Background and objectives <p>The present study aimed to investigate the association between the alkaline phosphatase-to-platelet ratio index (APPRI) and intensive care unit (ICU) mortality in patients with cardiac arrest (CA), and further explore its potential value for risk stratification in this specific population.</p> Methods <p>A total of 374 CA patients were included in our analysis. They were divided into the survivor group (<i>n</i> = 180) and non-survivor group (<i>n</i> = 194) based on ICU survival status. Baseline characteristics of the two groups were summarized and compared. Univariate and multivariate logistic regression analyses were conducted to explore the association between the alkaline APPRI and ICU mortality. Receiver operating characteristic (ROC) curve analysis was used to determine APPRI’s optimal cutoff value for predicting ICU mortality. The Kaplan-Meier method was applied to estimate survival curves of different groups, with the log-rank test used to compare survival differences.</p> Results <p>The non-survivor group exhibited higher APPRI values than the survivor group (0.430 [0.296, 0.733] vs.0.358 [0.246, 0.533)], <i>P</i> &lt; 0.001). Univariate logistic regression analysis showed that APPRI (odds ratio (OR) = 1.077, 95% confidence interval (CI): 1.013–1.146, <i>P</i> = 0.018) was associated with ICU mortality. Multivariate logistic regression analysis revealed that APPRI was one of the independent predictors of ICU mortality (OR = 1.110, 95% CI: 1.022–1.205, <i>P</i> = 0.013). The ROC curve determined the APPRI optimal cut-off value for ICU mortality to be 0.576. The Kaplan-Meier curves showed that patients with APPRI &gt; 0.576 had a higher ICU mortality than that of patients with APPRI ≤ 0.576 (log-rank test <i>P</i> = 0.017).</p> Conclusions <p>APPRI is independently associated with ICU mortality in patients with CA, and the index effectively stratifies CA patients at risk of ICU deat</p>