The comparison of amino-terminal probrain natriuretic peptide levels in preeclampsia and normotensive pregnancy

N-terminal prohormone of brain natriuretic peptide in gestational hypertension and preeclampsia - State of the art

N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is a non-active prohormone secreted by ventricular cardiomyocytes into the circulation in response to ventricle overload, mainly due to increased blood volume. The changes in NT-proBNP levels during pregnancy have been investigated in multiple studies. In the case of hypertensive disorders of pregnancy, increased vasoconstriction leads to increased blood pressure and afterload. Together with the volume overload of pregnancy, it leads to higher NT-proBNP secretion. As hypertensive disorders of pregnancy are among the leading causes of prematurity and perinatal mortality, early prediction and diagnosis of gestational hypertension, and preeclampsia are essential for improving maternal and infant prognosis. NT-proBNP has been regarded as a potential biomarker of hypertensive disorders of pregnancy. In this review, we have thoroughly summarized the current data on the prognostic and diagnostic utility of NT-proBNP in patients with gestational hypertension and preeclampsia. NT-proBNP values may help distinguish between non-preeclamptic and preeclamptic patients, even if there are no significant differences in blood pressure. Moreover, in pregnancies complicated by preeclampsia, the value of increased NT-proBNP level is related to the stage and the severity of the disease. Further improvement of our knowledge about NT-proBNP as a diagnostic biomarker and a putative predictor of adverse cardiac events in women with hypertensive disorders of pregnancy should lead to better management of these patients.

Genetic Associations of Circulating Cardiovascular Proteins With Gestational Hypertension and Preeclampsia

Importance

Hypertensive disorders of pregnancy (HDPs), including gestational hypertension and preeclampsia, are important contributors to maternal morbidity and mortality worldwide. In addition, women with HDPs face an elevated long-term risk of cardiovascular disease.

Objective

To identify proteins in the circulation associated with HDPs.

Design, Setting, and Participants

Two-sample mendelian randomization (MR) tested the associations of genetic instruments for cardiovascular disease-related proteins with gestational hypertension and preeclampsia. In downstream analyses, a systematic review of observational data was conducted to evaluate the identified proteins' dynamics across gestation in hypertensive vs normotensive pregnancies, and phenome-wide MR analyses were performed to identify potential non-HDP-related effects associated with the prioritized proteins. Genetic association data for cardiovascular disease-related proteins were obtained from the Systematic and Combined Analysis of Olink Proteins (SCALLOP) consortium. Genetic association data for the HDPs were obtained from recent European-ancestry genome-wide association study meta-analyses for gestational hypertension and preeclampsia. Study data were analyzed October 2022 to October 2023.

Exposures

Genetic instruments for 90 candidate proteins implicated in cardiovascular diseases, constructed using cis-protein quantitative trait loci (cis-pQTLs).

Main Outcomes and Measures

Gestational hypertension and preeclampsia.

Results

Genetic association data for cardiovascular disease-related proteins were obtained from 21 758 participants from the SCALLOP consortium. Genetic association data for the HDPs were obtained from 393 238 female individuals (8636 cases and 384 602 controls) for gestational hypertension and 606 903 female individuals (16 032 cases and 590 871 controls) for preeclampsia. Seventy-five of 90 proteins (83.3%) had at least 1 valid cis-pQTL. Of those, 10 proteins (13.3%) were significantly associated with HDPs. Four were robust to sensitivity analyses for gestational hypertension (cluster of differentiation 40, eosinophil cationic protein [ECP], galectin 3, N-terminal pro-brain natriuretic peptide [NT-proBNP]), and 2 were robust for preeclampsia (cystatin B, heat shock protein 27 [HSP27]). Consistent with the MR findings, observational data revealed that lower NT-proBNP (0.76- to 0.88-fold difference vs no HDPs) and higher HSP27 (2.40-fold difference vs no HDPs) levels during the first trimester of pregnancy were associated with increased risk of HDPs, as were higher levels of ECP (1.60-fold difference vs no HDPs). Phenome-wide MR analyses identified 37 unique non-HDP-related protein-disease associations, suggesting potential on-target effects associated with interventions lowering HDP risk through the identified proteins.

Conclusions and Relevance

Study findings suggest genetic associations of 4 cardiovascular disease-related proteins with gestational hypertension and 2 associated with preeclampsia. Future studies are required to test the efficacy of targeting the corresponding pathways to reduce HDP risk.

Biomarkers in Peripartum Cardiomyopathy-What We Know and What Is Still to Be Found

Peripartum cardiomyopathy (PPCM) is a form of heart failure, often severe, that occurs in previously healthy women at the end of their pregnancy or in the first few months after delivery. In PPCM, the recovery of heart function reaches 45-50%. However, the all-cause mortality in long-term observation remains high, reaching 20% irrespective of recovery status. The incidence of PPCM is increasing globally; therefore, effort is required to clarify the pathophysiological background of the disease, as well as to discover specific diagnostic and prognostic biomarkers. The etiology of the disease remains unclear, including oxidative stress; inflammation; hormonal disturbances; endothelial, microcirculatory, cardiomyocyte and extracellular matrix dysfunction; fibrosis; and genetic mutations. Currently, antiangiogenic 16-kDa prolactin (PRL), cleaved from standard 23-kDa PRL in the case of unbalanced oxidative stress, is recognized as the main trigger of the disease. In addition, 16-kDa PRL causes damage to cardiomyocytes, acting via microRNA-146a secreted from endothelial cells as a cause of the NF-κβ pathway. Bromocriptine, which inhibits the secretion of PRL from the pituitary gland, is now the only specific treatment for PPCM. Many different phenotypes of the disease, as well as cases of non-responders to bromocriptine treatment, indicate other pathophysiological pathways that need further investigation. Biomarkers in PPCM are not well established. There is a deficiency in specific diagnostic biomarkers. Pro-brain-type natriuretic peptide (BNP) and N-terminal BNP are the best, however unspecific, diagnostic biomarkers of heart failure at the moment. Therefore, more efforts should be engaged in investigating more specific biomolecules of a diagnostic and prognostic manner such as 16-kDa PRL, galectin-3, myeloperoxidase, or soluble Fms-like tyrosine kinase-1/placental growth factor ratio. In this review, we present the current state of knowledge and future directions of exploring PPCM pathophysiology, including microRNA and heat shock proteins, which may improve diagnosis, treatment monitoring, and the development of specific treatment strategies, and consequently improve patients' prognosis and outcome.

B-type natriuretic peptide in low-risk pregnancy and pregnancy with congenital heart disease

OBJECTIVE

To perform a longitudinal assessment of B-type natriuretic peptide (BNP) and its association with cardiac function in low-risk pregnant women and in pregnant women with congenital heart disease (CHD).

METHODS

Longitudinal study in low-risk pregnancy and pregnancy in women with CHD seen at 10-14, 18-22, and 30-34 weeks of pregnancy for BNP quantification and exercise studies using impedance cardiography (ICG).

RESULTS

Forty-three low-risk women with longitudinal samples (129 samples, 43 in each trimester) and 30 pregnant women with CHD with convenience samples (first trimester, five samples; second trimester, 20 samples; third trimester, 21 samples) were included. Women with CHD delivered earlier by 6 days (P = 0.002) and their newborns had lower birth weight independent of gestational age (birth weight centile 30.0 vs 55.0, P = 0.005). In low-risk women, BNP levels were lower in the third trimester (P < 0.001). There were no statistically significant differences in BNP concentrations across trimesters in the CHD group, no differences in BNP concentrations between the two groups, and no significant correlations between BNP concentration in each trimester with cardiac output, stroke volume, or heart rate (at rest/with exercise).

CONCLUSION

This study assessed BNP longitudinally in the first, second and third trimesters in singleton low-risk pregnancy, and showed that BNP concentration decreased with advancing gestational age, with no participants with levels greater than 40.0 pg/mL in the third trimester. BNP concentrations were similar in women with and without congenital heart disease. We found no correlation between circulating levels of BNP and maternal hemodynamics at rest or with exercise measured by ICG to support its use as a marker of cardiac function.

Serum Levels of NT-Pro BNP in Patients with Preeclampsia

Objective

This study aims to determine the serum levels of NT-proBNP in women with preeclampsia with and without severe signs and to evaluate the cardiovascular risks in these two groups of participants.

Methods

A descriptive cross-sectional study was conducted on 52 women with preeclampsia in the Department of Gynecology and Obstetrics – Hue Central Hospital, from August 2019 to September 2020.

Results

In preeclampsia women, the rate of hypertension in stage 3, stage 2, and stage 1 were 46.1%, 32.7%, and 21.2%, respectively. The average Sokolow-Lyon index in the preeclampsia group with and without severe signs was 22.25 ± 7.38mm, 20.16 ± 5.54mm, respectively. The average left ventricular mass index in the group of preeclampsia patients without and with severe signs was 92.27 ± 14.56g/m² and 120.68 ± 16.47g/m², respectively. The average ejection fraction in the group of preeclampsia patients without severe signs and with severe signs was 65.11 ± 3.45%, 56.21 ± 7.12%, correspondingly. In contrast, the difference between the two groups was statistically significant with p < 0.05. The plasma NT-proBNP level in the preeclampsia group without severe signs was 349.12 ± 93.51pg/mL, whereas the concentration in the preeclampsia group with severe signs was 725.32 ± 290.46pg/mL (p < 0.05).

Conclusion

The NT-proBNP level was statistically significantly increased in the patients with preeclampsia. Analyzing and comparing the figures and changes found in two groups of PE patients, with and without severe signs, we suggest that women diagnosed with PE with severe signs have a higher risk of developing cardiovascular problems forthwith and henceforth.

Pro-BNP Levels and Its Prognostic Role in Chronic Hypertensive Pregnancies: A Prospective Case-Control Study From A Tertiary Care Hospital

BACKGROUND

This study aimed to investigate the prognostic value of N-terminal B-type natriuretic peptide (NT-proBNP) in pregnancies with isolated chronic hypertension (HT).

METHOD

34 pregnant women with chronic HT and 40normotensive controls were enrolled. The association between plasma NT-proBNP levels obtained in the first trimester and perinatal complications were evaluated.

RESULTS

NT-proBNP levelsstrongly predicted low birth weight (AUC=0.842, p<0.001). NT-proBNP and birth weight were negatively correlated (r= -0.323, p=0.005). NT-proBNP was found to be an individual determinant of low birth weight in univariate analysis (OR:1.03; 95%CI:1.01-1.04).

CONCLUSION

NT-proBNP levels can be useful to predict low birth weight in pregnancies with chronic HT.

A more accurate prediction to rule in and rule out pre-eclampsia using the sFlt-1/PlGF ratio and NT-proBNP as biomarkers

Background The management of potential pre-eclamptic patients using the soluble FMS-like tyrosine kinase 1 (sFlt-1)/ placental growth factor (PlGF) ratio is characterised by frequent false-positive results. Methods A retrospective cohort study was conducted to identify and validate cut-off values, obtained using a machine learning model, for the sFlt-1/PlGF ratio and NT-proBNP that would be predictive of the absence or presence of early-onset pre-eclampsia (PE) in singleton pregnancies presenting at 24 to 33 + 6 weeks of gestation. Results For the development cohort, we defined two sFlt-1/PlGF ratio cut-off values of 23 and 45 to rule out and rule in early-onset PE at any time between 24 and 33 + 6 weeks of gestation. Using an sFlt-1/PlGF ratio cut-off value of 23, the negative predictive value (NPV) for the development of early-onset PE was 100% (95% confidence interval [CI]: 99.5-100). The positive predictive value (PPV) of an sFlt-1/PlGF ratio >45 for a diagnosis of early-onset PE was 49.5% (95% CI: 45.8-55.6). When an NT-proBNP value >174 was combined with an sFlt-1/PlGF ratio >45, the PPV was 86% (95% CI: 79.2-92.6). In the validation cohort, the negative and positive values were very similar to those found for the development cohort. Conclusions An sFlt-1/PlGF ratio <23 rules out early-onset PE between 24 and 33 + 6 weeks of gestation at any time, with an NPV of 100%. An sFlt-1/PlGF ratio >45 with an NT-proBNP value >174 significantly enhances the probability of developing early-onset PE.

Risk stratification and management of women with cardiomyopathy/heart failure planning pregnancy or presenting during/after pregnancy: a position statement from the Heart Failure Association of the European Society of Cardiology Study Group on Peripartum Cardiomyopathy

This position paper focusses on the pathophysiology, diagnosis and management of women diagnosed with a cardiomyopathy, or at risk of heart failure (HF), who are planning to conceive or present with (de novo or previously unknown) HF during or after pregnancy. This includes the heterogeneous group of heart muscle diseases such as hypertrophic, dilated, arrhythmogenic right ventricular and non-classified cardiomyopathies, left ventricular non-compaction, peripartum cardiomyopathy, Takotsubo syndrome, adult congenital heart disease with HF, and patients with right HF. Also, patients with a history of chemo-/radiotherapy for cancer or haematological malignancies need specific pre-, during and post-pregnancy assessment and counselling. We summarize the current knowledge about pathophysiological mechanisms, including gene mutations, clinical presentation, diagnosis, and medical and device management, as well as risk stratification. Women with a known diagnosis of a cardiomyopathy will often require continuation of drug therapy, which has the potential to exert negative effects on the foetus. This position paper assists in balancing benefits and detrimental effects.

NT-proBNP levels in preeclampsia, intrauterine growth restriction as well as in the prediction on an imminent delivery

OBJECTIVES

Studies of cardiovascular function in pregnancy have shown inconsistent and, in some cases, contradictory results, particularly regarding cardiac output. While some studies report preeclampsia associated with high cardiac output, other studies suggest that preeclampsia should be further subdivided into women with high or low cardiac output. This study was conducted to examine the NT-proBNP levels in preeclampsia, intrauterine growth restriction, and hypertensive pregnancies without preeclampsia. We also examined N-terminal pro-B natriuretic peptide (NT-proBNP) levels three to four months after delivery, in preeclamptic women as well as the prediction of delivery within 10 days. In a reduced number of preeclamptic women and controls we performed echocardiograms to study their diastolic function.

METHODS

We investigated the NT-proBNP levels in 213 subjects with preeclampsia only, 73 with intrauterine growth restriction, 44 with preeclampsia and intrauterine growth restriction, 211 who were hypertensive and 662 unaffected pregnancies (controls). We also performed echocardiograms on 36 preeclampsia and 19 controls before delivery and three to five months after delivery.

RESULTS

NT-proBNP levels are higher in early onset preeclampsia than in late onset preeclampsia. Intrauterine growth restriction pregnancies showed a NT-proBNP levels similar to hypertensive and unaffected pregnancies. Compared with healthy pregnancies, women with preterm preeclampsia (<37 gestational weeks) had altered left atrial segments.

CONCLUSIONS

We observed that NT-proBNP levels are higher in early onset preeclampsia than in late onset. Moreover, diastolic dysfunction is higher in early onset than in late-onset term preeclampsia. An NT-proBNP value >136 pg/mL has a high positive predictive value for an imminent delivery within 10 days.

Relevance of the assessment of natriuretic peptide plasma concentrations in hypertensive pregnant women

Assessment of the plasma concentrations of natriuretic peptides (NPs) is widely used to diagnose and evaluate the progression of cardiac failure, and their potential as markers of preeclampsia (PE) has been examined in recent years. It has been established that plasma concentrations of NPs do not change in the course of normal pregnancy. However, elevated levels of these peptides may have a prognostic value in patients with PE. This study presents information about the relevance of NPs assessment in the evaluation of physiological pregnancy, as well as in pregnancy complicated with arterial hypertension. The most commonly examined NPs is the N-terminal fragment of the brain natriuretic peptide (NT-proBNP), and it may be prognostic marker of PE and other complications of pregnancy.

Multiplex Analysis of Circulating Maternal Cardiovascular Biomarkers Comparing Preeclampsia Subtypes

Preeclampsia, a hypertensive pregnancy disorder, links to increased long-term maternal cardiovascular disease (CVD). The risk is further increased with early-onset preeclampsia (EPE) and delivery of a growth-restricted child. We hypothesized that circulating biomarkers associated with CVD risk differed between preeclampsia subtypes and controls. We compared EPE; n=37, delivery <week 34, late-onset preeclampsia (LPE); n=29, delivery ≥week 34, and normotensive controls (n=49) using Olink Proseek multiplex CVD I assay (targeting 92 biomarkers). We stratified analysis to uteroplacental spiral artery acute atherosis presence in preeclampsia patients, sharing morphological similarities with atherosclerosis. We found 47 CVD-related biomarkers differing between the groups, 42 markers between normotensive controls and EPE, 28 markers between normotensive controls and LPE, and 9 markers between EPE and LPE. Among these 9 markers, ST2 (ST2 protein), MMP (matrix metalloproteinase) 1, MMP3, and fractalkine (CX3CL1) were uniquely dysregulated in EPE. Principal component (PC) analysis of the differing markers identified 4 clusters (named PC1-PC4) that largely separated the preeclampsia and control groups as well as pregnancies with low and high circulating PlGF (placental growth factor). The combination of the single markers PlGF, ST2, MMP1, MMP3, and CX3CL1 had a high discriminatory property to differentiate between EPE and LPE. Preeclampsia with acute atherosis or with fetal growth restriction could be differentiated by Olink biomarkers as compared with preeclampsia without these features. We identified specific CVD-related biomarkers in pregnancy depending on preeclampsia subtypes and uteroplacental acute atherosis. Assessment of these pregnancy measured biomarkers' relation to long-term cardiovascular dysfunction and hard end points is warranted.

Circulating NT-proBNP but not soluble corin levels were associated with preeclampsia in pregnancy-associated hypertension

BACKGROUND

Corin is a serine protease known to convert B-type natriuretic peptide (BNP) prohormone into BNP and its amino-terminal fragment (NT-proBNP). In mice lacking corin, high blood pressure and proteinuria were found at late gestational stages, with associated delayed trophoblast invasion and impaired spiral artery remodeling in the uterus. We hypothesize that both NT-proBNP and soluble corin elevation predict the presence of preeclampsia in pregnant patients with hypertension.

METHODS

We prospectively enrolled 149 pregnant women with a history of chronic hypertension or gestational hypertension presenting at a tertiary-care hospital. We compared plasma NT-proBNP and soluble corin concentrations based on their preeclamptic status.

RESULTS

In our study cohort, 62 patients with preeclampsia had lower gestational age than 87 patients without preeclampsia (33.3 ± 3 versus 36.6 ± 3 weeks; P < .001), otherwise the baseline characteristics were similar. We observed higher NT-proBNP concentrations in patients with preeclampsia compared to those without preeclampsia (304.3 [96.34, 570.4] vs. 60.8 [35.61, 136.8] ng/L, P < .001), with no differences between chronic and gestational hypertension. However, the concentration of corin was not statistically different between the two groups (1756 [1214, 2133] vs. 1571 [1171, 1961] ng/L, P = .1087). ROC curve analysis demonstrated stronger predictive value of NT-proBNP compared to soluble corin in predicting the presence of preeclampsia in our study population (AUC 0.7406 vs. 0.5789, P < .0001).

CONCLUSION

While corin may contribute to mechanistic underpinnings of the development of preeclampsia in animal models, soluble corin likely has no diagnostic role in human pregnancies for preeclampsia beyond natriuretic peptide levels.

Maternal pregnancy-induced hypertension increases the subsequent risk of transient tachypnea of the newborn: A nationwide population-based cohort study

OBJECTIVE

To determine the association between pregnancy-induced hypertension (PIH) and transient tachypnea of the newborn (TTN) and to identify the predictive risk factors.

MATERIALS AND METHODS

Pregnant women with a newly diagnosed PIH (between 2000 and 2013) from the Taiwan National Health Insurance Research Database (NHIRD) were compared with a matched (with respect to age and year of delivery) cohort of pregnant women without PIH. The occurrence of TTN was evaluated in both cohorts.

RESULTS

Among the 23.3 million individuals registered in the NHIRD, 29,013 patients with PIH and 116,052 matched controls were identified. According to a multivariate analysis, PIH (odds ratio [OR] = 1.85, 95% confidence interval [CI] = 1.69-2.03, p < 0.0001), age ≥ 30 years (OR = 1.38, 95% CI = 1.26-1.51, p < 0.0001), primiparity (OR = 1.37, 95% CI = 1.24-1.5, p < 0.0001), preterm birth (OR = 3.4, 95% CI = 3.09-3.75, p < 0.0001), multiple births (OR = 2.54, 95% CI = 2.24-2.89, p < 0.0001), and cesarean section (OR = 1.71, 95% CI = 1.56-1.88, p < 0.0001) were independent risk factors for the development of TTN.

CONCLUSION

Women with PIH have an increased risk of having infants who develop TTN compared with those without PIH. Additionally, age ≥30 years, primiparity, preterm birth, multiple births, and cesarean section were independent risk factors for the development of TTN.

B-type natriuretic peptides in pregnant women with normal heart or cardiac disorders

Pregnancy is characterized by complex physiological changes of the cardiovascular system. B-type natriuretic peptides, represented by the bioactive molecule (BNP) and its inactive amino terminal fragment (NT-proBNP) are important biomarkers used in the management of the heart failure. Besides cardiac causes, BNP can grow in other noncardiac conditions such as pregnancy. The levels of natriuretic peptides during pregnancy have been the subject of multiple studies, whether it is a normal pregnancy, or there are pre-existing or developed cardiac conditions during pregnancy. It depends on the stage of pregnancy and comorbidities: obesity, preeclampsia, pre-existing cardiomyopathies or peripartum cardiomyopathy. High levels of NT-proBNP in pregnancy are associated with increased risk of cardiovascular events and involve careful supervision of pregnancy, including imaging procedures.

Addition of N-terminal pro-B natriuretic peptide to soluble fms-like tyrosine kinase-1/placental growth factor ratio > 38 improves prediction of pre-eclampsia requiring delivery within 1 week: a longitudinal cohort study

OBJECTIVE

Short-term prediction of pre-eclampsia (PE) using the soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio is characterized by frequent false-positive results. As such, no treatment can be recommended to test-positive patients and multiple measurements are often required. The aim of this study was to evaluate the effectiveness of N-terminal pro-B natriuretic peptide (NT-proBNP), uric acid and the sFlt-1/PlGF ratio for prediction of delivery with PE within 1 week in singleton pregnancies with suspected PE and sFlt-1/PlGF ratio > 38.

METHODS

This was a longitudinal prospective cohort study of singleton pregnancies presenting at 24 + 0 to 36 + 6 weeks of gestation with clinically suspected PE and sFlt-1/PlGF ratio > 38, enrolled between January 2015 and June 2017. Multiple samples per patient were allowed but were restricted to one sample per gestational week. From 495 enrolled patients, 270 blood samples from 134 patients were ultimately analyzed. By using generalized estimating equations (GEE), the best-fit model was selected for prediction of delivery with PE within 1 week. The predictive value of this model was then assessed using area under the paired-ROC curve (AUC) analysis.

RESULTS

The best-fit model included the sFlt-1/PlGF ratio, NT-proBNP and the gestational week at the time of the measurement. This combined model was compared with the GEE model based on the sFlt-1/PlGF ratio and the gestational week at the time of the measurement (reduced model). The AUC for the combined model was 0.845 (95% CI, 0.787-0.896), which was significantly greater (P = 0.011) than that of the reduced model (0.786 (95% CI, 0.722-0.844)).

CONCLUSION

The addition of NT-proBNP assessment improves the short-term prediction of delivery as a result of PE compared with sFlt-1/PlGF ratio alone, when the sFlt-1/PlGF ratio is > 38. This finding should be considered in future research on the assessment of short-term risk of delivery as a result of PE. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Strontium and its role in preeclampsia

BACKGROUND

Preeclampsia (PE) is considered a specific vascular disease in which endothelial dysfunction may be the crucial factor of its pathogenesis. It has been suggested that strontium (Sr) may play a role in the pathophysiology of PE. Our group established in a previous study the serum levels of Sr in healthy pregnancies, and the main aim of the present study was to evaluate Sr concentrations and oxidative status in preeclamptic women.

METHODS

The study population included women with early-onset PE (E-PE, n = 39), late-onset PE (L-PE, n = 67) and serial samples from a subset of preeclamptic women (PE-ss, n = 20). The control group included women with gestational hypertension (GH, n = 56) and healthy pregnancies (samples collected in the 1st (n = 50), 2nd (n = 51) and 3rd trimesters (n = 53)). Strontium, calcium (Ca), uric acid (UA), placental growth factor (PlGF), soluble fms-like tyrosine kinase 1 (sFlt-1), N-terminal pro-brain natriuretic peptide (NT-proBNP), lipid peroxidation and total antioxidant activity (TAA) were measured in these samples.

RESULTS

Mean Sr levels were significantly higher in PE than in control groups (p ≤ 0.0001). Calcium values were found to be significantly lower in E-PE compared to control groups (p = 0.03). Higher levels of NT-proBNP were found in PE vs. control groups (p < 0.001). sFlt-1/PlGF ratio was higher in E-PE compared to L-PE and GH (p < 0.001). Uric acid levels in PE were significantly higher than in control groups (p < 0.0001). There was a strong positive correlation between UA and Sr in the E-PE serial samples (r = 0.80, p < 0.0001). Lipid peroxidation and lipid peroxidation/TAA ratios were found to be higher in PE, with lower values of TAA.

CONCLUSION

The higher levels of Sr and the alterations of redox status found in preeclamptic women, along with the strong correlation between UA and Sr suggest that this element may be involved in the pathogenesis of PE.

Relationship between maternal hemodynamics and plasma natriuretic peptide concentrations during pregnancy complicated by preeclampsia and fetal growth restriction

OBJECTIVE

A proper maternal cardiovascular adaptation to the pregnancy plays a key role for promoting an adequate uteroplacental perfusion, for ensuring normal fetal development and for preventing gestational hypertensive complications such as preeclampsia. This study aims to evaluate hemodynamic measurements obtained by noninvasive methods among preclamptic women with and without fetal growth restriction (FGR) and the relationship with plasma levels of natriuretic peptides.

STUDY DESIGN

The study compared 98 pregnant women (n=48 with preeclampsia; n=50 normotensive pregnant women) and 50 nonpregnant normotensive control subjects undergoing anultrasonic cardiac output monitor (USCOM) and plasma assessment of atrial N-terminal pro B-type natriuretic peptide (NT-proBNP). The statistical analysis was carried out by analysis of variance and correlation analysis.

RESULTS

Preeclampsia state is associated with increased vascular resistance (mean 1587±236 vs 978±153 dyn s cm^-3) and lower cardiac output (mean 5.7±1.1 vs 6.78±0.8 l) and this hemodynamic state is associated with higher levels of NT-proBNP (mean 121.2±26.3 vs 42.5±11.4 pg ml^-1); furthermore, we found an inverse correlation between maternal cardiac output and plasma levels of NT-proBNP only if preeclampsia is associated with FGR.

CONCLUSION

The elevated NT-proBNP in preeclampsia may reflect ventricular stress and subclinical cardiac dysfunction worsening if FGR is present. This may have implications for the acute management of the preeclampsia and FGR women and for appropriately timed therapeutic interventions later in life.

Shared biomarkers between female diastolic heart failure and pre-eclampsia: a systematic review and meta-analysis

Evidence accumulates for associations between hypertensive pregnancy disorders and increased cardiovascular risk later. The main goal of this study was to explore shared biomarkers representing common pathogenic pathways between heart failure with preserved ejection fraction (HFpEF) and pre‐eclampsia where these biomarkers might be potentially eligible for cardiovascular risk stratification in women after hypertensive pregnancy disorders. We sought for blood markers in women with diastolic dysfunction in a first literature search, and through a second search, we investigated whether these same biochemical markers were present in pre‐eclampsia.This systematic review and meta‐analysis presents two subsequent systematic searches in PubMed and EMBASE. Search I yielded 3014 studies on biomarkers discriminating women with HFpEF from female controls, of which 13 studies on 11 biochemical markers were included. Cases had HFpEF, and controls had no heart failure. The second search was for studies discriminating women with pre‐eclampsia from women with non‐hypertensive pregnancies with at least one of the biomarkers found in Search I. Search II yielded 1869 studies, of which 51 studies on seven biomarkers were included in meta‐analyses and 79 studies on 12 biomarkers in systematic review.Eleven biological markers differentiated women with diastolic dysfunction from controls, of which the following 10 markers differentiated women with pre‐eclampsia from controls as well: C‐reactive protein, HDL, insulin, fatty acid‐binding protein 4, brain natriuretic peptide, N terminal pro brain natriuretic peptide, adrenomedullin, mid‐region pro adrenomedullin, cardiac troponin I, and cancer antigen 125.Our study supports the hypothesis that HFpEF in women shares a common pathogenic background with pre‐eclampsia. The biomarkers representing inflammatory state, disturbances in myocardial function/structure, and unfavourable lipid metabolism may possibly be eligible for future prognostic tools.

N-terminal pro B-type natriuretic peptide and angiogenic biomarkers in the prognosis of adverse outcomes in women with suspected preeclampsia

BACKGROUND

This study compares the performance of the soluble fms-like tyrosine kinase 1 to placental growth factor (sFlt-1/PlGF) ratio and the cardiac biomarker N-terminal pro-B type natriuretic peptide (NT-proBNP) in the prediction of adverse outcomes in women with suspicion of PE.

METHODS

A retrospective cohort study was conducted on women admitted at triage with signs and/or symptoms of PE (n=340). Serum levels of sFlt-1, PlGF and NT-proBNP were determined by an electrochemiluminescence immunoassay (Roche Diagnostics). The main outcomes were early- or late-onset PE and development of adverse outcome, defined as delivery within the first week since clinical presentation or fetal/early neonatal death.

RESULTS

NT-proBNP concentrations (ng/L) were significantly increased in PE versus non-PE women, both at <34 (169 versus 34) and ≥34weeks of gestation (101 versus 49) (p<0.001). A cut-point of 70 showed sensitivities/specificities of 78/74% for early-, and 70/62% for late-onset PE; slightly lower than those offered by the sFlt-1/PlGF ratio or uric acid. The respective cut-points of 178 and 219 for sFlt-1/PlGF ratio and NT-proBNP, demonstrated similar performance in the prediction of adverse outcome, with sensitivity/specificity of 95/84% and 94/76%, respectively.

CONCLUSION

NT-proBNP and sFlt-1/PlGF ratio can be used to predict the development of an adverse outcome.

Prenatal Clinical Assessment of NT-proBNP as a Diagnostic Tool for Preeclampsia, Gestational Hypertension and Gestational Diabetes Mellitus

Common complications of pregnancy include preeclampsia (PE), gestational hypertension (GH) and gestational diabetes mellitus (GDM). Hypertensive disorders (PE/GH) and GDM may result in greater maternal, fetal and neonatal morbidity and mortality. Women with PE/GH, one of the most common causes of heart burden in an obstetrical setting, present with elevated serum levels of BNP and NT-proBNP. The aim of this study was to shed more light on the role of NT-proBNP in pathophysiology of PE, GH and GDM. The study included 156 pregnant women with singleton pregnancies. A total of 26 women developed arterial hypertension during pregnancy, 14 were diagnosed with PE, and GDM was detected in 81 patients. The control group included 35 women with uncomplicated pregnancies, normal arterial blood pressure and normal glucose concentrations. Patients with GH presented with significantly higher serum concentrations of NT-proBNPthan normotensive women (65.5 vs. 37.4 pg/ml; p = 0.0136). Serum levels of NT-proBNP in patients with PE were the highest of all the analyzed subsets, being significantly higher than in women without this condition (89.00 vs. 37.4pg/ml,p = 0,0136). However, women with and without GDM did not differ significantly in terms of their serum NT-proBNPconcentrations. Serum NT-proBNP (pg/ml) (p = 0.0001) and BMI (p<0.0001) turned out to be independent predictors of GH on multivariate logistic regression analysis.Moreover, serum NT-proBNP (pg/ml) was identified as an independent indicator of PE (p = 0.0016). A significant inverse correlation was found between birth weight and maternal serum NT-proBNP concentrations. In our opinion, NT-proBNP can be a useful clinical marker of GH and PE. Determination of NT-proBNP levels may be helpful in identification of patients with PE and GH and in their qualification for intensive treatment; this in turn, may be reflected by better neonatal outcomes.

Prospective study on changes in blood variables in pregnant women at higher risk of peripartum cardiomyopathy

Aims

Echocardiography is necessary for the diagnosis of peripartum cardiomyopathy (PPCM). Multifetal pregnancies (MFP) and hypertensive disorders (HD) are prominent risk factors for PPCM. To determine which blood variables exhibit greater change in a late stage of pregnancy in women with MFP and/or HD compared with women with normotensive singleton pregnancies.

Methods and results

Serum levels of six variables—high‐sensitive troponin I (hs‐TnI), N‐terminal fragment of precursor protein brain‐type natriuretic peptide (NT‐proBNP), myoglobin, creatine kinase‐myocardial band, ferritin, and prolactin—were compared between 29 women with MFP (n = 13) and/or HD (n = 18) and 100 women with normotensive singleton pregnancies (control group). None of 129 women developed PPCM. All variables increased significantly peripartum in both groups. In 29 women with MFP and/or HD, the elevated hs‐TnI and NT‐proBNP levels (median) were significantly higher compared with the control group (5.4 vs. 3.7 pg/mL for hs‐TnI with P = 0.002, 185 vs. 68 pg/mL for NT‐proBNP with P = 0.007), and the prevalence rate of more than 90th percentile value specific for the 129 women was significantly more frequent for hs‐TnI (>12.2 pg/mL; 31% [9/29] vs. 4.0% [4/100], P < 0.001) and tended to be more frequent for NT‐proBNP (>342 pg/mL; 21% [6/29] vs. 7.0%, P = 0.072).

Conclusions

Both hs‐TnI and NT‐proBNP were likely to increase markedly in women with MFP and/or HD. The combination of hs‐TnI and NT‐proBNP may contribute to better selection of candidates for echocardiography.

Cardiovascular disease screening

Cardiovascular disease is the leading cause of death amongst women worldwide. Cardiovascular risk assessment and primary prevention are important strategies to improve morbidity and mortality. In additional to the traditional risk factors, pregnancy complications such as pre-eclampsia and gestational diabetes increment future risk of developing cardiovascular complications. Additionally, several serum biomarkers are valuable measures for both risk assessment and predictors of clinical outcomes in women. The purpose of this review is to describe current risk stratification schemes as well as outline the role of obstetric history and serum biomarkers in adjusting risk stratification in women.

Placental expression of proBNP/NT-proBNP and plasma levels of NT-proBNP in early- and late-onset preeclampsia

BACKGROUND

Levels of plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) are elevated in preeclampsia. In this study, the possibility that the placenta produces and releases proBNP/NT-proBNP was explored. Plasma levels of NT-proBNP in early- and late-onset preeclampsia were also measured.

METHODS

Placental proBNP mRNA in early-onset preeclampsia (n = 7), late-onset preeclampsia (n = 8), and controls of similar gestational age (n = 10) was assessed by quantitative real-time polymerase chain reaction. ProBNP/NT-proBNP protein was studied in placental samples with immunohistochemistry (n = 8) and tissue culture (n = 2). Plasma levels of NT-proBNP were measured in early-onset preeclampsia (n = 18), late-onset preeclampsia (n = 20), and relevant controls (n = 36).

RESULTS

Transcripts of proBNP mRNA were found in 20 out of 25 samples, there were no differences in expression between the groups. ProBNP/NT-proBNP protein was observed in maternal spiral arteries and in syncytiotrophoblasts in all placental samples. After placental tissue culture, there were measurable amounts of NT-proBNP in the culture media. Women with both early- (365 [14-9815] pg/ml) and late-onset preeclampsia (176 [33-2547] pg/ml) had higher levels of NT-proBNP than their controls (P < 0.001). There was a tendency toward higher levels of NT-proBNP in women with early-onset preeclampsia than in women with late-onset preeclampsia (P = 0.057).

CONCLUSION

The results indicate possible placental production and release of proBNP/NT-proBNP into the maternal circulation.

Association of NT-proBNP with plasma renin activity and plasma aldosterone concentration in women with singleton pregnancy

OBJECTIVE

To determine the association of the N-terminal fragment of precursor protein brain-type natriuretic peptide (NT-proBNP) levels with plasma renin activity (PRA) and plasma aldosterone concentration (PAC) in singleton pregnancies.

DESIGN

Serum NT-proBNP levels, PRA and PAC were determined in 215 blood specimens from 139 women with singleton pregnancies, including 34 and 105 women who did and did not develop hypertensive disorders in pregnancy, respectively. Twenty-five blood specimens were obtained from 25 women who later developed hypertension (systolic BP⩾140mmHg and/or diastolic BP⩾90mmHg), but were normotensive at the time of blood sampling.

RESULTS

The serum NT-proBNP levels [pg/ml, median (range), 32 (5-142)] did not change in normotensive women, but increased significantly to 97 (23-436) after the development of hypertension (D/H). The PRA [ng/ml/h, median (range), 7.1 (1-20)] did not change in normotensive women, but decreased significantly to 1.9 (1-16) after D/H. PAC (pg/ml) increased significantly from 397 (94-1750) to 667 (123-2010) between the 2nd and 3rd trimesters in normotensive women. However, as PAC of hypertensive women did not change significantly before and after D/H, PAC [293 (116-1720)] after D/H was significantly lower than that [667 (123-2010)] of the 3rd trimester in the normotensive women. The serum levels of NT-proBNP were significantly and negatively correlated with both PRA and PAC.

CONCLUSIONS

The renin-angiotensin-aldosterone system is suppressed in pregnant women with cardiac conditions associated with higher NT-proBNP levels.

Detection of peripartum myocardial burden by vector-projected 187 channel electrocardiography and serum NT-proBNP

There is no reliable method of screening for pregnant women at high risk of developing severe myocardial disorders. In this study, we used vector-projected 187 channel electrocardiography (DREAM-ECG) and serum biochemical markers to evaluate peripartum myocardial burden in pregnant women. Forty-one pregnant women were examined at 36-37 weeks gestation (GW36), 7 days postpartum (PPD7), and 1 month postpartum (PPM1). Ten non-pregnant control women were assessed at a single time point. Heart rate, sympathetic index, and repolarization index (RTc dispersion) were quantified using the DREAM-ECG system, and serum levels of NT-proBNP, cardiac troponin T, estrogen, and progesterone were determined. Heart rate and the sympathetic index decreased from GW36 to PPM1 (P = 0.0031). The repolarization index decreased over time and was greater than in non-pregnant controls (31 ± 13 ms). Estrogen and progesterone at PPD7 and PPM1 were significantly lower than those at GW36 (P < 0.0001, P < 0.001). NT-proBNP at PPD7 was greater than at GW36 (median 29 pg/mL at GW36, 86 pg/mL at PPD7), and decreased at PPM1 in comparison to PPD7 (median 18.5 pg/mL). Troponin T was in the normal range during the whole period (< 0.003 ng/mL). In conclusion, these results indicate that the peripartum myocardial burden in pregnant women does not return to normal nonpregnant levels by PPM1. We propose that both repolarization indexes such as RTc dispersion by DREAM-ECG and serum biochemical markers may identify pregnant women at high risk of developing severe myocardial damage in the peripartum period.

Cardiovascular haemodynamics in pre-eclampsia using brain naturetic peptide and tissue Doppler studies

AIM

To determine early haemodynamic changes in preeclampsia (PE) using tissue Doppler echocardiography and brain natriuretic peptide (BNP), and to relate these changes to obstetric outcomes.

METHODS

Consenting primigravidae patients in the third trimester of pregnancy were included in the study, which was carried out in a large regional hospital in Durban, South Africa; 115 primigravidae (52 pre-eclamptics and 63 normotensive pregnant patients) attending the maternity unit including the antenatal clinics at the study site were studied. The patients, matched for maternal and gestational age, were examined during pregnancy and within the puerperium. Transthoracic echocardiography (TTE), tissue Doppler imaging (TDI), umbilical artery Doppler and laboratory investigations were performed.

RESULTS

BNP levels were significantly increased in the antepartum period [23.8 (2-184.1) vs 6.0 (0.5-45.2) pmol/l; p < 0.0001] and during labour [15.0 (1.8-206.4) vs 8.7 (1.9-24.8) pmol/l; p < 0.01] in the pre-eclamptic group compared to the normotensive controls. In the postpartum period, mean BNP levels were 4.2 (1.7-51.4) and 5.95 (2.2-38.7) pmol/l in the preeclamptic and normotensive groups, respectively (p > 0.05). Tissue Doppler Em/Ea ratios were elevated in the pre-eclamptic compared to the normotensive group (11.02 ± 5.6 vs 9.16 ± 2.6; p < 0.05). Mean left atrial size was larger (38 mm) in the pre-eclamptic group than in the normotensive group (35 mm) but this difference was not significant (p > 0.05). The umbilical artery resistance index was significantly higher in the pre-eclamptic group compared to the normotensive group (0.68 ± 0.06 vs 0.63 ± 0.05; p < 0.001). There was an increased rate of Caesarean sections performed in the pre-eclamptic group (n = 24) compared to the normotensive group (n = 18; p < 0.001). There were two stillbirths in the pre-eclamptic group and none in the normotensive group. As expected, birth weight (2.6 ± 0.8 kg vs 3.14 ± 0.42 kg; p < 0.0001) was lower in the pre-eclamptic group compared to the normotensive group.

CONCLUSION

In pregnancies complicated by pre-eclampsia, BNP levels were increased in comparison to normotensive pregnancies and this was accompanied by early changes in left ventricular diastolic function as determined by the tissue Doppler Em/Ea ratios. These changes reverted to baseline values, as indicated by return of BNP levels in the pre-eclamptic group to levels seen in the normotensive group. These changes were associated with an increased Caesarean section rate and lower birth weights in pre-eclamptic mothers.

Effects of caesarean section on serum levels of NT-proBNP

OBJECTIVE

To determine the effects of delivery by caesarean on serum levels of N-terminal fragment of precursor protein brain-type natriuretic peptide (NT-proBNP).

METHODS

Serum NT-proBNP levels were determined longitudinally at 24 and 36 weeks of gestation (GW) and on post-partum day 3 and month 1 (PPD3 and PPM1, respectively) in 78 women with normotensive singleton pregnancies. Thirty-nine women underwent caesarean delivery. Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were determined on PPD3. Effects of maternal demographic characteristics on NT-proBNP levels were also analysed.

RESULTS

NT-proBNP levels (pg/ml) either in pregnancy or on PPM1 did not differ between women with vaginal and caesarean deliveries (44 ± 24 vs 41 ± 30, 24 GW; 37 ± 22 vs 29 ± 22, 36 GW; 43 ± 28 vs 39 ± 24, PPM1, respectively). Levels on PPD3 were significantly higher (94 ± 105 vs 247 ± 186, P < 0.0001) in women with caesarean delivery. Among women with caesarean delivery, a larger rise of NT-proBNP on PPD3 occurred in nulliparous than in multiparous women (319 ± 232 vs 185 ± 107, P = 0.023), while no rise occurred among multiparous women with vaginal delivery (108 ± 115 vs 47 ± 27). NT-proBNP levels on PPD3 were significantly and negatively correlated with PRA, PAC and maternal weight loss after childbirth on PPD3. These 3 variables on PPD3 were significantly lower in women undergoing caesarean than vaginal delivery (0.8 ± 0.4 vs 1.9 ± 1.4 ng/ml/h for PRA; 70 ± 38 vs 136 ± 88 pg/ml for PAC; 2.7 ± 1.2 vs 4.3 ± 1.1 kg for weight loss, each P < 0.0001).

CONCLUSIONS

The transient post-partum rise in serum NT-proBNP may reflect transient volume overload after parturition and is remarkable in nulliparous women, especially after caesarean section.

Utility of B-type natriuretic peptides in preeclampsia: a systematic review

BACKGROUND

Preeclampsia and its complications may be associated with elevated B-type natriuretic peptide levels during and after pregnancy.

METHODS

We conducted a systematic review to determine whether preeclampsia and/or related cardiovascular complications, eclampsia and preterm delivery are associated with elevated natriuretic peptide levels. Three bibliographic databases were searched, using the terms "natriuretic peptide", "pregnancy", "preeclampsia", "eclampsia" and "BNP". Twelve studies fulfilled our inclusion criteria for full paper analysis. The data were too heterogeneous to allow for meaningful quantitative analyses.

RESULTS

In healthy patients, B-type natriuretic peptide levels did not change during pregnancy. Compared with normal pregnancies, preeclamptic patients were shown to have significantly higher natriuretic peptide levels in the third trimester, which remained elevated for 3-6 months postpartum. Several papers suggested that cardiovascular dysfunction in preeclampsia is associated with NP elevation. Abnormalities were elevated systemic vascular resistance and cardiac filling pressures, decreased cardiac output, left ventricular diastolic dysfunction, and elevated left ventricular mass index. One investigation found that natriuretic peptide levels were higher in preeclamptic women who subsequently had preterm delivery, compared with those who delivered after 34 weeks. There were no data on natriuretic peptide levels in eclampsia.

CONCLUSIONS

Preeclampsia is associated with elevated natriuretic peptide levels. Cardiovascular complications and preterm delivery in this setting may also be associated with elevated natriuretic peptide levels. Large prospective studies of natriuretic peptide measurement in preeclampsia are needed to determine whether elevated levels predict the development of severe preeclampsia and/or associated complications.

Amino-terminal pro-brain natriuretic peptide levels in hypertensive disorders complicating pregnancy

OBJECTIVE

Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is synthesized in cardiac ventricles in response to volume expansion. This study evaluated NT-proBNP levels to determine the clinical correlation with the severity of hypertensive disorders complicating pregnancy.

METHODS

NT-proBNP levels of 95 pregnant women (severe preeclampsia [n = 26], mild preeclampsia [n = 15], gestational hypertension [n = 9], and healthy controls [n = 45]) were determined using an electrochemiluminescence immunoassay.

RESULTS

Comparisons of the mean values of NT-proBNP levels in the different groups were significantly different, as follows: 1766.43 ± 4197.39 pg/mL (median, 339.8 pg/mL) in severe preeclampsia, 214.97 ± 226.35 pg/mL (median, 152.3 pg/mL) in mild preeclampsia, 39.75 ± 24.85 pg/mL (median, 34.09 pg/mL) in gestational hypertension, and 78.78 ± 81.56 pg/mL (median, 48.54 pg/mL) in the healthy controls. The NT-proBNP levels of the patients with mild and severe preeclampsia were significantly higher than in the patients with gestational hypertension and the healthy control patients. There was no significant difference in NT-proBNP levels between patients with mild and severe preeclampsia (p = 0.17).

CONCLUSION

In patients with mild and severe preeclampsia, NT-proBNP levels were elevated. This may reflect ventricular stress and/or subclinical cardiac dysfunction associated with preeclampsia.