(1192) The Diagnostic Accuracy of the sFlt-1/PlGF Ratio vs. PlGF alone for Preeclampsia

Objective: Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. Abnormal levels of the angiogenic proteins soluble fms-like tyrosine kinase (sFLT-1) and placental growth factor (PlGF) have been shown to be predictive of preeclampsia. However, it remains unclear whether the combination of these proteins in the form of the sFlt1/PlGF ratio performs better than PlGF alone. The objective of the current study was to compare the diagnostic accuracy of the sFlt1/PlGF ratio for preeclampsia with that achieved with PlGF alone under real-life settings.

Study Design: A retrospective cohort study of patients with a singleton pregnancy evaluated in a single center for suspected preeclampsia using the Roche Elecsys sFlt1/PlGF Ratio Assay between 2020-2023. The sFlt1/PlGF ratio was interpreted as low-risk (≤ 38), moderate-risk (38-85), or high-risk ( > 85), while PlGF was defined as low-risk (≥ 100 pg/mL) or high-risk (< 100 pg/mL).

Results: Of the 509 patients who met the study criteria, 206 (40.5%) had a final diagnosis of preeclampsia. When compared to PlGF< 100 ng/pL, a sFLT-1/PlGF ratio > 85 was associated with a greater risk of delivery within < 14 (RR= 2.0 [1.8-2.4] vs 1.4 [1.3-1.6]), < 7 (RR= 2.7 [2.1-3.5] vs 1.5 [1.3-1.8]), and < 3 days (RR = 2.7 [2.0-3.8] vs 1.4 [1.2-1.8]). In addition, the area under the ROC curve was higher for the sFLT-1/PlGF ratio to PlGF for delivery within < 7 days (0.86 [0.83-0.89] vs. 0.64 [0.58-0.71]) and preeclampsia diagnosis within < 7 days (0.91 [0.91-0.95] vs. 0.72 [0.65-0.78]). Finally, in a time-to-event analysis, the cumulative risk of delivery was significantly higher among patients with sFLT-1/PlGF ratio > 85 compared to those with PlGF < 100 ng/pL (p< .001) (Figure 1).

Conclusion: The diagnostic accuracy and prognostic value of the sFLT-1/PlGF ratio appears to be greater than that achieved with PlGF alone.