Comparative Prognostic Performance of Lactate-to-Albumin Ratio and Inflammatory Biomarkers in Cardiac Arrest: A Retrospective Cohort Study

Background and Objectives: Various hematological and biochemical parameters, including derived indices such as the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR), have been investigated for prognostic assessment in cardiac arrest. The lactate-to-albumin ratio (LAR) may also predict mortality in critically ill patients. The primary objective of this study was to determine the prognostic value of hematological and biochemical parameters in predicting in-hospital mortality among patients who achieved ROSC following cardiac arrest. Materials and Methods: This retrospective cohort study was conducted in patients who experienced cardiac arrest. Laboratory parameters obtained at emergency department admission, including PLR, NLR, LAR, albumin and lactate, were recorded together with clinical outcomes, including return of spontaneous circulation (ROSC) and in-hospital mortality. The study examined the effectiveness of hematological and biochemical parameters in clinical ROSC prediction in patients experiencing both in-hospital and out-of-hospital cardiac arrest. The relationship between these parameters and in-hospital mortality in patients who achieved ROSC was also investigated. Results: During the study period, 505 patients were included, of whom 225 achieved ROSC and 168 died during hospitalization. LAR values were significantly higher in patients with in-hospital mortality (p < 0.001). For predicting in-hospital mortality after ROSC, LAR showed an AUC of 0.737 (95% CI: 0.661–0.812) and significantly outperformed lactate, PLR, and NLR (all p < 0.001). Adding LAR to the clinical model increased the AUC from 0.731 to 0.789 (ΔAUC = 0.058, p = 0.022). In multivariable analysis, higher LAR was independently associated with increased in-hospital mortality (aOR 1.61, 95% CI 1.21–2.16; p = 0.001). Conclusions: In patients who achieved ROSC after cardiac arrest, high initially recorded LAR levels were independently associated with in-hospital mortality. Although lower LAR values were associated with achievement of ROSC, the discriminative performance of LAR for predicting ROSC was insufficient to support its use as a standalone clinical predictor. However, the lack of standardized sampling times relative to cardiac arrest and ROSC limits the interpretation of LAR as a post-ROSC prognostic marker.