Bioflavonoid luteolin prevents sFlt-1 release via HIF-1α inhibition in cultured human placenta.

Preeclampsia (PE) is a serious hypertensive complication of pregnancy and is a leading cause of maternal death and major contributor to maternal and perinatal morbidity, including establishment of long-term complications. The continued prevalence of PE stresses the need for identification of novel treatments which can target prohypertensive factors implicated in the disease pathophysiology, such as soluble fms-like tyrosine kinase 1 (sFlt-1). We set out to identify novel compounds to reduce placental sFlt-1 and determine whether this occurs via hypoxia-inducible factor (HIF)-1α inhibition. We utilized a commercially available library of natural compounds to assess their ability to reduce sFlt-1 release from primary human placental cytotrophoblast cells (CTBs). Human placental explants from normotensive (NT) and preeclamptic (PE) pregnancies were treated with varying concentrations of luteolin. Protein and mRNA expression of sFlt-1 and upstream mediators were evaluated using ELISA, western blot, and real-time PCR. Of the natural compounds examined, luteolin showed the most potent inhibition of sFlt-1 release, with >95% reduction compared to vehicle-treated. Luteolin significantly inhibited sFlt-1 in cultured placental explants compared to vehicle-treated in a dose- and time-dependent manner. Additionally, significant decreases in HIF-1α expression were observed in luteolin-treated explants, suggesting a mechanism for sFlt-1 downregulation. The ability of luteolin to inhibit HIF-1α may be mediated through the Akt pathway, as inhibitors to Akt and its upstream regulator phosphatidylinositol-3 kinase (PI3K) resulted in significant HIF-1α reduction. Luteolin reduces anti-angiogenic sFlt-1 through inhibition of HIF-1α, making it a novel candidate for the treatment of PE.

Real-world evidence for the utility of serum soluble fms-like tyrosine kinase 1/placental growth factor test for routine clinical evaluation of hospitalized women with hypertensive disorders of pregnancy.

BACKGROUND: An imbalance of the antiangiogenic factor, soluble fms-like tyrosine kinase-1, and proangiogenic factor, placental growth factor, in the circulation is a reliable predictor for the development of preeclampsia with severe features and related adverse outcomes. In 2023, the US Food and Drug Administration approved a serum soluble fms-like tyrosine kinase-1/placental growth factor test at a cutoff of 40 to aid in the risk assessment of women hospitalized for hypertensive disorders of pregnancy for the progression to preeclampsia with severe features between 23 and 35 weeks. OBJECTIVE: This study aimed to generate real-world evidence for clinical utility for serum soluble fms-like tyrosine kinase-1/placental growth factor test when made available to clinicians in a timely fashion as an aid in risk stratification of development of preeclampsia with severe features within 2 weeks of testing among hospitalized patients with hypertensive disorders of pregnancy. STUDY DESIGN: Hospitalized patients with hypertensive disorders of pregnancy between 23 weeks to 34 weeks and 6 days of gestation were prospectively studied from June 2023 to January 2024 after the implementation of serum soluble fms-like tyrosine kinase-1/placental growth factor testing into routine clinical practice. Serum samples were obtained from patients via venipuncture and analyzed on an automated immunoassay platform (placental growth factor and soluble fms-like tyrosine kinase-1 assays; Thermo Fisher Scientific). Before implementation, physicians were educated on appropriate use and management guidelines on the basis of biomarkers but made pragmatic management decisions independently. Results of soluble fms-like tyrosine kinase-1/placental growth factor tests were available to clinicians within 24 hours of venipuncture. The association between soluble fms-like tyrosine kinase-1/placental growth factor ≥40 and progression to preeclampsia with severe features and adverse maternal/perinatal outcomes were assessed. RESULTS: Of the 65 patient encounters, 36 had a soluble fms-like tyrosine kinase-1/placental growth factor <40 (55.4%). The rate of delivery for indications related to hypertensive disorders of pregnancy within 2 weeks was significantly lower among encounters with a low ratio vs high ratio (2/36 [5.6%] vs 21/29 [72.4%]) even after controlling for relevant confounders (adjusted hazard ratio, 7.52; 95% confidence interval, 3.05-18.54; P<.001). A diagnosis of preeclampsia with severe features within 2 weeks of testing was also less likely among the encounters with soluble fms-like tyrosine kinase-1/placental growth factor ratio <40 when compared with soluble fms-like tyrosine kinase-1/placental growth factor ratio ≥40 (2/36 [5.6%] vs 23/29 [79.3%], P<.001; positive predictive value of 79% [95% confidence interval, 0.65-0.94] and negative predictive value of 0.94 [95% confidence interval, 0.87-1.00]). The positive and negative likelihood ratios for the development of preeclampsia with severe features within 2 weeks of testing were 6.13 and 0.09, respectively. Encounters with a soluble fms-like tyrosine kinase-1/placental growth factor ratio <40 were less likely to experience a maternal or fetal adverse event as compared with encounters with soluble fms-like tyrosine kinase-1/placental growth factor ratio ≥40 (3/36 [8.3%] vs 10/29 [34.5%], P=.01). Among 36 encounters involving low soluble fms-like tyrosine kinase-1/placental growth factor values, 22 had had equivocal clinical or laboratory criteria resembling preeclampsia at presentation but were expectantly managed on the basis of biomarkers, and none developed preeclampsia with severe features or adverse outcomes at 2 weeks. The median latency defined as days between biomarker measurement and delivery in patients with a low biomarker ratio was 33 (interquartile ratio, 23-47) vs 7 (interquartile ratio, 4-14) days among patients with a high ratio (P<.001). Corticosteroid use within 2 weeks was also significantly reduced in the low biomarker group when compared with the high biomarker group (8/35 [22.9%] vs 24/29 [82.8%], P<.001). CONCLUSION: In this study, the incorporation of soluble fms-like tyrosine kinase-1/placental growth factor ratio into clinical practice serves as a dependable supplement in assessing risk for progression to preeclampsia with severe features and adverse outcomes in patients with hypertensive disorders of pregnancy in the United States. Among patients with a low ratio, pregnancy may be prolonged, which results in better neonatal outcomes without harm to the mother.

Plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio of 11.5 multiples of median predicts preeclampsia with severe features within 2 weeks of testing.

BACKGROUND: Angiogenic imbalances, characterized by an excess of antiangiogenic factors (soluble fms-like tyrosine kinase 1) and reduced angiogenic factors (vascular endothelial growth factor and placental growth factor), contribute to the mechanisms of disease in preeclampsia. The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor has been used as a biomarker for preeclampsia, but the cutoff values may vary with gestational age and assay platform. OBJECTIVE: This study aimed to compare multiples of the median of the maternal plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio, soluble fms-like tyrosine kinase 1, placental growth factor, and conventional clinical and laboratory values in their ability to predict preeclampsia with severe features. STUDY DESIGN: We conducted a cohort study across 18 United States centers involving hospitalized individuals with hypertension between 23 and 35 weeks' gestation. Receiver operating characteristic curve analyses of maternal plasma biomarkers, highest systolic or diastolic blood pressures, and laboratory values at enrollment were performed for the prediction of preeclampsia with severe features. The areas under the curve were compared, and quasi-Poisson regression models were fitted to estimate relative risks. The primary outcome was preeclampsia with severe features within 2 weeks of enrollment. Secondary outcomes were a composite of severe adverse maternal outcomes (elevated liver enzymes, low platelets count, placental abruption, eclampsia, disseminated intravascular coagulation, and pulmonary edema) and a composite of severe adverse perinatal outcomes (birth weight below the third percentile, very preterm birth [<32 weeks' gestation], and fetal or neonatal death). RESULTS: Of the 543 individuals included in the study, preeclampsia with severe features within 2 weeks was observed in 33.1% (n=180) of them. A receiver operating characteristic curve-derived cutoff of 11.5 multiples of the median for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio provided good sensitivity (90.6%), specificity (76.9%), positive predictive value (66.0%), negative predictive value (94.3%), positive likelihood ratio (3.91), negative likelihood ratio (0.12), and accuracy (81.4%) for preeclampsia with severe features within 2 weeks. This cutoff was used to compare test positive cases (≥ cutoff) and test negative cases (< cutoff). Preeclampsia with severe features (66.0% vs 5.7%; P<.001) and composites of severe adverse maternal (8.11% vs 2.7%; P=.006) or perinatal (41.3% vs 10.14%; P=.001) outcomes within 2 weeks were more frequent in test positive cases than in test negative cases. A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the median was independently associated with preeclampsia with severe features (adjusted incidence rate ratio, 9.08; 95% confidence interval, 6.11-14.06; P<.001) and a composite of severe adverse perinatal outcomes (adjusted incidence rate ratio, 9.42; 95% confidence interval, 6.36-14.53; P<.001) but not with a composite of severe adverse maternal outcomes (adjusted incidence rate ratio, 2.20; 95% confidence interval, 0.95-5.54; P=.08). The area under the curve for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio in multiples of the median (0.91; 95% confidence interval, 0.89-0.94) for preeclampsia with severe features within 2 weeks was significantly higher (P<.001 for all comparisons) than either plasma biomarker alone or any other parameter with the exception of absolute soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio values. CONCLUSION: A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the mean among hospitalized patients with hypertension between 23 and 35 week's gestation predicts progression to preeclampsia with severe features and severe adverse perinatal outcomes within 2 weeks.

Report from a text-based blood pressure monitoring prospective cohort trial among postpartum women with hypertensive disorders of pregnancy.

BACKGROUND: Hypertensive disorders of pregnancy are a main cause of maternal morbidity and mortality in the United States and worldwide, and it is estimated that approximately 60% of maternal deaths in the United States occur during the postpartum period. The utilization of telehealth modalities such as home blood pressure monitoring has shown improvement in blood pressure control and adherence with follow up visits. Our study sought to determine if standardized education improved patient hypertension knowledge and if this when combined with home blood pressure telemonitoring increased participants' postpartum self-blood pressure monitoring and postpartum visit attendance. METHODS: This is an Institutional Review Board approved prospective cohort study conducted at the University of Mississippi Medical Center. Women with a hypertensive disorder of pregnancy who met the inclusion criteria and provided written informed consent to participate were enrolled. Participants received a baseline pre-education questionnaire designed to assess their knowledge of their hypertensive diagnosis, hypertension management, and postpartum preeclampsia (PreE). Participants then received standard education, a blood pressure monitor, and were scheduled a follow-up visit during the first 10 days following discharge. Remote home blood pressure monitoring was performed via text messages and voice calls for 6-weeks postpartum. At the conclusion of the study, participants repeated their original questionnaire. RESULTS: 250 women provided informed consent to participate in the study and were included in this analysis. Relative to the baseline survey, there was a significant increase (p = 0.0001) in the percentage of correct responses. There was not an association between study engagement and percentage of correct responses on end of study questionnaire (p = 0.33) or postpartum visit attendance (p = 0.69). Maternal age was found to drive study engagement, even when adjusted for community-level distress (p = 0.03) and maternal race (p = 0.0002). CONCLUSION: Implementing a standardized postpartum education session was associated with improvement in patient's knowledge. Further studies are needed with more longitudinal follow up to assess if this program would also result in improved long-term outcomes and decreased hospital readmission rates. TRIAL REGISTRATION: NCT04570124.

Patient perceptions of remote patient monitoring program for hypertensive disorders of pregnancy.

PURPOSE: The utilization of remote patient monitoring (RPM) with home blood pressure monitoring has shown improvement in blood pressure control and adherence with follow-up visits. Patient perceptions regarding its use in the obstetric population have not been widely studied. The aim of this study was to assess patients' knowledge about hypertensive disorders of pregnancy and perceptions and satisfaction of the RPM program. METHODS: Descriptive analysis of survey responses of patients with PPHTN enrolled into the RPM program for 6 weeks after delivery between October 2021 and April 2022. Surveys were automatically administered at 1-, 3-, and 6-week postpartum. Responses were further compared between Black and non-Black patient-reported race. RESULTS: 545 patients received the RPM program. Of these, 306 patients consented to data collection. At 1 week, 88% of patients that responded reported appropriately that a blood pressure greater than 160/110 is abnormal. At 3 weeks, 87.4% of patients responded reported they were "very" or "somewhat" likely to attend their postpartum follow-up visits because of RPM. At 6 weeks, 85.5% of the patients that responded were "very" or "somewhat" satisfied with the RPM program. Responses were not statistically different between races. CONCLUSIONS: Majority of postpartum patients enrolled in the RPM program had correct knowledge about hypertension. In addition, patients were highly satisfied with the RPM program and likely to attend postpartum follow-up based on responses. Further research is warranted to validate these findings and to address any barriers for patients who did not utilize the program.

The additive role of angiogenic markers for women with confirmed preeclampsia.

BACKGROUND: Hypertension complicates 2% to 8% of all pregnancies and is a leading cause of maternal and perinatal morbidity and mortality globally. Given the prognostic role that angiogenic markers play in evaluation of patients with "suspected preeclampsia," the International Society for the Study of Hypertension in Pregnancy incorporated angiogenic imbalance into the 2021 definition of preeclampsia. As women with "suspected preeclampsia" are a heterogeneous group, with some already meeting the diagnostic criteria for preeclampsia, we evaluated whether the soluble fms-like tyrosine kinase-1/placental growth factor ratio adds prognostic value among these women. OBJECTIVE: This study aimed to assess the additive value of soluble fms-like tyrosine kinase-1/placental growth factor ratio when the diagnostic criteria for preeclampsia have already been met. STUDY DESIGN: This was a secondary analysis of a prospective cohort study of patients presenting to obstetrical triage with suspected preeclampsia at ≥20+0 weeks' gestation from July 2009 to June 2012 in Boston, United States. Clinicians were masked to soluble fms-like tyrosine kinase-1/placental growth factor ratio results. Clinical records were reviewed for maternal and neonatal care and outcomes. The value of the soluble fms-like tyrosine kinase-1/placental growth factor ratio (≤38, >38, or >85) was assessed for identifying women at low or high risk of evolving into preeclampsia with severe features within 2 weeks of the triage visit, with preeclampsia with severe features being defined by the American College of Obstetricians and Gynecologists (2013 definition). Based on information in obstetrical triage, preeclampsia among triage patients was defined either by: (1) The International Society for the Study of Hypertension in Pregnancy "restrictive" criteria (ie, new-onset hypertension and proteinuria at ≥20 weeks), or (2) The International Society for the Study of Hypertension in Pregnancy "broad" maternal criteria (ie, new-onset hypertension with proteinuria or one/more relevant maternal end-organ complications). RESULTS: Of 1043 patients included, 459 presented at 20+0 to 34+6 weeks and 584 at ≥35+0 weeks. In triage, 25.8% of women with "suspected preeclampsia" already met the preeclampsia criteria based on the International Society for the Study of Hypertension in Pregnancy broad criteria and 22.0% based on the restrictive criteria. In separate multivariable analyses adjusted for gestational age, a soluble fms-like tyrosine kinase-1/placental growth factor ratio >38 was independently associated with preeclampsia with severe features within 2 weeks even after adjusting for preeclampsia diagnosis in obstetrical triage, whether that preeclampsia were defined restrictively (odds ratio, 15.62; 95% confidence interval, 8.91-27.40) or broadly (odds ratio, 14.56; 95% confidence interval, 8.30-25.56). A soluble fms-like tyrosine kinase-1/placental growth factor ratio ≤38 was good at ruling out development of preeclampsia with severe features within 2 weeks among all patients and among those meeting the restrictive or broad definitions of preeclampsia (negative likelihood ratios, ≤0.16), driven by performance of the ratio before 35 weeks (ie, negative likelihood ratio ≤0.12). A soluble fms-like tyrosine kinase-1/placental growth factor ratio >85 was good at ruling-in preeclampsia with severe features within 2 weeks among women with suspected preeclampsia, either before (positive likelihood ratio, 8.20) or after 35 weeks (positive likelihood ratio, 6.00) and fair at ruling-in preeclampsia with severe features within 2 weeks when preeclampsia had already been confirmed in patients at <35 weeks (restrictively positive likelihood ratio, 3.48, or broadly positive likelihood ratio, 3.40). CONCLUSION: Our findings support the prognostic value of the soluble fms-like tyrosine kinase-1/placental growth factor ratio among patients with confirmed preeclampsia, particularly to identify those both likely and unlikely to progress toward the development of severe features in the next 2 weeks and those who may be most appropriate for expectant and potentially outpatient care. Our findings support the incorporation of angiogenic imbalance into the definition of preeclampsia, particularly at 20-34+0 weeks.

Genetic and Phenotypic Landscape of Peripartum Cardiomyopathy.

BACKGROUND: Peripartum cardiomyopathy (PPCM) occurs in ≈1:2000 deliveries in the United States and worldwide. The genetic underpinnings of PPCM remain poorly defined. Approximately 10% of women with PPCM harbor truncating variants in TTN (TTNtvs). Whether mutations in other genes can predispose to PPCM is not known. It is also not known if the presence of TTNtvs predicts clinical presentation or outcomes. Nor is it known if the prevalence of TTNtvs differs in women with PPCM and preeclampsia, the strongest risk factor for PPCM. METHODS: Women with PPCM were retrospectively identified from several US and international academic centers, and clinical information and DNA samples were acquired. Next-generation sequencing was performed on 67 genes, including TTN, and evaluated for burden of truncating and missense variants. The impact of TTNtvs on the severity of clinical presentation, and on clinical outcomes, was evaluated. RESULTS: Four hundred sixty-nine women met inclusion criteria. Of the women with PPCM, 10.4% bore TTNtvs (odds ratio=9.4 compared with 1.2% in the reference population; Bonferroni-corrected P [P*]=1.2×10-46). We additionally identified overrepresentation of truncating variants in FLNC (odds ratio=24.8, P*=7.0×10-8), DSP (odds ratio=14.9, P*=1.0×10-8), and BAG3 (odds ratio=53.1, P*=0.02), genes not previously associated with PPCM. This profile is highly similar to that found in nonischemic dilated cardiomyopathy. Women with TTNtvs had lower left ventricular ejection fraction on presentation than did women without TTNtvs (23.5% versus 29%, P=2.5×10-4), but did not differ significantly in timing of presentation after delivery, in prevalence of preeclampsia, or in rates of clinical recovery. CONCLUSIONS: This study provides the first extensive genetic and phenotypic landscape of PPCM and demonstrates that predisposition to heart failure is an important risk factor for PPCM. The work reveals a degree of genetic similarity between PPCM and dilated cardiomyopathy, suggesting that gene-specific therapeutic approaches being developed for dilated cardiomyopathy may also apply to PPCM, and that approaches to genetic testing in PPCM should mirror those taken in dilated cardiomyopathy. Last, the clarification of genotype/phenotype associations has important implications for genetic counseling.

Angiogenic Biomarkers for Risk Stratification in Women with Preeclampsia.

BACKGROUND: Preeclampsia is a leading cause of maternal and neonatal mortality and morbidity worldwide. Diagnosis of the condition is currently limited to utilization of nonspecific signs and symptoms. However, identification of potential pathogenic biomarkers may support earlier diagnosis and ultimately improved prognosis. CONTENT: The current models of preeclampsia suggest that the disease has components of abnormal placentation, a degree of angiogenic imbalance and endothelial dysfunction. Angiogenic factors such as soluble fms-like tyrosine kinase-1 and soluble endoglin increase while placental growth factor concentrations decrease in the circulation weeks before the onset of the disease. Multiple studies have looked at the capacity of angiogenic factors for the prediction of preeclampsia and adverse pregnancy outcomes. SUMMARY: The goal of this review is to focus on the role of angiogenic factors in the pathogenesis of preeclampsia and use of angiogenic biomarkers for risk stratification, diagnosis, and prognosis of the disease.

Imbalances in circulating angiogenic factors in the pathophysiology of preeclampsia and related disorders.

Preeclampsia is a devastating medical complication of pregnancy that can lead to significant maternal and fetal morbidity and mortality. It is currently believed that there is abnormal placentation in as early as the first trimester in women destined to develop preeclampsia. Although the etiology of the abnormal placentation is being debated, numerous epidemiologic and experimental studies suggest that imbalances in circulating angiogenic factors released from the placenta are responsible for the maternal signs and symptoms of preeclampsia. In particular, circulating levels of soluble fms-like tyrosine kinase 1, an antiangiogenic factor, are markedly increased in women with preeclampsia, whereas free levels of its ligand, placental, growth factor are markedly diminished. Alterations in these angiogenic factors precede the onset of clinical signs of preeclampsia and correlate with disease severity. Recently, the availability of automated assays for the measurement of angiogenic biomarkers in the plasma, serum, and urine has helped investigators worldwide to demonstrate a key role for these factors in the clinical diagnosis and prediction of preeclampsia. Numerous studies have reported that circulating angiogenic biomarkers have a very high negative predictive value to rule out clinical disease among women with suspected preeclampsia. These blood-based biomarkers have provided a valuable tool to clinicians to accelerate the time to clinical diagnosis and minimize maternal adverse outcomes in women with preeclampsia. Angiogenic biomarkers have also been useful to elucidate the pathogenesis of related disorders of abnormal placentation such as intrauterine growth restriction, intrauterine fetal death, twin-to-twin transfusion syndrome, and fetal hydrops. In summary, the discovery and characterization of angiogenic proteins of placental origin have provided clinicians a noninvasive blood-based tool to monitor placental function and health and for early detection of disorders of placentation. Uncovering the mechanisms of altered angiogenic factors in preeclampsia and related disorders of placentation may provide insights into novel preventive and therapeutic options.

Racial Disparities in Diagnosis, Management, and Outcomes in Preeclampsia.

PURPOSE OF THE REVIEW: Racial disparities are prevalent in many aspects of obstetric care in the USA. Non-Hispanic black women have a higher prevalence of the diagnosis of hypertensive disorders of pregnancy in addition to associated morbidity and mortality. The purpose of this review is to review current data regarding racial disparities in the diagnosis and management of hypertensive disorders of pregnancy. RECENT FINDINGS: Diagnosis of hypertensive disorders of pregnancy is more common among non-Hispanic black women even after adjustment for comorbidities. Furthermore, prevalence of severe morbidity among those with hypertensive disorders of pregnancy is increased in non-Hispanic black women, including cardiovascular events related. Proposed management solutions include quality improvement initiatives, telehealth, and strategies to reduce both structural racism and implicit bias. Racial disparities exist in both diagnosis and management of hypertensive disorders of pregnancy; further innovative work is needed to reduce these disparities.

Preeclampsia: Pathophysiology, Challenges, and Perspectives

Hypertensive disorders of pregnancy-chronic hypertension, gestational hypertension, and preeclampsia-are uniquely challenging as the pathology and its therapeutic management simultaneously affect mother and fetus, sometimes putting their well-being at odds with each other. Preeclampsia, in particular, is one of the most feared complications of pregnancy. Often presenting as new-onset hypertension and proteinuria during the third trimester, preeclampsia can progress rapidly to serious complications, including death of both mother and fetus. While the cause of preeclampsia is still debated, clinical and pathological studies suggest that the placenta is central to the pathogenesis of this syndrome. In this review, we will discuss the current evidence for the role of abnormal placentation and the role of placental factors such as the antiangiogenic factor, sFLT1 (soluble fms-like tyrosine kinase 1) in the pathogenesis of the maternal syndrome of preeclampsia. We will discuss angiogenic biomarker assays for disease-risk stratification and for the development of therapeutic strategies targeting the angiogenic pathway. Finally, we will review the substantial long-term cardiovascular and metabolic risks to mothers and children associated with gestational hypertensive disorders, in particular, preterm preeclampsia, and the need for an increased focus on interventional studies during the asymptomatic phase to delay the onset of cardiovascular disease in women.

Cardiac angiogenic imbalance leads to peripartum cardiomyopathy.

Peripartum cardiomyopathy (PPCM) is an often fatal disease that affects pregnant women who are near delivery, and it occurs more frequently in women with pre-eclampsia and/or multiple gestation. The aetiology of PPCM, and why it is associated with pre-eclampsia, remain unknown. Here we show that PPCM is associated with a systemic angiogenic imbalance, accentuated by pre-eclampsia. Mice that lack cardiac PGC-1α, a powerful regulator of angiogenesis, develop profound PPCM. Importantly, the PPCM is entirely rescued by pro-angiogenic therapies. In humans, the placenta in late gestation secretes VEGF inhibitors like soluble FLT1 (sFLT1), and this is accentuated by multiple gestation and pre-eclampsia. This anti-angiogenic environment is accompanied by subclinical cardiac dysfunction, the extent of which correlates with circulating levels of sFLT1. Exogenous sFLT1 alone caused diastolic dysfunction in wild-type mice, and profound systolic dysfunction in mice lacking cardiac PGC-1α. Finally, plasma samples from women with PPCM contained abnormally high levels of sFLT1. These data indicate that PPCM is mainly a vascular disease, caused by excess anti-angiogenic signalling in the peripartum period. The data also explain how late pregnancy poses a threat to cardiac homeostasis, and why pre-eclampsia and multiple gestation are important risk factors for the development of PPCM.

Increased Perinatal Morbidity and Mortality Among Asian American and Pacific Islander Women in the United States.

BACKGROUND: Asian American/Pacific Islanders (AAPIs) are the fastest-growing racial group in the United States. Despite a higher socioeconomic status, AAPI women experience higher rates of maternal morbidity and mortality. METHODS: Using the National Inpatient Sample, we performed a retrospective cohort analysis of women who were hospitalized for delivery from 2002 to 2013. The primary outcome variable was inpatient mortality rate, and the presence of severe maternal morbidities was estimated using the Bateman Comorbidity Index, a validated tool for predicting obstetric morbidity. RESULTS: AAPI women presenting for delivery between 2003 and 2012 were older, more likely to reside in a zip code in the top quartile of annual income, be privately insured than Caucasian women, and less likely to have a higher Bateman Comorbidity Index. However, AAPI women had a higher likelihood of postpartum hemorrhage (3.4% vs 2.7%, P < .001), uterine atony, severe perineal lacerations, and severe maternal morbidities. Procedures such as transfusion, hysterectomy, and mechanical ventilation were also more common in AAPI women. Furthermore, AAPI women had a higher mortality rate that persisted despite adjustment for an apparently higher income and comorbidities (odds ratio 1.72, 95% confidence interval: 1.14-2.59, P = .01). CONCLUSIONS: Despite having a higher socioeconomic status, AAPI women had higher rates of maternal mortality during hospitalization for delivery. This increase persisted even after adjustment for factors known to affect peripartum outcomes. Further investigation is needed to better clarify the causes of racial differences in maternal morbidity and mortality.

Epidemiology and Mechanisms of De Novo and Persistent Hypertension in the Postpartum Period.

BACKGROUND: The pathophysiology of hypertension in the immediate postpartum period is unclear. METHODS AND RESULTS: We studied 988 consecutive women admitted to a tertiary medical center for cesarean section of a singleton pregnancy. The angiogenic factors soluble fms-like tyrosine kinase 1 and placental growth factor, both biomarkers associated with preeclampsia, were measured on antepartum blood samples. We then performed multivariable analyses to determine factors associated with the risk of developing postpartum hypertension. Of the 988 women, 184 women (18.6%) developed postpartum hypertension. Of the 184 women, 77 developed de novo hypertension in the postpartum period, and the remainder had a hypertensive disorder of pregnancy in the antepartum period. A higher body mass index and history of diabetes mellitus were associated with the development of postpartum hypertension. The antepartum ratio of soluble fms-like tyrosine kinase 1 to placental growth factor positively correlated with blood pressures in the postpartum period (highest postpartum systolic blood pressure [r=0.29, P<0.001] and diastolic blood pressure [r=0.28, P<0.001]). Moreover, the highest tertile of the antepartum ratio of soluble fms-like tyrosine kinase 1 to placental growth factor was independently associated with postpartum hypertension (de novo hypertensive group: odds ratio, 2.25; 95% confidence interval, 1.19-4.25; P=0.01; in the persistent hypertensive group: odds ratio, 2.61; 95% confidence interval, 1.12-6.05; P=0.02) in multivariable analysis. Women developing postpartum hypertension had longer hospitalizations than those who remained normotensive (6.5±3.5 versus 5.7±3.4 days; P<0.001). CONCLUSIONS: Hypertension in the postpartum period is relatively common and is associated with prolonged hospitalization. Women with postpartum hypertension have clinical risk factors and an antepartum plasma angiogenic profile similar to those found in women with preeclampsia. These data suggest that women with postpartum hypertension may represent a group of women with subclinical or unresolved preeclampsia.

Sequential plasma angiogenic factors levels in women with suspected preeclampsia.

BACKGROUND: Alterations in circulating angiogenic factors are associated with the diagnosis of preeclampsia and correlate with adverse perinatal outcomes during the third trimester. OBJECTIVE: Analysis of the sequential levels of plasma angiogenic factors among patients admitted for evaluation of preeclampsia. STUDY DESIGN: We performed an observational study among women with singleton pregnancies admitted to Beth Israel Deaconess Medical Center, Boston, Massachusetts, for evaluation of preeclampsia at less than 37 weeks of gestation. Plasma samples were collected on admission and daily for the first 3 days and then weekly until delivery. Doppler ultrasound was performed on admission (within 48 hours) and then weekly (within 24 hours of blood collection) to evaluate uteroplacental and umbilical blood flows. Maternal demographics, hospital course, mode of delivery, diagnosis of hypertensive disorder, adverse maternal outcomes (elevated liver function enzymes, low platelet count, pulmonary edema, cerebral hemorrhage, convulsion, acute renal insufficiency, or maternal death), and adverse fetal/neonatal outcomes (small for gestational age, abnormal umbilical artery Doppler, fetal death, and neonatal death) were recorded. Circulating angiogenic factors (soluble fms-like tyrosine kinase and placental growth factor were measured on automated platform in a single batch after delivery and in a blinded fashion. Data are presented as median (25th to 75th centile), mean, or proportions as appropriate. RESULTS: During the study period, data from 100 women were analyzed for the study, and 43 had adverse outcomes. Women with adverse outcomes had lower gestational age of delivery, higher systolic and diastolic blood pressures during hospitalization, and lower birthweight and placental weight (all P < .01). These patients had higher soluble fms-like tyrosine kinase and soluble fms-like tyrosine kinase/placental growth factor ratio on admission and continued to have an increase in levels throughout hospital course. The median (25th to 75th) soluble fms-like tyrosine kinase/placental growth factor ratio among patients with adverse outcomes was 205.9 (72.5, 453.1) versus 47.5 (9.7, 87.0) among women without adverse outcomes (P < .001). The median (25th to 75th) absolute change per day in soluble fms-like tyrosine kinase levels (pg/mL) was 491.0 pg/mL (120.3, 1587.2) among women with adverse outcomes versus 81.3 pg/mL (-177.9, 449.0) among women without adverse outcomes (P = .01). Similarly the absolute change per day for soluble fms-like tyrosine kinase/placental growth factor ratio was 15.1 (1.8, 58.1) versus 2.7 (-0.6, 8.3) between the two groups (P = .004). The mean (range) days from admission to delivery was 6 (0-35) among subjects with soluble fms-like tyrosine kinase/placental growth factor ratio ≥85 and 14 (0-39) below a ratio of 85 (P < .001). The positive predictive value for plasma soluble fms-like tyrosine kinase/placental growth factor ratio ≥85 at admission for indicated delivery within 2 weeks was 91% (83-99%). Admission plasma soluble fms-like tyrosine kinase/placental growth factor ratio positively correlated with pre-delivery uterine artery resistive index (r = 0.35; P = .004). CONCLUSION: Among women admitted for evaluation of preeclampsia, women at risk for adverse pregnancy outcomes have higher soluble fms-like tyrosine kinase/placental growth factor ratio on admission, which continued to rise until delivery. Women with high soluble fms-like tyrosine kinase/placental growth factor ratios delivered sooner than women with low soluble fms-like tyrosine kinase/placental growth factor levels. These data support the hypothesis that targeting angiogenic imbalance in preeclampsia may lead to prolongation of pregnancy.

Angiogenic factor imbalance early in pregnancy predicts adverse outcomes in patients with lupus and antiphospholipid antibodies: results of the PROMISSE study.

BACKGROUND: Over 20% of pregnancies in patients with systemic lupus erythematosus (SLE) and/or antiphospholipid antibodies (APL) result in an adverse pregnancy outcome (APO) related to abnormal placentation. The ability to identify, early in pregnancy, patients who are destined for poor outcomes would significantly impact care of this high-risk population. In nonautoimmune patients, circulating angiogenic factors are dysregulated in disorders of placentation, such as preeclampsia (PE) and fetal growth restriction. OBJECTIVE: We sought to determine whether early dysregulation of circulating angiogenic factors can predict APO in high-risk SLE and/or APL pregnancies. STUDY DESIGN: We used data and samples from the Predictors of Pregnancy Outcome: Biomarkers in APL Syndrome and SLE (PROMISSE), a multicenter prospective study that enrolled 492 pregnant women with SLE and/or APL from September 2003 through August 2013. Patients were followed through pregnancy from <12 weeks gestation. Circulating levels of soluble fms-like tyrosine kinase-1 (sFlt1), placental growth factor (PlGF), and soluble endoglin were measured monthly and subjects followed up for APO, classified as severe (PE <34 weeks, fetal/neonatal death, indicated preterm delivery <30 weeks) or moderate (PE ≥34 weeks, indicated preterm delivery 30-36 weeks, growth restriction without PE). RESULTS: Severe APOs occurred in 12% and moderate APOs in 10% of patients. By 12-15 weeks, sFlt1, PlGF, and soluble endoglin levels were markedly altered in women who developed severe APO. After adjusting for clinical risk factors, sFlt1 was the strongest predictor of severe APO among 12-15 week measures (odds ratio, 17.3 comparing highest and lowest quartiles; 95% confidence interval [CI], 3.5-84.8; positive predictive value [PPV], 61%; negative predictive value [NPV], 93%). At 16-19 weeks, the combination of sFlt1 and PlGF was most predictive of severe APO, with risk greatest for subjects with both PlGF in lowest quartile (<70.3 pg/mL) and sFlt1 in highest quartile (>1872 pg/mL; odds ratio, 31.1; 95% CI, 8.0-121.9; PPV, 58%; NPV, 95%). Severe APO rate in this high-risk subgroup was 94% (95% CI, 70-99.8%), if lupus anticoagulant or history of high blood pressure was additionally present. In contrast, among patients with both sFlt1 <1872 pg/mL and PlGF >70.3 pg/mL, rate of severe APO was only 4.6% (95% CI, 2.1-8.6%). CONCLUSION: Circulating angiogenic factors measured during early gestation have a high NPV in ruling out the development of severe adverse outcomes among patients with SLE and/or APL syndrome. Timely risk stratification of patients is important for effective clinical care and optimal allocation of health care resources.

Ouabain inhibits placental sFlt1 production by repressing HSP27-dependent HIF-1α pathway.

Up-regulation of placental soluble fms-like tyrosine kinase 1 (sFlt1) contributes to the pathogenesis of preeclampsia. To evaluate novel upstream pathways that regulate placental sFlt1 production, we screened a library of natural compounds (n=502) in human placental cell lines. Here, we report 3 compounds in the cardiac glycoside family, ouabain, gitoxigenin, and digitoxin, that inhibit placental sFlt1 production at nanomolar concentrations in vitro. We further characterized ouabain and demonstrated that it inhibits sFlt1 mRNA and protein expression in human placental cytotrophoblasts and explant cultures in a dose- and time-dependent manner. Ouabain down-regulated sFlt1 production by inhibiting hypoxia-inducible factor 1 (HIF-1α) protein expression in the placenta. Furthermore, we found that phosphorylation of heat-shock protein 27 (HSP27) was necessary for ouabain to inhibit HIF-1α translation. In a rat model of pregnancy-induced hypertension, ouabain reduced mean arterial pressure and enhanced placental HSP27 phosphorylation without any adverse effects on pups. Further studies are needed to explore the usefulness of targeting HIF-1α/HSP27 pathway in preeclampsia.