Preoperative Endothelial Activation and Stress Index as a predictor of in-hospital mortality and postoperative complications in cardiac surgery with cardiopulmonary bypass

BACKGROUND: Patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) are at risk for peri-operative complications, often linked to endothelial dysfunction. The Endothelial Activation and Stress Index (EASIX) has shown potential in predicting outcomes in various patient cohorts. OBJECTIVES: We aimed to assess the prognostic value of EASIX for in-hospital mortality and postoperative outcomes in cardiac surgery patients with CPB. DESIGN: A retrospective cohort study. SETTING: A review of patients undergoing cardiac surgery with CPB at University Hospital Heidelberg from 2015 to 2023. PATIENTS: A total of 9642 patients were considered. After applying the exclusion criteria, 7233 patients with available preoperative levels of creatinine, lactate dehydrogenase, and platelet counts for EASIX calculation were included. The cohort was divided into a training group ( n = 4446, until December 2019) and validation group ( n = 2787, from January 2020). MAIN OUTCOME MEASURES: The primary endpoint was in-hospital mortality, with secondary outcomes including ventilator days, ICU stay, and postoperative bleeding. Multivariate logistic regression was performed and ROC curve analyses were used to assess model performance and the added predictive value of EASIX. RESULTS: EASIX predicted in-hospital mortality in the training cohort [odds ratio (OR) per log 2 increase 2.08, P < 0.001]. In the validation cohort, adding EASIX to the model significantly increased the AUC from 0.74 to 0.78 ( P = 0.012). EASIX >2.32 is associated with an OR for mortality of 9.37 in the training, and for 4.47 in the validation cohort. Patients with EASIX >2.32 had significantly more ICU and ventilator days ( P < 0.001) and higher risk of postoperative bleeding. CONCLUSION: Preoperative EASIX is a validated, cost-effective tool for predicting in-hospital mortality and postoperative bleeding in patients undergoing cardiac surgery with CPB. It may enhance risk stratification and guide peri-operative management in high-risk patients.