Time-dependence of cardiac biomarker levels in newborns with congenital heart defects: Umbilical cord versus peripheral newborn blood

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.

Utility of perinatal natriuretic peptide for predicting neonatal heart failure

BACKGROUND

We evaluated the significance of perinatal plasma natriuretic peptide (NP) levels in neonates with congenital heart defects (CHDs) or arrhythmias and determined whether measurement of perinatal plasma NP levels and echocardiographic assessment in utero could predict heart failure after birth.

METHODS

The study was conducted between 2012 and 2016 to evaluate the correlation of perinatal atrial NP (ANP) and brain NP (BNP) levels at birth with the modified Ross score after birth and the cardiovascular profile (CVP) score before birth.

RESULTS

A total of 122 singletons with CHDs or arrhythmias and 27 controls were analyzed. Neonatal blood sampling was performed at a median of 0.7 h (range, 0.1-1.5) after birth. The neonatal plasma ANP and BNP levels shortly after birth were significantly higher than those in the umbilical artery (UA) plasma. The ANP and BNP levels in UA and neonatal blood were correlated with the modified Ross score. The neonatal plasma ANP and BNP levels and the modified Ross scores were inversely correlated with the CVP score in neonates with CHDs or arrhythmias. The area under the receiver operating characteristic curve of UA ANP levels for predicting neonatal heart failure was highest among those for the CVP score, perinatal plasma ANP and BNP levels, and their combinations.

CONCLUSIONS

The plasma ANP and BNP levels increased markedly shortly after birth. Assessment of the UA plasma ANP level at birth and the CVP score in utero may be utilized to predict neonatal heart failure.

Assessing SSRIs' effects on fetal cardiomyocytes utilizing placenta-fetus model

Selective serotonin reuptake inhibitors (SSRIs) have been shown to hinder cardiomyocyte signaling, raising concerns about their safety during pregnancy. Approaches to assess SSRI-induced effects on fetal cardiovascular cells following passage of drugs through the placental barrier in vitro have only recently become available. Herein, we report that the SSRIs, fluoxetine and sertraline, lead to slowed cardiomyocyte calcium oscillations and induce increased secretion of troponin T and creatine kinase-MB with reduced secretion of NT-proBNP, three key cardiac injury biomarkers. We show the cardiomyocyte calcium handling effects are further amplified following indirect exposure through a placental barrier model. These studies are the first to investigate the effects of placental barrier co-culture with cardiomyocytes in vitro and to show cardiotoxicity of SSRIs following passage through the placental barrier. STATEMENT OF SIGNIFICANCE: Use of selective serotonin reuptake inhibitors (SSRIs), a class of antidepressants, during pregnancy continues to rise despite multiple studies showing potential for detrimental effects on the developing fetus. SSRIs are particularly thought to slow cardiovascular electrical activity, such as ion signaling, yet few, if any, methods exist to rigorously study these drug-induced effects on human pregnancy and the developing fetus. Within this study, we utilized a placenta-fetus model to evaluate these drug-induced effects on cardiomyocytes, looking the drugs' effects on calcium handling and secretion of multiple cardiac injury biomarkers. Together, with existing literature, this study provides a platform for assessing pharmacologic effects of drugs on cells mimicking the fetus and the role the placenta plays in this process.

The Utility of Brain Natriuretic Peptide in Pediatric Cardiology: A Review

OBJECTIVE

The aim of this article is to evaluate the clinical utility of brain natriuretic peptide in pediatric patients, examining the diagnostic value, management, and prognostic relevance, by critical assessment of the literature.

DATA SOURCES

In December 2015, a literature search was performed (PubMed access to MEDLINE citations; http://www.ncbi.nlm.nih.gov/PubMed/) and included these Medical Subject Headings and text terms for the key words: "brain natriuretic peptide," "amino-terminal pro-brain natriuretic peptide," "children," "neonate/s," "newborn/s," "infant/s," and "echocardiography."

STUDY SELECTION

Each article title and abstract was screened to identify relevant studies. The search strategy was limited to published studies in English language concerning brain natriuretic peptide/amino-terminal pro-brain natriuretic peptide in pediatric patients.

DATA EXTRACTION

Data on age, gender, type of clinical condition, brain natriuretic peptide assay method, cardiac function variables evaluated by echocardiography, and prognosis were extracted.

DATA SYNTHESIS

Brain natriuretic peptide reference values in healthy newborns, infants, and children are presented. Brain natriuretic peptide diagnostic accuracy in newborns, infants, and children suspected to have congenital heart defects is discussed, and brain natriuretic peptide prognostic value reviewed. The data suggest that the determination of brain natriuretic peptide levels improves the diagnostic accuracy in the assessment of heart disease in the pediatric population. Brain natriuretic peptide assay may increase the accuracy of neonatal screening programs for diagnosing congenital heart defects. Echocardiographic variables correlated to brain natriuretic peptide levels. Additionally, brain natriuretic peptide levels predicted adverse outcomes in the postoperative period.

CONCLUSIONS

Brain natriuretic peptide assessment is a reliable test to diagnose significant structural or functional cardiovascular disease in children. In the integrated follow-up of these cases, several physiologic and clinical variables must be considered; brain natriuretic peptide may be an additional helpful marker. Nevertheless, larger prospective studies are warranted to elucidate the true prognostic value of brain natriuretic peptide in pediatric patients.