Association of the Endothelial Activation and Stress Index (EASIX) and the sFlt-1/PlGF Ratio in Patients with Preeclampsia

Background: Preeclampsia is a leading cause of maternal and perinatal morbidity, characterized by angiogenic imbalance reflected in the sFlt-1/PlGF ratio. While the Endothelial Activation and Stress Index (EASIX), a composite score of lactate dehydrogenase, creatinine, and platelet count, has recently been proposed as an independent predictor of adverse events in preeclampsia, it has not yet been evaluated against the established sFlt-1/PlGF ratio. This post hoc analysis of a prospective observational trial aimed to characterize the association between EASIX and sFlt-1/PlGF and to compare the prognostic performance of both markers in predicting adverse events. Methods: Thirty-two pregnant women diagnosed with preeclampsia were prospectively enrolled at the University of Heidelberg between 2015 and 2017. EASIX was calculated retrospectively from routine laboratory parameters. Spearman correlations, ROC analyses, and Kaplan–Meier curves were applied. Results: EASIX correlated significantly with the sFlt-1/PlGF ratio (r = 0.41, p = 0.019). While EASIX was not associated with mean uterine pulsatility index (PI) (r = 0.07, p = 0.74) or the cerebro–placental ratio, it showed a non-significant trend toward a positive association with mean arterial pressure (r = 0.35, p = 0.058). In contrast, sFlt-1/PlGF showed a moderate correlation with mean uterine PI (r = 0.53, p = 0.009). Both EASIX (AUC 0.73) and sFlt-1/PlGF (AUC 0.78) showed numerically similar AUC point estimates for adverse maternal events, while sFlt-1/PlGF showed a numerically higher AUC than EASIX for perinatal outcomes (AUC 0.80 vs. 0.66). Elevated EASIX was associated with an increased risk of imminent delivery (HR 3.00), although this estimate is limited by the sample size. Conclusions: EASIX and the sFlt-1/PlGF ratio were moderately correlated and were both associated with a shorter time to delivery. The sFlt-1/PlGF ratio showed a numerically higher AUC for predicting perinatal outcomes, while AUC point estimates for maternal outcomes were numerically similar for EASIX and sFlt-1/PlGF ratio.