Lactate-to-albumin ratio and cholesterol levels predict neurological outcome in cardiac arrest survivors

Abstract

Background: Out-of-hospital cardiac arrest (OHCA) increases lactate levels and reduces albumin levels on admission and tends to lead to a poor neurological prognosis. In our experience, reduced cholesterol levels predict poor neurological prognosis. However, the relationship between cholesterol levels and neurological prognosis in OHCA survivors remains unclear.

Methods: This retrospective observational study included data from January 2015 to June 2023 on 219 OHCA survivors at our intensive care unit. Patients were categorized into two groups based on cerebral functional classification (CPC) scores: Group A (CPC score of 1 or 2), including patients with a favorable neurological outcome, and Group B (CPC scores of 3 to 5), comprising those with a poor neurological outcome. We analyzed their lactate, albumin levels, and lipid profiles measured at 6 h after resuscitation. A model to predict the neurological prognosis of admission of OHCA survivors was developed.

Results: Approximately 40% of the patients had favorable neurological outcomes at the 30-day follow-up. The lactate-to-albumin ratio (LAR) was significantly lower in Group A than in Group B (3.1 vs. 5.0 mmol/dag, p < 0.001). However, the albumin, total cholesterol, and high-density lipoprotein (HDL) cholesterol levels were significantly higher in Group A than in Group B (3.6 vs. 2.9 g/dL, 166.1 vs. 131.4 mg/dL, and 38.8 vs. 29.7 mg/dL, respectively, p < 0.001). Favorable neurological outcome was indicated at the following thresholds: LAR < 3.7 mmol/dag, albumin level > 3.1 g/dL, total cholesterol level > 146.4 mg/dL, and HDL-cholesterol level > 31.9 mg/dL. These findings underscore the high sensitivity and negative predictive value of the biomarkers. Furthermore, the area under the curve values for LAR, albumin, total cholesterol, and HDL-cholesterol levels were 0.70, 0.75, 0.71, and 0.71, respectively. The corresponding odds ratios were 3.37, 7.08, 3.67, and 3.94, respectively.

Conclusions: The LAR, albumin, total cholesterol, and HDL-cholesterol levels measured on admission may predict neurological prognosis in OHCA survivors. Thus, routine practice should include the measurement of these biomarkers at 6 h after resuscitation, especially in patients with a lactate level of > 5 mmol/L.

Trial registration: ClinicalTrials.gov ID: NCT02633358.

Keywords: Albumin; High-density lipoprotein cholesterol; Lactate-to-albumin ratio; Neurological outcomes; Out-of-hospital cardiac arrest; Total cholesterol.