Maternal endothelial function and vascular stiffness after HELLP syndrome: a case-control study

Objectives: To assess endothelial function and arterial stiffness in women with a previous pregnancy complicated by pre-eclampsia (PE) with hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome, and to compare these findings to those in women with previous PE but no HELLP and to those in controls with previous uncomplicated pregnancy, in order to investigate the influence of HELLP syndrome on subsequent cardiovascular impairment.

Methods: In this prospective single-center case-control study, we performed peripheral arterial tonometry (PAT) (using the EndoPAT method) and pulse-wave velocity (PWV) assessment in 109 women who had had a singleton pregnancy complicated by PE with (n = 49) or without (n = 60) HELLP syndrome, as well as in 60 controls with previous uncomplicated pregnancy, between 6 months and 4 years after delivery. The following EndoPAT and PWV indices were compared between groups: reactive hyperemia index (RHI), as an indication of endothelial function, and peripheral and aortic heart-rate-corrected augmentation indices (AIx) standardized for a heart rate of 75 bpm (AIx@75) and carotid-femoral pulse-wave velocity (cfPWV), as indications of arterial stiffness.

Results: PAT and arterial stiffness indices were significantly different between PE cases, with or without previous HELLP, and controls, except for carotid-femoral PWV. There were no significant differences among PE groups: women who had experienced HELLP and those with a history of PE without HELLP showed similar rates of RHI ≤ 1.67 (28.6% vs 18.3%, P = 0.254) and RHI ≤ 2.00 (61.2% vs 41.7%, P = 0.055), peripheral AIx@75 ≥ 17% (38.8% vs 30.0%, P = 0.417), aortic AIx@75 ≥ 35% (29.2% vs 20.0%, P = 0.461) and cfPWV × 0.8 > 9.6 m/s, which occurred in only three women, all in the group without previous HELLP (0% vs 5.0%, P = 0.251). On multivariate regression analysis, HELLP syndrome, intrauterine growth restriction (IUGR) and early-onset PE independently predicted endothelial dysfunction at 6 months to 4 years postpartum, after correcting for uterine artery pulsatility index, birth-weight percentile, and maternal blood pressure, age and body mass index. Women with both previous HELLP and early-onset IUGR had a significantly higher prevalence of endothelial dysfunction (P = 0.001).

Conclusion: Similar vascular abnormalities were found in women previously affected by HELLP syndrome and those with previous PE without HELLP. However, a history of HELLP syndrome, IUGR and early-onset PE seems to identify a subgroup of women with a higher risk for future development of endothelial dysfunction. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.