Abstract
BACKGROUND: Alkaline phosphatase to albumin ratio (APAR) is an emerging prognostic indicator for sepsis, cancer, and coronary artery disease. However, the predictive value of APAR in patients with atrial fibrillation (AF) has not been investigated yet. Therefore, this study aims to explore the association between APAR and the risk of mortality in critically ill patients with AF. METHODS: The data of AF patients were extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. Patients with AF were divided into three groups according to the APAR tertiles. Study outcomes were defined as 28-day and 365-day all-cause mortality. The Kaplan-Meier analysis was conducted to compare the survival rates between groups. Cox proportional hazards regression and restricted cubic spline (RCS) were used to investigate the association between APAR and all-cause mortality. Receiver operating characteristic (ROC) curve analysis was utilized to evaluate the predictive value of APAR for study outcomes. RESULTS: A total of 1105 critically ill patients with AF were enrolled in the study. The Kaplan-Meier analysis demonstrated that patients with the highest APAR had the lowest survival rate. The Cox regression analysis indicated that the highest APAR tertile was significantly associated with 28-day (HR, 1.64 [95% CI 1.20-2.25]; p=0.002) and 365-day (HR, 1.87 [95% CI 1.47-2.39]; p < 0.001) all-cause mortality. Nonlinear relationships between APAR and 28-day and 365-day all-cause mortality were illustrated based on the RCS curves. The areas under the ROC curves for predicting 28-day and 365-day all-cause mortality were 0.617 and 0.642, respectively. CONCLUSIONS: Our research suggested that APAR was a simple biomarker for the prognosis in patients with AF.