Cardiac troponin T as a biochemical marker of cardiac dysfunction and ductus venosus Doppler velocimetry

Fetal cardiac troponin I levels decline toward birth in sheep

Elevated cardiac troponin I (cTnI), a myocardial damage biomarker, has been reported in cord blood of neonates delivered vaginally or by cesarean section. Although the neonatal peak likely reflects the physiological adjustment to extrauterine life, a better understanding of serial prepartum changes is required to determine physiological causes of fetal cTnI release. We longitudinally sampled eight healthy lambs (20 days before spontaneous birth to 5 days postnatal), and from three fetuses receiving intravenous IGF-1. Samples were collected into heparin, and the plasma was stored at -80°C for later determination of high-sensitivity (hs) cTnI levels (BeckmanCoulter UniCel DxI Access IA; log transformed detection limit = 0.30, quantification limit = 0.78, 99th percentile = 1.78). Positive and negative control samples were drawn from an adult ewe during a terminal experiment (myocardial ischemia) and similarly assessed. hs-cTnI data were log transformed from ng/L. Log(hs-cTnI) was 1.47 ± 0.30 (means ± SD) at 20 days before birth and declined to 1.02 ± 0.65 in fetuses 12 ± 4 h before birth (P < 0.0001, R2 = 0.7869). Birth stimulated a delayed, transient peak in hs-cTnI (P = 0.0058). Newborn (43 ± 19 min postnatal) levels were 1.39 ± 0.40 (P = 0.0650 vs. fetus on day of birth) and 2.14 ± 0.63 the day after birth (P = 0.0331 vs. newborn). The second day after birth, levels declined to 1.65 ± 0.48 (P = 0.0238 vs. day 1). IGF-1 infusion increased hs-cTnI levels 25-50% over baseline (P = 0.0252, R2 = 0.9938). Baseline adult ewe log(hs-cTnI) was below the limit of detection; 3 h following coronary artery ligation, levels were 3.21. In conclusion, we newly report that fetal hs-cTnI levels decline concomitantly with reduced proliferation of cardiomyocytes toward term.NEW & NOTEWORTHY Serial blood samples were collected from catheterized, normally developing fetal and newborn lambs and high-sensitivity cardiac troponin I (hs-cTnI) levels were assessed, providing unprecedented insight into the physiological processes leading to high levels in the perinatal period. Moderately high levels of hs-cTnI found in the normally developing fetus declined toward term. An elevation to high levels peaked the day after birth, after which hs-cTnI declined again. Stimulation of fetal cardiomyocyte proliferation with IGF-1 also elevated hs-cTnI.

Biomarkers of cardiovascular disease risk in the neonatal population

The consistently high prevalence of cardiovascular disease (CVD) has urged the need for punctual and effective prevention. Extended research on this specific area has demonstrated the influence of fetal and neonatal periods on the risk of developing CVD in adulthood. Thus, the role of traditional and novel biological markers to the effective screening of CVD among the neonatal population is widely investigated. The objective of the present narrative review is to examine those neonatal biomarkers that may play a role in the development of CVD, to exhibit scientific data that appertain to their association with various perinatal conditions leading to CVD predisposition, and their potential role on prediction and prevention strategies. Multiple biomarkers, traditional and novel, have been mined across the studied literature. Adiposity, insulin resistance, altered lipid profile, inflammation, and endothelial dysfunction seem among the headliners of CVD. Even though various novel molecules have been studied, their clinical utility remains controversial. Therefore, it is quite important for the scientific community to find elements with strong predictive value and practical clinical use.

Fetal cardiovascular hemodynamics in type 1 diabetic pregnancies at near-term gestation

INTRODUCTION

Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relation between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation.

MATERIAL AND METHODS

In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34⁺² and 40⁺² gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses.

RESULTS

Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups.

CONCLUSIONS

In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation.

Neural and cardiac injury markers in fetal growth restriction and their relation to perinatal outcomes

Objective:

To compare the levels of umbilical cord blood Neuron-Specific Enolase (NSE) and troponin T and venous blood gas samples between healthy newborns and growth-retarded fetuses with impaired Doppler velocity or low APGAR scores.

Materials and Methods:

This study was a prospective cohort study. The study group comprised 26 patients with intrauterine growth restriction and pathologic Doppler symptoms, and the control group included 24 healthy fetuses. Umbilical cord blood and blood gas samples were taken from all patients. The blood samples were centrifuged and sent to a laboratory to study NSE and troponin T Perinatal outcomes were evaluated from the medical records of the newborns.

Results:

Both groups were similar in terms of demographic characteristics. Fetuses with fetal growth restriction (FGR) were born earlier and had lower APGAR scores than the study group. Chronic hypoxemic fetuses in the study group had lower cord pH and HCO₃ levels. Further, troponin T levels were higher in the study group than in the control group. There were no major differences in Doppler velocity measurements.

Conclusion:

It has been understood that cardiac and neuronal injury detection on fetuses with FGR, troponin T, and NSE are indicators that can be used. In the literature there are studies with heterogeneous paradigms using different indicators to find neuronal injury. As a result of this study, it is clear that to assess neonatal prognosis, wider-scoped and comparative studies will provide more information about the subject.

Comparison of cardiac troponin T and N-terminal pro-B-type natriuretic peptide between fetuses with hemoglobin Bart's disease and nonanemic fetuses

OBJECTIVE

The objective of this study was to compare the levels of fetal serum cardiac troponin T (cTnT), representing cardiac injury, and N-terminal pro-B-type natriuretic peptide (nt-proBNP), representing cardiac volume overload, between fetuses affected and not affected by hemoglobin (Hb) Bart's disease, as well as between anemic and nonanemic fetuses.

METHODS

One hundred fourteen pregnancies at risk for fetal Hb Bart's disease scheduled for cordocentesis at 18 to 22 weeks were recruited into the study. Fetal blood was collected to test for cTnT, nt-proBNP and Hb levels as well as Hb typing.

RESULTS

Serum nt-proBNP was significantly higher in Hb Bart's fetuses (24 cases) than in unaffected fetuses (63 cases), whereas cTnT was significantly lower in the affected group than in the unaffected group. The serum nt-proBNP levels significantly increased with the degree of fetal anemia; cTnT levels decreased in fetuses with high degree of anemia.

CONCLUSIONS

At mid-pregnancy, nt-proBNP was significantly higher in fetuses with Hb Bart's disease than in nonanemic fetuses; cTnT was significantly lower in anemic than in normal fetuses. This study suggests that cardiomegaly from fetal anemia in early gestation is not associated with fetal cardiac injury or myocardial dysfunction but presents as cardiac volume overload from a compensatory process to maintain adequate tissue oxygenation.

Fetal venous circulation in monochorionic twin pregnancies with placental insufficiency: prediction of acidemia at birth or intrauterine fetal death

OBJECTIVES

To investigate fetal venous Doppler measurements in monochorionic twin pregnancies complicated by placental insufficiency and the relationship between fetal venous flow and acidemia at birth or intrauterine fetal death.

METHODS

This was a prospective study of 18 monochorionic twin pregnancies with placental insufficiency. Inclusion criteria were monochorionic-diamniotic twin pregnancy, abnormal umbilical artery (UA) Doppler indices, intact membranes and absence of fetal congenital abnormalities. Cases of twin-to-twin transfusion syndrome were excluded. The following Doppler measurements were studied: UA pulsatility index (PI), ductus venosus PI, middle cerebral artery PI and peak systolic velocity, intra-abdominal umbilical vein (UV) time-averaged maximum velocity (TAMXV) and left portal vein (LPV) TAMXV. Doppler parameters were transformed into Z-scores (SD values from the mean) or multiples of the median according to normative references.

RESULTS

UA pH < 7.20 occurred in nine (25.0%) neonates, pH < 7.15 in four (11.1%) and intrauterine death in four (11.1%) fetuses. The UV-TAMXV and LPV-TAMXV Z-scores were significantly lower in the group with pH < 7.20 or intrauterine fetal death (-1.79 vs -1.22, P = 0.006 and -2.26 vs -1.13, P = 0.04, respectively). In cases with pH < 7.15 or intrauterine fetal death, UV pulsations were more frequent (50.0% vs 10.7%, P = 0.03) and UV-TAMXV Z-score was significantly lower (-1.89 vs -1.26, P = 0.003). Mixed effects logistic regression analysis, accounting for the paired nature of the outcomes for the two twins in each pregnancy, demonstrated that the UV-TAMXV Z-score significantly predicted UA pH at birth < 7.20 or intrauterine fetal death. The Doppler parameter that independently predicted pH < 7.15 or intrauterine fetal death was presence of pulsation in the UV.

CONCLUSION

UV Doppler parameters may predict acidemia at birth or intrauterine fetal death in monochorionic twins complicated by placental insufficiency.

Cord blood B-type natriuretic peptide levels in placental insufficiency: correlation with fetal Doppler and pH at birth

OBJECTIVE

To examine the correlation of cardiac B-type natriuretic peptide (BNP) concentrations in umbilical cord blood at birth with fetal Doppler parameters and pH at birth.

STUDY DESIGN

Prospective cross-sectional study with the following inclusion criteria: women with a singleton pregnancy, placental insufficiency characterized by increased pulsatility index (PI) of the umbilical artery (UA), intact membranes, and absence of fetal abnormalities. The exclusion criteria kept out cases of newborns with postnatal diagnosis of abnormality and cases in which the blood analysis was not performed. The Doppler parameters used were the UA PI, middle cerebral artery (MCA) PI, cerebroplacental ratio (CPR), and ductus venosus (DV) PI for veins (PIV), all converted into zeta scores. Blood samples were obtained from the umbilical cord immediately after delivery to measure the pH of the UA and the BNP.

RESULTS

Thirty-two pregnancies with placental insufficiency were included, 21 (65%) with positive diastolic flow and 11 (35%) with absent or reversed end diastolic flow in the UA. The concentration of BNP correlated significantly with the UA PI z-score (rho=0.43, P=0.016), the CPR z-score (rho=-0.35, P=0.048), the DV PIV z-score (rho=0.61, P<0.001), pH at birth (rho=-0.39, P=0.031), and gestational age (rho=-0.51, P=0.003). In the multiple regression analysis, antenatal parameters were included; the DV PIV z-score (P=0.008) was found to be an independent parameter correlating with BNP at birth. Correlation between BNP and the DV PIV z-score was borne out by the regression equation Log[BNP]=2.34+0.13*DV (F=18.8, P<0.001). Correlation between BNP and pH at birth was confirmed by the regression equation Log[BNP]=21.36-2.62*pH (F=7.69, P=0.01).

CONCLUSION

The results suggest that fetal cardiac dysfunction identified by BNP concentrations at birth correlated independently with changes in DV PIV and correlated negatively with pH values at birth.

Doppler velocimetry of the fetal middle cerebral artery and other parameters of fetal well-being in neonatal survival during pregnancies with placental insufficiency

OBJECTIVE

To study the Doppler velocimetry of the fetal middle cerebral artery in pregnancies complicated by placental insufficiency, and to verify its role in the prognosis of neonatal survival.

METHODS

This was a prospective study of 93 pregnant women with diagnosis of placental insufficiency detected before the 34(th) week of pregnancy. Placental insufficiency was characterized by abnormal umbilical artery (UA) Doppler (> 95(th) percentile). The following parameters were analyzed: umbilical artery (UA) pulsatility index (PI); middle cerebral artery (MCA) PI; brain-placenta ratio--BPR (MCA-PI/UA-PI); MCA peak systolic velocity (MCA-PSV); and PI for veins (PIV) of ductus venosus (DV). The parameters were analyzed in terms of absolute values, z-scores (standard deviations from the mean), or multiples of the median (MoM). The outcome investigated was neonatal death during the hospitalization period after birth.

RESULTS

Of the 93 pregnancies analyzed, there were 25 (26.9%) neonatal deaths. The group that died, when compared to the survival group, presented a significant association with the diagnosis of absent or reversed end-diastolic flow (88% vs. 23.6%, p<0.001), with a higher median of UA PI (2.9 vs. 1.7, p<0.001) and UA PI z-score (10.4 vs. 4.9, p<0.001); higher MCA-PSV MoM (1.4 vs. 1.1, p=0.012); lower BPR (0.4 vs. 0.7, p<0.001); higher PIV-DV (1.2 vs. 0.8, p<0.001) and DV z-score (3.6 vs. 0.6, p<0.001). In the logistic regression, the independent variables predictive of neonatal death were: gestational age at birth (OR=0.45; 95% CI: 0.3 to 0.7; p<0.001) and UA PI z-score (OR=1.14, 95% CI: 1.0 to 1.3, p=0.046).

CONCLUSION

Despite the association verified by the univariate analysis between neonatal death and the parameters of fetal cerebral Doppler velocimetry, the multivariate analysis identified prematurity and degree of insufficiency of placental circulation as independent factors related to neonatal death in pregnancies complicated by placental insufficiency.

Is meconium stained amniotic fluid related to occult myocardial injury in term low risk pregnancies?

AIM

The present study aimed to compare Troponin T (Tp T) levels of infants born with meconium stained amniotic fluid (MSAF) to those with clear amniotic fluid.

STUDY DESIGN

Case-control study

SUBJECTS

Thirty-five women who had delivery complicated by MSAF between 37 and 41weeks of gestation were defined as the study group and women with healthy uncomplicated pregnancies with clear amniotic fluid who were matched for age, parity, and gestational age were defined as the control group.

OUTCOME MEASURES

Cord blood Tp T level, gas analysis and neonatal outcomes were compared between groups.

RESULTS

Tp T levels of the study and control groups were 0.026±0.013ng/ml and 0.031±0.016ng/ml, respectively. The difference was not statistically significant (p=0.132). On the other hand, the study group had a statistically lower HCO(3) level (21.80 vs 23.60mmol/l ) and higher rate of base deficit (4.85 vs 3.25mmol/l) than the control group.

CONCLUSION

The presence of meconium during labor is not related to occult myocardial injury in low-risk term pregnancies.