BRIEF TEXT

Background and Objective

Preterm delivery accounts for about 8-10% of all births and is responsible for 60-80% of deaths among infants without congenital anomalies worldwide [1]. … [2-4]. Patent ductus arteriosus (PDA) in these babies is the most important cause of cardiac dysfunction [5, 4]. … [6].

Therefore, the diagnosis and determination of cardiac disorders and primary supportive care play an important role in the prognosis of these infants. Disorders in myocardial contraction and cardiac output are common complications of respiratory distress syndrome in premature infants [7]. … [5, 6, 8].

Considering these cases, the need for simple diagnostic methods has led to the investigation of cardiac biological markers, including troponin, in premature infants [10, 9]. … [11-13].

Several studies of biomarkers in infants showed their usefulness in determining prognosis before and after the treatment of cardiopulmonary problems [14]. Meanwhile, the diagnosis of premature myocardial functional disorders in premature babies improves the prognosis of these patients by performing early treatment [15, 13]. For this purpose, this study was conducted to determine the relationship between troponin T level and the prognosis of premature infants admitted to the neonatal intensive care unit (NICU) of Fatemieh Hospital, Hamadan, Iran.

Materials and Methods

This cross-sectional study was conducted in Fatemieh Hospital in Hamadan, Iran, in 2018. The records of all 61 preterm infants who were admitted to the NICU department of Fatemieh Hospital in one year (from May 2018 to May 2019) that were subjected to the measurement of serum troponin T levels were examined in the form of a census. The information entered into the checklist included gender, intrauterine age, troponin T level, and factors related to the short-term prognosis of infants, such as PDA status, duration of NICU hospitalization, intraventricular hemorrhage, hemoglobin level, pneumothorax, and findings of Arterial Blood Gas (ABG) in different days and deaths reports. Considering the importance of the PDA presence in premature babies, babies were divided into three categories of large PDA that needed treatment with Apotel, small PDA that needed no treatments, and babies without PDA.

Results

A total of 61 babies were included in the study, and the mean gestational age was calculated at 31.5 ± 3.2 weeks, birth weight was 1647 ± 554 g, and troponin level was measured at 330 ± 345 pg/ml. The relationship of troponin level with gestational age (P=0.526) and birth weight (P=0.316) was not statistically significant. Moreover, 22 patients had a large PDA with a troponin level of 436 ± 50.2 pg/ml, 14 patients had a small PDA with a troponin level of 260.5 ± 89.8 pg/ml, and 25 patients were without PDA with a troponin level of 277.1 ± 229.7 pg/ml (P=0.203). No statistically significant difference was observed between the three groups. The mean levels of troponin were 423 ± 521 and 274 ± 154 pg/ml in the deceased and surviving neonates, respectively [P=0.194; Table 1].

Inotrope intake was significantly higher in the deceased patients (P=0.003), and troponin T level was statistically significantly related to the inotrope intake (P=0.008). Due to little difference, the relationship between troponin level and severe acidosis was not significant (P=0.051), which is valuable from a clinical point of view. The results of comparison of the risk factors with the prognosis of the studied infants are shown in Table 2.

Discussion

[1-20]…. In a study similar to the current research conducted by Asrani et al. [16] in 2017, the mean troponin level in infants with PDA was higher than in infants without PDA, as in the present study. Although this difference was significant in the mentioned study, the level of troponin before and after treatment was not significantly different. In our study, the relationship of troponin level with gestational age and birth weight was not significant, which is not in line with the results of the mentioned study. In both studies, the level of troponin in premature infants, both in the groups of with and without PDA, was 14 pg/ml higher than the level declared by international guidelines for managing the medical infarction for myocardial infarction.

The troponin level in infants with and without PDA in a study conducted by Asrani et al. was 251.5 ± 65.6 and 161 ± 22.4 pg/ml, respectively, and in our study it was 436 ± 50.2 and 277.1 ± 229.7, respectively. In comparison with the abovementioned study, the amount of troponin in our patients, both in the study group and in the control group, was almost two times higher than the Asrani et al. s’   study. The comparison of the troponin levels in the deceased and surviving patients showed the deterioration of the infants’ health in our study. Despite the high level of troponin in the group of the deceased patients, 423 ± 521 vs. 274 ± 154 pg/ml in the surviving patients, this difference was not statistically significant as this value is higher than the sensitive level of troponin T declared as 14 pg/ml in patients with myocardial infarction in adults [21].

In our study, the gestational age of infants with large PDA was lower than other infants and the birth weight was significantly lower than other infants. Although these differences was not significant in the deceased babies, the gestational age and birth weight were lower compared to the alive infants. These cases, along with large PDA, were the clinical causes of the malaise of the infants in the present research. Some studies showed that high serum troponin levels in premature babies with PDA are related to myocardial dysfunction, and successful treatments in the first 48 h have an effect on troponin levels [17].

Conclusion

Troponin T is a valuable biomarker in determining myocardial dysfunction in premature infants with PDA, and its increase in patients with hemodynamic disorders is associated with a poor prognosis.

REFERENCES

1.      Kroll ME, Kurinczuk JJ, Hollowell J, Macfarlane A, Li Y, Quigley MA. Ethnic and socioeconomic variation in cause-specific preterm infant mortality by gestational age at birth: national cohort study. Arch Dis Child Fetal Neonatal Ed. 2020;105(1):56-63. DOI: 10.1136/archdischild-2018-316463

2.      Bhasin H, Kohli C. Myocardial dysfunction as a predictor of the severity and mortality of hypoxic ischaemic encephalopathy in severe perinatal asphyxia: a case–control study. Paediatr Int Child Health. 2019;39(4):259-64. PMID: 30810512 DOI: 10.1080/20469047.2019. 1581462

3.      Hirose A, Khoo NS, Aziz K, Al-Rajaa N, van den Boom J, Savard W, et al. Evolution of left ventricular function in the preterm infant. J Am Soc Echocardiogr. 2015;28(3):302-8. PMID: 25533193 DOI: 10.1016/j.echo.2014.10.017

4.      Schmitz L, Stiller B, Koch H, Koehne P, Lange P. Diastolic left ventricular function in preterm infants with a patent ductus arteriosus: a serial Doppler echocardiography study. Early Hum Dev. 2004;76(2):91-100. PMID: 14757261 DOI: 10.1016/j.earlhumdev.2003.11.002

5.      Vijlbrief DC, van Bel F, Molenschot MC, Benders MJ, Pistorius LR, Kemperman H, et al. Early detection of prenatal cardiocirculatory compromise in small for gestational age infants. Neonatology. 2014;105(4):256-62. PMID: 24556944 DOI: 10.1159/000357552

6.      Mezu-Ndubuisi OJ, Agarwal G, Raghavan A, Pham JT, Ohler KH, Maheshwari A. Patent ductus arteriosus in premature neonates. Drugs. 2012;72(7):907-16. PMID: 22564132 DOI: 10.2165/11632870-000000000-00000

7.      Clark S, Newland P, Yoxall C, Subhedar N. Concentrations of cardiac troponin T in neonates with and without respiratory distress. Arch Dis Child Fetal Neonatal Ed. 2004;89(4):348-52. PMID: 15210673 DOI: 10.1136/ adc.2002.025478

8.      Broadhouse KM, Finnemore AE, Price AN, Durighel G, Cox DJ, Edwards AD, et al. Cardiovascular magnetic resonance of cardiac function and myocardial mass in preterm infants: a preliminary study of the impact of patent ductus arteriosus. J Cardiovasc Magn Reson. 2014;16(1):1-9. DOI: 10.1186/s12968-014-0054-4

9.      Breatnach CR, Franklin O, James AT, McCallion N. The impact of a hyperdynamic left ventricle on right ventricular function measurements in preterm infants with a patent ductus arteriosus. Arch Dis Child Fetal Neonatal Ed. 2017;102(5):446-50. PMID: 28232519 DOI: 10.1136/ archdischild-2016-311189

10.   Yajamanyam PK, Negrine RJ, Rasiah SV, Zamora J, Ewer AK. Assessment of myocardial function in preterm infants with chronic lung disease using tissue Doppler imaging. Arch Dis Child Fetal Neonatal Ed. 2016;101(6):527-32. PMID: 27048431 DOI: 10.1136/ archdischild-2015-308929

11.   Distefano G, Sciacca P, Mattia C, Betta P, Falsaperla R, Romeo M, et al. Troponin I as a biomarker of cardiac injury in neonates with idiopathic respiratory distress. Am J Perinatol. 2006;23(04):229-32. PMID: 16625503 DOI: 10. 1055/s-2006-939537

12.   Karlén J, Karlsson M, Eliasson H, Bonamy A-KE, Halvorsen CP. Cardiac troponin T in healthy full-term infants. Pediatr Cardiol. 2019;40(8):1645-54. DOI: 10. 1007/s00246-019-02199-9

13.   Rouatbi H, Zigabe S, Gkiougki E, Vranken L, Van Linthout C, Seghaye MC. Biomarkers of neonatal stress assessment: A prospective study. Early Hum Dev. 2019;137:104826. PMID: 31362253 DOI: 10.1016/ j.earlhumdev.2019.104826

14.   Jiang L, Li Y, Zhang Z, Lin L, Liu X. Use of high-sensitivity cardiac troponin I levels for early diagnosis of myocardial injury after neonatal asphyxia. J Int Med Res. 2019;47(7):3234-42. DOI: 10.1177/0300060519831187

15.   Kanik E, Arun Ozer E, Rahmi Bakiler A, Aydinlioglu H, Dorak C, Dogrusoz B, et al. Assessment of myocardial dysfunction in neonates with hypoxic-ischemic encephalopathy: is it a significant predictor of mortality? J Matern Fetal Neonatal Med. 2009;22(3):239-42. PMID: 19330708 DOI: 10.1080/14767050802430834

16.   Asrani P, Aly AM, Jiwani AK, Niebuhr BR, Christenson RH, Jain SK. High-sensitivity troponin T in preterm infants with a hemodynamically significant patent ductus arteriosus. J Perinatol. 2018;38(11):1483-9. PMID: 30171214 DOI: 10.1038/s41372-018-0192-x

17.   El-Khuffash AF, Molloy EJ. Influence of a patent ductus arteriosus on cardiac troponin T levels in preterm infants. J Pediatr. 2008;153(3):350-3. PMID: 18534211 DOI: 10.1016/j.jpeds.2008.04.014

18.   Yildirim A, Ozgen F, Ucar B, Alatas O, Tekin N, Kilic ZJF, et al. The diagnostic value of Troponin T level in the determination of cardiac damage in perinatal asphyxia newborns. Fetal Pediatr Pathol. 2016;35(1):29-36. DOI: 10.3109/15513815.2015.1122128

19.   Abiramalatha T, Kumar M, Chandran S, Sudhakar Y, Thenmozhi M, Thomas N. Troponin-T as a biomarker in neonates with perinatal asphyxia. J Neonatal Perinatal Med. 2017;10(3):275-80. PMID: 28854510 DOI: 10.3233/NPM-16119

20.   Joseph S, Kumar S, Lakshmi S. Cardiac troponin-T as a marker of myocardial dysfunction in term neonates with perinatal asphyxia; Correspondence. Indian J Pediatr. 2018;85(10):877-84. PMID: 30825063 DOI: 10.1007/ s12098-019-02884-w

21.   Freund Y, Chenevier-Gobeaux C, Bonnet P, Claessens YE, Allo JC, Doumenc B, et al. High-sensitivity versus conventional troponin in the emergency department for the diagnosis of acute myocardial infarction. Crit Care. 2011;15(3):1-9. PMID: 21663627 DOI: 10.1186/cc10270

22.   Lopes DN, Ramos JM, Moreira ME, Cabral JA, de Carvalho M, Lopes JM. Cardiac troponin T and illness severity in the very-low-birth-weight infant. Int J Pediatr. 2012;2012:1-5. PMID: 22518175 DOI: 10.1155/ 2012/479242

23.   Awada H, Al-Tannir M, Ziade MF, Alameh J, El Rajab M. Cardiac troponin T: a useful early marker for cardiac and respiratory dysfunction in neonates. Neonatology. 2007;92(2):105–10. PMID: 17377410 DOI: 10.1159/ 000100964

24.   Fahmey SS, Fathy H, Abo Gabal K, Khairy H. Cardiac troponin T in neonates with respiratory distress. Egypt Paediatr Assoc Gaz. 2018;66(4):100-2.