Association of the Endothelial Activation and Stress Index (EASIX) with short-term mortality in critically ill patients with congestive heart failure: A retrospective cohort study from the MIMIC database

The role of endothelial injury in worsening congestive heart failure (CHF) remains unquantified. This study evaluates the Endothelial Activation and Stress Index (EASIX) for predicting short-term mortality in patients with critical CHF. This was a retrospective cohort study using the Medical Information Mart for Intensive Care-IV (2008–2022). Adults with CHF admitted to the intensive care unit were stratified by ln(EASIX) quartiles. The primary endpoint was 30-day all-cause mortality. Multivariable Cox regression, restricted cubic splines, and subgroup analyses were performed. Among 4556 patients (median age 72.1 years, 42.8% female), the highest EASIX quartile (Q4) had a 44.2% 30-day mortality rate versus 19.2% in Q1 (adjusted hazard ratio HR = 1.6, 95% confidence interval CI: 1.27–2.02, P < .001). A nonlinear association was observed (nonlinearity P = .008) with an inflection point at ln(EASIX) = 0.05. Beyond this threshold, each unit increase in ln(EASIX) conferred a 14.2% higher mortality risk (HR = 1.142, 95% CI: 1.062–1.227). Ln(EASIX) remained predictive after full adjustment for severity scores and treatments, with the highest quartile (Q4) exhibiting a 60% increased mortality risk (adjusted HR = 1.60, 95% CI: 1.27–2.02). EASIX is a robust predictor of short-term mortality in patients with critical CHF, particularly valuable in nonsepsis populations. Its simple calculation (lactate dehydrogenase/creatinine/platelets) that refines risk stratification beyond conventional severity scores.