Cardiac Troponin T: A Useful Early Marker for Cardiac and Respiratory Dysfunction in Neonates

BACKGROUND: Cardiac troponin T (cTnT) has been proposed as specific biochemical marker for myocardial infarction in adults. Cardiac function in neonates could be influenced by the severity of respiratory distress and its ventilatory management. OBJECTIVES: To establish a normal range of cTnT in healthy neonates, compare troponin concentrations among healthy neonates and those in respiratory distress (sick) and detect whether any correlation occurs between severity of respiratory distress and troponin concentrations. METHODS: Concentrations of cTnT were compared between sick and healthy infants, accounting for confounding variables in a prospective investigation manner. Age at sampling, need for ventilation, duration of respiratory support, and inotropic use in addition to neonatal and maternal characteristics were assessed. RESULTS: Samples were collected from 164 neonates (116 healthy and 48 sick). The medians [interquartile ranges] of cTnT in healthy and sick infants were 0.044 [0.027-0.073]mug/l and 0.121 [0.065-0.238] microg/l, respectively, with p < 0.0001. The 99th percentile for healthy neonates was 0.244 microg/l. Comparing both groups, there were significant differences concerning gestation, birth weight, Apgar at 5 min and admission to neonatal intensive care unit. Troponin concentrations in subgroups of sick infants including hypotensive, ventilated and dead infants were higher than other infants of the same subgroup. CTnT was positively correlated to the duration of respiratory support in ventilated neonates. CONCLUSION: CTnT may prove to be a useful early marker for cardiac and respiratory dysfunction in newborns.