Relationship of systemic hemodynamics, left ventricular structure and function, and plasma natriuretic peptide concentrations during pregnancy complicated by preeclampsia

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.

Evaluating circulating soluble markers of endothelial dysfunction and risk factors associated with PE: A multicentre longitudinal case control study in northern Ghana

Serpin E1/PAI-1, N-terminal pro-brain natriuretic peptide (NTpro-BNP) and neuropilin-1 are markers which have been associated with endothelial dysfunction. However, data on the levels of these markers in PE is limited. The limited data on the pathophysiology of PE in relation to these markers necessitated the study. This was a multicentre case-control study conducted at the Obstetrics and Gynaecology Department of the Tamale Teaching Hospital, the Bawku Presbyterian Hospital and the Bolgatanga Regional Hospital. Out of 520 consenting pregnant women, 127 pregnant women met the inclusion criteria (53 with PE and 74 controls) and were included in this study. Venous, placental, cord and peripheral blood were collected for biomarker assay, haematological parameters and placental parasite determination. Placental tissue sections were obtained for placental malaria and histopathological lesions associated with hypoperfusion. Maternal heart rate and foetal umbilical artery Doppler impedance indices; resistance index (RI) and systolic diastolic (SD) ratio were determined to confirm utero-placental hypoperfusion. Significantly higher proportions of foeto-maternal complications; eclampsia, low birth weight (LBW), neonatal intensive care unit admissions (NICU), intrauterine growth restriction (IUGR), caesarian deliveries and early gestational age at delivery were associated with PE. Women with PE had lower concentrations of platelet (p = 0.02) whereas red cell distribution width (RDW) was markedly elevated (p = 0.01). NTPro-BNP concentration was markedly elevated (p = 0.01) in women with PE whereas neuropilin-1 concentration was lower (p = 0.03) compared to the non-PE group. Maternal heart rate was elevated in women with PE and Doppler resistance indices (RI and SD) were significantly elevated in foetuses of PE women than foetuses of the controls. Placental mal-perfusion lesions were higher in women with PE compared to the non-PE group. Women with PE had increased risk of adverse foeto-maternal complications, significantly associated with placental mal-perfusion lesions, had reduced platelet concentration and elevated RDW-CV levels. NTPro-BNP, RI and SD are elevated in women with PE whereas neuropilin-1 concentration is reduced. Significant changes in these pathological variables in PE women is indicative of significant derangement in endothelial function culminating in adverse maternal and perinatal outcomes of pregnancy.

Cardiac Complications in Pregnancy: A Systematic Review and Meta-Analysis of Diagnostic Accuracy of BNP and N-Terminal Pro-BNP

Introduction

Serum brain-type natriuretic peptide (BNP) levels may be involved in detecting the breakdown of defense mechanisms in pregnant women. BNP and N-terminal pro-BNP (NT-proBNP) levels can be used in emergency settings as a biomarker to rule out or confirm cardiac complications. The present study was conducted as an attempt to evaluate the performance of BNP and NT-proBNP as diagnostic tools for cardiac complications, including heart failure and pre-eclampsia, in pregnant and recently-delivered women.

Methods

This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. To extract the data, articles meeting the inclusion criteria were directly reviewed by two of the authors. Disputes were resolved through discussion with all authors before data mining. In cases of unresolved disagreement, a third reviewer was consulted to achieve consensus. A quantitative analysis of the total bias of publications was performed using Stata software version 14.0, using funnel plots and Deek’s test.

Results

Overall, 13 unique studies were included in this review. The pooled sensitivity, specificity and positive and negative predictive values for diagnosing cardiac complications in pregnant women when BNP level was ≤ 100 ng/L, were determined to be 95, 62, 71 and 91%, respectively. The corresponding measures when the BNP levels were 100–500 ng/L were calculated to be 98, 92, 97 and 92%, respectively. The pooled sensitivity, specificity and positive and negative predictive values for diagnosing cardiac complications in pregnant women using NT-proBNP were 78, 74, 20.5 and 97%, respectively.

Conclusion

Our results suggest that both BNP and NT-proBNP levels can be used as diagnostic tools among pregnant and newly-delivered women to diagnose cardiac complications, including heart failure and pre-eclampsia. While BNP showed a relatively better diagnostic accuracy compared to NT-proBNP, it must be noted that the number of studies evaluating NT-proBNP included in this meta-analysis was low and the studies were inconsistent in terms of cutoff value. Further studies are required to confirm the prospective use of BNP and NT-pro BNP in assessing common symptoms that indicate cardiac complications during labor. Moreover, the clinical use of the NT-proBNP test in this field requires further study.

Maternal plasma pro-atrial and C-type natriuretic peptide levels and their associations with cardiovascular and renal function in the second half of normal pregnancy: a longitudinal study

BACKGROUND

Physiological adaptation in pregnancy is characterized by remodeling of endocrine, cardiovascular and renal functions leading to fluid retention, volume expansion, altered cardiac loading conditions and hyperdynamic circulation. Natriuretic peptides have been used as biomarkers of cardiovascular function, but their associations with gestational age-related changes in maternal cardiac, endothelial and renal function have not been elucidated. The aim of this study was to establish longitudinal reference values for maternal plasma atrial natriuretic peptide (proANP) and C-type natriuretic peptide (CNP) and investigate their temporal association with cardiovascular and renal function in the second half of pregnancy.

METHODS

This study was a prospective longitudinal study of 53 low-risk pregnancies. Women were examined every 3-5 weeks during 22-40 weeks of gestation (252 observations). Fasting maternal blood samples were obtained to measure proANP, CNP, creatinine, cystatin C, uric acid, and fibrinogen levels. Cardiac function and systemic hemodynamics were assessed noninvasively by impedance cardiography (ICG) and vascular endothelial function by flow-mediated vasodilation of brachial artery (FMD).

RESULTS

The plasma proANP (R²adj = 0.79; P = 0.007), CNP (R2adj = 0.54; P = 0.005) decreased between 22 and 40 weeks. The creatinine (R²adj = 0.90; P < 0.001), cystatin C (R²adj = 0.93; P = < 0.001) and uric acid (R²adj = 0.83; P < 0.001) increased significantly, whereas the estimated glomerular filtration rate (R²adj = 0.93; P < 0.001) decreased with gestational age. The FMD did not change significantly but fibrinogen (R²adj = 0.79; P < 0.001) increased with advancing gestation. The maternal systemic vascular resistance index (R²adj = 0.50; P < 0.001) increased, stroke index (R²adj = 0.62; P < 0.001) decreased, whereas the cardiac index (R²adj = 0.62; P = 0.438) and thoracic fluid content (R²adj = 0.72; P = 0.132) did not change significantly with gestation. The proANP was associated with thoracic fluid content (R²adj = 0.74; P < 0.001) and fibrinogen (R²adj = 0.78; P = 0.034) but not with other variables of systemic hemodynamics, endothelial function, or renal function. The CNP was not associated significantly with parameters of cardiovascular or renal function.

CONCLUSION

Longitudinal reference values for maternal plasma proANP and CNP were established. These natriuretic peptides decreased slightly with advancing gestation, but they did not reflect the temporal physiological changes in maternal systemic hemodynamics, vascular endothelial function and renal function during the second half of pregnancy. The proANP correlated with the thoracic fluid content reflecting volume load in pregnancy.

Managing Heart Disease in Pregnancy

Cardiac disease is an important cause of mortality in pregnancy. It has the potential to remain undiagnosed and may present with cardiovascular decompensation during pregnancy, at the time of delivery, or immediately postpartum. It can have long-term implications to the life of the affected women and their families. This review summarises the current knowledge of the incidence, prevalence, and management of pregnancy-related cardiovascular disease in women presenting preconceptionally or during pregnancy.

The Use of Echocardiography and Advanced Cardiac Ultrasonography During Pregnancy

PURPOSE OF REVIEW

Pregnancy is a time of significant cardiovascular change. Echocardiography is the primary imaging modality used to assess cardiovascular anatomy and physiology during pregnancy. Both two-dimensional (2D) echocardiography and advanced cardiac ultrasound modalities play pivotal roles in identifying and monitoring these changes, especially in women with preexisting or new cardiac disease. This paper reviews the role of echocardiography and advanced cardiac ultrasound during normal pregnancy and pregnancy complicated by hypertensive disorders, valvular disorders, and cardiomyopathy. It also examines the role of echocardiography in guiding decisions about delivery.

RECENT FINDINGS

The data establishing normal echo parameters during pregnancy are inconsistent. In addition, there is limited research exploring the role of advanced cardiac ultrasound modalities, such as tissue Doppler imaging or speckle tracking echocardiography, in assessing cardiac function during pregnancy. What data there are suggest that these advanced modalities can be used to identify subclinical changes before traditional echocardiography can, and thus have clear utility in identifying early abnormal cardiac responses to pregnancy. Echocardiography is the modality of choice for imaging the heart in pregnant women. Advanced ultrasound modalities increasingly play a role in identifying abnormal adaptations to pregnancy and detecting subclinical changes. This, in turn, can help promote a healthy pregnancy for both mother and fetus.

Comparison of left ventricular systolic function by 2D speckle-tracking echocardiography between normal pregnant women and pregnant women with preeclampsia

Introduction: In light of previous studies reporting the significant effects of preeclampsia on cardiac dimensions, we sought to evaluate changes in the left ventricular (LV) systolic and diastolic functions in patients with preeclampsia with a view to investigating changes in cardiac strain.

Methods: This cross-sectional study evaluated healthy pregnant women and pregnant women suffering from preeclampsia who were referred to our hospital for routine healthcare services. LV strain was measured by 2D speckle-tracking echocardiography.

Results: Compared with the healthy group, echocardiography in the group with preeclampsia showed a significant increase in the LV end-diastolic diameter (47.43 ± 4.94 mm vs 44.84 ± 4.30 mm; P = 0.008), the LV end-systolic diameter (31.16 ± 33.3 mm vs 29.20 ± 3.75 mm; P = 0.008), and the right ventricular diameter (27.93 ± 1.71 mm vs 24.53 ± 23.3; P = 0.001). The mean global longitudinal strain was -18.69 ± 2.8 in the group with preeclampsia and -19.39 ± 3.49 in the healthy group, with the difference not constituting statistical significance (P = 0.164). The mean global circumferential strain in the groups with and without preeclampsia was -20.4 ± 12.4 and -22.68 ± 5.50, respectively, which was significantly lower in the preeclampsia group (P = 0.028).

Conclusion: The development of preeclampsia was associated with an increase in the right and left ventricular diameters, as well as a decrease in the ventricular systolic function, demonstrated by a decline in global circumferential strain.

Acute Cardiac Effects of Severe Pre-Eclampsia

BACKGROUND

Pre-eclampsia with severe features (PEC) is a pregnancy-specific syndrome characterized by severe hypertension and end-organ dysfunction, and is associated with short-term adverse cardiovascular events, including heart failure, pulmonary edema, and stroke.

OBJECTIVES

The authors aimed to characterize the short-term echocardiographic, clinical, and laboratory changes in women with PEC, focusing on right ventricular (RV) systolic pressure (RVSP) and echocardiographic-derived diastolic, systolic, and speckle tracking parameters.

METHODS

In this prospective observational study, the authors recruited 63 women with PEC and 36 pregnant control patients.

RESULTS

The PEC cohort had higher RVSP (31.0 ± 7.9 mm Hg vs. 22.5 ± 6.1 mm Hg; p < 0.001) and decreased global RV longitudinal systolic strain (RVLSS) (-19.6 ± 3.2% vs. -23.8 ± 2.9% [p < 0.0001]) when compared with the control cohort. For left-sided cardiac parameters, there were differences (p < 0.001) in mitral septal e' velocity (9.6 ± 2.4 cm/s vs. 11.6 ± 1.9 cm/s), septal E/e' ratio (10.8 ± 2.8 vs. 7.4 ± 1.6), left atrial area size (20.1 ± 3.8 cm² vs. 17.3 ± 2.9 cm²), and posterior and septal wall thickness (median [interquartile range]: 1.0 cm [0.9 to 1.1 cm] vs. 0.8 cm [0.7 to 0.9 cm], and 1.0 cm [0.8 to 1.2 cm] vs. 0.8 cm [0.7 to 0.9 cm]). Eight women (12.7%) with PEC had grade II diastolic dysfunction, and 6 women (9.5%) had peripartum pulmonary edema.

CONCLUSIONS

Women with PEC have higher RVSP, higher rates of abnormal diastolic function, decreased global RVLSS, increased left-sided chamber remodeling, and higher rates of peripartum pulmonary edema, when compared with healthy pregnant women.

Early-onset preeclampsia predisposes to preclinical diastolic left ventricular dysfunction in the fifth decade of life: An observational study

Background

Systemic inflammation, endothelial dysfunction and deficient vascularization of either uterus or myocardium are mechanistic hallmarks of early-onset preeclampsia and heart failure with preserved ejection fraction (HFpEF). HFpEF is especially prevalent in elderly women and preceded in middle age by preclinical left ventricular (LV) diastolic dysfunction.

To detect if preeclampsia predisposes to HFpEF at later age, echocardiographic indices of LV function and of LV structure and biomarkers of systemic inflammation and of endothelial dysfunction were compared in middle-aged women with a history of early-onset preeclampsia or uncomplicated pregnancy.

Methods and findings

Middle-aged women with a history of early-onset preeclampsia (n = 131) or uncomplicated pregnancy (n = 56) were prospectively recruited 9 to 16 years after pregnancy.

Women with a history of preeclampsia had higher body mass index (p = 0.006), blood pressure (p<0.001) and plasma levels of interleukin-6 (p = 0.005) and soluble intercellular adhesion molecule-1 (sICAM-1) (p = 0.014). They had thicker septal (p = 0.001) and posterior (p = 0.003) LV walls and worse diastolic LV function evident from reduced mean mitral annular lengthening velocity (E’mean; p = 0.007) and higher ratio of early diastolic mitral flow velocity (E) over E’mean (E/E’mean; p<0.001). Differences of sICAM-1, E’mean and E/E’mean remained significant after accounting for BMI and blood pressure.

Conclusions

History of preeclampsia predisposes in middle age to worse LV diastolic function, which could increase the likelihood of later HFpEF development. This predisposition derives not only from persistent cardiovascular risk but may also be caused by persistent endothelial dysfunction hindering adequate vascularization in the uterus during pregnancy and in the myocardium in middle age.

Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy

BACKGROUND

In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues.

OBJECTIVES

The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues.

METHODS

A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility.

RESULTS

The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions.

CONCLUSION

The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.

Impact of a History of Hypertension in Pregnancy on Later Diagnosis of Atrial Fibrillation

Background

Atrial fibrillation/flutter (AF) produces significant morbidity in women and is typically attributed to cardiac remodeling from multiple causes, particularly hypertension. Hypertensive pregnancy disorders (HPDs) are associated with future hypertension and adverse cardiac remodeling. We evaluated whether women with AF were more likely to have experienced a HPD compared with those without.

Methods and Results

A nested case–control study was conducted within a cohort of 7566 women who had a live or stillbirth delivery in Olmsted County, Minnesota between 1976 and 1982. AF cases were matched (1:1) to controls based on date of birth, age at first pregnancy, and parity. AF and pregnancy history were confirmed by chart review. We identified 105 AF cases: mean age 57±8 (mean±SD) years, (controls 56±8 years), 32±8 years (controls 31±8 years) after the first pregnancy. Cases were more likely to have obesity during childbearing years, and hypertension, diabetes mellitus, dyslipidemia, coronary disease, valvular disease, and heart failure at the time of AF diagnosis. Cases were more likely to have a history of HPDs, compared with controls: 28/105 (26.7%) cases versus 12/105 (11.4%) controls, odds ratio: 2.60 (95% confidence interval, 1.21–6.04). After adjustment for hypertension and obesity, the association was attenuated and no longer statistically significant; odds ratio (95% confidence interval, 2.12 (0.92–5.23).

Conclusions

Women with AF are more likely to have had a HPD, a relationship at least partially mediated by associated obesity and hypertension. Given the high morbidity of AF, studies evaluating the benefit of screening for and management of cardiovascular risk factors in women with a history of HPD should be performed.

Cardiac diastolic function after recovery from pre-eclampsia

BACKGROUND

Pre-eclampsia is associated with significant changes to the cardiovascular system during pregnancy. Eccentric and concentric remodelling of the left ventricle occurs, resulting in impaired contractility and diastolic dysfunction. It is unclear whether these structural and functional changes resolve completely after delivery.

AIMS

The objective of the study was to determine cardiac diastolic function at delivery and one year post-partum in women with severe pre-eclampsia, and to determine possible future cardiovascular risk.

METHODS

This was a descriptive study performed at Steve Biko Academic Hospital, a tertiary referral hospital in Pretoria, South Africa. Ninety-six women with severe preeclampsia and 45 normotensive women with uncomplicated pregnancies were recruited during the delivery admission. Seventy-four (77.1%) women in the pre-eclamptic group were classified as a maternal near miss. Transthoracic Doppler echocardiography was performed at delivery and one year post-partum.

RESULTS

At one year post-partum, women with pre-eclampsia had a higher diastolic blood pressure (p = 0.001) and body mass index (p = 0.02) than women in the normotensive control group. Women with early onset pre-eclampsia requiring delivery prior to 34 weeks' gestation had an increased risk of diastolic dysfunction at one year post-partum (RR 3.41, 95% CI: 1.11-10.5, p = 0.04) and this was irrespective of whether the patient had chronic hypertension or not.

CONCLUSION

Women who develop early-onset pre-eclampsia requiring delivery before 34 weeks are at a significant risk of developing cardiac diastolic dysfunction one year after delivery compared to normotensive women with a history of a low-risk pregnancy.

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.

Abnormal maternal echocardiographic findings in triplet pregnancies presenting with dyspnoea

OBJECTIVE

The objective of our study was to evaluate the prevalence of abnormal maternal echocardiographic findings in triplet pregnancies presenting with dyspnoea.

STUDY DESIGN

Between 2003 and 2013, patients' records of 96 triplet pregnancies at our department were analysed including maternal and fetal outcome, echocardiographic parameters and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. After exclusion of triplet pregnancies with fetal demise before 23 + 0 weeks, selective feticide or missing outcome data, the study population consisted of 60 triplet pregnancies. All women with dyspnoea underwent echocardiography and measurement of NT-proBNP.

RESULTS

Dyspnoea towards the end of pregnancy was observed in 13.3% (8/60) of all women with triplet pregnancies, and all of these women underwent echocardiography. The prevalence of abnormal echocardiographic findings in women with dyspnoea was 37.5% (3/8) with peripartum cardiomyopathy in one woman. Median serum NT-proBNP was significantly higher in women with abnormal echocardiographic findings compared with those without (1779 ng/ml, range 1045-6076 ng/ml vs 172 ng/ml, range 50-311 ng/ml; p < 0.001 by Mann-Whitney-U Test).

CONCLUSION

We conclude that triplet pregnancies presenting with dyspnoea show a high prevalence of abnormal echocardiographic findings. Since dyspnoea is a common sign in triplet pregnancies and is associated with a high rate of cardiac involvement, echocardiography and evaluation of maternal NT-proBNP could be considered to improve early diagnosis and perinatal management.

Novel Electrocardiographic Patterns for the Prediction of Hypertensive Disorders of Pregnancy--From Pathophysiology to Practical Implications

Hypertensive disorders of pregnancy are a major cause of poor outcome, including placental abruption, organ failure, cerebrovascular accident and disseminated intravascular coagulation. These disorders are associated with increased fetal risk of intrauterine growth restriction, intrauterine death and prematurity. Electrocardiography (ECG) recently emerged as a useful tool to evaluate cardiovascular complications during pregnancy. Specifically, left atrial abnormalities detected by standard ECG are associated with a fourfold increased risk of developing hypertensive disorders during pregnancy. The mechanisms linking left atrial abnormality on ECG with hypertensive disorders are still elusive. Several mechanisms, possibly reflected by abnormal left atrial activation on ECG, has been suggested. These include increased reactivity to angiotensin II and up-regulation of angiotensin type 1 receptors, with activation of autoantibodies targeting these receptors.

Natriuretic peptide testing in high-risk pregnancy: a preventive opportunity?

Natriuretic peptide testing has been widely utilized in the heart failure and cardiac patient population, but there is limited utilization during pregnancy. Patients with hypertensive diseases of pregnancy have been shown to experience elevation of circulating natriuretic peptide levels compared to normal pregnancies, especially in the setting of preeclampsia. Natriuretic peptide testing can be utilized in patients presenting with signs and symptoms suspicious of heart failure in order to rule out underlying cardiac causes. Meanwhile, monitoring natriuretic peptide levels in those with established heart diseases (both congenital and acquired) may facilitate careful management of cardiac status during the course of pregnancy. Further investigations in the judicious use of selected medications (particularly loop diuretics) in the setting of elevated natriuretic peptide levels are warranted.

Low baseline proBNP associated with increased risk of intraoperative hypotension during spinal anaesthesia for cesarean delivery

BACKGROUND AND OBJECTIVES

Brain natriuretic peptide (BNP) has a role in the regulation of body fluid volume and blood pressure (BP). BNP remains within a normal range during spinal anaesthesia (SA) in patients undergoing cesarean delivery. However, the effect of BNP on changes in BP during the perioperative period has not been evaluated. We aimed to investigate the effect of preoperative serum BNP on the risk of hypotension during cesarean delivery with SA.

DESIGN AND SETTINGS

Patients were randomly selected among the patient group who were attending routine clinic visits for pregnancy monitoring. All had a healthy pregnancy and no other acute or chronic disease by their obstetrician. The study design was cross-sectional.

PATIENTS AND METHODS

Patients who had uncomplicated pregnancy process and no known medical dis.ease were selected consecutively during their last outpatient clinical examination. Baseline BP was recorded before SA. Simultaneously, blood samples were drawn for routine biochemistry and BNP. BP, SaO2, and electrocardiography were monitored during surgery. Intraoperative hypotension (IOH) was defined as >=25% decrease in mean arterial pressure (MAP) at the 5th minute of SA.

RESULTS

In 41 term pregnant women, 18 of the 41 patients (43.9%) fulfilled the criteria for IOH, while 23 (56.1%) showed a decrease 13.1 (11.3%) and were classified as normotensive. Baseline BNP was significantly lower in patients with IOH compared with normotensive patients 45.7 (26.9) vs.70.2 (40.5); P=.05. Baseline BNP had no significant correlation MAP at any time point. Age, body mass index, hemoglobin, baseline MAP and heart rate were not different between patients with and without IOH.

CONCLUSION

Those findings suggest that higher baseline BNP levels might have a protective role in development of hypotension in healthy term pregnant women during SA for cesarean delivery.

Maternal plasma concentrations of sST2 and angiogenic/anti-angiogenic factors in preeclampsia

OBJECTIVES

Angiogenic/anti-angiogenic factors have emerged as one of the promising biomarkers for the prediction of preeclampsia. Since not all patients with preeclampsia can be identified by these analytes, the search for additional biomarkers continues. The soluble form of ST2 (sST2), a protein capable of binding to interleukin (IL)-33 and thus contributing to a Th1-biased immune response, has been reported to be elevated in maternal plasma of women with preeclampsia. The aims of this study were to examine: (1) differences in maternal plasma concentrations of sST2 and IL-33 between women diagnosed with preeclampsia and those having uncomplicated pregnancies; (2) the relationship between sST2, umbilical and uterine artery Doppler velocimetry, and the severity of preeclampsia; and (3) the performance of sST2 and angiogenic/anti-angiogenic factors in identifying patients with preeclampsia at the time of diagnosis.

METHODS

This cross-sectional study included women with preeclampsia (n = 106) and women with an uncomplicated pregnancy (n = 131). Plasma concentrations of sST2, IL-33, soluble vascular endothelial growth factor receptor (sVEGFR)-1, soluble endoglin (sEng) and placental growth factor (PlGF) were determined by enzyme linked immune sorbent assay. Area under the receiver operating characteristic curve (AUC) for the identification of preeclampsia was examined for each analyte.

RESULTS

(1) Patients with preeclampsia had a higher mean plasma concentrations of sST2 than those with an uncomplicated pregnancy (p < 0.0001), while no significant difference in the mean plasma concentration of IL-33 between the two groups was observed; (2) the magnitude of this difference was greater in early-onset, compared to late-onset disease, and in severe compared to mild preeclampsia; (3) sST2 plasma concentrations did not correlate with the results of uterine or umbilical artery Doppler velocimetry (p = 0.7 and p = 1, respectively) among women with preeclampsia; (4) sST2 correlated positively with plasma concentrations of sVEGFR1-1 and sEng (Spearman's Rho = 0.72 and 0.63; each p < 0.0001), and negatively with PlGF (Spearman's Rho = -0.56, p < 0.0001); and (5) while the AUC achieved by sST2 and angiogenic/anti-angiogenic factors in identifying women with preeclampsia at the time of diagnosis were non-significantly different prior to term (<37 weeks of gestation), thereafter the AUC achieved by sST2 was significantly less than that achieved by angiogenic/anti-angiogenic factors.

CONCLUSIONS

Preeclampsia is associated with increased maternal plasma concentrations of sST2. The findings that sST2 concentrations do not correlate with uterine or umbilical artery Doppler velocimetry in women with preeclampsia suggest that elevated maternal plasma sST2 concentrations in preeclampsia are not related to the increased impedance to flow in the utero-placental circulation. The performance of sST2 in identifying preeclampsia at the time of diagnosis prior to 37 weeks of gestation was comparable to that of angiogenic/anti-angiogenic factors. It remains to be elucidated if an elevation of maternal plasma sST2 concentrations in pregnancy is specific to preeclampsia.

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.

Placental ischemia and cardiovascular dysfunction in preeclampsia and beyond: making the connections

Hypertensive disorders of pregnancy continue to be a significant source of maternal and fetal morbidity and mortality, and recent evidence suggests that the incidence of preeclampsia (PE) is increasing. Recent epidemiological studies indicate that the effects of PE may persist long after pregnancy, in both the mother and the offspring, as increased incidence of cardiovascular disease. The last decade has produced new insights into the pathogenesis of PE. The initiating event in PE appears to be impaired placental perfusion and subsequent placental ischemia, which results in the elaboration of numerous factors. Factors such as soluble fms-like tyrosine kinase-1, soluble endoglin and the angiotensin II type-1 receptor autoantibodies contribute to maternal endothelial and cardiovascular dysfunction, marked by increased reactive oxygen species and decreased bioavailable VEGF, nitric oxide and prostacyclin. However, the importance of the various endothelial and humoral factors that mediate these changes during PE remain to be elucidated.

Maternal haemodynamics in pre-eclampsia compared with normal pregnancy during caesarean delivery

OBJECTIVE

To determine how pre-eclampsia modifies maternal haemodynamics during caesarean delivery.

DESIGN

Prospective study.

SETTING

Tampere University Hospital, Finland.

POPULATION

Ten pre-eclamptic parturients and ten healthy parturients with uncomplicated pregnancies scheduled for elective caesarean section under spinal anaesthesia.

METHODS

Haemodynamic parameters were assessed by whole-body impedance cardiography noninvasively.

MAIN OUTCOME MEASURES

Stroke index (SI), heart rate (HR), cardiac index (CI), systemic vascular resistance index (SVRI) and mean arterial pressure (MAP) were recorded before operation, continuously during caesarean section, during the period of dissipation of anaesthesia and on the second to fifth postpartum day.

RESULTS

Baseline haemodynamics in women with pre-eclampsia differed significantly from healthy women in higher SVRI and MAP and lower SI and CI. In women with pre-eclampsia, preload infusion increased both SI and HR, causing a significant rise in CI, while in healthy parturients, only HR rose. In both the groups, spinal blockade reduced SVRI but CI remained stable. At the moment of delivery, CI increased in both groups. In uncomplicated pregnancies, both SI and HR increased, but in women with pre-eclampsia, SI was not altered and the rise in CI was due to an increase in HR only. After the reversal of anaesthesia, haemodynamics in the control group returned to baseline values, whereas in women with pre-eclampsia, SI and CI fell to levels that were significantly lower than the levels observed before surgery.

CONCLUSIONS

In women with pre-eclampsia, inability to increase SI at the moment of delivery may suggest dysfunction of the left ventricle to adapt to volume load caused by delivery and prompts concern for the increased risk of pulmonary oedema.

Left atrial mechanical functions in pre-eclampsia

AIM

To assess the effect of short-term pressure overload on left atrial (LA) mechanical function in pre-eclampsia.

METHODS

Twenty women with pre-eclampsia and 17 age-matched healthy pregnant women were included. LA volumes were measured echocardiographically at the time of mitral valve opening (Vmax), onset of atrial systole (p-wave at the electrocardiography = Vp) and mitral valve closure (Vmin) according to the biplane area-length method.

RESULTS

The mean age, gestational age, weight and body surface area were similar in pre-eclampsia and controls. The ventricular septal and posterior wall thickness were greater in pre-eclampsia (P < 0.001). There were no significant differences in LA diameter, Vmax, Vmin, Vp, LA-passive emptying volume, LA-passive emptying fraction, LA-active emptying volume, LA-active emptying fraction, conduit volume, LA-total emptying volume and LA-total emptying fraction between the groups.

CONCLUSION

Left atrial mechanical function didn't change in pre-eclampsia. We conclude that short-lasting pressure overload is not capable of inducing changes in LA function.