Cardiac Troponin T in Healthy Full-Term Infants

Jonna Karlén,Cecilia Pegelow Halvorsen,Anna-Karin Edstedt Bonamy,Håkan Eliasson,Mathias Karlsson

doi:10.1007/s00246-019-02199-9

Abstract

In this prospective cohort study of healthy full-term infants, we hypothesized that high-sensitivity cardiac troponin T (hs-cTnT) would be elevated in cord blood, compared with adult reference values, and that it would further increase over the first days of age. Cardiac troponin T has been shown to be significantly increased in healthy full-term newborns compared with adult reference values, but there is no established reference range. Most studies of cTnT in newborns have been performed before the introduction of high-sensitivity cTnT (hs-cTnT) assay. We conducted a study including 158 full-term newborns, at Stockholm South General Hospital. High-sensitivity cTnT was analyzed in umbilical cord blood and at 2–5 days of age. Median hs-cTnT (interquartile range) in cord blood was 34(26–44) ng/L; 99th percentile 88 ng/L. Median hs-cTnT at 2–5 days of age was 92(54–158) ng/L; 99th percentile 664 ng/L. We conclude that hs-cTnT is elevated in cord blood in healthy, full-term newborn infants compared with adult reference values, and that it increases significantly during the first days of life. Our findings further underline the need of caution when using hs-cTnT as a measurement of cardiac impact in newborns.

Highlights

Cardiac troponin T has been reported to be elevated in healthy full-term infants [1, 2]
The assessment was made that there was no indication to carry out any further examination on the infant sampled at day 11. In this prospective study of healthy infants, term born after planned caesarean section (CS) or a spontaneous onset of delivery, we showed that high-sensitivity Cardiac troponin T (cTnT) (hs-cTnT) was elevated already in cord blood compared with adult reference values, and that it increased further during the first 2–5 days of life
The broad range in hs-cTnT seen in our study indicates that even significantly elevated values during this time period might be considered normal

Summary

Introduction

Cardiac troponin T (cTnT) has been reported to be elevated in healthy full-term infants [1, 2]. In the neonatal intensive care unit (NICU), cTnT is most commonly used to measure. Troponin is a calcium-regulated inhibitory protein complex consisting of three subunits: troponin C, I, and T. Troponin T facilitates the contraction of myocytes and is a cardiac-specific protein expressed in four different isoforms in the human heart (cTnT 1–4) [8]. It has been shown that different isoforms are expressed differently in fetuses and adults [9]. What causes the transient rise of cTnT in newborn infants is not fully understood. One possible explanation could be the transient hypoxia related to delivery, in combination with the physiological circulatory adaptation starting

Objectives

Methods

Results

Conclusion