New developments in the biochemical assessment of myocardial injury in children: troponins T and I as highly sensitive and specific markers of myocardial injury

In this review, we discuss the potential impact of the newly developed and recently clinically available cardiac-specific markers, troponin T, cTnT and troponin I, cTnI, for the pediatric practitioner. Biochemical markers have not been used routinely in this patient population and relatively few studies have been performed to determine the indications for their use or the manner of their interpretation, yet subclinical myocardial damage in children is of considerable clinical significance due to their long life expectancy and future somatic growth. We will begin with a short overview of the history of biochemical markers and then briefly describe the properties and physiologic role of these particular muscle proteins. Salient developments in the use of these markers in adults will be highlighted, including: acute myocardial infarction (AMI), unstable angina pectoris (UA), post-surgical or post-trauma AMI assessment, myocarditis, pre-cardiac transplant screening of organs for suitability. We will relate these to similar pediatric contexts where they exist. Where appropriate, we will discuss situations that are unique to pediatric care, such as neonatal stress monitoring and doxorubicin-induced cardiac injury. Finally, some confounding problems that have arisen are considered and we discuss the manner in which these issues are either being or have been resolved.