Cardiac Troponin-T as a Marker of Myocardial Dysfunction in Term Neonates with Perinatal Asphyxia

Abstract

Objectives: To describe the diagnostic test properties of Cardiac Troponin-T (cTnT) in predicting myocardial dysfunction in asphyxiated term neonates by taking echocardiography as the gold standard and to establish the optimum cut-off values of cTnT for myocardial dysfunction, shock, severe hypoxic ischemic encephalopathy (HIE) and mortality by receiver operator characteristic (ROC) curve analysis.

Methods: This was a prospective study based on diagnostic test evaluation. The study included 120 term asphyxiated neonates in a tertiary care neonatal intensive care unit (NICU) in Southern India from June 2011 through June 2015. All the neonates were clinically evaluated. Venous blood was taken at 4 h of life for cTnT estimation. Echocardiography was done within 24 h of birth.

Results: The mean cTnT level of asphyxiated term neonates was 0.207±0.289 ng/ml (mean ± SD). Asphyxiated neonates with myocardial dysfunction had higher cTnT levels (0.277±0.231) as compared to those without myocardial dysfunction (0.061±0.036, p = 0.0001). Using ROC curve, the cut-off cTnT values for myocardial dysfunction was 0.1145 ng/ml with sensitivity 92.4% and specificity 94.1%. Cardiac Troponin-T levels were significantly higher among asphyxiated neonates with shock (0.378±0.348, p = 0.0001) and the levels also correlated positively with increasing grades of HIE. The cut-off cTnT value for mortality was 0.2505 ng/ml with sensitivity 83.9% and specificity 96.6%.

Conclusions: In asphyxiated term neonates, early cTnT elevation is a marker for predicting myocardial dysfunction and elevated cTnT levels had high sensitivity and specificity. There was significant relation with increasing cTnT values and increasing grades of HIE.

Keywords: Cardiac troponin–T (cTnT); HIE (Hypoxic ischemic encephalopathy); Myocardial dysfunction; Perinatal asphyxia; Shock.