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

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

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

Genetic Associations of Circulating Cardiovascular Proteins With Gestational Hypertension and Preeclampsia

Importance

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

Objective

To identify proteins in the circulation associated with HDPs.

Design, Setting, and Participants

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

Exposures

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

Main Outcomes and Measures

Gestational hypertension and preeclampsia.

Results

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

Conclusions and Relevance

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

Renin-Angiotensin-Aldosterone Profiles in Pregnant Women With Chronic Hypertension

Pregnant women with chronic hypertension are at risk for increased blood pressure and superimposed preeclampsia (SPE) in late pregnancy. Alterations in the renin-aldosterone system are a feature of normal pregnancy; however, their role in chronic hypertension with and without SPE is less clear. We performed a prospective, longitudinal trial of 108 women with chronic hypertension and measured plasma renin activity (PRA), 24-hour urine sodium, urine potassium, and urine aldosterone (Ualdo) at 12, 20, 28, and 36 weeks and postpartum. SPE developed in 34% of pregnancies. PRA was lower in women who developed SPE at weeks 28 (5.99 versus 6.22 ng/mL per hour; P<0.001) and 36 (5.71 versus 7.74 ng/mL per hour; P=0.002). Ualdo was lower in women with SPE compared with those without SPE at 28 weeks (59.6 versus 81.3 μg/d; P=0.039). Mean arterial pressure was inversely related to both PRA (r=-0.23; P<0.0001) and Ualdo (r=-0.11; P=0.029). PRA and Ualdo were positively associated with each other (r=0.5327; P<0.0001) after adjusting for urine potassium, urine sodium, serum potassium, and mean arterial pressure. PRA and Ualdo were lower in women of black race compared with other racial groups (P<0.001). Our results demonstrate that in women with chronic hypertension PRA and Ualdo increase in early pregnancy and subsequently decrease in women who develop SPE. These findings are consistent with the hypothesis that sodium retention may contribute to the elevation in blood pressure in SPE.

Changes in echocardiography and blood variables during and after development of Ballantyne syndrome

We report a pregnant woman who was monitored by echocardiography and determination of blood variables, including components of the renin-angiotensin-aldosterone system (RAAS), cardiac biomarkers and soluble fms-like tyrosine kinase-1 (sFlt-1), during and after the development of Ballantyne syndrome. Generalised maternal oedema with dyspnoea following fetal and placental hydrops necessitated a caesarean section at 33 weeks of gestation. Changes in blood variables and simultaneous echocardiography changes indicated acutely enhanced RAAS and hyperdynamic left ventricular function in response to excessive volume overload (as evidenced by brain-type natriuretic peptide level of 523 pg/mL) in the absence of increased systemic vascular resistance. Elevated sFlt-1 (15 600 pg/mL) and human chorionic gonadotrophin (404 000 IU/L) levels were also noted. The increased plasma aldosterone concentration (2070 pg/mL) may have been responsible for the increase in circulating plasma volume, and the increased sFlt-1 level was responsible for generalised maternal oedema. It remains unclear which factor(s) triggered RAAS activation.