Endothelial Activation and Stress Index-A Novel and Simple Prognostic Tool in Coronary Artery Bypass Grafting

Objectives: Risk stratification in coronary artery bypass grafting (CABG) remains challenging despite existing models. The Endothelial Activation and Stress Index (EASIX), originally developed for hematological conditions, has shown promise in various medical fields as a predictor of adverse outcomes. EASIX, calculated from lactate dehydrogenase, creatinine, and platelet count, reflects endothelial dysfunction and systemic inflammation. This study investigates EASIX's potential in predicting mortality and morbidity in patients undergoing CABG. Methods: A total of 475 patients undergoing isolated CABG between January 2017 and June 2020 were retrospectively analyzed. EASIX scores were calculated from pre-operative blood samples. Patients were stratified based on an EASIX cut-off value of 1.16. Results: Patients with EASIX ≥ 1.16 were older and had more comorbidities. They experienced higher 30-day mortality (5.0% vs. 0.8%, p = 0.004), increased wound infections (6.7% vs. 2.5%, p = 0.035), and more frequent prolonged ventilation (9.2% vs. 4.2%, p = 0.040). The long-term survival analysis showed significant differences at 3 years (p = 0.030) and 5 years (p < 0.001). EASIX demonstrated moderate discriminatory power for long-term survival (AUROC 0.669, 95% CI: 0.598-0.740, p < 0.001). Importantly, the multivariable analysis revealed EASIX as an independent risk factor for long-term mortality, even after adjusting for traditional risk factors and comorbidities (HR: 2.65, 95% CI: 1.59-4.42, p < 0.001). Conclusions: EASIX ≥ 1.16 was associated with postoperative morbidity and poorer long-term survival in patients undergoing CABG. This easily calculable score could enhance risk stratification and guide personalized postoperative management.