Troponin-I for prediction of early postoperative course after pediatric cardiac surgery

Association Between High Sensitivity Troponin Levels Following Pediatric Orthotopic Heart Transplantation and Intensive Care Unit Resource Utilization

The utility of troponin levels, including high sensitivity troponin T (hs-TnT), after orthotopic heart transplant (OHT) is controversial. Conflicting data exist regarding its use as a marker of acute rejection. Few studies have examined possible associations of hs-TnT levels immediately after OHT with metrics of intensive care unit (ICU) resource utilization or risk of acute rejection. We performed a retrospective cohort chart review including all OHT recipients < 20 years of age at our center between June 2019 and December 2022. Patients were divided into two groups based on supra- or sub-median initial hs-TnT levels (median 3462.5 ng/L). Primary outcome was days requiring ICU-level care, secondary outcomes included days intubated, days requiring positive pressure ventilation (PPV), days on inotropic medications, actual ICU length of stay, Vasoactive Inotrope Scores (VIS) on postoperative days (POD) 0 through 7, and acute rejection at 30 days and one year after OHT. Patients with higher hs-TnT required ICU level care for longer [13.5 (10-17.5) vs. 9.5 (8-12) days, p = 0.01] and spent more days intubated [6 (4-7) vs. 3 (3-5) days, p < 0.001], on PPV [9 (6-15) vs. 6 (5-8.5) days, p = 0.02], and on inotropes [11 (9-14) vs. 8 (7-11) days, p = 0.025]. VIS was only different between groups on POD7 [5 (3-7) vs. 3 (0-5), p = 0.04]. There was no difference in rejection between the groups. Higher hs-TnT immediately following pediatric OHT may predict higher ICU resource utilization, despite no difference in VIS, although it does not predict acute rejection in the first year after OHT.

Postoperative Troponin Levels in Children Undergoing Open Heart Surgery With and Without Coronary Intervention

We aimed to characterize the ranges, temporal trends, influencing factors, and prognostic significance of postoperative troponin levels after congenital heart surgery. This single-center retrospective study included patients from 2006 to 2021 who had ≥ 1 postoperative troponin-T measurement collected within 96 h of congenital heart surgery (CHS). Patients were grouped as Anomalous Aortic Origin of the Coronary Artery-"AAOCA repair," or congenital heart surgery with "Other Coronary Interventions" other than AAOCA repair, or "No Coronary Intervention." In each group, information on concomitant surgery requiring one or more of the following-atriotomy, ventriculotomy, right ventricular muscle bundle resection, and/or septal myectomy-was collected. Clinical correlates of troponin values were analyzed in three postoperative windows: < 8, 8-24, and 24-48 h. The highest median [range] troponin levels (ng/mL) for the samples were 0.34 [0.06, 1.32] at < 8 h for "AAOCA repair," 1.35 [0.14, 12.0] at < 8 h for those undergoing CHS with "Other Coronary Interventions," and 0.87 [0.06, 25.1] at 8-24 h for those undergoing CHS with "No Coronary Interventions." Atriotomy was associated with higher median troponin levels in the AAOCA group at < 8 h (0.40 [0.31, 0.77] vs. 0.29 [0.17, 0.54], P = 0.043) and in the Other Coronary Intervention group at 8-24 h (1.67 [1.04, 2.63] vs. 0.40 [0.19, 1.32], P = 0.002). Patients experiencing major postoperative complications (vs. those who did not) had higher troponin levels in the AAOCA group as early as 8-24 h (0.36 [0.24, 0.57] vs. 0.21 [0.14, 0.33], P = 0.03). Similar findings were noted in the Coronary Intervention (2.20 [1.34, 3.90] vs. 1.11 [0.51, 2.90], P = 0.028) and No Coronary Intervention (2.2 [1.49, 15.1] vs. 0.74 [0.40, 2.34], P = 0.027) groups but earlier at < 8 h. In the AAOCA group, 2/18 (11%) troponin outliers experienced cardiac arrest in comparison to 0/80 (0%) non-outliers (P = 0.032). In the Other Coronary Intervention group, troponin outliers had longer median times to ICU discharge (10 vs. 4 days) and hospital discharge (21 vs. 10 days) (both P < 0.001). Postoperative troponin levels depend on a multitude of factors and may have prognostic value in patients undergoing congenital heart surgery with coronary interventions.

Do quantitative levels of cardiac troponin I implicate on severity of disease in children, adolescences, and young adults with acute myocarditis and myopericarditis?

OBJECTIVES

When cardiac muscle damage occurs, cardiac troponins are released to blood and their detection is used as a marker in clinical setting. The prognostic value of the quantitative levels of blood troponin I in cases of myocarditis and myopericarditis is unclear. The aim of this study was to analyse whether troponin quantitative blood levels can be correlated with the course of hospitalisation and prognosis.

METHODS

Retrospective data was collected from all consecutive patients aged ≤30 hospitalised with a diagnosis of acute myocarditis or acute myopericarditis in our health Care Campus between the years 2010-2016.

RESULTS

Ninety-three patients with myocarditis and myopericarditis were identified. Higher peak troponin levels correlated with longer hospitalisation times in the cardiac or paediatric wards (p = 0.03, Pearson correlation: r -0.23), and median troponin level at admission correlated with longer overall hospitalisation (p = 0.026, Pearson correlation: r = 0.23). Patients admitted to ICU, received oral cardiac supportive therapy or that were discharged with cardiac drugs had higher median troponin compared to patients who were not but this was not statistically significant. A small group of patients that needed intravenous cardiac support had significantly lower median peak troponin levels (n = 4, 0.375ng/ml, p = 0.048). Only two patients needed extracorporeal membrane oxygenation support, and one died. The small number of patients precludes statistical analysis.

CONCLUSION

Higher troponin levels correlated significantly with longer hospitalisation, lower troponin values correlated with intravenous cardiac support, while other variables related to the severity of disease could not be significantly related to higher troponin levels.

Post-operative troponin levels and left ventricular function in patients with d-transposition of the great arteries following the arterial switch operation

The aim of this study was to assess the significance of post-operative troponin levels as a surrogate for left ventricular (LV) dysfunction measured by global longitudinal strain (GLS) in patients with dextro-transposition of the great arteries (d-TGA) who undergo an arterial switch operation (ASO), and to explore the LV GLS recovery in the mid-term follow-up period. Seventy-eight neonates were included, of whom 41 had troponin-I measurements and 37 had troponin-T measurements. The primary outcome of LV GLS was assessed and compared with healthy controls at the pre-operative stage and time of discharge, 3 months, 6 months and 12 months of age. Secondary outcomes included deaths or transplantations and other clinical markers such as length of hospital stay. D-TGA patients had worse LV GLS post-operatively compared to age-matched controls (p < 0.01) which improved by 12 months of age (p = 0.53). No association was found between changes in troponin-I or troponin-T levels and LV GLS at the time of discharge (r = 0.4, p = 0.64 and r = -0.5, p = 0.91, respectively). In addition, there were no deaths or transplantations in this cohort over a period of 12 months. LV GLS appears to worsen in the early post-operative period for d-TGA patients who undergo neonatal ASO but this recovers through the first post-operative year. Troponin levels have limited value in predicting early or midterm LV dysfunction and recovery.

How to interpret cardiac biomarkers in children?

Cardiac biomarkers are used as first-line diagnostic tools in suspected myocardial injury and heart failure in adult patients. Their use in paediatric patients has been limited by variability caused by age, gender and the presence of an underlying congenital cardiac condition. There are established reference ranges for both NT-proBNP and troponin in healthy children, but these cannot be applied to all paediatric patients because of limited large studies focusing on children with congenital heart disease and/or cardiomyopathy.This article will focus on the pathophysiology of myocardial injury and heart failure in children and the subsequent cardiac biomarker correlation. It will explain how to interpret the biomarker assay levels obtained for both troponin and NT-proBNP and highlights the importance of a clear clinical question prior to requesting a cardiac biomarker assay level.Clinical cases outline scenarios that may prompt consideration of biomarker analysis in children and aims to equip the reader with an understanding of how to interpret the results.

Myocardial injury and inflammatory response in percutaneous device closures of pediatric patent ductus arteriosus

Background

The percutaneous device closure of patent ductus arteriosus (PDA) is widely used in clinical practice, however full data on the changes in myocardial injury and systemic inflammatory markers’ levels after PDA in children are not fully reported.

Methods

We have conducted a retrospective analysis of the medical records of 385 pediatric patients in our hospital from January 2017 to December 2019. The patients were distributed into five groups. The first four (A, B, C and D) included patients divided by the type of the surgical closure methods, namely ligation, clamping, ligation-combined suturing and ligation-combined clamping, respectively. The fifth group E comprised of percutaneous device PDA patients. All recorded medical and trial data from the five groups were statistically studied.

Results

No serious complications in the patients regardless of the classification group were reported. Our results suggested that there were no considerable differences between the groups at the baseline (with all P > 0.05). Group E demonstrated a significantly smaller operative time (42.39 ± 3.88, min) and length of hospital stay (LOS) (4.49 ± 0.50, day), less intraoperative blood loss (7.12 ± 2.09, ml) while on the other hand, a higher total hospital cost (24,001.35 ± 1152.80, RMB) than the other four groups (with all P < 0.001). Interestingly, the comparison of the inflammatory factors such as white blood cells (WBC) count, C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6), as well as the myocardial injury markers (CKMB and troponin I) did not show a significant increase (P > 0.05) among the four groups. On the contrary, when the aforementioned factors and markers of all the surgical groups were compared to those in group E, we observed significantly higher speed and magnitude of changes in group E than those in groups A, B, C, and D (with all P < 0.001).

Conclusion

Although the percutaneous device closure of PDA is more comforting and drives fast recuperation in comparison to conventional surgery, it provokes myocardial injury and overall inflammation. Timely substantial and aggressive intervention measures such as the use of antibiotics before operation and active glucocorticoids to suppress inflammation and nourish the myocardium need be applied if the myocardial and inflammatory markers are eminent.

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.

Cardiac biomarkers in pediatric CKD-a prospective follow-up study

BACKGROUND

The N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitive cardiac-specific troponin T (hs-cTnT) are associated with abnormal cardiac structure and function and an increased risk of cardiovascular death in chronic kidney disease (CKD) patients. There is limited knowledge about these cardiac markers in pediatric CKD patients.

METHODS

Longitudinal levels of NT-proBNP and hs-cTnT were analyzed in 48 pediatric patients, 22 with CKD (GFR range 8.8-68 mL/min/1.73 m²) and 26 transplanted patients (CKD-T; GFR range 30-99 mL/min/1.73 m²). Follow-up was scheduled after 1 and 3 years. Longitudinal patterns and associations to kidney function, cardiovascular risk markers, and echocardiographic parameters were assessed.

RESULTS

High NT-proBNP was present in 27% of CKD and 11% of CKD-T patients. Similarly 32% of CKD and 8% of CKD-T patients had elevated hs-cTnT levels. In longitudinal multivariate analyses, high log NT-proBNP was associated with low GFR (β =  - 0.01, p = 0.01) and elevated left ventricular mass index (LVMI; β = 0.02, p = 0.05). The strong association to LVMI remained when using GFR-adjusted NT-proBNP in similar analysis. Patients with left ventricular hypertrophy (LVH) also had higher NT-proBNP (235 [146-301] ng/L) than patients without LVH (86 [11-477] ng/L), p = 0.02. High hs-cTnT over-time was also associated with low GFR (β =  - 0.007, p = 0.01) and a low cc-TDI e´/a´, indicating a worse LV diastolic function (β =  - 0.09, p = 0.05). This association did not persist for GFR-adjusted hs-cTnT.

CONCLUSIONS

NT-proBNP and hs-cTnT are elevated in pediatric CKD and CKD-T patients. GFR-adjusted NT-proBNP was associated with longitudinal levels of elevated LVMI suggesting this might be a marker for early subclinical myocardial damage. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Risk Factors for Cardiac Adverse Events in Infants and Children with Complex Heart Disease Scheduled for Bi-ventricular Repair: Prognostic Value of Pre-operative B-Type Natriuretic Peptide and High-Sensitivity Troponin T

Few reports have described the prognostic value of measuring both B-type natriuretic peptides (BNP) and high-sensitivity troponin T (hs-TnT) in pediatric patients with complex congenital heart disease (CHD) undergoing surgery. We assessed demographic, hemodynamic, and laboratory data, including BNP and hs-TnT levels, for the prediction of cardiac adverse events in 85 patients. Cardiac adverse events were defined as death, cardiac arrest, worsening heart failure requiring inotropic agents and/or respiratory support, and unscheduled surgery/intervention either within or after 12 months of surgery. There were 17 cardiac adverse events. Of the demographic variables, low birth weight (< 2500 g: Odds ratio [OR], 5.97; 95% confidential interval [CI] 1.48-24.0; p = 0.001) and Ross/New York Heart Association [NYHA] class (≥ 2.0) (OR 12.7; 95% CI 3.08-52.7; p = 0.0004) were strongly association with cardiac adverse events. Among hemodynamic and laboratory variables, preoperative BNP (OR 14.04; 95% CI 2.15-91.7; p = 0.001) and hs-TnT levels (OR 16.66; 95% CI 2.27-122; p = 0.002) were found to be independent risk factors. Receiver operating characteristic analysis determined BNP and hs-TnT levels of 60.9 pg/mL and 0.025 ng/mL, respectively, to be markers of high risk. Kaplan-Meier analysis demonstrated significant differences in the freedom from cardiac adverse events between Group A (BNP or hs-TnT elevated, n = 26) and Group B (both biomarkers elevated, n = 19; log-rank, p < 0.001). In conclusion, low birth weight (< 2500 g) and Ross/NYHA class ≥ 2.0 are strongly associated with cardiac adverse events. Preoperative BNP and hs-TnT also provide prognostic information in patients with complex CHD scheduled for surgery. Using both markers in combination predicts cardiac adverse events better than using either separately.

Detection of Early Myocardial Injury in Children with Ventricular Septal Defect Using Cardiac Troponin I and Two-Dimensional Speckle Tracking Echocardiography

Children with ventricular septal defects (VSDs) are subjected to hemodynamic overload which causes myocardial injury and subsequent heart failure. Early stages of myocardial damage cannot be detected by conventional echocardiography. Two-dimensional speckle tracking echocardiography (2D-STE) and cardiac troponin I (cTnI) have been recently introduced as more accurate tools for early assessment of cardiovascular diseases. The purpose of this study is to evaluate the role of cardiac troponin I (cTnI) and 2D-STE in the early detection of VSD-induced myocardial injury. Thirty children with VSD (symptomatic and asymptomatic) and 30 controls were assessed serologically by measuring serum cTnI and by conventional echocardiography. STE was performed to measure the averaged global peak longitudinal systolic stain [G peak SL(AVG)]. Serum cTnI levels were significantly higher in patients when compared to controls (P < 0.05) and in the symptomatic group when compared to the asymptomatic group (P < 0.05). Serum cTn I level correlated positively with the left atrial (r = 0.37, P = 0.045) and left ventricular dimensions (r = 0.46, P = 0.01) and negatively with the G peak SL(AVG) (r = -0.39, P = 0.03). There were no statistically significant differences between patients and controls or between symptomatic and asymptomatic groups with regard to the G peak SL(AVG). The peak longitudinal systolic strain (measured by 2D-STE) is not affected despite the elevation of serum cTnI. Serum cTnI is a sensitive marker for early detection of myocardial injury in VSD patients even before the development of ventricular dilatation or dysfunction.

Bilateral Remote Ischaemic Conditioning in Children (BRICC) trial: protocol for a two-centre, double-blind, randomised controlled trial in young children undergoing cardiac surgery

INTRODUCTION

Myocardial protection against ischaemic-reperfusion injury is a key determinant of heart function and outcome following cardiac surgery in children. However, with current strategies, myocardial injury occurs routinely following aortic cross-clamping, as demonstrated by the ubiquitous rise in circulating troponin. Remote ischaemic preconditioning, the application of brief, non-lethal cycles of ischaemia and reperfusion to a distant organ or tissue, is a simple, low-risk and readily available technique which may improve myocardial protection. The Bilateral Remote Ischaemic Conditioning in Children (BRICC) trial will assess whether remote ischaemic preconditioning, applied to both lower limbs immediately prior to surgery, reduces myocardial injury in cyanotic and acyanotic young children.

METHODS AND ANALYSIS

The BRICC trial is a two-centre, double-blind, randomised controlled trial recruiting up to 120 young children (age 3 months to 3 years) undergoing primary repair of tetralogy of Fallot or surgical closure of an isolated ventricular septal defect. Participants will be randomised in a 1:1 ratio to either bilateral remote ischaemic preconditioning (3×5 min cycles) or sham immediately prior to surgery, with follow-up until discharge from hospital or 30 days, whichever is sooner. The primary outcome is reduction in area under the time-concentration curve for high-sensitivity (hs) troponin-T release in the first 24 hours after aortic cross-clamp release. Secondary outcome measures include peak hs-troponin-T, vasoactive inotrope score, arterial lactate and central venous oxygen saturations in the first 12 hours, and lengths of stay in the paediatric intensive care unit and the hospital.

ETHICS AND DISSEMINATION

The trial was approved by the West Midlands-Solihull National Health Service Research Ethics Committee (16/WM/0309) on 5 August 2016. Findings will be disseminated to the academic community through peer-reviewed publications and presentation at national and international meetings. Parents will be informed of the results through a newsletter in conjunction with a local charity.

TRIAL REGISTRATION NUMBER

ISRCTN12923441.

Early assessment of cardiac troponin I predicts the postoperative cardiac status and clinical course after congenital heart disease surgery

Cardiac troponin I (cTnI) is a regulatory protein with a high sensitivity and specificity for cardiac injury. Preoperative and postoperative elevations of cTnI are usually considered predictors of the mortality and morbidity. However, little is known about the relationship between the cTnI and postoperative course after the congenital heart disease (CHD) operation. Sixty-five consecutive patients who underwent cardiac surgery for CHD at our institution between March 2016 and January 2017 were included. The cTnI was measured after the operation. Also, the association between the cTnI and duration of the catecholamine use, ICU stay, aortic cross clamp time, and other clinical parameters were assessed. The cTnI level on postoperative day 1 was positively correlated with the duration of the catecholamine use (p < 0.001) and ICU stay (p < 0.001). Also, a higher cTnI level was associated with a lower urine volume and higher lactate level 24 h after the ICU admission. In the multivariable regression analysis, the cTnI was a significant independent predictor of the catecholamine use (p = 0.002) and ICU stay (p = 0.003). The cTnI level on postoperative day 1 was a predictor of the duration of the catecholamine use and ICU stay.

Selective versus standard cerebro-myocardial perfusion in neonates undergoing aortic arch repair: A multi-center study

The results of neonatal aortic arch surgery using cerebro-myocardial perfusion were analyzed. Selective cerebral and myocardial perfusion, using two separate pump rotors, was compared with standard perfusion, using a single pump rotor with an arterial line Y-connector. Between May 2008 and May 2016, 69 consecutive neonates underwent arch repair using either selective cerebro-myocardial perfusion (Group A, n = 34) or standard perfusion (Group B, n = 35). The groups were similar for age, weight, BSA, prevalence of one-stage or staged repair, and single ventricle palliation; male gender was more frequent in Group A. The duration of the cerebro-myocardial perfusion was comparable (27 ± 8 vs. 28 ± 7 min, P = 0.9), with higher flows in Group A (57 ± 27 vs. 39 ± 19 mL/kg/min, P = 0.01). Although cardioplegic arrest was more common in Group B (13/34 vs. 23/35, P = 0.03), the duration of myocardial ischemia was longer in Group A (64 ± 41 vs. 44 ± 14 min, P = 0.04). There was 1 hospital death in each group, with no permanent neurological injury in either group. Cardiac morbidity (1/34 vs. 7/35, P = 0.02) was more common in Group B, while extracardiac morbidity was similar in both the groups. During follow-up (3.2 ± 2.4 years), 5 late deaths occurred with a comparable 5-year survival rate (75 ± 17% vs. 88 ± 6%, P = 0.7) and freedom from arch reintervention (86 ± 6% vs. 84 ± 7%, P = 0.6). Risk of cardiac morbidity was greater with standard cerebro-myocardial perfusion (OR = 5.2, CI 3.3-6.8, P = 0.001) and with perfusion flows less than 50 mL/kg/min (OR 3.7, CI 1.87-5.95, P = 0.04). Cerebro-myocardial perfusion is a safe and effective strategy to protect the brain and heart in neonates undergoing arch repair. Selective techniques using higher perfusion flows may further attenuate cardiac morbidity.

Neonatal Myocardial Perfusion in Right Ventricle Dependent Coronary Circulation: Clinical Surrogates and Role of Troponin-I in Postoperative Management Following Systemic-to-Pulmonary Shunt Physiology

Right ventricle dependent coronary circulation (RVDCC) in pulmonary atresia with intact ventricular septum (PA/IVS) is associated with significant mortality risk in the immediate post-operative period following the initial stage of surgical palliation. Prognosis remains guarded during the interstage period towards conversion to the superior cavopulmonary shunt physiology. Current literature is scarce regarding this specific patient population. Cardiac troponin-I is widely used as a marker of coronary ischemia in adults, but its use for routine monitoring of neonatal myocardial tissue injury due to supply/demand perfusion mismatch is, yet to be determined. We sought to evaluate the clinical correlation of cTnl perioperative use in a PA/IVS RVDCC case and assess its interplay with established clinical, echocardiographic, and laboratory variables in guiding a real-time (dynamic) management strategy following systemic-to-pulmonary shunt palliation.

Postoperative Serum Troponin Trends in Infants Undergoing Cardiac Surgery

Troponin-I (TN-I) levels are elevated following pediatric cardiac surgery with speculation that particular patterns may have prognostic significance. There is lack of procedure-specific data regarding postoperative TN-I levels in infants undergoing cardiac surgery. We hypothesized that TN-I elevation varies with type of surgery and persistent elevation predicts poor prognosis. We prospectively measured serial TN-I levels (preoperatively, 4, 8, 12, 24, and 48 hours postoperatively) in 90 infants (age < 1 year) undergoing cardiac surgery: off cardiopulmonary bypass (CPB) (n = 15), on CPB (n = 43), and on CPB with ventricular incision (CPB with ventricular incision; n = 32). All patients had undetectable baseline TN-I levels. The area under the curve of TN-I levels over the 48-hour period was significantly different among the surgical groups (P < 0.002), and highest in patients with CPB with ventricular incision. Generally, TN-I levels peaked by 4 hours after surgery and returned to near-normal levels within 48 hours. A persistent TN-I rise beyond 8 hours after surgery was a strong predictor of postoperative hypoperfusion injury (defined as a composite endpoint of end-organ injury resulting from inadequate perfusion, odds ratio 21.5; P = 0.001) and mortality (30% in those with persistently high TN-I, compared with 3.5% in the remaining patients; P < 0.001), independent of patient age, anatomy and/or complexity of surgery, and level of postoperative support. Our data provide benchmark values for TN-I levels following cardiac surgery in infants. Extent of TN-I elevation correlates with type of surgery. Persistent TN-I elevation beyond 8 hours after surgery is strongly associated with postoperative hypoperfusion injury and mortality.

Risk factor analysis for a complicated postoperative course after neonatal arterial switch operation: The role of troponin T

OBJECTIVE

To find risk factors for a complicated early postoperative course after arterial switch operation (ASO) in neonates with d-transposition of the great arteries (dTGA). In addition to anatomical and surgical parameters, the predictive value of early postoperative troponin T (TnT) values in correlation to the early postoperative course after ASO is analyzed.

METHODS

Seventy-nine neonates (57 (72%) male) with simple dTGA treated by ASO between 2009 and 2016 were included in the analysis. A complicated early postoperative course (30 days) was defined by one of the following criteria: (A) moderate to severe cardiac dysfunction without rhythm disturbances, (B) rhythm disturbances causing hemodynamic instability with the need for medical treatment, (C) signs for ischemia in ECG, (D) need for surgical or catheter interventional reinterventions other than diagnostic, or (E) other reasons.

RESULTS

Forty of 79 patients (51%) showed a complicated early postoperative course after ASO, with 2 patients dying after 13 and 16 days. Patients with a complicated early postoperative course had a longer PICU stay (P < .001), needed longer mechanical ventilator support (P = .001) and longer inotropic support (P = .03), and more reinterventions (surgical or catheter interventional) were necessary (P = .001). Only the presence of a VSD (P = .001) and longer surgery duration (P = .026) were associated to a complicated postoperative course. TnT values only showed a trend toward higher values in patients with a complicated postoperative course (P = .06). A secondary rise in TnT was seen in 10 patients, ranging from 11.6% to 410.2%, of whom 7 could be classified in the complicated postoperative group.

CONCLUSIONS

The postoperative course after ASO in dTGA neonates is influenced by other cardiac comorbidities like a VSD with the need for surgical treatment, influencing surgery duration. Postoperative higher TnT values reflect a longer and more vulnerable intraoperative course with limited predictive value on the early postoperative course.

Cardiac injury biomarkers in paediatric age: Are we there yet?

The aim of this article is to evaluate the clinical utility of cardiac injury biomarkers in paediatric age. In December 2015, a literature search was performed (PubMed access to MEDLINE citations; http://www.ncbi.nlm.nih.gov/PubMed/ ). The search strategy included the following medical subject headings and text terms for the key words: "cardiac injury biomarkers", "creatine kinase-MB", "myoglobin", "troponin", "children", "neonate/s", "newborn/s", "infant/s" and echocardiography. In the paediatric population, troponins show a good correlation with the extent of myocardial damage following cardiac surgery and cardiotoxic medication and can be used as predictors of subsequent cardiac recovery and mortality. Elevation of cardiac injury biomarkers may also have diagnostic value in cases when cardiac contusion or pericarditis is suspected. Cardiac injury biomarkers are very sensitive markers for the detection of myocardial injury and have been studied in healthy newborns, after tocolysis, intrauterine growth restriction, respiratory distress and asphyxia. The proportion of newborns with elevated troponin was higher than that in ill infants, children, and adolescents and in healthy adults, suggesting that myocardial injury, although clinically occult, is common in this young age group. Results suggest that significant elevation of cord troponin is an excellent early predictor of severity of hypoxic-ischaemic encephalopathy and mortality in term infants. Cardiac biomarkers may also benefit centres without on-site echocardiography with evidence showing good correlation with echo-derived markers of myocardial function. Further studies are needed to better clarify the role of cardiac biomarkers in paediatric age and their correlation with echocardiographic parameters.

Arrhythmias in Children in Early Postoperative Period After Cardiac Surgery

Background:

Postoperative arrhythmias are a known complication after cardiac surgical repairs for congenital heart disease.

Methods:

Data were reviewed pertaining to incidence, diagnosis, potential risk factors, and management of postoperative arrhythmias in 369 consecutive patients under 18 years of age, undergoing elective open heart surgery. All children were admitted to the intensive care unit and continuous electrocardiographic monitoring was performed. Patient factors such as Aristotle Basic Complexity Score, total surgical duration, hypotension, tachycardia, serum lactate level, and inotropic score were analyzed. Univariate analysis was done to assess associations between these factors and the occurrence of postoperative arrhythmias.

Results:

Twenty-five (6.7%) patients developed arrhythmias. Junctional ectopic tachycardia (JET) was the most common arrhythmia occurring in 15 (60%) patients, followed by supraventricular tachycardia in 3 (12%), ventricular premature contractions in 3 (12%), hemodynamically unstable ventricular tachycardia and fibrillation in 3 (12%), and atrial fibrillation in 1 (4%) patient. Different grades of heart block were noted in 13 patients. Aristotle score (P = .014), total surgical duration (P < .01), hypotension (P = .02), heart rate (beats per minute) (P = .001), serum lactate level (P = .04), and inotropic score (P = .02) in the early postoperative period were associated with arrhythmia occurrence. Surgeries for ventricular septal defect alone or in association with other diseases including tetralogy of Fallot (TOF) and transposition of the great arteries (TGA) were found to be associated with higher risk of arrhythmias.

Conclusion:

This study showed a low incidence of arrhythmias, JET being the commonest, seen more in TOF repair and these could be treated efficiently. Higher Aristotle score, longer surgical time, hypotension, tachycardia, high inotropic score, and high serum lactate levels were associated with the occurrence of arrhythmias postoperatively.

Management of postoperative junctional ectopic tachycardia in pediatric patients: a survey of 30 centers in Germany, Austria, and Switzerland

Postoperative junctional ectopic tachycardia (JET) is a frequent complication after pediatric cardiac surgery. Current recommendations on how and when to treat JET are inconsistent. We evaluated the management strategies of postoperative JET in German-speaking countries. We sent an online survey to 30 centers of pediatric cardiology that perform surgery for congenital heart defects in Germany (24), Austria (4), and Switzerland (2). The survey asked 18 questions about how and in what treatment sequence postoperative JET was managed. All 30 centers completed the survey (100% return rate). There was general agreement that the management of JET is based on administration of antiarrhythmic drugs, body surface cooling, and temporary pacing. Many centers presented treatment algorithms based on published literature, all centers named amiodarone as the first drug of choice. Significant disagreement was found concerning the timing and sequential order of additional therapeutic measures and particularly about the dosing of amiodarone and the role of R-wave synchronized atrial pacing.

CONCLUSION

This survey reveals that from center to center, the treatment of postoperative JET may vary substantially. Future work should focus on those treatment modalities where a high rate of variation is found. Such studies may be of value to achieve commonly adopted treatment recommendations. What is known: • Treatment of postoperative junctional ectopic tachycardia is predominantly based on administration of antiarrhythmic drugs, therapeutic cooling, and temporary pacing. • Amiodarone is the antiarrhythmic drug of choice in this context. What is new: • Dosing and duration of administration of amiodarone differ relevantly from center to center. • The sequential order of drug administration, therapeutic cooling, and pacing is not consistent.

Arterial Switch Operation and Plasma Biomarkers: Analysis and Correlation with Early Postoperative Outcomes

The aims of our study were to describe plasma brain natriuretic peptide (BNP), Troponin I (TnI), and Cystatin C (Cys-C) concentration kinetics in the postoperative period after arterial switch operation in neonate, and to test the correlation between the plasma biomarkers and early clinical outcomes. We prospectively enrolled 29 neonates who underwent ASO. All patients received Custodiol cardioplegia. Blood samples were collected preoperatively (one day before) and in the ICU immediately after admission, and then 6, 12, 24, and 48 h after surgery. TnI peak (mean 17.23 ± 7.0 ng/mL) occurred between the arrival in the ICU and the 6th hour, then we had a constant decrease. TnI had a good correlation with the inotropic support time (r = 0.560, p = 0.0015) and ICU time (r = 0.407, p = 0.028), less than with ventilation and Hospital stay (r = 0.37, p = 0.0451 and r = 0.385, p = 0.0404). BNP peak (mean 4773.79 ± 2724.52 ng/L) was in the preoperative time with a constant decrease after the operation and it had no significant correlations with clinical outcomes. The CyS-C had the highest preoperative values, which decreased during the operating phase, and then constantly increased upon arrival to the ICU with a peak at 48 h (mean 1.76 ± 0.35 mg/L). CyS-C peak had a good correlation with a plasmatic creatinine peak (r = 0.579, p = 0.0009) but not with other clinical outcomes. Our study demonstrated significant correlations between the Tnl peak and early clinical outcomes in neonates undergoing arterial switch operation. Other plasma biomarkers such as the BNP and CyS-C had no direct correlation.

Cardiac Biomarkers of Low Cardiac Output Syndrome in the Postoperative Period After Congenital Heart Disease Surgery in Children

INTRODUCTION AND OBJECTIVES

To assess the predictive value of atrial natriuretic peptide, β-type natriuretic peptide, copeptin, mid-regional pro-adrenomedullin (MR-proADM) and cardiac troponin I (cTn-I) as indicators of low cardiac output syndrome in children with congenital heart disease undergoing cardiopulmonary bypass (CPB).

METHODS

After corrective surgery for congenital heart disease under CPB, 117 children (aged 10 days to 180 months) were enrolled in a prospective observational pilot study during a 2-year period. The patients were classified according to whether they developed low cardiac output syndrome. Biomarker levels were measured at 2, 12, 24, and 48 hours post-CPB. The clinical data and outcome variables were analyzed by a multiple logistic regression model.

RESULTS

Thirty-three (29%) patients developed low cardiac output syndrome (group 1) and the remaining 84 (71%) patients were included in group 2. cTn-I levels >14 ng/mL at 2hours after CPB (OR, 4.05; 95%CI, 1.29-12.64; P=.016) and MR-proADM levels>1.5 nmol/L at 24hours following CPB (OR, 15.54; 95%CI, 4.41-54.71; P<.001) were independent predictors of low cardiac output syndrome.

CONCLUSIONS

Our results suggest that cTn-I at 2hours post-CPB is, by itself, an evident independent early predictor of low cardiac output syndrome. This predictive capacity is, moreover, reinforced when cTn-I is combined with MR-proADM levels at 24hours following CPB. These 2 cardiac biomarkers would aid in therapeutic decision-making in clinical practice and would also enable clinicians to modify the type of support to be used in the pediatric intensive care unit.

Micro-RNA-208a, -208b, and -499 as Biomarkers for Myocardial Damage After Cardiac Surgery in Children

OBJECTIVES

To test the hypothesis that cardiac-enriched micro-RNAs can serve as accurate biomarkers that reflect myocardial injury and to predict the postoperative course following pediatric cardiac surgery. Micro-RNAs have emerged as plasma biomarkers for many pathologic states. We aimed to quantify preoperative and postoperative plasma levels of cardiac-enriched micro-RNA-208a, -208b, and -499 in children undergoing cardiac surgery and to evaluate correlations between their levels, the extent of myocardial damage, and the postoperative clinical course.

DESIGN

PICU.

PATIENTS

Thirty pediatric patients that underwent open heart surgery for the correction of congenital heart defects between January 2012 to July 2013.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

At 12 hours post surgery, the plasma levels of the micro-RNAs increased by 300- to 4,000-fold. At 24 hours, their levels decreased but remained significantly higher than before surgery. Micro-RNA levels were associated with troponin levels, longer cardiopulmonary bypass and aortic crossclamp times, maximal postoperative aspartate aminotransferase levels, and delayed hospital discharge.

CONCLUSIONS

Circulating micro-RNA-208a, -208b, and -499 are detectable in the plasma of children undergoing cardiac surgery and may serve as novel biomarkers for monitoring and forecasting postoperative myocardial injury and recovery.

Does Postoperative Cardiac Troponin-I Have Any Prognostic Value in Predicting Midterm Mortality After Congenital Cardiac Surgery?

OBJECTIVES

This study evaluated the prognostic value of postoperative cardiac troponin-I (cTnI) in predicting all-cause mortality up to 3 months after normothermic congenital cardiac surgery.

DESIGN

Prospective observational study.

SETTING

University hospital.

PARTICIPANTS

All children ages 0 to 10 years.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

cTnI was measured after the induction of anesthesia but before the surgery, at the pediatric intensive care unit arrival, and at 4, 12, and 24 hours postoperatively. Follow-up was extended up to 6 months. Overall, 169 children were analyzed, of whom 165 were survivors and 4 were nonsurvivors. cTnI levels were significantly higher in nonsurvivors only at 24 hours (p = 0.047). Children undergoing surgery with cardiopulmonary bypass (CPB) had significantly higher cTnI concentrations compared with those without CPB (p<0.001). Logistic regression analysis was performed on the 146 children in the CPB group with the following predictive variables: CPB time, postoperative cTnI concentrations, the presence of a cyanotic malformation, and intramyocardial incision. None of the variables predicted mortality. Postoperative cTnI concentrations did not predict 6 months׳ mortality. Only cTnI at 24 hours predicted the length of stay in the pediatric intensive care unit.

CONCLUSIONS

This study did not find that postoperative cTnI concentration predicted midterm mortality after normothermic congenital heart surgery. (ClinicalTrials.gov identifier: NCT01616394).

Early postoperative arrhythmias after pediatric cardiac surgery

BACKGROUND

This prospective study proposed to determine the incidence, risk factors, and management protocols for early postoperative arrhythmias after pediatric cardiac surgery, with focus on outcomes, using a uniform protocol, and also to see if children operated on at a later age have different issues from those operated on earlier.

METHODS

Of 224 consecutive pediatric patients undergoing cardiac surgery from September 2013 to July 2014, 24 were excluded because their procedures were performed without cardiopulmonary bypass.

RESULTS

The median age was 24 months (mean 50.1 ± 62.4 months, range 0.5-216 months). Fifteen (7.5%) patients developed arrhythmia, the most common was junctional ectopic tachycardia (n = 7, 46.6%) followed by supraventricular tachycardia (n = 5, 33.3%). All junctional ectopic tachycardias occurred within 24 h of intensive care unit admission. Of the 7 patients with junctional ectopic tachycardia, 5 responded to conventional measures and 2 required amiodarone infusion. There was a significant longer cardiopulmonary bypass time in patients with arrhythmias compared to those without arrhythmias.

CONCLUSION

We observed a very low incidence of arrhythmias, particularly junctional ectopic tachycardia, after open heart surgery in children. Other than a longer cardiopulmonary bypass time, no specific predictors were identified. It appears that the cause of arrhythmias following pediatric cardiac surgery is multifactorial and needs further study with a greater number of patients.

Prevalence of and risk factors for early postoperative arrhythmia in children after cardiac surgery

BACKGROUND

The aims of this study were to (i) evaluate postoperative arrhythmias following congenital heart surgery, on 12-lead electrocardiography and Holter monitoring; and (ii) analyze the association between the type of repair and postoperative arrhythmia.

METHODS

A total of 229 children and 10 neonates with a mean age of 4.71 ± 0.41 years (range, 15 days-17 years) who underwent congenital cardiac surgery were included the study. Twelve-lead electrocardiography and Holter monitoring were used to evaluate arrhythmias after the operation.

RESULTS

Within the evaluation period, 104 patients (43.5%) developed arrhythmias after surgery. No arrhythmias were observed in neonates. Female sex (51.9%) was slightly associated with the occurrence of arrhythmias after operation. The most common arrhythmia was supraventricular extra-systoles (65.4%). Risk factors for supraventricular extra-systoles were repair of secundum atrial septal defect (32.3%), ventricular septal defect (25%) and tetralogy of Fallot (14.7%). Also, ventricular extra-systoles were associated with repair of ventricular septal defect.

CONCLUSIONS

Postoperative arrhythmia is usually a frequent and transient phenomenon after congenital cardiac surgery, and is provoked by both mechanical irritation of the conduction system and humoral factors. Postoperative arrhythmia should be anticipated in patients with congenital cardiac surgery. Finally, the association between this type of surgical repair and arrhythmia may be helpful for estimating the type of arrhythmia that develops after congenital cardiac surgery in children.

Cardiac troponin I after cardiopulmonary bypass in infants in comparison with older children

OBJECTIVE

At the present time, there is a trend towards performing open heart surgery at a younger age. Myocardium of infants has been thought to be more vulnerable to cardiopulmonary bypass in comparison with adults. For this study, we evaluated the degree of myocardial injury by measurement of cardiac troponin levels in infants in comparison with older children for similar surgeries.

METHODS

Serum was collected before bypass, after bypass, and daily after surgery and serum cardiac troponin I level (micrograms per litre). The demographic data, cardiac diagnoses, types of surgery performed, and peri-operative parameters were collected.

RESULTS

Of the 21 children enrolled consecutively, five were infants. Among the 21 patients, four patients had post-operative peak troponin values greater than 100 (three were infants) and all four patients survived and had normal left ventricular systolic function upon discharge echocardiogram. The five infants had peak troponin levels of 222.3, 202, 129, 26.7, and 82.3. The post-operative peak troponin levels were significantly higher in infants (mean 132.5 with a standard deviation of 81.6) than in the older children (mean 40.3 with a standard deviation of 33.4), although there was no significant difference in bypass time, bypass temperature, cross-clamp time, or the length of stay in the intensive care unit between the two age groups.

CONCLUSIONS

Higher troponin release is seen in infants in comparison with older children after bypass for similar surgeries. A troponin level greater than 100 after bypass does not necessarily predict death or a severe cardiovascular event in the very young.

Effect of remote ischemic preconditioning on phosphorylated protein signaling in children undergoing tetralogy of Fallot repair: a randomized controlled trial

BACKGROUND

Our previous randomized controlled trial demonstrated cardiorespiratory protection by remote ischemic preconditioning (RIPC) in children before cardiac surgery. However, the impact of RIPC on myocardial prosurvival intracellular signaling remains unknown in cyanosis. RIPC may augment phosphorylated protein signaling in myocardium and circulating leukocytes during tetralogy of Fallot (ToF) repair.

METHODS AND RESULTS

Children (n=40) undergoing ToF repair were double-blind randomized to RIPC (n=11 boys, 9 girls) or control (sham RIPC: n=9 boys, 11 girls). Blood samples were taken before, immediately after, and 24 hours after cardiopulmonary bypass. Resected right ventricular outflow tract muscle and leukocytes were processed for protein expression and mitochondrial respiration. There was no difference in age (7.1 ± 3.4 versus 7.1 ± 3.4 months), weight (7.7 ± 1.8 versus 7.5 ± 1.9 kg), or bypass or aortic cross-clamp times between the groups (control versus RIPC, mean±SD). No differences were seen between the groups for an increase in the ratio of phosphorylated to total protein for protein kinase B, p38 mitogen activated protein kinase, signal transducer and activator of transcription 3, glycogen synthase kinase 3β, heat shock protein 27, Connexin43, or markers associated with promotion of necrosis (serum cardiac troponin I), apoptosis (Bax, Bcl-2), and autophagy (Parkin, Beclin-1, LC3B). A high proportion of total proteins were in phosphorylated form in control and RIPC myocardium. In leukocytes, mitochondrial respiration and assessed protein levels did not differ between groups.

CONCLUSIONS

In patients with cyanotic heart disease, a high proportion of proteins are in phosphorylated form. RIPC does not further enhance phosphorylated protein signaling in myocardium or circulating leukocytes in children undergoing ToF repair.

CLINICAL TRIAL REGISTRATION

URL: (http://www.anzctr.org.au/trial_view.aspx?id=335613. Unique identifier: Australian New Zealand Clinical Trials Registry number ACTRN12610000496011.

Use and misuse of serum troponin assays in pediatric practice

Cardiac troponin (cTn) is instrumental in screening and diagnosing myocardial ischemia in adults. However, the role of cTn screening in the pediatric population is less clear. The purpose of this study was to evaluate the current clinical practice, diagnostic and prognostic value, and resource utilization associated with cTn assays in the pediatric population. A multicenter, retrospective review of all cTn assays performed on patients aged ≤18 years from January 2003 to December 2010 in the Intermountain Healthcare system was conducted. Data collected included patient demographics, location, presenting symptoms, provisional and discharge diagnoses, additional tests, clinical outcomes (hospitalization days, ventilation, and death), and patient charges. During the study period, cTn assays were performed on 3,497 pediatric patients. The most common presenting diagnoses were chest pain (40%), trauma (11%), and poisoning or drug overdose (9%). Irrespective of diagnosis, elevated cTn was associated with an increased rate of hospitalization, ventilation, and death. Overall, 12% of patients had elevated cTn. Of the patients with chest pain, 4% had elevated cTn, 53% of whom were diagnosed with myopericarditis. In the myopericarditis group, 66% presented with fever, and 98% had abnormal electrocardiographic findings. For patients presenting with chest pain, approximately $162,000 was spent per positive result. In conclusion, cTn screening has strong prognostic value in pediatric patients, even in noncardiac diagnoses such as trauma or drug overdose. However, cTn screening in pediatric patients with chest pain provides minimal benefits and is associated with increased resource utilization, unless patients have constitutional symptoms, such as fever and/or electrocardiographic abnormalities.

Early elevation of cardiac troponin I is predictive of short-term outcome in neonates and infants with coronary anomalies or reduced ventricular mass undergoing cardiac surgery

OBJECTIVE

The present study aimed to assess the usefulness of routine monitoring of cardiac troponin I concentrations within 24 hours of surgery (cTn-I<24h) in neonates and infants undergoing cardiac surgery.

METHODS

The added predictive ability of a high peak cTn-I<24h (within the upper quintile per procedure) for a composite outcome, including 30-day mortality and severe morbidity, was assessed retrospectively. The predicted risk for the composite outcome was estimated from a logistic regression model including preoperative and intraoperative variables. Adding a high peak cTn-I<24h to the risk model resulted in reclassification of the predicted risk. It also allowed quantification of the improvement in reclassification and discrimination by the difference between c-indexes, the Net Reclassification and the Integrated Discrimination Indexes (NRI and IDI).

RESULTS

Overall, 1023 consecutive patients were included. Adding a high peak cTn-I<24h to the model resulted in no improvement in reclassification or discrimination in the overall population (difference between c-indexes: 0.011 [-0.004 to 0.029], NRI = 0.06, P = .22, IDI = 0.02, P = .06), except in a subgroup of patients undergoing the arterial switch operation with or without ventricular septal defect closure and/or aortic arc repair, anomalous origin of the left coronary artery from the pulmonary artery repair, truncus arteriosus repair, Norwood procedure, and Sano modification, in whom NRI = 0.23 (P = .005) and IDI = 0.05 (P < .001).

CONCLUSIONS

Patients with coronary anomalies and patients with reduced ventricular mass should benefit from the routine monitoring of cTn-I concentrations after surgery for congenital cardiac disease.

Prevalence of and risk factors for perioperative arrhythmias in neonates and children after cardiopulmonary bypass: continuous holter monitoring before and for three days after surgery

Background

A comprehensive evaluation of postoperative arrhythmias following surgery for congenital heart disease by continuous Holter monitoring has not been carried out. We aimed, firstly, to establish the time course of pre- and early postoperative arrhythmias by beat-to-beat analysis following cardiopulmonary bypass and, secondly, to examine which surgical procedures present risk factors for specific arrhythmias.

Methods

494 consecutive patients, including 96 neonates, were studied with serial 24-hour Holter electrocardiograms before as well as uninterruptedly during the first 72 hours after surgery and prior to discharge.

Results

Within 24 hours of surgery 59% of the neonates and 79% of the older children developed arrhythmias. Junctional ectopic tachycardia occurred in 9% of neonates and 5% of non-neonates and ventricular tachycardia in 3% and 15%, respectively.

For neonates, male sex and longer cross-clamping time independently increased the risk for arrhythmias (odds ratios 2.83 and 1.96/minute, respectively). Ventricular septal defect repair was a strong risk factor for junctional ectopic tachycardia in neonates and in older children (odds ratios 18.8 and 3.69, respectively). For infants and children, older age (odds ratio 1.01/month) and closure of atrial septal defects (odds ratio 2.68) predisposed to arrhythmias of any type.

Conclusions

We present the largest cohort of neonates, infants and children that has been prospectively studied for the occurrence of arrhythmias after cardiac surgery. Postoperative arrhythmias are a frequent and transient phenomenon after cardiopulmonary bypass, provoked both by mechanical irritation of the conduction system and by humoral factors.

Early pleural effusions related to the myocardial injury after open-heart surgery for congenital heart disease

OBJECTIVES

The degree of effusion immediately after cardiopulmonary bypass (CPB) can vary and may reflect several factors including the degree of myocardial injury. We compared the degree of pleural effusions after CPB to the overall myocardial injury as determined by serum cardiac troponin I (cTnI) levels after elective repair of a variety of congenital heart defects, including univentricular surgeries via cavopulmonary shunts.

METHODS

Serum was collected pre-CPB, post-CPB, and daily after that and cTnI level measured. The postoperative pleural effusion was measured each day until the chest tube was removed. Results. The 21 study patients were of average age of 5.5 years (+/-5.6). The duration of chest-tube drainage after open-heart surgery was 4.3 days (+/-3.5) and the amount was 2.4 mL/kg/hour (+/-2.9). For the biventricular repairs, cTnI levels on the postoperative day (POD) 1 best correlated with amount of effusion (n = 16, r = 0.5, P = 0.02) and the average (POD 0-3) cTnI levels with the total duration (n = 16, r = 0.4, P = 0.01) and also the amount (n = 16, r = 0.5, P = 0.02) of effusions. For the cavopulmonary shunts, the post-CBP cTnI level best correlated with the duration (n = 5, r = 0.8, P = 0.02) and amount (n = 5, r = 0.9, P = 0.02) of effusions. A cTnI level on the first postoperative day >or=15 microg/L was associated with effusions >2 days (sensitivity of 81% and specificity of 80%).

CONCLUSION

We found that higher the cTnI released, especially >or=15 microg/L, longer the duration and greater the amount of early pleural effusions for a variety of congenital heart surgeries including cavopulmonary shunts. A number of factors may lead to excessive pleural effusions and the degree of myocardial injury may be one of them.

Increases of cardiac troponin in conditions other than acute coronary syndrome and heart failure

BACKGROUND

Although cardiac troponin (cTn) is a cornerstone marker in the assessment and management of patients with acute coronary syndrome (ACS) and heart failure (HF), cTn is not diagnostically specific for any single myocardial disease process. This narrative review discusses increases in cTn that result from acute and chronic diseases, iatrogenic causes, and myocardial injury other than ACS and HF.

CONTENT

Increased cTn concentrations have been reported in cardiac, vascular, and respiratory disease and in association with infectious processes. In cases involving acute aortic dissection, cerebrovascular accident, treatment in an intensive care unit, and upper gastrointestinal bleeding, increased cTn predicts a longer time to diagnosis and treatment, increased length of hospital stay, and increased mortality. cTn increases are diagnostically and prognostically useful in patients with cardiac inflammatory diseases and in patients with respiratory disease; in respiratory disease cTn can help identify patients who would benefit from aggressive management. In chronic renal failure patients the diagnostic sensitivity of cTn for ACS is decreased, but cTn is prognostic for the development of cardiovascular disease. cTn also provides useful information when increases are attributable to various iatrogenic causes and blunt chest trauma.

SUMMARY

Information on the diagnostic and prognostic uses of cTn in conditions other than ACS and heart failure is accumulating. Although increased cTn in settings other than ACS or heart failure is frequently considered a clinical confounder, the astute physician must be able to interpret cTn as a dynamic marker of myocardial damage, using clinical acumen to determine the source and significance of any reported cTn increase.

[Cardiac biomarkers for diagnosis of myocardial infarction]

Diagnosis of postoperative myocardial infarction is often difficult, based on tools with a low sensitivity (clinical symptoms, EKG), or with a low specifity (old biomarkers, echocardiographic abnormalities) or inadequate for clinical practice (scintigraphy). Since 1995, clinicians may use more cardiospecific markers (troponin) allowing to modify strategy for postoperative myocardial infarction diagnosis. The aim of this review is to resume such an attitude.

Release of cardiac biochemical and inflammatory markers in patients on cardiopulmonary bypass undergoing coronary artery bypass grafting

BACKGROUND

Determination of cardiac markers can assess cardiac injury induced by cardiopulmonary bypass (CPB) during coronary artery bypass grafting (CABG). However, the markers and their release pattern are not well defined. This study was aimed at assessing the release and timing of cardiac biochemical and inflammatory markers in patients undergoing elective CABG with CPB.

METHODS

Forty patients undergoing elective CABG were included in this study. Blood samples were collected for biochemical measurements at the following time points: immediately prior to the induction of anesthesia, one, six, 12, and 24 hours after initiation of CPB.

RESULTS

Increased release of cardiac troponin I was observed one hour after initiation of CPB (p < 0.05) and reached the maximum at 12 hours after CPB (p < 0.01). Serum CK-MB enzyme activity and CK-MB mass both were highly elevated starting at one hour after initiation of CPB, peaked at six hours, and remained elevated until 24 hours after CPB. Both lactate and lactate dehydrogenase were highly elevated six hours after CPB and peaked at 12 hours after CPB (p < 0.01). Serum levels of interleukin-6 and tumor necrosis factor-alpha increased significantly one hour after initiation of CPB and peaked at six hours (p < 0.01), while serum high sensitivity C-reactive protein levels started to elevate 12 hours after CPB (p < 0.01).

CONCLUSION

Monitoring of these markers could help to determine implementation of protective interventions during CABG with CPB to prevent myocardial deterioration and to predict the risk and prognosis.

Value of brain natriuretic peptide in the perioperative follow-up of children with valvular disease

OBJECTIVE

To characterize N-terminal pro-brain natriuretic peptide (N-proBNP) and troponin I (TnI) profile following mitral and/or aortic valve surgery and to evaluate correlations with echocardiography measures and outcome criteria.

DESIGN AND SETTING

Prospective cross-controlled study in a university children's hospital.

PATIENTS

Twenty children with acquired valvular disease requiring valvular surgery.

INTERVENTIONS

We prospectively studied clinical, biochemical, and echocardiographic characteristics at baseline and 6, 12, 24 h and 3-4 weeks postoperatively.

RESULTS

TnI peaked 6 h after surgery and remained elevated during the first 24 h. N-proBNP was significantly lower 3-4 weeks after surgery than during the perioperative period. Overall, N-proBNP was correlated with the Pediatric Heart Failure Index, left ventricle shortening fraction, left atrium to aorta ratio, left ventricle mass index, end-systolic wall stress, and with outcome measures such as inotropic score, duration of inotropic support, and ICU length of stay. Preoperative N-proBNP was significantly more elevated in patients with complicated outcome than in patients with uneventful postoperative course.

CONCLUSIONS

In pediatric valvular patients, perioperative N-proBNP is a promising risk stratification predicting factor. It is correlated with evolutive echocardiographic measures, need for inotropic support, and ICU length of stay.

Serum troponin in neonatal intensive care

Cardiac troponins have a major role in screening and diagnosis of myocardial ischaemia in adults and children. Their introduction has redefined the diagnosis of myocardial infarction in adults and provided valuable prognostic information. In the paediatric population, troponins show a good correlation with the extent of myocardial damage following cardiac surgery and cardiotoxic medication, and can be used as predictors of subsequent cardiac recovery and mortality. This review discusses the current established reference values in term and preterm infants and demonstrates their potential use in neonatology. They may serve as a useful adjunct in the assessment of the magnitude of myocardial injury in respiratory distress syndrome and asphyxia. They may also benefit centres without on-site echocardiography with some evidence showing good correlation with echo-derived markers of myocardial function. The use of troponins in the neonatal unit remains a research tool. More work is needed to explore their prognostic role and monitoring response to treatment following cardioprotective strategies. In preterm infants the effect of inotropes on myocardial function needs further study and troponin may form an integral part of this research.

Time course and prognostic value of plasma B-type natriuretic peptide concentration in neonates undergoing the arterial switch operation

BACKGROUND

Plasma B-type natriuretic peptide (BNP) can predict postoperative complications after cardiac surgery in adults. Our aim was to investigate BNP kinetics and prognostic value in neonates undergoing the arterial switch operation (ASO) for transposition of the great arteries (TGA).

METHODS

We measured BNP concentrations in 30 neonates before, immediately after, and 6, 12, 24, and 48 h after ASO for TGA. Complicated postoperative evolution was defined as patients requiring mechanical ventilation or presenting low cardiac output syndrome for more than 72 h. We studied the ability of postoperative BNP concentrations to predict complicated evolution.

RESULTS

Intubation duration, inotropic support duration, and intensive care unit stay were 68 (48-121) h, 78 (69-141) h, and 96 (76-149) h respectively. Patients with complicated evolution had higher 6 and 12-h BNP concentrations than patients with simple evolution (459 (210-897) vs 137 (67-248) ng/L and 547 (193-868) vs 185 (79-354) ng/L respectively; P < 0.05) and had longer intubation, inotropic support, and intensive care unit stay (96 (70-190) vs 50 (48-66) h, 100 (83-190) vs 70 (59-72) h, and 120 (90-240) vs 84 (72-96) h, P < 0.05). A 6-h BNP concentration >160 ng/L was able to predict complicated evolution with a sensitivity of 93% and a specificity of 67%.

CONCLUSION

In neonates, BNP concentrations can predict adverse outcome in the postoperative period after ASO for TGA. This marker has potential clinical applications.

Intermittent warm blood cardioplegia in the surgical treatment of congenital heart disease: Clinical experience with 1400 cases

OBJECTIVE

To analyze our experience with warm blood cardioplegia in pediatric cardiac surgery.

METHODS

We used intermittent (every 15 minutes after initial injection) warm blood cardioplegia in the treatment of 1400 patients. Results were retrospectively compared with those of 950 patients treated with cold blood cardioplegia. The following parameters were analyzed: (1) hydric balance of cardioplegic solution; (2) resumption of rhythm after aortic crossclamp removal; (3) duration of mechanical ventilation, intensive care unit stay, and incidence of mortality in 4 selected diagnostic groups: ventricular septal defect, tetralogy of Fallot, atrioventricular septal defect, and transposition of the great arteries. These 4 groups, treated with warm or cold cardioplegia, were comparable with regard to age, weight, crossclamp times, and percent with Down syndrome; (4) troponin level at 12 hours after aortic crossclamping; and (5) duration of intensive care unit stay for the 1400 patients.

RESULTS

Warm versus cold cardioplegia: negligible fluid addition with warm cardioplegia compared with blood loss/prime dilution induced by cold cardioplegia; spontaneous resumption of sinus rhythm in 99% versus 77% of patients (P < .001); shorter duration of ventilatory support in each diagnostic group, significant in all cases; smaller increase in troponin in each group (P < .05). Incidence of early death was not different in the 2 groups. For the whole group, duration of the intensive care unit stay was less than 48 hours in 86% versus 75% (P < .001).

CONCLUSION

In our experience, normothermic cardioplegia has not generated any particular inconvenience and its use was contemporary, with improved outcomes.

Segmental Wall-Motion Abnormalities After an Arterial Switch Operation Indicate Ischemia

We prospectively studied 29 consecutive neonates undergoing an arterial switch operation to determine if segmental wall motion abnormalities (SWMA) represented myocardial ischemia. Intraoperative transesophageal echocardiogram was recorded at baseline and twice after cardiopulmonary bypass. Cardiac troponin I (cTnI) levels were measured before sternal incision and 3, 6, 12, 24, 48, and 72 h after removal of the aortic cross-clamp. Immediate postoperative Holter and 15-lead electrocardiograms (ECG) were evaluated for ischemia. Transthoracic echocardiograms were obtained before hospital discharge. At bypass termination, immediately after protamine administration, segmental wall motion was normal in nine neonates and abnormal in 20. SWMA were transient in five and present at the time of chest closure in 15 neonates. Neonates in whom SWMA were present at chest closure had more segments involved than those in whom SWMA were transient (P > 0.001). Neonates with SWMA at chest closure had higher cTnI levels postoperatively versus neonates with normal wall motion (P = 0.02). Postoperative ECG data were available in 26 neonates. There was ECG evidence of myocardial ischemia in two of eight neonates with normal wall motion, one of five with transient SWMA, and nine of 13 with SWMA at chest closure. CTnI levels at 12, 24, and 48 h and intraoperative SWMA were predictive of postoperative SWMA. We believe these data indicate that SWMA, which persist at the completion of an arterial switch operation, and which are present in multiple myocardial segments, correlate with myocardial ischemia. Further follow-up of these patients is needed to determine if increased intraoperative myocardial ischemia correlates with long-term outcomes.

Sodium pump reduction correlates with aortic clamp time in pediatric heart surgery

Myocardial depression after cardiac surgery is modulated by cardiopulmonary bypass (CPB) and the underlying heart disease. The sodium pump is a key component for myocardial function. We hypothesized that the change in sodium pump expression during CPB correlates with intraoperative and postoperative laboratory and clinical parameters in neonates and children with various congenital heart defects. Sodium pump isoforms alpha1 (ATP1A1) and alpha3 (ATP1A3) mRNA expression in right atrial myocardium, excised before and after CPB, was quantified. Groups were assigned according to presence (VO group, n = 8) or absence (NO group, n = 8) of right atrial volume overload. CPB and aortic clamp time correlated with postoperative troponin-I values and ICU stay. ATP1A1 (P = 0.008) and ATP1A3 (P = 0.038) mRNA expression were significantly reduced during CPB. Longer aortic clamp times were associated with lower postoperative ATP1A1 (P = 0.045) and ATP1A3 (P = 0.002) mRNA expression. Low postoperative ATP1A1 (P = 0.043) and ATP1A3 (P = 0.002) expressions were associated with high troponin-I values. These results were restricted to the VO group. No correlation of sodium pump mRNA expression was found with the duration of ICU stay or ventilation. The postoperative troponin-I and clinical parameters correlated with the length of CPB, regardless of volume overload. In contrast, only dilated right atrium seemed to be susceptible to CPB in terms of sodium pump expression, showing a reduction during the operation and a correlation of sodium pump with postoperative troponin-I values.

Comparison of classifications for heart failure in children undergoing valvular surgery

OBJECTIVES

To characterize correlations between clinical classifications of heart failure and diagnostic workup.

STUDY DESIGN

Pre- and postoperative characteristics of 20 children with heart failure secondary to valvular rheumatic disease were studied.

RESULTS

Both scoring systems correlated with N-terminal pro-brain natriuretic peptide (N-proBNP) but not with troponin I (TnI). The PHFI correlated with N-proBNP, end-systolic wall stress, left ventricular mass index and left atrium to aorta diameter ratio. No correlation could be established between modified Ross score, or the New York Heart Association (NYHA) grade and echocardiographic measurements. Cardiothoracic and Sokolow indexes were correlated with the PHFI as well as to the NYHA classification.

CONCLUSION

In this study, PHFI seems better correlated with radiologic, electrocardiographic, echocardiographic, and biologic assessment of heart failure in children. Clinical severity was correlated with N-proBNP but not with TnI.

Frequency of clinically unsuspected myocardial injury at a children's hospital

BACKGROUND

Ill children are at risk but rarely screened for myocardial injury. The frequency of such injury in ill children is unknown. Elevated levels of plasma cardiac troponin I (cTnI) can detect subclinical myocardial injury.

METHODS

We measured cTnI levels from 283 Children's Hospital, Boston patients (median age 2.10 years, range 0.13-22.4 years) seen in an outpatient or emergency clinic without clinically apparent cardiac disease. We took > or = 0.5 ng/mL as an indication of myocardial injury. We also measured plasma creatine kinase-MB, total creatine kinase, and myoglobin, and performed a chart review.

RESULTS

Fifteen (7.8%) of the 193 acutely ill children and 4 (4.4%) of the 90 well children had an elevated cTnI level (P = .44). Within the acutely ill group, the children with elevated cTnI were younger and had lower mean hemoglobin and hematocrit levels. Cardiac troponin I levels correlated with creatine kinase-MB (r = 0.22; P < .001) but not with creatine kinase or myoglobin. The 4 children with cTnI > 0.89 ng/mL, who also had plasma cardiac troponin T measured, showed cardiac troponin T elevations that were consistent with unstable angina levels in adults. Four children had high-level cTnI elevations (> 2 ng/mL) consistent with acute myocardial infarction levels in adults.

CONCLUSIONS

Elevated cTnI levels occur in children without clinically apparent cardiac disease and can be at adult unstable angina or acute myocardial infarction levels. Prospective studies to determine the clinical significance of these findings and their relationship to the development of cardiomyopathy are warranted.