CARDIAC TROPONIN - I AS A MARKER OF MYO CARDIAL DAMAGE IN NEWBORNS WITH HYPOXI C ISCHEMIC ENCEPHALO PATHY

Abstract

BACKGROUND: Perinatal asphyxia is a common problem with the incidence varying from 0.5-2% of live births. The incidence of cardiac dysfunction in perinatal asphyxia varies from 24-60%. However there is paucity of reports from our country where mothers often report to hospital quite late with obstetric complications and neonates suffer from birth asphyxia with high mortality. So it becomes important to detect myocardial dysfunction and to provide early treatment. OBJECTIVES: To assess the usefulness of cardiac marker in evaluating myocardial damage in hypoxic ischemic encephalopathy. MATERIALS AND METHODS: Prospective case control study was conducted on 50 neonates comprising the cases and 50 neonates comprising the controls meeting the inclusion and exclusion criteria born in Basaweshwar Teaching and General Hospital and Sangameshwar Teaching and General Hospital, Gulbarga. After written informed consent, venous blood sample was taken by aseptic precaution within 72 hours of birth. Blood was centrifuged and serum tested for, Cardiac troponin I-done by Electro-Chemiluminescence Immunoassay (ECLIA). RESULTS: The mean cTnI value of asphyxiated neonates was 47.23±37.50 pg/L, compared to control group 4.33±1.97 pg/L which was statistically significant. Serum cTnI concentrations significantly greater with increasing severity of HIE. Mean cTnI concentrations were: 9.56±5.05 pg/L in HIE-I, 49.84 ±15.88 pg/L in HIE-II, and 106.9±31.01 pg/L in HIE -III. Mean cTnI value among cases with shock was 71.796±32.16 pg/L and those without shock was 15.79±11.64 pg/L. There was significant difference of mean cTnI value among cases with myocardial involvement and without myocardial involvement with P-value <0.001. CONCLUSION: In asphyxiated neonates, cardiac troponin I concentrations within 72h of birth correlate strongly with clinical grade of hypoxic ischemic encephalopathy. Early cardiac troponin I concentrations provide a useful proxy marker for the anticipated severity of myocardial damage. INTRODUCTION: Perinatal asphyxia is a common neonatal problem and contributes significantly to neonatal morbidity and mortality. Globally, hypoxia of the newborn (birth asphyxia) or the fetus (" fresh stillbirth ") is estimated to account for 23% of the 4 million neonatal deaths and 26% of the 3.2 million stillbirths each year. 1 Perinatal hypoxia-ischaemia can cause multi-organ injury and dysfunction of brain, heart, lungs, kidneys and bone marrow. Cardiac dysfunction results from hypoxic ischaemic damage to sub-endocardial tissue, papillary muscle and myocardium. 2 Cardiac-specific isomorphs of troponins T and I in adults have proved to be sensitive and specific biochemical markers of myocardial damage in acute coronary syndromes. 3 Asphyxiated neonates have higher cardiac troponin I (cTnI) concentrations than controls. 4 cTnT and cTnI have been proposed to be biochemical indices of myocardial injury in