Increase of augmentation index (AIx@75): a promising tool for screening hypertensive pregnancy disorders

Screening tools in the first trimester of pregnancy for hypertensive pregnancy disorders need to be determined.

To compare cardiovascular parameters between pregnant (PG) and non-pregnant women (NPG) and to evaluate the sensitivity and specificity of arterial stiffness indices in screening for hypertensive pregnancy disorders and their possible association with the mean uterine artery pulsatility index (MUA-PI).

This study included 77 pregnant women (11-13.6 gestational weeks) and 77 age-matched non-pregnant women. Cardiovascular parameters were non-invasively measured using Mobil- O-Graph^®, a cuff-based oscillometric device. The Doppler Ultrasonographic was used to evaluate the MUA-PI.

Augmentation index (AIx@75) was significantly higher in PG compared to NPG. ROC curve of AIx@75 showed area under curve (AUC): 0.7303, Sensitivity: 74.03% and Specificity: 64.94% and Cutoff: 22.50%. The systolic volume index was lower and the heart rate was higher in PG compared to NPG. Of the 77 pregnant women, 12 had an unfavorable outcome with hypertensive changes. Central systolic blood pressure (109.1 ± 8.84mmHg) and AIx@75 (31.97 ± 5.47%) were significantly higher in the group of pregnant women with outcome compared to the group without outcome (103.0 ± 8.53mmHg and 26.80 ± 8.71%). ROC curve showed better performance of the AIx@75 [AUC: 0.7179, Sensitivity: 83.33% and Specificity: 60.00%, Cutoff: 27.67%] compared to MUA-PI [AUC: 0.5098, Sensitivity: 8.333% and Specificity 98.44%].

AIx@75 was significantly higher in PG compared to NPG. We compared the AIx@75 of PG with and without outcomes. ROC curve analysis showed that this index could discriminate between PG with and without an outcome. Differently, the MUA-PI did not differ between PG with and without outcome, suggesting the superiority of AIx@75 in relation to MUA-PI as a method of screening in the first trimester for hypertensive disease of pregnancy. AIx@75 did not assotiate with MUA-PI. Prospective studies will be needed to confirm these findings.