Abnormal pressure-wave reflection in pregnant women with chronic hypertension: association with maternal and fetal outcomes

Abstract

The current study tested the hypothesis that abnormal pressure-wave reflection may have an important role in identifying pregnant women with chronic hypertension who might develop pre-eclampsia (PE) and/or fetal growth restriction. Pulse-wave analyses were performed to assess maternal arterial stiffness during 26-32 weeks of gestation in 41 women with chronic hypertension. We measured the central systolic pressure (CSP) and augmentation index (AIx) noninvasively using pulse waveforms of the radial artery with an automated applanation tonometric system. In a multiple regression analysis that included AIx-75 (AIx at a heart rate of 75 beats per minute), brachial systolic pressure, maternal height, smoking status, gestational age at testing and the presence of antihypertensive treatment at testing as independent determinants, AIx-75 was the only significant determinant of birth weight, whereas the brachial systolic pressure was not. In pregnant women with chronic hypertension who subsequently developed both superimposed PE and fetal growth restriction, CSP, AIx, AIx-75, and the brachial systolic and pulse pressures were all significantly higher than those who did not develop superimposed PE nor small for gestational age. In contrast, AIx-75 was the only significantly elevated hemodynamic parameter in patients who developed fetal growth restriction but not superimposed PE. In addition, CSP was the only significantly elevated hemodynamic parameter in patients who developed superimposed PE but not fetal growth restriction. Abnormal pressure-wave reflection during 26-32 weeks of gestation showed a stronger correlation with birth weight than conventional brachial blood pressure. Our findings might provide new insight into the pathophysiology of fetal growth restriction as well as superimposed PE in pregnancies complicated with chronic hypertension.

Longitudinal changes in vascular function parameters in pregnant women with chronic hypertension and association with adverse outcome: a cohort study

“…Limits of y-axis represent maximum and minimum values within dataset. cross-sectional cohort study of 41 pregnant women with chronic hypertension, conducted by Tomimatsu et al 12 , also demonstrated an association between increased AIx-75 and SPE. This study found that increased brachial 12-15.9 SPE readings (n) CHT control readings (n) of subdividing their cohort reduced the power and may have affected the results.…”

“…In those who developed SPE, compared with those who did not, the central aortic pressure was increased, but there was no significant difference in PWV or AIx‐75. A cross‐sectional cohort study of 41 pregnant women with chronic hypertension, conducted by Tomimatsu et al , also demonstrated an association between increased AIx‐75 and SPE. This study found that increased brachial SBP and central aortic pressure predated the development of SPE with SGA at 26 to 32 weeks' gestation compared to women with chronic hypertension who had SPE alone, SGA alone or no SPE or SGA.…”

“…CHT control readings (n) In a population screening study examining the utility of arterial stiffness assessment in predicting adverse pregnancy outcome (including 7500 women), 68 women had chronic hypertension, including 21 who subsequently [12][13][14][15] developed SPE and 47 who did not 33 . In those who developed SPE, compared with those who did not, the central aortic pressure was increased, but there was no significant difference in PWV or AIx-75 33…”

“…Performing longitudinal pulse-wave analyses allowed assessment of changes in vascular function parameters that occurred prior to clinical diagnosis of any adverse outcome. The limitations include the relatively small number of participants, though our study was larger than previous cross-sectional studies that examined vascular function in chronic hypertension alone 12 . The potential clinical utility of these parameters in diagnosis of SPE could not be ascertained as no time of disease readings were obtained, and 8.4% of readings did not record AIx or PWV suggesting that further optimization of this technique is required prior to establishing the use of this device in clinical practice.…”

Potential Role of Antihypertensive Medications in Preventing Excessive Arterial Stiffening

“…Importantly, there is an important interaction bewteen arterial stiffness and hypertension. In this regard, arterial stiffness has been associated with brachial blood pressure in pregnant women [6]. There are increases in forearm vascular resistance in young men with first-degree relatives suffering from essential hypertension [7].…”