Prognostic value of neutrophil-lymphocyte ratio in out-of-hospital cardiac arrest patients receiving targeted temperature management: An observational cohort study

Abstract

Background: Out-hospital cardiac arrest (OHCA) is a major cause of mortality and morbidity worldwide. The magnitude of the post-resuscitation inflammatory response is closely related to the severity of the circulatory dysfunction. Currently, targeted temperature management (TTM) has become an essential part of the post-resuscitation care for unconscious OHCA survivors. Some novel prognostic inflammatory markers may help predict outcomes of OHCA patients after TTM. Methods: A retrospective observational cohort study of 65 OHCA patients treated with TTM was conducted in a tertiary hospital in Taiwan. The primary outcome measure was in-hospital mortality. Baseline and post-TTM neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte (PLR), and the systemic immune inflammation index (SII) were identified as potential predictors. Results: These patients had a mean age of 62.2 ± 17.0 years. Among the total sample, 53.8% had an initial shockable rhythm and 61.5% had a presumed cardiac etiology. The median resuscitation duration was 20 min (IQR 13.5–28.5) and 60% received subsequent percutaneous coronary intervention. The mean baseline NLR, PLR and SII were 7.5 ± 16.7, 118 ± 207, 1395 ± 3004, and the mean post-TTM NLR, PLR and SII were 15.0 ± 11.6, 206 ± 124, 2369 ± 2569, respectively. Using multiple logistic regression analysis, post-TTM NLR was one of the independent factors which predicted in-hospital mortality (adjusted odds ratio (aOR): 1.249, 95% confidence interval (CI): 1.040–1.501, p = 0.017). Conclusion: Post-TTM NLR is a predictor of in-hospital mortality in OHCA patients who underwent TTM.

Keywords

• Cardiac arrest
• Mortality
• Neurological outcome
• Neutrophil-to-lymphocyte ratio
• Targeted temperature management
• Therapeutic hypothermia