Association between Corticosteroids and In-Hospital Mortality After Cardiac Arrest: A Multicenter Study Using the eICU Collaborative Research Database.

BACKGROUND: Clinical outcomes following cardiac arrest remain poor, and the therapeutic value of corticosteroids is controversial. We investigated the association between corticosteroid administration and in-hospital mortality across clinical phenotypes. METHODS: Using the eICU Collaborative Research Database, we included 4,580 adults admitted to the ICU post-cardiac arrest. Exposure was defined as systemic corticosteroid administration during the ICU stay. We employed multivariable logistic regression, propensity score matching, and multiple imputation to adjust for baseline confounders. A 24-hour landmark analysis addressed immortal time bias. RESULTS: Corticosteroid administration was independently associated with lower in-hospital mortality (adjusted OR 0.67; 95% CI 0.56-0.81; p<0.001), remaining robust across propensity-matched and landmark analyses. Significant effect heterogeneity emerged across phenotypes. Survival benefits were exclusively observed in comatose patients (Glasgow Coma Scale ≤8) and those with comorbid chronic obstructive pulmonary disease, whereas non-comatose patients derived no benefit. Notably, while corticosteroids were associated with higher rates of favorable functional neurological recovery, mortality benefits did not significantly differ across systemic inflammatory marker strata. CONCLUSIONS: Corticosteroid exposure was associated with lower in-hospital mortality among post-cardiac arrest patients, with benefits predominantly observed in comatose phenotypes. These hypothesis-generating findings underscore the importance of phenotype-guided approaches in future prospective trials.