Abstract: Objective To provide a novel reference indicator for the clinical assessment of heart failure(HF)prognosis by exploring the correlation between the pre-endothelial activation and stress index(pre-EASIX)and mortality risk in HF patients. Methods Data from 7,146 HF patients in the open-source database MIMIC-IV v3.1 were used. The endothelial activation and stress index(EASIX)was calculated for each patient and converted into a log₂ value(pre-EASIX). Patients were categorized based on the tertiles of pre-EASIX. The correlation between pre-EASIX and mortality risk in HF patients was evaluated using restricted cubic spline(RCS)analysis, Kaplan-Meier survival curve, and Cox regression model. Results RCS analysis revealed a J-shaped curve relationship between pre-EASIX and mortality risk in HF patients, suggesting that the predictive capacity of pre-EASIX for HF patient mortality risk was statistically significant(P<0.05). Kaplan-Meier survival curve demonstrated that with increasing pre-EASIX, the survival rate of HF patients declined, and its predictive capacity for the survival rate of HF patients was statistically significant(P<0.001). Multivariate Cox regression analysis confirmed that pre-EASIX was an independent risk factor for 30-, 90-, 180-, and 365-day mortality in HF patients, with statistical significance(P<0.01). Following a subgroup analysis of Cox regression in HF patients stratified by left ventricular ejection fraction, pre-EASIX remained an independent risk factor for mortality in HF subgroup patients, with statistical significance(P<0.001). Conclusion Pre-EASIX is closely associated with the risk of mortality in HF patients. It aids in the early identification of high-risk patients and can serve as an important indicator for evaluating the prognosis of HF patients and different subgroups.

Key words: Pre-endothelial activation and stress index, Heart failure, Mortality risk, Endothelial dysfunction, Prognosis