Andreas Hanslik

Predictors of Spontaneous Closure of Isolated Secundum Atrial Septal Defect in Children: A Longitudinal Study

OBJECTIVES. The goals were to assess the frequency of spontaneous closure of isolated secundum atrial septal defect in children and to identify predictors of spontaneous atrial septal defect closure. METHODS. A retrospective cohort study was performed in a tertiary care pediatric cardiology center. Consecutive patients (n = 200) diagnosed as having isolated atrial septal defects (no multiple or fenestrated atrial septal defects, no additional congenital heart disease, and no syndromes) were monitored for >6 months with serial 2-dimensional echocardiography, according to a standardized protocol. RESULTS. The median age at diagnosis was 5 months (minimum: 0 months; maximum: 13.9 years). The atrial septal defect diameter at diagnosis was 4 to 5 mm in 40% of cases, 6 to 7 mm in 28% of cases, 8 to 10 mm in 21% of cases, and >10 mm in 11% of cases. The median age at the final follow-up evaluation was 4.5 years (range: 6.8 months to 16.2 years). Thirty-four percent of atrial septal defects showed spontaneous closure, and 28% decreased to a diameter of ≤3 mm. Logistic regression analysis revealed atrial septal defect diameter and age at diagnosis as independent predictors of spontaneous closure or regression to ≤3-mm defect size. Of atrial septal defects with a diameter of 4 to 5 mm at diagnosis, 56% showed spontaneous closure, 30% regressed to a diameter of ≤3 mm, and none required surgical closure. Of atrial septal defects with a diameter of >10 mm at diagnosis, none closed spontaneously, whereas 77% required surgical or device closure. Gender and observation time were not associated with spontaneous atrial septal defect closure or regression to ≤3 mm. CONCLUSIONS. In the present study population of children with atrial septal defects, 62% showed spontaneous closure (34%) or regression to ≤3 mm (28%). Initial atrial septal defect diameter was the main predictor of spontaneous closure.

Incidence and Diagnosis of Thrombosis in Children With Short-Term Central Venous Lines of the Upper Venous System

OBJECTIVES. Deep venous thrombosis in children is frequently related to central venous lines. Study objectives were to determine objectively the incidence of deep venous thrombosis in children with short-term central venous lines and to assess the diagnostic value of venography, venous ultrasonography, and echocardiography, in a prospective cohort study. METHODS. Consecutive children with congenital heart disease requiring short-term central venous lines in the upper venous system were screened systematically for deep venous thrombosis by using venography, venous ultrasonography, and echocardiography, according to standardized protocols. RESULTS. The study population consisted of 90 children (median age: 2.7 years; range: birth to 18 years). Most central venous lines (97%) were located in the jugular veins. The overall incidence of deep venous thrombosis was 25 cases (28%) among 90 children. Venography identified deep venous thrombosis located in the subclavian and central veins but missed most deep venous thrombosis in the jugular veins. Venous ultrasonography had good sensitivity in the jugular veins but did not detect deep venous thrombosis in central veins. Echocardiography detected only 1 case of central deep venous thrombosis. CONCLUSIONS. The incidence of central venous line-related deep venous thrombosis in children with short-term central venous lines is high and comparable to reports for children with long-term central venous lines. Sensitivities of venography, venous ultrasonography, and echocardiography in children vary depending on the affected venous segment. A combination of diagnostic tests is required for sensitive detection of central venous line-related deep venous thrombosis in the upper venous system.

Incidence of thrombotic and bleeding complications during cardiac catheterization in children: comparison of high-dose vs. low-dose heparin protocols.

Summary.  Background: During cardiac catheterization (CC) in children, unfractionated heparin (UFH) is used for primary prophylaxis of thrombotic events (TE). However, the optimal UFH dose to minimize TE and bleeding in children has yet to be established. Objectives: To (i) objectively assess the incidence of TE and bleeding during pediatric CC using clinical assessment and ultrasound; and (ii) compare a high‐dose vs. low‐dose UFH protocol for thromboprophylaxis. Methods: A randomized controlled trial (RCT) comparing high‐dose UFH (100 units kg−1 bolus, followed by 20 units kg h−1 continuous infusion) vs. low‐dose UFH (50 units kg−1 bolus) during CC. Outcome assessment was by clinical examination and vascular ultrasound, performed by blinded examiners before and within 48 h after CC. Children with no consent for randomization were followed in a cohort receiving standard‐of‐care UFH (parallel‐cohort RCT). Results: A total of 227 children were included; 137 were randomized and 90 followed in the cohort study. The overall incidence of TE was 4.6% and bleeding 6.6%. The RCT was stopped early for futility as there were no differences between the high‐dose and the low‐dose UFH in TE (5% vs. 3%; risk ratios [RR] 1.5, 95% confidence interval [CI] 0.3; 9) and bleeding (7% vs. 12%, RR 0.6, 95% CI 0.2; 2). There were also no differences when RCT and cohort study populations were combined. Conclusions: The incidences of TE and bleeding during CC in children were low. There were no differences between the high‐dose and the low‐dose UFH protocols studied. Although Heparin Anticoagulation Randomized Trial in Cardiac Catheterization (HEARTCAT) was not designed as non‐inferiority trial, low‐dose UFH (50 units kg−1 bolus) appears sufficient for thromboprophylaxis during CC.

Prenatal diagnosis of giant cardiac rhabdomyoma in tuberous sclerosis complex: a new therapeutic option with everolimus.

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by abnormal cell proliferation and tumor growth in a number of organ systems, primarily the brain, kidneys, eyes and heart. Clinical symptoms vary according to the location of the tumor. The most common disorders are seizures, neurodevelopmental disorders, renal failure and arrhythmias. TSC was found to be influenced by inhibitors of the protein kinase mammalian target of rapamycin (mTOR), which regulates abnormal cellular proliferation. mTOR inhibitors have been studied effectively in patients with subependymal giant‐cell astrocytomas and renal angiolipomas in the context of TSC. We describe a prenatally diagnosed case of giant rhabdomyoma, due to right ventricular outflow tract obstruction, which presented as a duct‐dependent lesion. Postnatal treatment with the mTOR inhibitor everolimus initiated significant regression of the cardiac tumor. This finding suggests that mTOR inhibitor therapy is an option for giant rhabdomyomas that develop in the neonatal period. Copyright

No impact of endogenous prothrombotic conditions on the risk of central venous line-related thrombotic events in children: results of the KIDCAT study (KIDs with Catheter Associated Thrombosis)

Central venous lines (CVLs) are the major exogenous risk factor for deep venous thrombosis (DVT) in children. The study objective was to assess whether endogenous prothrombotic conditions contribute to the risk of CVL‐related DVT in children.

Monitoring unfractionated heparin in children: a parallel-cohort randomized controlled trial comparing 2 dose protocols.

Monitoring unfractionated heparin (UFH) is crucial to prevent over- or under-anticoagulation. However, the optimal parameters for monitoring UFH in children are not well established. The study objectives were to investigate (1) the relationship between UFH dose and its anticoagulant effect as assessed by anti-Xa, activated partial thromboplastin time (aPTT) and activated clotting time (ACT); (2) other factors influencing UFH effect; (3) the agreement between the assays; and (4) the association between UFH effect and clinical outcome. HEARTCAT was a parallel-cohort randomized controlled trial comparing high-dose (100 U/kg bolus followed by age-based continuous infusion in randomized children) vs low-dose UFH (50 U/kg bolus) during cardiac catheterization in children. Blood samples were drawn before and after UFH administration at 30, 60, and 90 minutes. Four-hundred and two samples of 149 patients were evaluable. Anti-Xa, aPTT, and ACT all showed good discrimination between UFH doses. Regression models demonstrated the following determinants of UFH effect: UFH dose, age, baseline antithrombin (for anti-Xa), and baseline levels of aPTT and ACT, respectively. UFH effects were lower in infants compared with older children, which was more pronounced at low-dose than at high-dose UFH. Agreement between the 3 assays was poor. Most aPTT values were above therapeutic range or beyond measuring limit and thus of limited value for UFH monitoring. No association of UFH dose or effect with clinical outcome could be observed. In conclusion, all assays reflected a significant UFH dose-effect relationship, however, with poor agreement between the respective tests. The age-dependency of UFH effect was confirmed. Notably, the influence of age on UFH effect was dose-dependent.

Paediatric patients with inflammatory bowel disease who received infliximab experienced improved growth and bone health

Children with inflammatory bowel disease (IBD) have a high prevalence of growth retardation and low bone mineral density (BMD). This retrospective study investigated whether the start of infliximab treatment (IFX) was associated with improvement of growth and bone health.

Radiofrequency catheter ablation can be performed with high success rates and very low complication rates in children and adolescents

Radiofrequency catheter ablation is a standard treatment for tachyarrhythmia in children. Recently, several centres using cryoenergy for ablation have reported high success and low complication rates, but an increased risk of recurrence of arrhythmia. The aim of this study was to report success, complications and recurrence rates for radiofrequency catheter ablation in children under current conditions.

Anti‐activated factor II assay for monitoring unfractionated heparin in children: results of the HEARTCAT study

Essentials Unfractionated heparin has variable effects in children and therefore, monitoring is essential. A randomized controlled trial substudy investigating an anti‐IIa assay in children was conducted. Anti‐IIa values are lower in younger children, an effect more pronounced at low‐dose heparin. Heparin effect on Xa and IIa is not equal, particularly in infants and after high‐dose heparin.

Special Schooling in Children with Congenital Heart Disease: A Risk Factor for Being Disadvantaged in the World of Employment

The objective of this study was to evaluate type of schooling in children with congenital heart disease (CHD) who were inpatients at a tertiary pediatric cardiology center. This retrospective cohort study included 227 consecutive children with CHD (male, 125; female, 102) who had been inpatients from 1996 to 2005. Data on type of schooling had been documented by the in-hospital teacher at the time of admission. Medical data were obtained by reviewing medical charts. The primary endpoint was the percentage of children requiring special schooling, which was related to the respective percentage in the Austrian pediatric background population. Furthermore, the influence of clinical and demographic covariables was assessed. Fifteen percent (vs. 3.6% in the background population) of the study cohort required special schooling; 86% of them had a history of cardiac surgery. Cardiopulmonary bypass surgery in the first year of life showed a trend for an association with an increased frequency of special schooling. There were no significant associations with the Aristotle Basic Score (a measure for procedure complexity in CHD), gender, or first language. In conclusion, the need for special schooling is increased in children with CHD.