albumin ratio and 28-day mortality in intensive care unit patients following cardiac surgery: analysis of mimic-iv data,” published in the February 2025 issue of the BMC Cardiovascular Disorders by Shi et al.

The creatinine-to-albumin ratio (CAR) has been recognized as a prognostic marker in various postoperative settings; however, its role in predicting outcomes in patients undergoing cardiac surgery remains inadequately explored. This study aimed to investigate the association between CAR and 28-day mortality in patients admitted to the intensive care unit (ICU) following cardiac surgery, with the goal of identifying potential avenues for targeted interventions to improve patient outcomes. Utilizing data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, patients admitted to the ICU post-cardiac surgery were classified into three groups based on CAR levels. The 28-day ICU mortality rates among these groups were analyzed using Kaplan–Meier survival curves, while multivariate Cox regression and restricted cubic spline (RCS) analysis were employed to assess the relationship between CAR and mortality risk. 

Additionally, receiver operating characteristic curve analysis was conducted to evaluate the predictive accuracy of CAR, and mediation analysis was performed to explore potential biomarkers influencing the association between CAR and 28-day ICU mortality. A total of 5,670 patients were included in the study. Patients with elevated CAR levels (≥0.31) exhibited a significantly higher 28-day ICU mortality rate (11.4%) compared to those with lower CAR levels (<0.23, 1.83%). Furthermore, Kaplan–Meier analysis demonstrated that the high CAR group had the lowest survival rate among the three groups (p < 0.0001). ROC curve analysis revealed that CAR had moderate predictive power for 28-day ICU mortality (AUC = 0.748), and a dose-response relationship was identified, with higher CAR levels correlating with increased mortality risk. 

Subgroup analysis indicated that the association between CAR and mortality was particularly pronounced in female patients and those without chronic conditions such as chronic kidney disease and type 2 diabetes mellitus (T2DM). Mediation analysis further revealed that CAR influenced 28-day ICU mortality through multiple key biomarkers, including chloride (39.8%), glucose (11.8%), potassium (24.4%), and sodium (28.3%). These findings highlight the clinical significance of CAR as a predictive biomarker for mortality in patients who are critically ill in cardiac surgery and underscore its potential utility in risk stratification. The identification of specific biomarker pathways suggests avenues for targeted therapeutic interventions that may improve survival outcomes. Given the complex interplay between CAR and mortality risk, further research is warranted to explore underlying mechanisms and to refine its application in perioperative risk assessment and critical care management.

Source: bmccardiovascdisord.biomedcentral.com/articles/10.1186/s12872-025-04505-1