Original Articles
Patterns and Potential Value of Cardiac Troponin I Elevations After Pediatric Cardiac Operations

https://doi.org/10.1016/S0003-4975(98)00228-8Get rights and content

Abstract

Background. Perioperative myocardial injury is a major determinant of postoperative cardiac dysfunction for congenital heart disease, but its assessment during this period is difficult. The objective of this study was to determine the suitability of using postoperative serum concentrations of cardiac troponin I (cTnI) for this purpose.

Methods. Cardiac troponin I levels were measured serially in the serum of patients undergoing uncomplicated repairs of atrial septal defect (n = 23), ventricular septal defect (n = 16) or tetralogy of Fallot (n = 16). The concentrations were correlated with intraoperative parameters (cardiopulmonary bypass time, aortic cross-clamp time, and cardiac bypass temperature), and postoperative parameters (magnitude of inotropic support, duration of intubation, and postoperative intensive care and hospital stay).

Results. Postoperative absolute cTnI levels were lesion specific, with a pattern of increase and decrease similar for each lesion. For the total cohort, significant correlations between postoperative cTnI levels at all times (r = 0.43 to 0.83, p < 0.05) until 72 hours were noted for all parameters, except for cardiac bypass temperature. When evaluated as individual procedure groups, no significant relationships were noted in the atrial septal defect group, whereas postoperative cTnI levels were more strongly correlated with all intraoperative and postoperative parameters in the ventricular septal defect group than in the tetralogy of Fallot group.

Conclusions. This study suggests that cTnI values immediately after operation reflect the extent of myocardial damage from both incisional injury and intraoperative factors. Cardiac tropinin I levels in the first hours after operation for congenital heart disease are a potentially useful prognostic indicator for difficulty of recovery.

Section snippets

Patient Population

All patients undergoing elective repair of congenital heart defects requiring cardiopulmonary bypass were prospectively enrolled in the study protocol from January to December 1995. Only patients who had repair of secundum type atrial septal defects (ASD), paramembranous ventricular septal defects (VSD), and tetralogy of Fallot (TOF) were included in this analysis. Other surgical procedures were not analyzed as the numbers in each category were small. To establish baseline cTnI levels in

Patient Population and Outcome Variables

Between January and December 1995, 61 children underwent surgical repair of either an ASD (n = 23), VSD (n = 19), or TOF (n = 19). Six patients with complications were excluded, leaving 55 patients in the study cohort (Table 1). The 6 excluded subjects included 3 with postoperative junctional tachycardia, 2 from the VSD group and 1 from the TOF group. Hemodynamically significant pericardial effusions were diagnosed and drained in 1 patient each from the VSD and TOF groups, and another patient

Comment

Cardiac troponin I is one component of a complex of three separate proteins that, together with tropomysin, confers calcium sensitivity to the process of actin–myosin cross-bridge formation in the myocardial cell. Found exclusively in the myocardial cell, it is a potent inhibitor of those interactions [5]. Assay for cTnI is sensitive and specific, with no detectable cross-reactivity with skeletal muscle troponin. The level of cTnI is a more sensitive index of myocardial cell damage than either

Acknowledgements

We thank Marsha Kuhns for technical assistance. Doctor Ladenson is a consultant to Dade-Behring Corporation (Wilmington, DE).

References (13)

There are more references available in the full text version of this article.

Cited by (0)

View full text