# Serum creatinine-to-albumin ratio as a prognostic marker for short- and long-term mortality in critically ill stroke patients: a MIMIC-IV study

## TL;DR

This study shows that the serum creatinine-to-albumin ratio (sCAR) can predict both short- and long-term mortality in ICU stroke patients better than traditional markers.

## Contribution

The study introduces sCAR as a novel, easily measurable biomarker for mortality risk in critically ill stroke patients.

## Key findings

- High sCAR was linked to significantly higher 28-day and 1-year mortality in ICU stroke patients.
- sCAR outperformed traditional markers in predicting mortality with AUCs of 0.618 and 0.639.
- RCS curves showed a non-linear relationship between sCAR and mortality risk.

## Abstract

Stroke remains a leading cause of mortality and disability worldwide, with critically ill patients facing particularly poor outcomes. Existing prognostic markers often fail to capture the full spectrum of metabolic and nutritional disturbances in stroke. The serum creatinine-to-albumin ratio (sCAR), reflecting renal function and nutritional status, may offer improved mortality prediction for the intensive care unit (ICU)-admitted stroke patients.

This retrospective cohort study used the MIMIC-IV database (v2.2) to analyze 2,819 adult stroke patients admitted to the ICU. Patients were stratified into low- and high-sCAR groups based on an optimal cutoff of 0.419. Predictive performance was assessed using Cox regression, Kaplan–Meier survival analysis, and ROC and RCS curve modeling.

Patients in the high sCAR group (≥0.419) demonstrated significantly higher short- and long-term mortality, including 28-day (31.7% vs. 16.7%, p < 0.001) and 1-year mortality (51.0% vs. 27.6%, p < 0.001). Multivariate Cox regression confirmed that elevated sCAR was independently associated with increased mortality risk at all endpoints, including 28-day (HR = 2.68, 95% CI: 2.28–3.14, p < 0.001) and 1-year (HR = 3.01, 95% CI: 2.61–3.47, p < 0.001). ROC analysis showed sCAR outperformed traditional markers, with an AUC of 0.618 for 28-day mortality and 0.639 for 1-year mortality. RCS curves revealed a non-linear association between sCAR and mortality risk, with thresholds indicating elevated risk for both short- and long-term outcomes.

The sCAR is a powerful and clinically relevant biomarker for mortality prediction in critically ill stroke patients. By integrating renal and nutritional assessments, sCAR enhances early risk stratification and supports individualized ICU management.