Diagnosis and Diagnostic Modalities in Pediatric Patients with Elevated Troponin

Effect of treadmill exercise stress testing on troponin levels in children and adolescents

BACKGROUND

Chest pain is a common complaint among paediatric patients and cardiac troponin (cTn) level is often part of the initial emergency department evaluation. It is well known that after intense endurance exercise cTn levels can be elevated in patients with otherwise healthy hearts, however the effect shorter duration exercise has on cTn levels in this population is not known.

OBJECTIVE

Determine the behaviour of cTn levels in healthy children and adolescent patients after short burst, high-intensity aerobic exercise.

METHODS

Patients without haemodynamically significant heart disease referred for a treadmill exercise stress test (EST) were recruited over a 6-month period. cTn levels were measured prior to exercise and 4 hours after exercise.

RESULTS

Thirteen patients enrolled. Indications for EST were exertional syncope (six), chest pain (four), and long QT syndrome (three). The median exercise time was 12.9 (9.9-13.7) minutes with an average endurance at the fiftieth percentile for age and maximum heart rate rose to an average of 92 (74-98)% of the predicted peak for age. cTn levels prior to exercise were undetectable in all patients. There was no cTn rise in any patient after exercise. There were no ischaemic changes or arrhythmias on exercise electrocardiograms.

CONCLUSION

Serum cTn levels do not rise significantly in healthy children after short duration, high-intensity aerobic exercise. Physicians evaluating paediatric patients with an elevated cTn level after less than prolonged strenuous activity likely cannot attribute this lab value solely to exercise and may need to undertake further cardiac investigation.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

High-Sensitivity Troponin T Testing for Pediatric Patients in the Emergency Department

Debate exists on the usefulness of high-sensitivity cardiac troponin (hs-cTn) testing in pediatric patients due to the perceived low incidence of myocardial injury and lack of data concerning its efficacy. We evaluated the contribution of an increased hs-cTnT above the 99th percentile upper-reference limit (URL) to clinical diagnoses made in pediatric patients presenting to the emergency department (ED). Retrospective cohort study including patients aged 0-18 years presenting to the ED from 2018 to 2020 where hs-cTnT was measured. Sex-specific 99th percentile URLs of 15 and 10 ng/L for males and females, respectively, were used, with concentrations above these thresholds considered indicative of myocardial injury. Overall, 356 patients were identified in whom hs-cTnT concentrations were measured during ED clinical evaluation. Hs-cTnT was increased above the 99th percentile on presentation in 36 patients (10.1%). Twelve patients (3.4%) had a clinical cardiac diagnosis made. Hs-cTnT was increased in 6 of these (50.0%). Serial hs-cTnT from 106 patients with an initial hs-cTnT < 99th percentile was subsequently elevated in 5 (4.6%); none of whom had a final clinical cardiac diagnosis. Hs-cTnT has high specificity, but low sensitivity when used as a screening tool for myocardial injury when the gold standard is mostly clinical assessment. In present practice, however, they do not appear to track well with clinical diagnoses. Further studies are needed to more clearly define the role of hs-cTnT in this patient population.

High-sensitivity cardiac troponins in pediatric population

Apparently healthy children often complain of chest pain, especially after physical exercise. Cardiac biomarker levels are often measured, but the clinical relevance of these assays in children is still debated, even when a cardiac disease is present. Coronary artery disease is exceedingly rare in children, but elevated circulating levels of cardiac troponin I (cTnI) and T (cTnT) in an acute setting may help detect heart failure due to an unknown cardiac disorder, or worsening heart failure, particularly in combination with other biomarkers such as B-type natriuretic peptides. However, the interpretation of biomarkers is often challenging, especially when institutions transition from conventional cTn assays to high-sensitivity (hs-cTn) methods, as well demonstrated in the emergency setting for adult patients. From a clinical perspective, the lack of established reference values in the pediatric age is the main problem limiting the use of hs-cTn methods for the diagnosis and managements of cardiac diseases in infants, children and adolescents. This review aims to discuss the possibility to use hs-cTnI and hs-cTnT to detect cardiac disease and to explore age-related differences in biomarker levels in the pediatric age. We start from some analytical and pathophysiological considerations related to hs-cTn assays. Then, after a systematic literature search, we discuss the current evidence and possible limitations of hs-cTn assay as indicators of cardiac disease in the most frequently cardiac disease in pediatric setting.

Role of Troponin Determination to Diagnose Chest Pain in the Pediatric Emergency Department

OBJECTIVES

Chest pain is a common cause to admission to the pediatric emergency department and often leads to an extensive cardiac evaluation. The objective of this study was to evaluate the usefulness of the troponin (TN) plasma level determination in the initial phase of the differential diagnosis of chest pain in children.

METHODS

This is a retrospective observational study on 107 patients, aged 0 to 19 years, admitted for chest pain to the pediatric emergency department of our institution. Demographics, clinical data, and patient outcomes were analyzed. Troponin values of >0.03 ng/mL but <0.1 ng/mL were considered suspected for cardiac pathology, whereas levels of >0.1 ng/mL were indicative of cardiac pathology. In these latter patients, an echocardiographic examination was also performed.

RESULTS

Only 99 patients were evaluated with electrocardiogram (ECG). In 91 of 99 patients of our series, both TN determination and ECG recording were performed. Troponin was higher than the cutoff value (0.03 ng/mL) in 9 patients (9.1%). Only 2 of the 9 patients who presented high TN values showed a nonpathological ECG, whereas 16 (17.5%) of 91 patients in whom both ECG and TN determination were performed had ECG abnormalities without a simultaneous elevation of TN. Of the 26 patients who had medical history and suggestive targets of cardiac pathology, only in 6 (23.1%) of them the diagnosis was confirmed. The final diagnosis of the 99 patients was idiopathic chest pain in 45.4% of cases.

CONCLUSIONS

Even with the low cost and the relatively easiness for the plasma level determination, TN should be measured only in children with chest pain associated to familiar history suggestive of cardiovascular disease and/or clinical symptoms and/or ECG alterations.

Cardiac Biomarkers in Pediatrics: An Undervalued Resource

BACKGROUND

The clinical use of common cardiac biomarkers, such as brain natriuretic peptides and troponins, has traditionally been limited to adult populations in the assessment of heart failure and acute coronary syndrome, respectively. While many have discounted the value of these markers in pediatric populations, emerging evidence suggests they may be useful in the diagnosis and prognostication of many cardiac and noncardiac pathologies in neonates, children, and adolescents, and an increasing number of pediatric hospitals are routinely measuring cardiac markers in their clinical practice.

CONTENT

This review summarizes and critically evaluates the current literature regarding the application of cardiac biomarkers for clinical decision-making in the pediatric population. Main potential clinical indications discussed herein include primary cardiac disease, immune-related conditions, and noncardiac disease. Important diagnostic and interpretative challenges are also described in relation to each potential indication.

SUMMARY

Despite a general lack of clinical awareness regarding the value of cardiac biomarkers in pediatrics, there is increasing literature to support their application in various contexts. Cardiac biomarkers should be considered an undervalued resource in the pediatric population with potential value in the diagnosis and prognosis of myocarditis, congenital heart disease, and heart failure, as well as in the assessment of severity and cardiac involvement in immune-related and other systemic conditions. While interpretation remains challenging in pediatrics due to the age- and sex-specific dynamics occurring throughout growth and development, this should not prevent their application. Future research should focus on defining evidence-based cut-offs for specific indications using the most up-to-date assays.

Evaluating Chest Pain and Heart Murmurs in Pediatric and Adolescent Patients

Chest pain and heart murmurs are common issues primary care providers must evaluate and manage. Both are a source of anxiety for patients, parents, and providers, necessitating evaluation and understanding to ensure appropriate management. Most pediatric chest pain can be treated symptomatically and with reassurance. This article examines the approach to pediatric chest pain including identification of key historical points, common causes of chest pain, and when to refer. The article also delineates our approach to auscultation, describes common benign murmurs, and offers suggestions on when to refer for further evaluation.

Prorenin and active renin levels in paediatrics: a bioanalytical review

As part of the extended renin-angiotensin-aldosterone system, active renin and its precursor prorenin have been an area of research interest for decades. Although several studies showed a correlation with disease, other studies found no significant association, e.g. attributed to limited sample size or pharmacological effects of antihypertensive drugs. Since the measurement of both proteins has typically been carried out in adult populations, the data in paediatrics is limited. This review aimed to collate the current data on plasma renin and prorenin levels in children and compare the levels of healthy vs. the diseased state. A literature search using Medline resulted in 213 publications of which 15 studies were classified as relevant. In the extant studies in the literature, an age-dependent decline of renin plasma concentration was observed in newborns compared to adolescents. For children with cardiovascular disease, five studies were identified that provide limited insight into the pathophysiological regulation of renin. In general, sample handling is still a crucial step, which might particularly affect measured active renin concentrations due to conformational changes of its precursor prorenin. A reliable assessment for prorenin levels in the maturating population is yet not possible due to the low number of available publications. Three different approaches to quantify prorenin were found and raise the question on the comparability of these methods. The review emphazised several weaknesses and highlights the need for an accurate procedure to determine levels of active renin as well as prorenin in its closed and open form.

Value of Troponin Testing for Detection of Heart Disease in Previously Healthy Children

Background

Troponin levels are frequently obtained in pediatric patients, but the benefit remains unclear.

Methods and Results

This retrospective study included 1993 patients aged 0 to 21 years without history of cardiac disease in whom troponin levels were obtained during clinical evaluation of cardiac and noncardiac presentations. Troponin was elevated (≥0.1 ng/mL) in 182 patients (9%). A cardiac diagnosis was made in 109 (60%) of those with elevated troponin and in 208 (12%) of those without (P<0.001). The positive predictive value of elevated troponin for a cardiac diagnosis was 60% for the entire cohort and 85% for patients with a cardiac presentation. The negative predictive value of nonelevated troponin was 89% for the entire cohort and 96% in patients without a cardiac presentation. Serial testing did not improve these predictive values. However, among 404 patients with initially nonelevated levels who had serial measurements, subsequent elevation was found in 80 (20%), of whom 15 (19%) had a cardiac diagnosis. The optimal troponin cutoff value to differentiate cardiac from noncardiac diagnosis was higher in children aged <3 months (0.045 ng/mL) compared with those aged ≥3 months (0.005 ng/mL).

Conclusions

Troponin can be a useful adjunctive test in the evaluation of children when the differential diagnosis includes cardiac etiologies. Serial measurement was not helpful when troponin was elevated at presentation but may merit consideration when the initial level is not elevated and there is ongoing concern about cardiac involvement. Lower reference values may be appropriate when evaluating children in contrast to adults.

What is the Significance of Elevated Troponin I in Children and Adolescents? A Diagnostic Approach

Troponin is a marker that displays cardiac injury quickly and accurately. In adults, troponin elevation is usually associated with coronary artery disease and requires urgent cardiac catheterization. In healthy children, myocardial injury is rare and may develop due to many different causes. Therefore, troponin elevation in children and adolescents does not usually require emergency cardiac catheterization. The aim of this study is to assess the most common causes of troponin elevation in children and adolescents and to show which diagnostic tests are helpful in assessing pediatric patients with elevated troponin. Patients who had been diagnosed with troponin I elevation (> 0.06 ng/ml) at Dr. Sami Ulus Maternity, Children's Health and Disease Training and Research Hospital between 2007 and 2018 were retrospectively evaluated. Patients undergoing cardiac surgery and those with severe congenital heart disease were excluded from the study. The medical records of the patients were examined and age, gender, diagnostic tests, and diagnosis were evaluated. During the study period, the records of 972 patients were obtained. 213 patients were excluded from the study because of heart surgery, congenital heart disease, and neonatal asphyxia or sepsis. Of the remaining 759 patients, 58% were male, 42% were female, and the median age was 4 years (3 days to 17 years). The most frequent causes are myopericarditis (n: 164), drug intoxications (n: 85), carbon monoxide poisoning (n: 74), perimyocarditis (n: 65), and intensive inhalation β agonist use in acute asthma and lower respiratory tract infections (n: 70). Patients diagnosed with myocarditis and myopericarditis were admitted with a complaint of chest pain, and the diagnosis was made by history, physical examination, ECG, and echocardiographic findings. Unlike adults, troponin I elevation may be associated with many cardiac and non-cardiac pathologies in children. The most common pathologies in cardiac etiology are myopericarditis and perimyocarditis and can be diagnosed by history, physical examination, ECG, and echocardiography. Cardiac catheterization is not necessary except for rare cardiac pathologies and does not alter the prognosis.

Infant acute myocarditis mimicking acute myocardial infarction

Myocarditis is an inflammatory disease of the myocardium with heterogeneous clinical manifestations and progression. In clinical practice, although there are many methods of diagnosis of acute myocarditis, the diagnosis remains an embarrassing dilemma for clinicians. The authors report the case of 9-month-old infant who was brought to the Pediatric Emergency Department with sudden onset dyspnea. Examination disclosed heart failure and resuscitation was undertaken. The electrocardiogram showed an ST segment elevation in the anterolateral leads with a mirror image. Cardiac enzyme tests revealed a significant elevation of troponin and creatine phosphokinase levels. A diagnosis of acute myocardial infarction was made, and heparin therapy was prescribed. The infant died on the third day after admission with cardiogenic shock. The autopsy showed dilatation of the ventricles and massive edema of the lungs. Histological examinations of myocardium samples revealed the presence of a marked lymphocytic infiltrate dissociating myocardiocytes. Death was attributed to acute myocarditis. The authors call attention to the difficulties of differential diagnosis between acute myocarditis and acute myocardial infarction especially in children, and to the important therapeutic implications of a correct diagnosis.