Multicenter Cohort Study, With a Nested Randomized Comparison, to Examine the Cardiovascular Impact of Preterm Preeclampsia

Streamlined Analysis of Maternal Plasma Indicates Small Extracellular Vesicles are Significantly Elevated in Early-Onset Preeclampsia

Preeclampsia (PE) is a leading cause of maternal and fetal mortality and morbidity. While placental dysfunction is a core underlying issue, the pathogenesis of this disorder is thought to differ between early-onset (EOPE) and late-onset (LOPE) subtypes. As recent reports suggest that small extracellular vesicles (sEVs) contribute to the development of PE, we have compared systemic sEV concentrations between normotensive, EOPE, and LOPE pregnancies. To circumvent lengthy isolation techniques and intermediate filtration steps, a streamlined approach was developed to evaluate circulating plasma sEVs from maternal plasma. Polymer-based precipitation and purification were used to isolate total systemic circulating maternal sEVs, free from bias toward specific surface marker expression or extensive subpurification. Immediate Nanoparticle Tracking Analysis (NTA) of freshly isolated sEV samples afforded a comprehensive analysis that can be completed within hours, avoiding confounding freeze-thaw effects of particle aggregation and degradation.Rather than exosomal subpopulations, our findings indicate a significant elevation in the total number of circulating maternal sEVs in patients with EOPE. This streamlined approach also preserves sEV-bound protein and microRNA (miRNA) that can be used for potential biomarker analysis. This study is one of the first to demonstrate that maternal plasma sEVs harbor full-length hypoxia inducible factor 1 alpha (HIF-1α) protein, with EOPE sEVs carrying higher levels of HIF-1α compared to control sEVs. The detection of HIF-1α and its direct signaling partner microRNA-210 (miR-210) within systemic maternal sEVs lays the groundwork for identifying how sEV signaling contributes to the development of preeclampsia. When taken together, our quantitative and qualitative results provide compelling evidence to support the translational potential of streamlined sEV analysis for future use in the clinical management of patients with EOPE.

Can heart failure phenotypes be predicted by cardiac remodelling peripartum or postpartum?

Hypertension during pregnancy affects up to 10% of pregnancies and is associated with significant cardiovascular morbidity and mortality. In the short-term it can result in pre-eclampsia, haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome, or even hypertension associated acute heart failure, all of which may necessitate pre-term delivery to prevent maternal or neonatal death. In the long term, a history of gestational hypertension and pre-eclampsia significantly increases the risk of future cardiovascular disease including chronic hypertension, coronary artery disease, heart failure and stroke. This review explores our current level of knowledge of the phenotypes of heart failure, paying particular attention to those specific to women, and the role of pregnancy and non-pregnancy related risk factors in the development of this condition. We discuss why women with hypertensive pregnancy may be disproportionately affected by heart failure with preserved ejection fraction (HFpEF) and whether a unique phenotype of heart failure unique to hypertensive pregnancy exists. Finally, we explore how future cardiovascular risk may be predicted based on cardiac remodelling during or after pregnancy and suggest potential areas of further research in the field.

Left Atrial Mechanics Following Preeclamptic Pregnancy

BACKGROUND

Preterm preeclampsia is a pregnancy complication associated with myocardial dysfunction and premature cardiovascular disease morbidity and mortality. Left atrial (LA) strain is a noninvasive index of left ventricular end diastolic pressure and an early marker of heart failure risk. This study aimed to evaluate LA strain during the postpartum period in participants with and without preterm preeclampsia and to assess whether this varied in the presence of hypertension, cardiac dysfunction or both.

METHODS

In this longitudinal cohort study, 321 women from 28 hospitals with preterm preeclampsia (cases) underwent cardiovascular assessment 6 months postpartum. This is a secondary analysis of the PHOEBE study (ISRCTN01879376). An uncomplicated pregnancy control group (n=30) was recruited from a single center for comparison. A full cross-sectional transthoracic echocardiogram was performed, and from these images, the myocardial strain of the left atrium, including reservoir, conduit, and contractile strain, as well as LA stiffness, were calculated.

RESULTS

At 6 months postpartum, compared with controls, prior preeclampsia was associated with a significantly attenuated LA reservoir, conduit, and contractile strain, as well as increased LA stiffness (all P<0.001). LA strain was further reduced in preeclamptic women who had and had not developed hypertension, systolic, or diastolic dysfunction at 6 months postpartum (all P<0.05).

CONCLUSIONS

LA mechanics were significantly attenuated at 6 months postpartum in participants with preterm preeclampsia, whether or not they remained hypertensive or had evidence of ventricular dysfunction. Further studies are needed to determine whether postnatal LA strain may identify women at greater risk for future cardiovascular disease.

Three-dimensional echocardiography and strain cardiac imaging in women with pre-eclampsia with follow-up to 6 months postpartum

OBJECTIVE

Epidemiological studies have established that women with pre-eclampsia (PE) are at increased long-term cardiovascular risk. Mild cardiac functional changes have been documented during pregnancy in women with PE, but their evolution from presentation to the postpartum period remains poorly defined. The aim of this study was to assess biventricular cardiovascular indices using novel and sensitive two-dimensional and three-dimensional (3D) echocardiographic modalities in pregnancy and to track alterations in both risk factors and cardiovascular indices in the postpartum period.

METHODS

A total of 59 women with PE were examined at 34 (interquartile range, 31-37) weeks' gestation and at 2-3 days, 3 months and 6 months postpartum. During pregnancy, 118 women with a normotensive pregnancy were also recruited as controls. Biventricular ejection fraction and left ventricular mass were measured by 3D echocardiography. Biventricular global longitudinal strain and strain of the left atrium were assessed using speckle-tracking imaging.

RESULTS

In women with PE, compared with controls, there was lower left ventricular diastolic function (left atrial reservoir strain, 44.1% vs 49.2%) and increased left ventricular mass index (148 vs 128 g/m2 ), but there was no significant difference in right ventricular functional indices. These alterations in cardiac indices were mostly explained by differences in maternal risk factors. In the postpartum period, most cardiac indices improved by 3 months. Multivariable linear mixed-model analysis demonstrated that this improvement was mostly attributed to reduction in weight and blood pressure.

CONCLUSION

In women with PE, there is postpartum improvement in cardiac functional and structural indices in parallel with improvement in their risk factor profile. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Postpartum cardiovascular function in patients with hypertensive disorders of pregnancy: a longitudinal study

BACKGROUND

Women with a history of hypertensive disorders of pregnancy are at increased risk of cardiovascular diseases, which are usually mediated by the development of cardiovascular risk factors, such as chronic hypertension, metabolic syndrome, or subclinical myocardial dysfunction. Increasing evidence has been showing that little time elapses between the end of pregnancy and the development of these cardiovascular risk factors.

OBJECTIVE

This study aimed to assess the persistence of hypertension and myocardial dysfunction at 4 months postpartum in a cohort of women with hypertensive disorders of pregnancy, and to compare the echocardiographic parameters between the peripartum and the postpartum period.

STUDY DESIGN

In a longitudinal prospective study, a cohort of women with preterm or term hypertensive disorders of pregnancy and an unmatched group of women with term normotensive pregnancy were recruited. Women with preexisting chronic hypertension (n=29) were included in the hypertensive disorders of pregnancy cohort. All participants underwent 2 cardiovascular assessments: the first was conducted either before or within 1 week of delivery (V1: peripartum assessment), and the second between 3 and 12 months following delivery (V2: postpartum assessment). The cardiovascular evaluation included blood pressure profile, maternal transthoracic echocardiography (left ventricular mass index, relative wall thickness, left atrial volume index, E/A, E/e', peak velocity of tricuspid regurgitation, ejection fraction, and left ventricular global longitudinal strain and twist), and metabolic assessment (fasting glycemia, insulin, lipid profile, and waist measurement). Echocardiographic data were compared between V1 and V2 using paired t test or McNemar test in hypertensive disorders of pregnancy and in the control groups.

RESULTS

Among 260 patients with pregnancies complicated by hypertensive disorders of pregnancy and 33 patients with normotensive pregnancies, 219 (84.2%) and 30 (90.9%) attended postpartum follow-up, respectively. Patients were evaluated at a median of 124 days (interquartile range, 103-145) after delivery. Paired comparisons of echocardiographic findings demonstrated significant improvements in cardiac remodeling rates (left ventricular mass index [g/m2], 63.4±14.4 vs 78.9±16.2; P<.001; relative wall thickness, 0.35±0.1 vs 0.42±0.1; P<.001), most diastolic indices (E/e', 6.3±1.6 vs 7.4±1.9; P<.001), ejection fraction (ejection fraction <55%, 9 [4.1%] vs 28 [13.0%]; P<.001), and global longitudinal strain (-17.3±2.6% vs -16.2±2.4%; P<.001) in the postpartum period compared with the peripartum. The same improvements in cardiac indices were observed in the normotensive group. However, at the postnatal assessment, 153 of 219 (69.9%) had either hypertension (76/219; 34.7%) or an abnormal global longitudinal strain (125/219; 57.1%), 13 of 67 (19.4%) had metabolic syndrome, and 18 of 67 (26.9%) exhibited insulin resistance.

CONCLUSION

Although persistent postpartum cardiovascular impairment was evident in a substantial proportion of patients given that more than two-thirds had either hypertension or myocardial dysfunction postpartum, cardiac modifications because of pregnancy-related overload and hypertension were more pronounced in the peripartum than in the postpartum period.

Maternal and Offspring Cardiovascular Function following Pregnancy with Hypertensive Disorder

BACKGROUND

Hypertensive disorders of pregnancy (HDP) have been associated with increased cardiovascular risk for the mother and her offspring. However, it remains unknown whether cardiovascular changes are present in the postpartum period.

METHODS

This was a cross-sectional study of women with singleton pregnancies. We recruited 33 women (20 following preeclampsia and 13 following gestational hypertension) and an equal number of women with uncomplicated pregnancy. Conventional and more advanced echocardiographic modalities such as speckle tracking were used to assess maternal and offspring cardiac function at 3-9 months postpartum.

RESULTS

In women with HDP compared to those without, there was higher mean arterial pressure (mean 92.3 (SD 7.3) vs. 86.8 (8.3) mmHg, p = 0.007), left-ventricular mass indexed for body-surface area (64.5 (10.5) vs. 56.8 (10.03), p < 0.003), and E/e' (3.6 (0.8) vs. 3.1 (0.9), p = 0.022). There were no significant differences between groups in maternal left-ventricular systolic-functional indices and in offspring cardiac function between groups.

CONCLUSIONS

At 3-9 months postpartum, mothers with HDP had higher blood pressure, higher left-ventricular mass, and reduced left-ventricular diastolic function. However, in their offspring, cardiac function was preserved. These findings suggest that mothers who experienced an HDP would benefit from cardio-obstetric follow-up in the postpartum period.

Third-Trimester Maternal Serum Chemerin and Hypertension After Preeclampsia: A Prospective Cohort Study

Background Limited data are available for postpartum hypertension prediction after preeclampsia. Methods and Results We examined the association between maternal serum chemerin levels in patients with preeclampsia and blood pressure (BP) levels after delivery in a prospective birth cohort of 15 041 singleton pregnant women. A total of 310 cases among 322 patients with preeclampsia (follow-up rate, 96.3%) were followed up during a mean 2.8 years after delivery. Compared with matched uncomplicated controls (n=310), serum chemerin measured at ≈35 gestational weeks was significantly increased in preeclampsia (171.8±49.2 versus 140.2±53.5 ng/mL; P<0.01) and positively correlated with the occurrence of postpartum hypertension, defined as either BP ≥130/80 mm Hg (per 1-SD increase: odds ratio [OR], 4.01 [95% CI, 2.77-5.81]) or as BP ≥140/90 mm Hg (per 1-SD increase: OR, 1.70 [95% CI, 1.28-2.25]) in patients with preeclampsia. The addition of chemerin levels improved the predictive performance of the clinical variable-derived prediction models for postpartum hypertension (for BP ≥130/80 mm Hg: area under the curve, 0.903 [95% CI, 0.869-0.937], Δ area under the curve, 0.070, P<0.001; for BP ≥140/90 mm Hg: area under the curve, 0.852 [95% CI, 0.803-0.902], Δ area under the curve, 0.030, P=0.002). The decision curve analysis revealed a net benefit of the chemerin-based prediction model for postpartum BP ≥130/80 mm Hg. Conclusions This study provides the first evidence supporting the independent predictive role of third-trimester maternal chemerin levels for postpartum hypertension after preeclampsia. Future study is warranted for external validation of this finding.

Peripartum and Long-Term Maternal Cardiovascular Health After Preeclampsia

There is widespread acceptance of the increased prevalence of cardiovascular diseases occurring within 1 to 2 decades in women following a preeclamptic pregnancy. More recent evidence suggests that the deranged biochemical and echocardiographic findings in women do not resolve in the majority of preeclamptic women following giving birth. Many women continue to be hypertensive in the immediate postnatal period with some exhibiting occult signs of cardiac dysfunction. There is now promising evidence that with close monitoring and effective control of blood pressure control in the immediate postnatal period, women may have persistently lower blood pressures many years after stopping their medication. This review highlights the evidence that delivering effective medical care in the fourth trimester of pregnancy can improve the long-term cardiovascular health after a preeclamptic birth.

Planned delivery for pre-eclampsia between 34 and 37 weeks of gestation: the PHOENIX RCT

BACKGROUND

In women with late preterm pre-eclampsia (i.e. at 34+0 to 36+6 weeks' gestation), the optimal delivery time is unclear because limitation of maternal-fetal disease progression needs to be balanced against infant complications. The aim of this trial was to determine whether or not planned earlier initiation of delivery reduces maternal adverse outcomes without substantial worsening of perinatal or infant outcomes, compared with expectant management, in women with late preterm pre-eclampsia.

METHODS

We undertook an individually randomised, triple non-masked controlled trial in 46 maternity units across England and Wales, with an embedded health economic evaluation, comparing planned delivery and expectant management (usual care) in women with late preterm pre-eclampsia. The co-primary maternal outcome was a maternal morbidity composite or recorded systolic blood pressure of ≥ 160 mmHg (superiority hypothesis). The co-primary short-term perinatal outcome was a composite of perinatal deaths or neonatal unit admission (non-inferiority hypothesis). Analyses were by intention to treat, with an additional per-protocol analysis for the perinatal outcome. The primary 2-year infant neurodevelopmental outcome was measured using the PARCA-R (Parent Report of Children's Abilities-Revised) composite score. The planned sample size of the trial was 900 women; the trial is now completed. We undertook two linked substudies.

RESULTS

Between 29 September 2014 and 10 December 2018, 901 women were recruited; 450 women [448 women (two withdrew consent) and 471 infants] were allocated to planned delivery and 451 women (451 women and 475 infants) were allocated to expectant management. The incidence of the co-primary maternal outcome was significantly lower in the planned delivery group [289 (65%) women] than in the expectant management group [338 (75%) women] (adjusted relative risk 0.86, 95% confidence interval 0.79 to 0.94; p = 0.0005). The incidence of the co-primary perinatal outcome was significantly higher in the planned delivery group [196 (42%) infants] than in the expectant management group [159 (34%) infants] (adjusted relative risk 1.26, 95% confidence interval 1.08 to 1.47; p = 0.0034), but indicators of neonatal morbidity were similar in both groups. At 2-year follow-up, the mean PARCA-R scores were 89.5 points (standard deviation 18.2 points) for the planned delivery group (290 infants) and 91.9 points (standard deviation 18.4 points) for the expectant management group (256 infants), both within the normal developmental range (adjusted mean difference -2.4 points, 95% confidence interval -5.4 to 0.5 points; non-inferiority p = 0.147). Planned delivery was significantly cost-saving (-£2711, 95% confidence interval -£4840 to -£637) compared with expectant management. There were nine serious adverse events in the planned delivery group and 12 in the expectant management group.

CONCLUSION

In women with late preterm pre-eclampsia, planned delivery reduces short-term maternal morbidity compared with expectant management, with more neonatal unit admissions related to prematurity but no indicators of greater short-term neonatal morbidity (such as need for respiratory support). At 2-year follow-up, around 60% of parents reported follow-up scores. Average infant development was within the normal range for both groups; the small between-group mean difference in PARCA-R scores is unlikely to be clinically important. Planned delivery was significantly cost-saving to the health service. These findings should be discussed with women with late preterm pre-eclampsia to allow shared decision-making on timing of delivery.

LIMITATIONS

Limitations of the trial include the challenges of finding a perinatal outcome that adequately represented the potential risks of both groups and a maternal outcome that reflects the multiorgan manifestations of pre-eclampsia. The incidences of maternal and perinatal primary outcomes were higher than anticipated on the basis of previous studies, but this did not limit interpretation of the analysis. The trial was limited by a higher loss to follow-up rate than expected, meaning that the extent and direction of bias in outcomes (between responders and non-responders) is uncertain. A longer follow-up period (e.g. up to 5 years) would have enabled us to provide further evidence on long-term infant outcomes, but this runs the risk of greater attrition and increased expense.

FUTURE WORK

We identified a number of further questions that could be prioritised through a formal scoping process, including uncertainties around disease-modifying interventions, prognostic factors, longer-term follow-up, the perspectives of women and their families, meta-analysis with other studies, effect of a similar intervention in other health-care settings, and clinical effectiveness and cost-effectiveness of other related policies around neonatal unit admission in late preterm birth.

TRIAL REGISTRATION

The trial was prospectively registered as ISRCTN01879376.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in Health Technology Assessment. See the NIHR Journals Library website for further project information.

Remote multimodality monitoring of maternal physiology from the first trimester to postpartum period: study results

OBJECTIVES

Current antenatal care largely relies on widely spaced appointments, hence only a fraction of the pregnancy period is subject to monitoring. Continuous monitoring of physiological parameters could represent a paradigm shift in obstetric care. Here, we analyse the data from daily home monitoring in pregnancy and consider the implications of this approach for tracking pregnancy health.

METHODS

Prospective feasibility study of continuous home monitoring of blood pressure, weight, heart rate, sleep and activity patterns from the first trimester to 6 weeks postpartum.

RESULTS

Fourteen out of 24 women completed the study (58%). Compared to early pregnancy [week 13, median heart rate (HR) 72/min, interquartile range (IQR) 12.8], heart rate increased by week 35 (HR 78/min, IQR 16.6; P  = 0.041) and fell postpartum (HR 66/min, IQR 11.5, P  = 0.021). Both systolic and diastolic blood pressure were lower at mid-gestation (week 20: SBP 103 mmHg, IQR 6.6; DPB 63 mmHg, IQR 5.3 P  = 0.005 and P  = 0.045, respectively) compared to early pregnancy (week 13, SBP 107 mmHg, IQR 12.4; DPB 67 mmHg, IQR 7.1). Weight increased during pregnancy between each time period analyzed, starting from week 15. Smartwatch recordings indicated that activity increased in the prepartum period, while deep sleep declined as pregnancy progressed.

CONCLUSION

Home monitoring tracks individual physiological responses to pregnancy in high resolution that routine clinic visits cannot. Changes in the study protocol suggested by the study participants may improve compliance for future studies, which was particularly low in the postpartum period. Future work will investigate whether distinct adaptative patterns predate obstetric complications, or can predict long-term maternal cardiovascular health.

Human placenta-based genome-wide mRNA sequencing to identify TEK/IGF1/CSF1/ANGPT2 as crucial segments in the pathogenesis of pre-eclampsia

Pre-eclampsia is a pregnancy-specific disease commonly occurring in late pregnancy and has always been threatening maternal and fetal lives, yet the etiology and pathogenesis of pre-eclampsia are still uncertain. To depict the overall changes of genes at the genome-wide level and identify potential biomarkers for early diagnosis of pre-eclampsia, we conducted this study by collecting placenta samples donated by six pregnancy women, among whom three healthy women were included as controls and three women were diagnosed with pre-eclampsia. The placental sample tissues were then subjected to high-throughput sequencing. Furthermore, we proceeded with bioinformatics analysis and formulated the hypothesis of pre-eclampsia development and verified the potential targets of pre-eclampsia by immunohistochemistry. Demographically, we found that the baseline characteristics of study subjects were highly homogeneous except for gestational weeks and blood pressure, where the blood pressure was higher and gestational weeks were shorter in the pre-eclampsia group (systolic blood pressure 123.33 ± 4.62 vs. 148.67 ± 3.79 mmHg, p = 0.046; diastolic blood pressure 79.00 ± 5.20 vs. 88.33 ± 2.89 mmHg, p = 0.068; gestational weeks 39.33 ± 1.03 vs. 35.76 ± 2.41, p = 0.050). Specific pathological changes were identified, shown as syncytial knots, fibrinoid necrosis, perivillous fibrin deposition, and vasculitis. For high-throughput sequencing, a total of 1,891 dysregulated genes were determined, of which 960 genes were downregulated and 931 genes were upregulated. The bioinformatics analysis indicated that these genes, with different molecular functions in different parts of cells, were primarily responsible for endothelium development and vascular process in the circulatory system, and more than 10 signaling pathways were involved. By focusing on the PI3K-Akt signaling pathway, Rap1 signaling pathway, and disease enrichment analysis item pre-eclampsia, TEK, CSF1, IGF1, and ANGPT2 were identified to promote the development of pre-eclampsia. After confirming the placental expression of these genes at the protein level, we proposed the pathogenesis of pre-eclampsia as follows: the downregulation of TEK, CSF1, IGF1, and ANGPT2 may inhibit trophoblast proliferation and affect the remodeling of spiral arteries, causing maternal and fetal malperfusion and impeding nutrient exchange, thereby leading to clinical manifestations of pre-eclampsia.

The Mechanism of Downregulation of Twist1 Inhibiting Trophoblast Invasion and Aggravating the Development of Preeclampsia

To study the expression of under expressed transcription factor Twist1 in preeclampsia (PE) and its effect on the invasion of placental trophoblast cells and to explore its related mechanism on the development of PE by establishing a pregnant rat model. Methods: the villi were collected from the induced abortion in the first trimester (6–8 weeks), the normal placenta (18–20 weeks) induced by the second trimester, the term placenta tissue of normal pregnancy (37–40 weeks), and the placental tissue of patients with PE, to detect the expression of Twist1. Trophoblast cells were subjected to primary culture in placental tissues of normal pregnant women and placental tissues of PE patients. The invasion ability of the two groups of trophoblasts was detected, and the primary cultured trophoblasts were divided into two groups: an experimental group and a control group. Specific Twist1 siRNA was added to the experimental group, and no reagents were added to the control group. The above-mentioned cells were given different interventions. To explore the effect of Twist1 on trophoblast cell invasion, cells were cultivated for 72 h. The SD rats were conceived. After the pregnancy was stable, the SD rats in different groups were treated with different treatments (interference with Twist1), and the average systolic blood pressure and urine protein of the gestational mothers in the different treatment groups were measured at 1 week, 2 weeks, and full-term pregnancy. The expression of Twist1 in the placenta tissue of SD rats with different interventions at full-term pregnancy was detected. The results showed that Twist1 expression is down-regulated in PE, and the invasion ability of placental trophoblast cells in PE patients is weak. After inhibiting Twist1, the mean tail artery pressure and urine protein level of SD pregnant rats increase, showing a trend of PE. The mechanism may be related to the inhibition of the placenta by Twist1 Trophoblast cell invasion.