Serum concentration of cardiac troponin I (cTnI)‎, creatine kinase (CK)‎ and CK-MB in newborn infants with severe perinatal asphyxia

Abstract EN

To evaluate the possible diagnostic performance and prognostic value of a newly introduced myocardial hypoxia indicator-Troponin 1 (cTnl) in comparison with the current widely used biochemical markers CK and CK- MB in perinatal asphyxia and to determine the frequency and the extent of myocardial damage in the presence of neurological injury, we assessed the serum concentrations of cTnI,CK and CK-MB in 40 severely asphyxiated full term newborn infants (on admission ,24 hrs and 5 days after admission) and in 15 healthy full term newborn infants (on admission).

Blood gases and pH were measured on admission..

In addition to the routine investigations to exclude septicemia.

ECG, Echocardiography for all cases and controls, cranial sonography and CTwere performed when indicated Apgar score (at 1,5 and 10 minutes), arterial pH and arterial p02 were significantly decreased while the arterial pC02 was significantly increased in neonates with perinatal asphyxia when compared to control group.

Serum concentrations of cTnl on admission, 24 hrs and 5 days after admission were significantly higher in asphyxiated infants than in controls, in asphyxiated infants with heart failure than in those without heart failure, in asphyxiated infants with stage III hypoxic ischemic encephalopathy(HIE) than in those with stage II HIE and in dead than in survivors.

However, no significant differences in serum concentrations of the current widely used biochemical markers, CK and CK-MB could be detected between the same groups except in samples taken 24 hrs after admission.

Cardiac failure was developed in 27.5 % (11/40) of our cases.

The mortality rate was unexpectedly high (54.55 %-6/U) in neonates with myocardial damage proved by elevated cTnl level.

cTnl showed the best specificity and the highest +ve predictive value in postnatal diagnosis of myocardial damage ofperinatal hypoxia.

On admission, there were significant -ve correlation between cTnl and each of 5 minutes Apgar score, arterial pH and arterial p02.

However, cTnl did not correlate significantly with CK, CK-MB, gestational age and birth weight.

Only 60% of asphyxiated neonates with high serum concentrations of cTnl had ECG and Echocardiography changes.

In conclusion: cTnl is an earlier, more convenient and specific marker for the degree of myocardial damage in cases with perinatal asphyxia than CK and CK-MB.

cTnl seems to be more useful to identify myocardial damage than ECG or echocardiography.

Elevation of blood concentrations of cTnl in newborn infants reflects the severity of myocardial damage and predicts subsequent morbidity and mortality.