High-Sensitivity Cardiac Troponin I Levels in Normal and Hypertensive Pregnancy

Cardiovascular risk evaluation in pregnancy: focus on cardiac specific biomarkers

Despite the evidence demonstrating the clinical utility of cardiac specific biomarkers in improving cardiovascular risk evaluation in several clinical conditions, even the most recent reviews and guidelines fail to consider their measurement in order to enhance the accuracy of the evaluation of cardiovascular risk in pregnant women. The aim of this review article was to examine whether the assay of cardiac specific biomarkers can enhance cardiovascular risk evaluation in pregnant women, first by reviewing the relationships between the physiological state of pregnancy and cardiac specific biomarkers. The clinical relevance of brain natriuretic peptide (BNP)/NT-proBNP and high-sensitivity cardiac troponin I/high-sensitivity cardiac troponin T (hs-cTnI/hs-cTnT) assay in improving cardiovascular risk evaluation is examined based on the results of clinical studies on subjects with normal and those with complicated pregnancy. Finally, the analytical approaches and clinical objectives related to cardio specific biomarkers are advocated in order to allow an early and more accurate evaluation of cardiovascular risk in pregnant women.

Mendelian randomization supports genetic liability to hospitalization for COVID-19 as a risk factor of pre-eclampsia

Background

Pre-eclampsia and eclampsia are among the major threats to pregnant women and fetuses, but they can be mitigated by prevention and early screening. Existing observational research presents conflicting evidence regarding the causal effects of coronavirus disease 2019 (COVID-19) on pre-eclampsia risk. Through Mendelian randomization (MR), this study aims to investigate the causal effect of three COVID-19 severity phenotypes on the risk of pre-eclampsia and eclampsia to provide more rigorous evidence.

Methods

Two-sample MR was utilized to examine causal effects. Summary-level data from genome-wide association studies (GWAS) of individuals of European ancestry were acquired from the GWAS catalog and FinnGen databases. Single-nucleotide polymorphisms associated with COVID-19 traits at p < 5 × -8 were obtained and pruned for linkage disequilibrium to generate instrumental variables for COVID-19. Inverse variance weighted estimates were used as the primary MR results, with weighted median and MR-Egger as auxiliary analyses. The robustness of the MR findings was also evaluated through sensitivity analyses. Bonferroni correction was applied to primary results, with a p < 0.0083 considered significant evidence and a p within 0.083-0.05 considered suggestive evidence.

Results

Critical ill COVID-19 [defined as hospitalization for COVID-19 with either a death outcome or respiratory support, OR (95% CI): 1.17 (1.03-1.33), p = 0.020] and hospitalized COVID-19 [defined as hospitalization for COVID-19, OR (95% CI): 1.10 (1.01-1.19), p = 0.026] demonstrated suggestive causal effects on pre-eclampsia, while general severe acute respiratory syndrome coronavirus 2 infection did not exhibit a significant causal effect on pre-eclampsia. None of the three COVID-19 severity phenotypes exhibited a significant causal effect on eclampsia.

Conclusions

Our investigation demonstrates a suggestive causal effect of genetic susceptibility to critical ill COVID-19 and hospitalized COVID-19 on pre-eclampsia. The COVID-19 severity exhibited a suggestive positive dose-response relationship with the risk of pre-eclampsia. Augmented attention should be paid to pregnant women hospitalized for COVID-19, especially those needing respiratory support.

High-Sensitivity Cardiac Troponin I Enhances Preeclampsia Prediction Beyond Maternal Factors and the sFlt-1/PlGF Ratio

BACKGROUND

Preeclampsia shares numerous risk factors with cardiovascular diseases. Here, we aimed to assess the potential utility of high-sensitivity cardiac troponin I (hs-cTnI) values during pregnancy in predicting preeclampsia occurrence.

METHODS

This study measured hs-cTnI levels in 3721 blood samples of 2245 pregnant women from 4 international, prospective cohorts. Three analytical approaches were used: (1) a cross-sectional analysis of all women using a single blood sample, (2) a longitudinal analysis of hs-cTnI trajectories in women with multiple samples, and (3) analyses of prediction models incorporating hs-cTnI, maternal factors, and the sFlt-1 (soluble fms-like tyrosine kinase 1)/PlGF (placental growth factor) ratio.

RESULTS

Women with hs-cTnI levels in the upper quarter had higher odds ratios for preeclampsia occurrence compared with women with levels in the lower quarter. Associations were driven by preterm preeclampsia (odds ratio, 5.78 [95% CI, 2.73-12.26]) and remained significant when using hs-cTnI as a continuous variable adjusted for confounders. Between-trimester hs-cTnI trajectories were independent of subsequent preeclampsia occurrence. A prediction model incorporating a practical hs-cTnI level of detection cutoff (≥1.9 pg/mL) alongside maternal factors provided comparable performance with the sFlt-1/PlGF ratio. A comprehensive model including sFlt-1/PlGF, maternal factors, and hs-cTnI provided added value (cross-validated area under the receiver operator characteristic, 0.78 [95% CI, 0.73-0.82]) above the sFlt-1/PlGF ratio alone (cross-validated area under the receiver operator characteristic, 0.70 [95% CI, 0.65-0.76]; P=0.027). As assessed by likelihood ratio tests, the addition of hs-cTnI to each prediction model significantly improved the respective prediction model not incorporating hs-cTnI, particularly for preterm preeclampsia. Net reclassification improvement analyses indicated that incorporating hs-cTnI improved risk prediction predominantly by correctly reclassifying women with subsequent preeclampsia occurrence.

CONCLUSIONS

These exploratory findings uncover a potential role for hs-cTnI as a complementary biomarker in the prediction of preeclampsia. After validation in prospective studies, hs-cTnI, alongside maternal factors, may either be considered as a substitute for angiogenic biomarkers in health care systems where they are sparce or unavailable, or as an enhancement to established prediction models using angiogenic markers.

Cardiospecific Troponins as Laboratory Biomarkers of Myocardial Cell Injury in Hypertension: A Mini-Review

To date, it is well known that a significant number of diseases of cardiovascular genesis (coronary heart disease, myocardial infarction, cardiomyopathy, Takotsubo syndrome, heart failure, etc.) and extra-cardiac genesis (renal failure, chronic obstructive pulmonary disease, sepsis, diabetes mellitus, etc.) cause injury to contractile cells of the heart muscle (myocardial cells). The most sensitive and specific criteria for proving myocardial cell injury are cardiospecific troponins (CSTns) - CSTnI and CSTnT. According to the current clinical recommendations of the European, American, and Russian Cardiological Communities, CSTnI and CSTnT are the main biomarkers for early diagnosis of myocardial infarction. Hypertension is one of the most dangerous and common risk factors for the development of cardiovascular pathologies and is associated with a high risk of dangerous cardiovascular complications. Therefore, there is an urgent need to search for new biomarkers for the timely assessment of the prognosis of patients with hypertension. This mini-review aims to substantiate the possibilities of using the cardiomarkers (CSTnI and CSTnT) to assess the prognosis of patients suffering from hypertension and to discuss potential mechanisms that cause injury to myocardial cells and increase serum levels of CSTnI and CSTnT. This is a narrative mini-review, which was prepared using the following databases: Pubmed/Medline, PubMed Central, Embase, Scopus, and Web of Science. The following keywords were used in the literature search: "myocardial cells", "injury", "damage", and "hypertension" in combination with the terms "mechanisms of injury" "predictive significance", "cardiac troponins", or "cardiospecific troponins".

Pericarditis Management in Individuals Contemplating Pregnancy, Currently Pregnant, or Breastfeeding

PURPOSE OF REVIEW

Pericarditis complicates pregnancy planning, pregnancy, or the postpartum period, and the management approach requires special considerations. Here, we aim to summarize the latest research, diagnostic, and treatment strategies.

RECENT FINDINGS

Physiologic cardiovascular (CV) adaptations occurring during pregnancy complicate diagnosis, but for most patients, an electrocardiogram (ECG) and transthoracic echocardiogram (TTE) are sufficient to diagnosis pericarditis in the appropriate clinical context. Aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) can be used until 20 weeks gestation as needed. The use of colchicine is encouraged at any time point to reduce the risk of recurrence. Glucocorticoids may be used at the lowest possible dose for the least amount of time throughout pregnancy and breastfeeding. For incessant, recurrent, or refractory pericarditis, or when the above therapies are contraindicated, there may be a consideration of the use of IL-1 inhibition during pregnancy, recognizing the limited data in pregnant patients. Finally, we encourage the use of a multidisciplinary team approach including OB-GYN, cardiology, and rheumatology when available. The diagnosis and treatment of pericarditis in female patients of reproductive age require special considerations. Although highly effective treatment options are available, there is a need for greater data and larger international registries to improve treatment recommendations.

SARS-CoV-2 Infection and Preeclampsia-How an Infection Can Help Us to Know More about an Obstetric Condition

Pregnant women with SARS-CoV-2 infection have a significantly higher risk of maternal death, ICU admission, preterm delivery, and stillbirth compared to those without infection. Additionally, the risk of preeclampsia (PE) increases in pregnant women infected with SARS-CoV-2, particularly in severe cases. The association between COVID-19 and PE is likely attributed to various mechanisms, including direct effects of the virus on trophoblast function and the arterial wall, exaggerated inflammatory response in pregnant women, local inflammation leading to placental ischemia, SARS-CoV-2-related myocardial injury, cytokine storm, and thrombotic microangiopathy. This paper aims to explore the similarities between PE and SARS-CoV-2 infection, considering COVID-19 as a valuable study model. By examining these parallels, we can enhance our knowledge and comprehension of PE. We wish to emphasize the potential for COVID-19-induced myocardial injury in pregnant women and its connection to the increased maternal mortality rate.

Impact of Angiogenic and Cardiovascular Biomarkers for Prediction of Placental Dysfunction in the First Trimester of Pregnancy

Algorithms for first-trimester prediction of pre-eclampsia usually include maternal risk factors, blood pressure, placental growth factor (PlGF), and uterine artery Doppler pulsatility index. However, these models lack sensitivity for the prediction of late-onset pre-eclampsia and other placental complications of pregnancy, such as small for gestational age infants or preterm birth. The aim of this study was to assess the screening performance of PlGF, soluble fms-like tyrosine kinase-1 (sFlt-1), N-terminal pro-brain natriuretic peptide (NT-proBNP), uric acid, and high-sensitivity cardiac troponin T (hs-TnT) in the prediction of adverse obstetric outcomes related to placental insufficiency. This retrospective case-control study was based on a cohort of 1390 pregnant women, among which 210 presented pre-eclampsia, small for gestational age infants, or preterm birth. Two hundred and eight women with healthy pregnancies were selected as controls. Serum samples were collected between weeks 9 and 13 of gestation, and maternal serum concentrations of PlGF, sFlt-1, NT-proBNP, uric acid, and hs-TnT were measured. Multivariate regression analysis was used to generate predictive models combining maternal factors with the above-mentioned biomarkers. Women with placental dysfunction had lower median concentrations of PlGF (25.77 vs. 32.00 pg/mL; p < 0.001), sFlt-1 (1212.0 vs. 1363.5 pg/mL; p = 0.001), and NT-proBNP (51.22 vs. 68.71 ng/L; p < 0.001) and higher levels of uric acid (193.66 µmol/L vs. 177.40 µmol/L; p = 0.001). There was no significant difference between groups regarding the sFlt-1/PlGF ratio. Hs-TnT was not detected in 70% of the maternal serums analyzed. Altered biomarker concentrations increased the risk of the analyzed complications both in univariate and multivariate analyses. The addition of PlGF, sFlt-1, and NT-proBNP to maternal variables improved the prediction of pre-eclampsia, small for gestational age infants, and preterm birth (area under the curve: 0.710, 0.697, 0.727, and 0.697 vs. 0.668, respectively). Reclassification improvement was greater in maternal factors plus the PlGF model and maternal factors plus the NT-p roBNP model (net reclassification index, NRI: 42.2% and 53.5%, respectively). PlGF, sFlt-1, NT-proBNP, and uric acid measurements in the first trimester of pregnancy, combined with maternal factors, can improve the prediction of adverse perinatal outcomes related to placental dysfunction. In addition to PlGF, uric acid and NT-proBNP are two promising predictive biomarkers for placental dysfunction in the first trimester of pregnancy.

First Trimester Cardiac Biomarkers among Women with Peripartum Cardiomyopathy: Are There Early Clues to This Late-Pregnancy Phenomenon?

OBJECTIVE

Whether biomarkers may enable early identification of women who develop peripartum cardiomyopathy (PPCM) prior to disease onset remains a question of interest.

STUDY DESIGN

A retrospective nested case-control study was conducted to determine whether first trimester N-terminal pro-B type natriuretic peptide (NT-proBNP) or high sensitivity cardiac troponin I (hs-cTnI) differed among women who developed PPCM versus unaffected pregnancies. Cases were matched to unaffected women by age, race, parity, and gestational age of sample (control A) and then further by blood pressure and pregnancy weight gain (control B).

RESULTS

First trimester NT-proBNP concentrations were numerically higher among women who subsequently developed PPCM (116 pg/mL [83-177]) as compared with women in control A (56.1 pg/mL [38.7-118.7], p = 0.3) or control B (37.6 [23.3 - 53.8], p <0.05). A higher proportion of women who subsequently developed PPCM (50%) had detectable levels of hs-cTnI as compared with control A (0%, p = 0.03) or control B (18.8%, p = 0.52). Among both cases and controls, hs-cTnI values were low and often below the limit of detection.

CONCLUSION

There were differences in first trimester NT-proBNP and hs-cTnI concentrations between women who subsequently developed PPCM and those who did not, raising the possibility the early pregnancy subclinical myocardial dysfunction may be associated with this late-pregnancy disease.

KEY POINTS

· First trimester NT-proBNP is numerically higher among women who subsequently develop PPCM.. · First trimester hs-cTnI was nominally higher among women who developed PPCM versus those who did not.. · A significant proportion of normal pregnant women have undetectable hs-cTnI..

Hypertension as One of the Main Non-Myocardial Infarction-Related Causes of Increased Cardiospecific Troponins: From Mechanisms to Significance in Current Medical Practice

It is well known that many pathological conditions of both cardiovascular diseases (CVDs) (coronary heart disease, myocardial infarction, arrhythmias, myocarditis, cardiomyopathy, etc.) and non-cardiac (sepsis, anemia, kidney diseases, diabetes mellitus, etc.) origin in the course of their development cause injury to contractile cardiac muscle cells - myocardial cells (MCs). One of the most sensitive and specific criteria for detecting MC injury are cardiospecific troponins (CTs), which are regulatory protein molecules that are released into the blood serum from MC upon their death or injury. Current methods for determining CTs are called high-sensitive ones, and their main advantage is a very low minimum detectable concentration (limit of detection) (average 1 - 10 ng/L or less), which allows early detection of minor MC injury at the earliest stages of CVDs, and therefore they can change the understanding of disease development mechanisms and open up new diagnostic possibilities. One of the most common and dangerous early diseases of the cardiovascular system is hypertension (HT). The novelty of this article lies in the discussion of a new diagnostic direction - predicting the risk of developing CVDs and their dangerous complications in patients with HT by determining the concentration of CTs. In addition, pathophysiological mechanisms underlying MC injury and the release of CTs into the bloodstream and the elimination of CTs into the urine are proposed. This information will contribute to additional fundamental and clinical research to verify the new diagnostic possibility of using CTs in clinical practice (for the management of patients with HT).

Prognostic Value of High-Sensitivity Cardiac Troponin in Women

High-sensitivity cardiac troponin assays have become the gold standard for diagnosing acute and chronic myocardial injury. The detection of troponin levels beyond the 99th percentile is included in the fourth universal definition of myocardial infarction, specifically recommending the use of sex-specific thresholds. Measurable concentrations below the proposed diagnostic thresholds have been shown to inform prognosis in different categories of inpatients and outpatients. However, clinical investigations from the last twenty years have yielded conflicting results regarding the incremental value of using different cut-offs for men and women. While advocates of a sex-specific approach claim it may help reduce gender bias in cardiovascular medicine, particularly in acute coronary syndromes, other groups question the alleged incremental diagnostic and prognostic value of sex-specific thresholds, ultimately asserting that less is more. In the present review, we aimed to synthesize our current understanding of sex-based differences in cardiac troponin levels and to reappraise the available evidence with regard to (i) the prognostic significance of sex-specific diagnostic thresholds of high-sensitivity cardiac troponin assays compared to common cut-offs in both men and women undergoing cardiovascular disease risk assessment, and (ii) the clinical utility of high-sensitivity cardiac troponin assays for cardiovascular disease prevention in women.

Circulating cardiovascular biomarkers during and after preeclampsia: Crosstalk with placental function?

Cardiovascular disease (CVD) is the leading cause of death in women, yet sex-specific risk factors remain understudied. Preeclampsia and other adverse pregnancy outcomes imply an increased maternal cardiovascular risk. We hypothesized that cardiac troponin T (cTnT), N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) are increased in such pregnancies and correlate with markers of placental dysfunction. We also investigated these cardiovascular biomarkers 1 or 3 years postpartum. Prior to delivery, we included serum from 417 pregnant women: 55 early-onset preeclampsia (EO-PE), 63 late-onset preeclampsia (LO-PE), 30 gestational hypertension (GH) and 269 healthy controls. Postpartum, we included 341 women 1 or 3 years after delivery: 26 EO-PE, 107 LO-PE, 61 GH, and 147 healthy pregnancies. Prior to delivery, median cTnT and NT-proBNP concentrations were higher in women with EO-PE, LO-PE, or GH than in controls. Median GDF-15 was higher in EO-PE and LO-PE compared to controls. Postpartum, GDF-15 was elevated in women with previous EO-PE. Markers of placental dysfunction correlated with CVD biomarkers in pregnancy, but not postpartum. Our findings underscore the cardiovascular burden of hypertensive disorders of pregnancy and the crosstalk with placental function. The upregulation of circulating GDF-15 following early-onset preeclampsia is in line with the epidemiological excessive risk of premature CVD in this group of women. GDF-15 may be explored for targeting postpartum women with most to gain from intensified preventive follow-up for CVD.

The Utilization and Interpretation of Cardiac Biomarkers During Pregnancy: JACC: Advances Expert Panel

Cardiac biomarkers are widely used in the nonpregnant population when acute cardiovascular (CV) pathology is suspected; however, the behavior of these biomarkers in the context of pregnancy is less well understood. Pregnant individuals often have symptoms that mimic those of cardiac dysfunction, and complications of pregnancy may include CV disease. This paper will summarize our current knowledge on the use of cardiac biomarkers in pregnancy and provide suggestions on how to use these tools in clinical practice based on the available evidence. Natriuretic peptides and troponin should not be measured routinely in uncomplicated pregnancy, where values should remain low as in the nonpregnant population. In the context of pre-existing or suspected CV disease, these biomarkers retain their negative predictive value. Elevations of both natriuretic peptides and troponin may occur without clear clinical significance in the immediate postpartum period. Elevations of these markers should always prompt further investigation into possible CV pathology.

Trending Cardiac Biomarkers During Pregnancy in Women With Cardiovascular Disease

BACKGROUND

Clinical utility of cardiac biomarker testing during pregnancy in women with preexisting cardiac disease is not well known. We studied the levels and temporal trends of NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-cTnI (high-sensitivity cardiac troponin I) throughout pregnancy in women with preexisting cardiac disease and sought to assess the association between NT-proBNP and hs-cTnI and pregnancy outcomes.

METHODS

Three hundred seven pregnant women with preexisting cardiac disease were prospectively recruited. Mixed-effects linear regression analysis was used to compare the NT-proBNP and hs-cTnI levels between time periods and subgroups. Logistic regression analysis adjusted for maternal age and CARPREG II (Cardiac Disease in Pregnancy) risk score assessed the association between NT-proBNP levels and adverse events.

RESULTS

Geometric mean NT-proBNP (95% CI) was stable through pregnancy with a transient significant increase with labor and delivery (101.4 pg/mL [87.1-118.1], 90.2 pg/mL [78.5-103.6], 153.6 pg/mL [126.8-186.1], and 112.2 pg/mL [94.2-133.7] for first/second trimester, third trimester, labor/delivery and postpartum, respectively). We observed a statistically significant difference in the NT-proBNP between women with preserved versus decreased systemic ventricular function, structurally normal versus abnormal heart, modified World Health Organization class 1, 2 versus modified World Health Organization class 3, 4 and no congenital heart disease versus congenital heart disease. Compared to those without events, median (interquartile range) NT-proBNP levels were significantly higher in those who had heart failure (204 pg/mL [51-450] versus 55 pg/mL [31-97]; P=0.001) and preeclampsia (98 pg/mL [40-319] versus 55 pg/mL [31-99]; P=0.027). NT-proBNP, adjusted for age and CARPREG II risk score, was significantly associated with combined heart failure and preeclampsia (adjusted odds ratio, 2.14 [95% CI, 1.48-3.10] per log NT-proBNP increase; P<0.001). NT-proBNP <200 pg/mL had a specificity of 91% and negative predictive value of 95% in predicting combined heart failure and preeclampsia.

CONCLUSIONS

NT-proBNP remains steady over the course of pregnancy with a transient increase during labor and delivery with higher levels in subgroups of stable cardiac patients. NT-proBNP level of 200 pg/mL can be used in the diagnosis of heart failure/preeclampsia in the pregnant cardiac population.

Acute Myocardial Infarction in Pregnancy

Cardiovascular disease, and particularly ischemic heart disease, is a leading cause of maternal morbidity and mortality in high-income countries. The incidence of acute myocardial infarction (AMI) has been rising over the past two decades due to increasing maternal age and a higher prevalence of cardiovascular risk factors in the pregnant population. Causes of AMI in pregnancy are diverse and may require specific considerations for their diagnosis and management. In this narrative review, we provide an overview of physiologic changes, risk factors, and etiologies leading to AMI in pregnancy, as well as diagnostic tools, reperfusion strategies, and pharmacological treatments for this complex population. In addition, we outline considerations for labor and delivery planning and long-term follow-up of patients with AMI in pregnancy.

Interpreting High-Sensitive Troponins in Patients with Hypertension

PURPOSE OF REVIEW

As the high-sensitivity cardiac troponin (hs-cTn) becomes more broadly used, physicians must understand the strengths and limitations of using the hs-cTn in the hypertensive population.

RECENT FINDINGS

The most common cause of hs-cTn elevation is cardiac myocyte injury and death; alternate mechanisms for hs-cTn elevation in the absence of cardiac myocyte death are not clearly understood. Hs-cTn elevation has been found in significant proportions of patients with asymptomatic hypertension, in patients with acute hypertensive crisis, and has even been used to predict patients who will go on to develop hypertension. While the mechanisms remain undefined, there is evidence that elevations in hs-cTn are associated with both short- and long-term morbidity and mortality. While ongoing research further defines the relationship between hypertension and hs-cTn, the emergency medicine physician must make clinical decisions today regarding the utility of this increasingly used biomarker. Given the current evidence, clinical context must be utilized including a complete clinical picture, EKGs findings, and importantly serial hs-cTn when needed to establish whether myocardial injury or myocardial infarction is occurring.

Cardiac dysfunction and remodeling regulated by anti-angiogenic environment in patients with preeclampsia: the ANGIOCOR prospective cohort study protocol

Background

Cardiovascular diseases (CVD) are cause of increased morbidity and mortality in spite of advances for diagnosis and treatment. Changes during pregnancy affect importantly the maternal CV system. Pregnant women that develop preeclampsia (PE) have higher risk (up to 4 times) of clinical CVD in the short- and long-term. Predominance of an anti-angiogenic environment during pregnancy is known as main cause of PE, but its relationship with CV complications is still under research. We hypothesize that angiogenic factors are associated to maternal cardiac dysfunction/remodeling and that these may be detected by new cardiac biomarkers and maternal echocardiography.

Methods

Prospective cohort study of pregnant women with high-risk of PE in first trimester screening, established diagnosis of PE during gestation, and healthy pregnant women (total intended sample size n = 440). Placental biochemical and biophysical cardiovascular markers will be assessed in the first and third trimesters of pregnancy, along with maternal echocardiographic parameters. Fetal cardiac function at third trimester of pregnancy will be also evaluated and correlated with maternal variables. Maternal cardiac function assessment will be determined 12 months after delivery, and correlation with CV and PE risk variables obtained during pregnancy will be evaluated.

Discussion

The study will contribute to characterize the relationship between anti-angiogenic environment and maternal CV dysfunction/remodeling, during and after pregnancy, as well as its impact on future CVD risk in patients with PE. The ultimate goal is to improve CV health of women with high-risk or previous PE, and thus, reduce the burden of the disease.

Trial registration

NCT04162236

Physiological and metabolic adaptations in pregnancy: importance of trimester-specific reference intervals to investigate maternal health and complications

Diagnosis, prognostication, and monitoring of maternal health throughout pregnancy relies on laboratory testing, including but not limited to key markers of thyroid, hepatic, cardiac, hematology, and renal function. Dynamic physiological processes during gestation significantly influence the maternal biochemistry that supports both the mother and fetus. Resultant changes in blood biochemistry alter the expected values of common laboratory tests. However, the importance of pregnancy-specific reference intervals for laboratory test result interpretation and appropriate monitoring of maternal health and complications is underappreciated. Most clinical laboratories continue to use non-pregnant adult reference intervals for laboratory test interpretation in pregnancy. The current review summarizes and critically evaluates the available literature regarding physiological and metabolic adaptations in pregnancy and their influence on common biomarkers of health and disease. The main laboratory parameters discussed include thyroid, hepatic, metabolic, renal, hematology, inflammatory, and cardiac markers. Considering the available data, further studies are urgently needed to establish trimester-specific reference intervals in healthy pregnant women on updated analytical platforms. Without such data, the standard of clinical laboratory service in pregnancy remains compromised and affects the quality of maternal-fetal healthcare.

Cardiovascular Testing and Imaging in Pregnant Women

Cardiovascular disease is a major contributor to maternal morbidity and mortality and frequently preventable. Women with known cardiovascular disease should undergo cardiac evaluation before pregnancy. Many women with pregnancy-associated cardiac complications are not previously known to have cardiac disease. Women at high risk or who have signs or symptoms suggestive of heart failure, angina, or arrhythmias should undergo prompt evaluation. This article describes various diagnostic imaging modalities that can be used in pregnancy, including indications, strengths, and limitations.

Cardiac Biomarkers in hypertensive disorders of pregnancy

In recent years, biomarkers have taken a central place in the assessment of cardiovascular diseases – from prediction to management and prognosis. On the other hand, enough evidence exists to assume that hypertensive disorders of pregnancy share a certain connection with cardiovascular diseases – from common risk factors and underlying mechanisms to the presence of a higher risk for women for the development of a great number of cardiovascular diseases, such as arterial hypertension, coronary atherosclerosis, stroke, peripheral artery disease, venous thromboembolism, and even a higher cardiovascular mortality. The key to a better understanding of the unfavorable cardiovascular profile of women with a hypertensive disorder of pregnancy may lie in their assessment with biomarkers, typically used in the field of cardiology. In this review, we have included studies investigating the use of cardiovascular biomarkers during or after a hypertensive pregnancy, namely, natriuretic peptides, high-sensitivity cardiac troponins, growth/differentiation factor 15 (GDF15), soluble suppression of tumorigenicity-2 (sST2), and galectin-3.

Cardiac-specific troponins in uncomplicated pregnancy and pre-eclampsia: A systematic review

Background

The risk of myocardial infarction (MI) increases during pregnancy, particularly in women with pre-eclampsia. MI is diagnosed by measuring high blood levels of cardiac-specific troponin (cTn), although this may be elevated in women with pre-eclampsia without MI, which increases diagnostic uncertainty. It is unclear how much cTn is elevated in uncomplicated and complicated pregnancy, which may affect whether the existing reference intervals can be used in pregnant women. Previous reviews have not investigated high-sensitivity troponin in pregnancy, compared to older, less sensitive methods.

Methods

Electronic searches using the terms “troponin I” or “troponin T”, and “pregnancy”, “pregnancy complications” or “obstetrics”. cTn levels were extracted from studies of women with uncomplicated pregnancies or pre-eclampsia.

Results

The search identified ten studies with 1581 women. Eight studies used contemporary methods that may be too insensitive to use reliably in this clinical setting. Two studies used high-sensitivity assays, with one reporting an elevation in troponin I (TnI) in pre-eclampsia compared to uncomplicated pregnancy, and the other only examining women with pre-eclampsia.

Seven studies compared cTn between women with pre-eclampsia or uncomplicated pregnancy using any assay. Seven studies showed elevated TnI in pre-eclampsia compared to uncomplicated pregnancy or non-pregnant women. One study measured troponin T (TnT) in pregnancy but did not examine pre-eclampsia.

Conclusion

TnI appears to be elevated in pre-eclampsia, irrespective of methodology, which may reflect the role of cardiac stress in this condition. TnI may be similar in healthy pregnant and non-pregnant women, but we found no literature reporting pregnancy-specific reference intervals using high-sensitivity tests. This limits broader application of cTn in pregnancy. There is a need to define reference intervals for cTn in pregnant women, which should involve serial sampling throughout pregnancy, with careful consideration for gestational age and body mass index, which cause dynamic changes in normal maternal physiology.

Pregnancy in a healthy population: dynamics of NTproBNP and hs-cTroponin T

OBJECTIVE

To describe the intraindividual changes of heart biomarker levels during and after pregnancy and to evaluate existing cut-off levels for heart failure or myocardial ischaemia in pregnant women.

METHOD

A total of 196 healthy pregnant women were recruited from maternal outpatient clinics and included in the study. Blood samples were obtained on four occasions: at 10-12 gestational weeks (gw), 20-25 gw, after delivery and 6 months postpartum and analysed for N-terminal pro-brain natriuretic peptide (NTproBNP) and high sensitive cardiac troponin T (hs-cTNT). Echocardiography ruled out existing cardiac disease. Estimated glomerular filtration rate (eGFR) was calculated.

RESULTS

There were significant changes in NTproBNP between the measurements with the highest NTproBNP at 10-12 gw and the lowest value being at 20-25 gw, (with eGFR being the highest). Hs-cTNT was significantly higher at the peripartum measurement compared with the other measurements (p<0.05). Regardless, the 95th percentile for both biomarkers was below cut-off levels of 300 ng/L for NTproBNP and 14 ng/L for hs-cTNT. There was an association between NTproBNP above the upper limit of normal of 125 ng/L and eGFR (p=0.04) and between hs-cTNT >5.0 ng/L and time from delivery to blood sample (p=0.001) at the peripartum measurement. Both were associated with the use of oxytocin.

CONCLUSION

Existing cut-off values for ruling out heart failure (NTproBNP <300 ng/L) and myocardial ischaemia (hs-cTNT <14 ng/L) are applicable during pregnancy and after delivery. Elevated levels mandate further attention on cardiac symptoms and renal function.

Physiological Changes and Cardiovascular Investigations in Pregnancy

Profound physiological changes in the maternal cardiovascular system occur shortly after conception. These changes may impact upon the investigation of healthy and complicated pregnancies. Additionally, concerns regarding fetal exposure to ionising radiation are important considerations in maternal testing. This manuscript reviews the important physiological changes pertinent to the investigation of maternal cardiovascular disease in pregnancy.

High-sensitivity cardiac troponin I in women with a history of early-onset preeclampsia

OBJECTIVE

Preeclampsia is associated with an elevated risk of cardiovascular disease later in life. Women with a history of preeclampsia are at risk of developing hypertension as well as ischemic heart disease. Identification of women at the highest risk is important to initiate preventive strategies. We investigated whether high-sensitivity cardiac troponin I (hs-cTnI) levels are associated with a history of early-onset preeclampsia, and with hypertension in these high-risk women.

METHODS

Approximately 9-10 years after pregnancy, hs-cTnI levels were measured for 339 women of the Preeclampsia Risk Evaluation in FEMales cohort, consisting of 177 women with a history of early-onset preeclampsia and 162 women with a previous uncomplicated index pregnancy. Associations were analyzed using several statistical tests and linear regression analysis.

RESULTS

The median hs-cTnI levels (IQR) were 2.50 ng/l (2.30) in women with a history of early-onset preeclampsia and 2.35 ng/l (2.50) in women without a history of preeclampsia, P = 0.53. Among women with a history of early-onset preeclampsia, the hs-cTnI levels were higher in women who were hypertensive compared with their normotensive counterparts (medians 2.60 versus 2.30; P = 0.03). In addition, blood pressure levels increased with increasing hs-cTnI levels.

CONCLUSION

We did not find a difference in hs-cTnI levels between women with and without a history of early-onset preeclampsia. Nonetheless, hs-cTnI levels were statistically significantly higher in current hypertensive women with a history of preeclampsia compared with their normotensive counterparts. Therefore, hs-cTnI levels might improve risk prediction for women at the highest risk of cardiovascular disease.

Urinary troponin concentration as a marker of cardiac damage in pregnancies complicated with preeclampsia

Pregnant women with preeclampsia experience significant hemodynamic changes which lead to an increased myocardial workload. In response to increased demands in pregnancy, the heart muscle responds with ventricular remodeling process which involves cardiac muscle hypertrophy. Opposed to occurrence of eccentric ventricular hypertrophy in normal pregnancy, myocardial remodeling in a form of concentric hypertrophy will occur in pregnant patients with preeclampsia. Increased myocardial workload is manifested by an increased troponin release. As process of troponin degradation continue, filtration of degradation fragment through glomerular membrane occur, raising the possibility of it's detection in urine. Degradation fragments of troponin molecules are estimated to be 20 kDa with preserved immunoreactivity to high-sensitivity assays. Some of the authors suggest that serum levels of cardiac troponin I might be elevated in patients with hypertension, as well as in preeclamptic pregnant women. It is to be expected that evaluation of severity of the myocardial damage in pregnant woman with preeclampsia may be performed by measuring levels of troponin in the urine using high-sensitivity assays. Designing of urine dipstick will help to detect an early phase of myocardial involvement in preeclamptic pregnancies.

Acute myocardial infarction in pregnancy: Current diagnosis and management approaches

Acute myocardial infarction during pregnancy is a very uncommon condition; atherosclerotic coronary artery disease is by far the most common cause of an acute coronary syndrome in the general population. The causes of an acute coronary syndrome in the pregnant patient are wide and varied. This has important implications with respect to the diagnosis of the etiology and the subsequent management of the cause of the acute coronary syndrome. There are a number of diagnostic tools for the diagnosis of coronary artery disease but it is important to understand their role in pregnant patients. Spontaneous coronary artery dissection is one of the most common causes of acute coronary syndrome in pregnant patients. Understanding its pathophysiology and knowing the natural history of this condition is paramount in the management of this condition. The article also lists the various therapeutic modalities available to the clinician faced with an acute coronary syndrome in the pregnant patient. Finally, we discuss the delivery of the baby and post partum care of these complex patients.