Preliminary study of the effects of furosemide on blood pressure during late-onset pre-eclampsia in patients with high cardiac output

Furosemide to lower antenatal severe hypertension: a randomized placebo-controlled trial

BACKGROUND

Hypertensive disorders of pregnancy are a leading cause of perinatal morbidity, and timely treatment of severely elevated blood pressure is recommended to prevent serious sequelae. In acute hypertension marked by increased blood volume, it is unknown whether diuretics used as an adjunct to antihypertensive medications lead to more effective blood pressure control.

OBJECTIVE

This study aimed to evaluate whether the addition of intravenous furosemide to first-line antihypertensive agents reduces systolic blood pressure in acute-onset, severe antenatal hypertension with wide (≥60 mm Hg) pulse pressure.

STUDY DESIGN

In this double-blinded randomized trial, participants received 40 mg of intravenous furosemide or placebo in addition to a first-line antihypertensive agent. The primary outcome was mean systolic blood pressure during the first hour after intervention. Secondary outcomes included corresponding diastolic blood pressure; systolic blood pressure, diastolic blood pressure, and pulse pressure at 2 hours after intervention; total reduction from qualifying blood pressure; duration of blood pressure control; need for additional antihypertensive doses within 1 hour; and electrolytes and urine output. A sample size of 35 participants per group was planned to detect a 15-mm Hg difference in blood pressure.

RESULTS

Between January 2021 and March 2022, 65 individuals were randomized: 33 to furosemide and 32 to placebo. Baseline characteristics were similar between the groups. There was no difference in the primary outcome of mean 1-hour systolic blood pressure (147 [14.8] vs 152 [13.8] mm Hg; P=.200). We found a reduction in 2-hour systolic blood pressure (139 [18.5] vs 154 [18.4] mm Hg; P=.007) and a decrease in 2-hour pulse pressure (55 [12.5] vs 67 [15.1]; P=.003) in the furosemide group. Subgroup analysis according to hypertension type showed a significant reduction in 2-hour systolic blood pressure and 2-hour pulse pressure among patients with new-onset hypertension, but not among those with preexisting hypertension. Urine output was greater in the furosemide group, with no difference in electrolytes and creatinine before and after intervention.

CONCLUSION

Intravenous furosemide in conjunction with a first-line antihypertensive agent did not significantly reduce systolic blood pressure in the first hour after administration. However, both systolic blood pressure and pulse pressure at 2 hours were decreased in the furosemide group. These findings suggest that a 1-time dose of intravenous furosemide is a reasonable adjunct to achieve blood pressure control, particularly in patients in whom increased volume is suspected.

The dilemma of sodium intake in preeclampsia: beneficial or detrimental?

Preeclampsia (PE) is a disorder involving de novo development of hypertension plus end organ damage after 20 weeks of gestation. PE is considered to be a heterogeneous disease. There are 2 main types of PE: early-onset (<34 weeks of gestation), which is considered to be a placental disorder and is associated with vasoconstriction, low cardiac output, and placental hypoperfusion and organ damage due to decreased microcirculation to maternal organs; and late-onset PE, which is primarily a disorder of pregnant women with obesity, diabetes, and/or cardiovascular abnormalities. In late-onset PE, there is avid sodium reabsorption by the maternal kidneys, causing hypervolemia and increased cardiac output, along with vasodilatation causing venous congestion of organs. Although PE has been a well-known disease for a long time, it is interesting to note that there is no specific sodium (salt) intake recommendation for these patients. This may be due to the fact that studies since as far back as the 1900s have shown conflicting results, and the reasons for the inconsistent findings have not been fully explained; furthermore, the type of PE in these studies was not specifically defined. Some studies suggest that sodium restriction may be detrimental in early-onset PE, but may be feasible in late-onset PE. To explore this paradox, the current review explains the hemodynamic factors involved in these 2 types of PE, summarizes the findings of the current studies, and highlights the knowledge gaps and the research needed to determine whether increase or restriction of salt or sodium intake is beneficial in different types of PE.

The use of loop diuretics in the context of hypertensive disorders of pregnancy: a systematic review and meta-analysis

AIMS

Addressing volume expansion may improve the management of hypertension across the pregnancy continuum. We conducted a systematic review to summarize the evidence on the use of loop diuretics in the context of hypertensive disorders during pregnancy and the postpartum period.

METHODS AND RESULTS

Medline, Embase, Cochrane library, ClinicalTrials.gov, and Google Scholar were searched for original research articles published up to 29 June 2021. Of the 2801 results screened, 15 studies were included: eight randomized controlled trials, six before-after studies, and one cohort study. Based on random effects meta-analysis of before-after studies, antepartum use of loop diuretics was associated with lower DBP [mean difference -17.73 mmHg, (95% confidence intervals -34.50 to -0.96); I2 = 94%] and lower cardiac output [mean difference -0.75 l/min, (-1.11 to -0.39); I2 = 0%], with no difference in SBP, mean arterial pressure, heart rate, or total peripheral resistance. Meta-analysis of randomized controlled trials revealed that postpartum use of loop diuretics was associated with decreased need for additional antihypertensive patients [relative risk 0.69, (0.50-0.97); I2 = 14%], and an increased duration of hospitalization [mean difference 8.80 h, (4.46-13.14); I2 = 83%], with no difference in the need for antihypertensive therapy at hospital discharge, or persistent postpartum hypertension.

CONCLUSION

Antepartum use of loop diuretics lowered DBP and cardiac output, while their postpartum use reduced the need for additional antihypertensive medications. There was insufficient evidence to suggest a clear benefit. Future studies focusing on women with hypertensive pregnancy disorders who may most likely benefit from loop diuretics are required.

Preeclampsia subtypes: Clinical aspects regarding pathogenesis, signs, and management with special attention to diuretic administration

During normal pregnancy, blood volume increases by nearly two liters. Distinctively, the absence coupled with the extreme extent regarding the volume expansion, are likely accompanied with pathological conditions. Undoubtedly, preeclampsia, defined as the appearance of hypertension and organ deficiency, such as proteinuria during the second half of pregnancy, is not a homogenous disease. Clinically speaking, two main types of preeclampsia can be distinguished, in which a marked difference between them is vascular condition, and consequently, the blood volume. The "classic" preeclampsia, as a two-phase disease, described in the first, latent phase, in which, placenta development is diminished. Agents from this malperfused placenta generate a maternal disease, the second phase, in which endothelial damage leads to hypertension and organ damage due to vasoconstriction and thrombotic microangiopathy. In this hypovolemia-associated condition, decreasing platelet count, signs of hemolysis, renal and liver involvement are characteristic findings; proteinuria is marked and increasing. In the terminal phase, visible edema develops due to increasing capillary transparency, augmenting end-organ damages. "Classic" preeclampsia is a severe and quickly progressing condition with placental insufficiency and consequent fetal growth restriction and oligohydramnios. The outcome of this condition often leads to fetal hypoxia, eclampsia or placental abruption. The management is limited to a diligent prolongation of pregnancy to accomplish improved neonatal pulmonary function, careful diminishing high blood pressure, and delivery induction in due time. The other subtype, associated with relaxed vasculature and high cardiac output, is a maternal disease, in which obesity is an important risk factor since predisposes to enhanced water retention, hypertension, and a weakened endothelial dysfunction. Initially, enhanced water retention leads to lowered extremity edema, which oftentimes progresses to a generalized form and hypertension. In several cases, proteinuria appears most likely due to tissue edema. This condition already fully meets preeclampsia criteria. Laboratory alterations, including proteinuria, are modest and platelet count remains within the normal range. Fetal weight is also normal or frequently over average due to enhanced placental blood supply. It is very likely, further water retention leads to venous congestion, a parenchyma stasis, responsible for ascites, eclampsia, or placental abruption. During the management of this hypervolemia-associated preeclampsia, the administration of diuretic furosemide treatment seemingly offers promise.

Cardiovascular determinants of impaired placental function in women with cardiac dysfunction

Female heart disease has for a long time been an underrecognized problem in the field of cardiology. With an ever-growing number of these patients getting pregnant, cardiac dysfunction during pregnancy is an increasingly large medical problem. Previous work has shown that maternal heart disease may have an adverse effect on pregnancy outcome in both mother and child. The placenta forms the connection and it is postulated that cardiac dysfunction negatively affects the placenta, and consequently, neonatal outcome. Given the paucity of data in this field, more research on the influence of cardiac (mal)function on placental (mal)function is needed. The present review describes placental function in women with various types of cardiac dysfunction, thereby aiming to provide more insight into possible underlying mechanisms of placental malfunction. Organ dysfunction in patients with heart failure is for an important part based on reduced perfusion and venous congestion. This has been shown in other organs such as kidneys, liver and brain. In pregnant women with cardiac dysfunction, placental dysfunction may follow similar patterns. Moreover, other factors, such as pre-existing hypertension and chronic hypoxia may lead to further impairment of placental function, through abnormal vascular remodeling of the uterine spiral arteries. The pathophysiology of placental dysfunction in pregnant women with cardiac dysfunction may thus be multifactorial. It is therefore important to monitor closely cardiac and placental function in such high-risk pregnancies. Gaining a better understanding of the underlying pathophysiological mechanisms may have important clinical implications in terms of pregnancy counseling, monitoring and outcome.

Preeclampsia has two phenotypes which require different treatment strategies

The opinion on the mechanisms underlying the pathogenesis of preeclampsia still divides scientists and clinicians. This common complication of pregnancy has long been viewed as a disorder linked primarily to placental dysfunction, which is caused by abnormal trophoblast invasion, however, evidence from the previous two decades has triggered and supported a major shift in viewing preeclampsia as a condition that is caused by inherent maternal cardiovascular dysfunction, perhaps entirely independent of the placenta. In fact, abnormalities in the arterial and cardiac functions are evident from the early subclinical stages of preeclampsia and even before conception. Moving away from simply observing the peripheral blood pressure changes, studies on the central hemodynamics reveal two different mechanisms of cardiovascular dysfunction thought to be reflective of the early-onset and late-onset phenotypes of preeclampsia. More recent evidence identified that the underlying cardiovascular dysfunction in these phenotypes can be categorized according to the presence of coexisting fetal growth restriction instead of according to the gestational period at onset, the former being far more common at early gestational ages. The purpose of this review is to summarize the hemodynamic research observations for the two phenotypes of preeclampsia. We delineate the physiological hemodynamic changes that occur in normal pregnancy and those that are observed with the pathologic processes associated with preeclampsia. From this, we propose how the two phenotypes of preeclampsia could be managed to mitigate or redress the hemodynamic dysfunction, and we consider the implications for future research based on the current evidence. Maternal hemodynamic modifications throughout pregnancy can be recorded with simple-to-use, noninvasive devices in obstetrical settings, which require only basic training. This review includes a brief overview of the methodologies and techniques used to study hemodynamics and arterial function, specifically the noninvasive techniques that have been utilized in preeclampsia research.

High-output Cardiac Failure: A Forgotten Phenotype in Clinical Practice

INTRODUCTION

The knowledge on High-Output Cardiac Failure (HOCF) has greatly improved in the last two decades. One of the advances was the identification of a new phenotype of HOCF, characterized by the absence of ventricular dilation, already associated with liver disease, Arteriovenous Fistulas (AVF), lung disease, myelodysplastic syndromes, and obesity. However, it has been noted that any aetiology can present with one of the two phenotypes, depending on the evolution.

OBJECTIVE

The study aims to describe, through an integrative review, the physiopathology and aetiologies of HOCF and to discuss phenotypes associated with this condition.

METHODS

Revisions, guidelines, case-controls, cohort studies and clinical studies were searched in MEDLINE and LILACS, using the connectives in the "cardiac output, high" database (MeSH Terms) OR "high cardiac output" (All Fields).

DISCUSSION

Two distinct phenotypes are currently described in the HOCF, regardless of the aetiology: 1) one with enlarged cardiac chambers; and 2) with normal heart chambers. The mechanisms related to HOCF are vasodilation, arteriovenous shunts that cause increased microvascular density, Reduced Systemic Vascular Resistance (RSVR), and high metabolism. These mechanisms lead to activation of the renin-angiotensin-aldosterone system, sodium and water retention, activation of neprilysin, of the sodium-glucose-2 transporter, which promote interstitial fibrosis, ventricular remodeling and a consequent increase in cardiac output >8L/min.

CONCLUSION

Many aetiologies of HOCF have been described, and some of them are potentially curable. Prompt recognition of this condition and proper treatment may lead to better outcomes.

Proteomic identification of Placental Protein 1 (PP1), PP8, and PP22 and characterization of their placental expression in healthy pregnancies and in preeclampsia

INTRODUCTION

Placental Protein 1 (PP1), PP8, and PP22 were isolated from the placenta. Herein, we aimed to identify PP1, PP8, and PP22 proteins and their placental and trophoblastic expression patterns to reveal potential involvement in pregnancy complications.

METHODS

We analyzed PP1, PP8, and PP22 proteins with LC-MS. We compared the placental behaviors of PP1, PP8, and PP22 to the predominantly placenta-expressed PP5/TFPI-2. Placenta-specificity scores were generated from microarray data. Trophoblasts were isolated from healthy placentas and differentiated; total RNA was isolated and subjected to microarray analysis. We assigned the placentas to the following groups: preterm controls, early-onset preeclampsia, early-onset preeclampsia with HELLP syndrome, term controls, and late-onset preeclampsia. After histopathologic examination, placentas were used for tissue microarray construction, immunostaining with anti-PP1, anti-PP5, anti-PP8, or anti-PP22 antibodies, and immunoscoring.

RESULTS

PP1, PP8, and PP22 were identified as 'nicotinate-nucleotide pyrophosphorylase', 'serpin B6', and 'protein disulfide-isomerase', respectively. Genes encoding PP1, PP8, and PP22 are not predominantly placenta-expressed, in contrast with PP5. PP1, PP8, and PP22 mRNA expression levels did not increase during trophoblast differentiation, in contrast with PP5. PP1, PP8, and PP22 immunostaining were detected primarily in trophoblasts, while PP5 expression was restricted to the syncytiotrophoblast. The PP1 immunoscore was higher in late-onset preeclampsia, while the PP5 immunoscore was higher in early-onset preeclampsia.

DISCUSSION

PP1, PP8, and PP22 are expressed primarily in trophoblasts but do not have trophoblast-specific regulation or functions. The distinct dysregulation of PP1 and PP5 expression in either late-onset or early-onset preeclampsia reflects different pathophysiological pathways in these preeclampsia subsets.

Identifying key genes and drug screening for preeclampsia based on gene expression profiles

Preeclampsia (PE) is characterized by gestational hypertension and proteinuria, and is a leading cause of maternal death and perinatal morbidity globally. Although the exact cause of PE remains unclear, several studies have suggested a role for abnormal expression of multiple genes. The aim of the present study was to identify key genes and related pathways, and to screen for drugs that regulate these genes for potential PE therapy. The GSE60438 dataset was acquired from the Gene Expression Omnibus database to analyze differentially expressed genes (DEGs). By constructing a protein-protein interaction network and performing reverse transcription-quantitative PCR verification, proteasome 26S subunit, non-ATPase 14, prostaglandin E synthase 3 and ubiquinol-cytochrome c reductase core protein 2 were identified as key genes in PE. In addition, PE was found to be associated with ‘circadian rhythm’, ‘fatty acid metabolism’, ‘DNA damage response detection of DNA damage’, ‘regulation of DNA repair’ and ‘endothelial cell development’. Through connectivity map analysis of DEGs, furosemide and droperidol were suggested to be therapeutic drugs that may target the hub genes for PE treatment. Results analysis of GSEA were included in the discussion section of this article. In conclusion, the current study identified novel key genes associated with the onset of PE and potential drugs for PE treatment.

Diagnostic value of neutrophil-lymphocyte ratio in preeclampsia: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Neutrophil-lymphocyte ratio (NLR) is one of the markers of systemic inflammation. Recent studies have associated NLR with diagnosis of preeclampsia (PE). However, due to small sample sizes and different research design, the diagnostic value of NLR in PE patients is not well understood. In this study, we evaluate the potential diagnostic value of NLR in PE.

METHODS

We searched PubMed, Embase, Cochrane Library, the Chinese National Knowledge Infrastructure (CNKI) databases, Wanfang data, VIP database and China Biomedical Literature Database systematically for relevant literatures up to May 20, 2018. All analyses were conducted using Meta-DiSc1.4 and Stata 12.0 software. Sensitivity, specificity and other measures of accuracy of NLR for the diagnosis of PE were pooled. Meta-regression was performed to identify the sources of heterogeneity.

RESULTS

This meta-analysis included a total of 7 studies. The pooled sensitivity and specificity were 0.74 (95% CI 0.71-0.76) and 0.64 (95%CI 0.61-0.68), positive likelihood ratio, 2.62 (95%CI1.79-3.84); negative likelihood ratio, 0.34 (95%CI 0.24-0.48); diagnostic odds ratio, 8.44 (95%CI 4-17.78), and area under the curve was 0.82. Meta regression showed that sample size was the main source of heterogeneity. Deeks funnel plot showed that there was no statistical significance for the evaluation of publication bias (P = .16).

CONCLUSION

Current evidence suggests that the diagnostic accuracy of NLR has unsatisfactory specificity but acceptable sensitivity for diagnosis of PE. Further large-scale prospective studies are required to validate the potential applicability of using NLR alone or in combination other markers as PE diagnostic biomarker and explore potential factors that may influence the accuracy of NLR for PE diagnosis.

Preeclampsia: a gestational cardiorenal syndrome

It is generally accepted today that there are two different types of preeclampsia: an early-onset or placental type and a late-onset or maternal type. In the latent phase, the first one presents with a low output/high resistance circulation eventually leading in the late second or early third trimester to an intense and acutely aggravating systemic disorder with an important impact on maternal and neonatal mortality and morbidity; the other type presents initially as a high volume/low resistance circulation, gradually evolving to a state of circulatory decompensation usually in the later stages of pregnancy, with a less severe impact on maternal and neonatal outcome. For both processes, numerous dysfunctions of the heart, kidneys, arteries, veins and interconnecting systems are reported, most of them presenting earlier and more severely in early- than in late-onset preeclampsia; however, some very specific dysfunctions exist for either type. Experimental, clinical and epidemiological observations before, during and after pregnancy are consistent with gestation-induced worsening of subclinical pre-existing chronic cardiovascular dysfunction in early-onset preeclampsia, and thus sharing the pathophysiology of cardiorenal syndrome type II, and with acute volume overload decompensation of the maternal circulation in late-onset preeclampsia, thus sharing the pathophysiology of cardiorenal syndrome type 1. Cardiorenal syndrome type V is consistent with the process of preeclampsia superimposed upon clinical cardiovascular and/or renal disease, alone or as part of a systemic disorder. This review focuses on the specific differences in haemodynamic dysfunctions between the two types of preeclampsia, with special emphasis on the interorgan interactions between heart and kidneys, introducing the theoretical concept that the pathophysiological processes of preeclampsia can be regarded as the gestational manifestations of cardiorenal syndromes.

Maternal Venous Hemodynamic Dysfunction in Proteinuric Gestational Hypertension: Evidence and Implications

This review summarizes current knowledge from experimental and clinical studies on renal function and venous hemodynamics in normal pregnancy, in gestational hypertension (GH) and in two types of preeclampsia: placental or early-onset preeclampsia (EPE) and maternal or late-onset (LPE) preeclampsia, presenting at <34 weeks and ≥34 weeks respectively. In addition, data from maternal venous Doppler studies are summarized, showing evidence for (1) the maternal circulation functioning closer to the upper limits of capacitance than in non-pregnant conditions, with intrinsic risks for volume overload, (2) abnormal venous Doppler measurements obtainable in preeclampsia, more pronounced in EPE than LPE, however not observed in GH, and (3) abnormal venous hemodynamic function installing gradually from first to third trimester within unique pathways of general circulatory deterioration in GH, EPE and LPE. These associations have important clinical implications in terms of screening, diagnosis, prevention and management of gestational hypertensive diseases. They invite for further hypothesis-driven research on the role of retrograde venous congestion in the etiology of preeclampsia-related organ dysfunctions and their absence in GH, and also challenge the generally accepted view of abnormal placentation as the primary cause of preeclampsia. The striking similarity between abnormal maternal venous Doppler flow patterns and those observed at the ductus venosus and other abdominal veins of the intra-uterine growth restricted fetus, also invites to explore the role of venous congestion in the intra-uterine programming of some adult diseases.

Review of Cardiovascular Drugs in Pregnancy

Cardiovascular disease is now the leading cause of pregnancy-related deaths in the United States. Increasing maternal mortality in the United States underscores the importance of proper cardiovascular management. Significant physiological changes during pregnancy affect the heart's ability to respond to pathological processes such as hypertension and heart failure. These physiological changes further affect the pharmacokinetic and pharmacodynamic properties of cardiac medications. During pregnancy, these changes can significantly alter medication efficacy and metabolism. This article systematically reviews the literature on safety, efficacy, pharmacokinetics, and pharmacodynamics of cardiovascular drugs used for hypertension and heart failure during pregnancy and lactation. The 2017 American College of Cardiology/American Heart Association hypertension guidelines recommend transitioning pregnant patients to methyldopa, nifedipine, or labetalol. Heart failure medications, including beta-blockers, furosemide, and digoxin, are relatively safe and can be used effectively. Medications that block the renin angiotensin-aldosterone system have been shown to be beneficial in the general population; however, they are teratogenic and, therefore, contraindicated in pregnancy. Cardiovascular medications can also enter breast milk and, therefore, care must be taken when selecting drugs during the lactation period. A summary of the safety of drugs during pregnancy and lactation from an online resource, LactMed by the National Library of Medicine's TOXNET database, is included. High-risk pregnant patients with cardiovascular disease require a multispecialty team of doctors, including health care providers from obstetrics and gynecology, maternal fetal medicine, internal medicine, cardiovascular disease specialists, and specialized pharmacology expertise.