Endothelial Activation and Stress Index as a predictor of mortality in patients with atrial fibrillation

1. The Endothelial Activation and Stress Index (EASIX) is associated with in-hospital, short-term (28-day), and long-term (365-day) all-cause mortality in critically ill patients with atrial fibrillation (AF).

2. EASIX is a reliable indicator of poor prognosis in critically ill patients with AF.

Evidence Rating Level: 2 (Good)

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is strongly linked to increased risks of all-cause mortality, heart failure, hospitalization, and thromboembolic events. Many studies have shown an association between endothelial dysfunction (ED) and the development and progression of AF. The Endothelial Activation and Stress Index (EASIX) is a novel biomarker for assessing endothelial health and has been validated as a prognostic marker for mortality in various health conditions. However, research on the role of EASIX as a prognostic marker in patients with AF is limited. This study thus assessed the association between EASIX and prognosis in critically ill patients with AF. This retrospective study analyzed data from the Medical Information Mart for Intensive Care IV(MIMIC-IV) database and included patients aged 18-99 years with AF who had an intensive care unit stay of more than 24 hours. EASIX was calculated using the formula: lactate dehydrogenase (U/L) × creatinine (mg/dL)/platelets (109 cells/L) and log2-transformed for statistical analysis. Patients were grouped by EASIX quartiles: Q1: < 4.56, Q2: 4.56–5.64, Q3: 5.64–6.84, and Q4: > 6.84. In total, 4,896 patients were included (median age [interquartile range] = 75 [66, 83] years, male [%] = 2,871[58.64%]). All-cause mortality rates for in-hospital, 28-day, and 365-day were 26.04%, 29.25%, and 49.75%, respectively. Higher EASIX was associated with increased in-hospital (OR 1.28, 95% confidence interval [CI] 1.19–1.37), 28-day (HR 1.21, 95% CI 1.16–1.26, P < 0.001), and 365-day HR 1.16, 95% CI 1.12–1.21) all-cause mortality after multivariable adjustment. For each time point, patients in quartiles Q2, Q3, and Q4 had significantly higher mortality than those in Q1. The performance of EASIX in predicting both 28-day and 365-day all-cause mortality was comparable to the Sequential Organ Failure Assessment (SOFA) and higher than the CHA₂DS₂–VASc score. Overall, this study found that EASIX is associated with in-hospital, short-term, and long-term all-cause mortality in critically ill patients with AF and that EASIX is a reliable indicator of poor prognosis in this patient population. Future prospective studies are necessary to confirm study findings.

Click to read the study in EJMR

Image: PD

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