Immunonutritional status and survival after cardiac arrest: prognostic value of the prognostic nutritional index, the cholesterol-modified prognostic nutritional index, and the controlling nutritional status score in post-cardiopulmonary resuscitation intensive care patients.

Abstract

Background: Patients achieving return of spontaneous circulation (ROSC) after cardiac arrest experience marked systemic inflammation, metabolic stress, and nutritional impairment, all of which contribute to high mortality. Practical prognostic indices reflecting immunonutritional status may facilitate early risk stratification in this population.

Aim: To evaluate the prognostic value of immunonutritional indices for predicting mortality in patients with ROSC after out-of-hospital cardiac arrest.

Methods: This single-center, retrospective cohort study included adult patients admitted to the intensive care unit after ROSC following out-of-hospital cardiac arrest between January 2015 and January 2025. Prognostic Nutritional Index (PNI), cholesterol-modified Prognostic Nutritional Index (CPNI), and Controlling Nutritional Status (CONUT) scores were calculated from laboratory parameters obtained within the first 24 h of ICU admission. Patients were classified as survivors or non-survivors based on ICU outcome. Associations with mortality were evaluated using univariate and multivariate logistic regression analyses, and discriminatory performance was assessed using receiver operating characteristic curve analysis.

Results: Among 444 post-ROSC patients, non-survivors had lower PNI (43.66 ± 15.47 vs. 55.06 ± 17.21) and higher CPNI (81.10 ± 13.70 vs. 66.90 ± 18.25) and CONUT scores (4.27 ± 3.04 vs. 2.43 ± 2.43; all p < 0.001). In separate stepwise multivariable models, PNI (aOR 0.64 per 10-point increase), CPNI (aOR 1.25 per 10-point increase), and CONUT (aOR 1.24 per 1-point increase) remained independently associated with mortality. AUCs were 0.689, 0.631, and 0.681, respectively; PNI showed the highest sensitivity (86.3%) at a cut-off of ≤ 59.90.

Conclusion: PNI, CPNI, and CONUT were significantly associated with ICU mortality after out-of-hospital cardiac arrest. These indices may reflect systemic inflammation, immune dysfunction, metabolic stress, and nutritional reserve rather than nutritional status alone. Their availability from routine laboratory parameters may support early risk stratification. Further prospective studies are needed to confirm their prognostic value and clinical applicability.