Immunological differences between heart- and kidney-transplanted children: a cross-sectional study.

Post-transplantation lymphoproliferative disorder is a potentially mortal complication after heart transplantation in children. As the immune system plays a crucial role in the development of lymphoma, we explored the influence of thymus function in relation to immunosuppressive treatment in organ-transplanted children and healthy control subjects. A prospective case-control study was performed at a single centre, in which 36 children who had undergone heart transplantation were compared to two control groups: 34 kidney-transplanted children and 33 healthy age- and sex-matched children. T- and B-lymphocyte subtypes and monocytes were analysed by flow cytometry, and T-cell receptor excision circles were assessed using quantitative polymerase chain reaction. Heart-transplanted children had a lymphocyte profile characterised by reduced or absent thymic function with low numbers of T-cell receptor excision circles and total and naïve T cells, together with immune activation against the allograft. Despite similar immunosuppressive treatment, the kidney-transplanted group showed an activated T-lymphocyte compartment.

Congenital heart disease does not entail an increased risk for severe COVID-19.

AIM: To analyse the risk of developing serious disease or death due to COVID-19 among patients who underwent heart surgery during childhood. METHODS: A retrospective combined register and patient file study. We identified all individuals who had undergone surgery for congenital heart disease in childhood between 1994 and 2019 in our Local Surgical Register that covers half of the Swedish population. This effort was cross-tabulated with the diagnosis of COVID-19 entered in the National Register of Diagnoses in Sweden from 1 March 2020 to 1 March 2021. Severe disease was defined as treatment at an intensive care unit (ICU). RESULTS: We identified 3950 individuals, and the median age at follow-up was 16 years (1-44). A total of 32 patients were diagnosed with COVID-19. Five of them were hospitalised for more than 2 days (5-32 days). Two adults required treatment at an ICU; both had additional comorbidity and one died. The corresponding number of ICU stays for this age range in Sweden was 2020 approximately 0.13/1000 person-years, reported from The Swedish Intensive Care Registry. CONCLUSIONS: There was no increased rate of severe COVID-19 among individuals who had undergone surgery for congenital heart disease in childhood. Additional comorbidity is related to outcome.

Survival With Respect to Morphology in Pulmonary Atresia and Intact Ventricular Septum in Sweden.

BACKGROUND: Patients born with pulmonary atresia and intact ventricular septum represent a challenge to pediatric cardiologists. Our objective was to study changes in survival with respect to morphology in all children born with pulmonary atresia and intact ventricular septum in Sweden during 36 years. METHODS: A retrospective, descriptive study based on medical reports and echocardiographic examinations consisting of those born between 1980 and 1998 (early group) and those born between 1999 and 2016 (late group). RESULTS: The cohort consists of 171 patients (early group, n = 86 and late group, n = 85) yielding an incidence of 4.35 and 4.46 per 100,000 live births, respectively. One-year survival in the early group was 76% compared to 92% in the late group (P = .0004). For patients with membranous atresia, one-year survival increased from 78% to 98%, and for muscular pulmonary atresia, from 68% to 85%. In patients with muscular pulmonary atresia and ventriculocoronary arterial communications, there was no significant increase in survival. Risk factors for death were being born in the early time period hazard ratio (HR), 6; 95% CI (2.33-14.28) P = .0002, low birth weight HR, 1.26; 95% CI (1.14-1.4) P < .0001 and having muscular pulmonary atresia HR, 3.74; 95% CI (1.71-8.19) P = .0010. CONCLUSION: The incidence of pulmonary atresia and intact ventricular septum remained unchanged during the study period. Survival has improved, especially for patients with membranous pulmonary atresia, while being born with muscular pulmonary atresia is still a risk factor for death. To further improve survival, greater focus on patients with muscular pulmonary atresia and ventriculocoronary arterial communications is required.

Parental reactions, distress, and sense of coherence after prenatal versus postnatal diagnosis of complex congenital heart disease.

INTRODUCTION: A diagnosis of congenital heart disease (CHD) in offspring triggers psychological distress in parents. Results of previous studies have been inconsistent regarding the psychological impact of a prenatal versus a postnatal diagnosis. The aim of this study was to evaluate the influence of the time of diagnosis on levels of parental distress. METHODS: Pregnant women and their partners with a fetus diagnosed with complex CHD, parents of children with postnatally diagnosed CHD, and pregnant women and their partners with uncomplicated pregnancies were invited to participate. Data were collected during pregnancy and 2-6 months after delivery using the Hospital Anxiety and Depression Scale, sense of coherence, life satisfaction, and Dyadic Adjustment Scale. RESULTS: During pregnancy, the prenatal group scored lower sense of coherence compared to controls (p=0.044). Postnatally the prenatal group scored lower on sense of coherence compared to the postnatal group and controls (p=0.001; p=0.001). Postnatally, the prenatal and postnatal groups had higher levels of anxiety compared to controls (p=0.025; p=0.0003). Life satisfaction was lower in the prenatal group compared to that in the postnatal group and in controls (p=0.000; p=0.0004). CONCLUSION: Parents with a prenatal diagnosis of CHD in offspring report a low sense of coherence already during pregnancy which decreased further at follow-up. The same group reported a lower satisfaction with life compared to parents of a child with postnatal diagnosis of CHD and parents of a healthy child. This motivates further efforts to improve counselling and support during pregnancy and for parents after a prenatal diagnosis.

Post-transplant lymphoproliferative disease is associated with early sternotomy and left ventricular hypoplasia during infancy: a population-based retrospective review.

BACKGROUND: Heart transplantation has been an option for children in Sweden since 1989. As our unit faced an increased rate of post-transplant lymphoproliferative disorder, the objective of the study was to identify possible risk factors. METHODS: This is a retrospective study of all children aged 0-18 years who underwent heart transplantation in Gothenburg from 1989 to 2014. RESULTS: A total of 71 children underwent heart transplantation. The overall incidence of post-transplant lymphoproliferative disorder was 14% (10/71); however, 17% (6/36) of those undergoing transplantation after 2007 developed lymphoma, compared with only 10% (4/35) of transplantation cases before 2007 (p=0.85). The mean age at transplantation was 9 years (0-17). The mean post-transplant follow-up time was 5.5 years (0.5-21.9) in the group that developed post-transplant lymphoproliferative disorder, compared with 10.2 years (0.02-25.2) in those who did not. In our study group, risk factors for post-transplant lymphoproliferative disorder were surgically palliated CHD (p=0.0005), sternotomy during infancy (p⩽0.0001), hypoplastic left ventricle (p=0.0001), number of surgical events (p=0.0022), mismatch concerning Epstein-Barr virus infection - that is, a positive donor-negative recipient (p⩽0.0001) - and immunosuppressive treatment with tacrolimus compared with ciclosporine (p=0.028). Discussion This study has three major findings. First, post-transplant lymphoproliferative disorder only developed in subjects born with CHD. Second, the vast majority (9/10) of the subjects developing the disorder had undergone sternotomy as infants. Third, the number of surgical events correlated with a higher risk for developing post-transplant lymphoproliferative disorder.

Parent's experiences of counselling and their need for support following a prenatal diagnosis of congenital heart disease--a qualitative study in a Swedish context.

BACKGROUND: Prenatal screening for foetal cardiac abnormalities has been increasingly practiced in Sweden during the last 25 years. A prenatal diagnosis may have medical benefits but may also cause sustained parental psychological distress. The aim of this study was to explore pregnant women's, and their partner's, experiences of counselling and need for support during continued pregnancy following a prenatal diagnosis of a cardiac defect. A second aim was to use this information to propose a structured follow-up programme for continued support after the first counselling. DESIGN: Qualitative study, using interviews performed 5-9 weeks after a prenatal diagnosis of congenital heart disease. SETTING: A tertiary foetal cardiology unit in Sweden Sample: Six pregnant women and their 6 partners, consecutively recruited after a prenatal diagnosis of an isolated and significant cardiac defect. DATA ANALYSIS: Qualitative content analysis. RESULTS: The analysis resulted in three themes. 1/ Counselling and making a decision--the importance of knowledge and understanding: Short waiting time for specialist evaluation together with clear and straightforward information was essential. Parents called for written information together with a high-quality website with relevant information about congenital heart disease. 2/ Continued support during pregnancy: Continued and easy access to health care professionals, including a paediatric specialist nurse, throughout pregnancy, was important. Contact with couples with similar experiences and social media were also considered valuable sources of support. 3/ Next step--the near future: Practical and economical issues during the postnatal hospital stay and the initial period following the hospital stay were common concerns. CONCLUSIONS: The following aspects should be considered in a structured follow up program during pregnancy after a prenatal diagnosis of CHD; written information, access to a safe web-site with information of high quality in their native language, support from parents with similar experiences and continued contact with a specialist liaison nurse with experience of paediatric cardiology.

Foetal tachyarrhythmia treatment remains challenging even if the vast majority of cases have a favourable outcome.

AIM: The optimal treatment for foetal tachyarrhythmia remains controversial, and this study aimed to fill this gap in the knowledge. METHODS: We retrospectively reviewed all cases of foetal tachyarrhythmia diagnosed at two tertiary foetal cardiology centres in Sweden from 1990 to 2012. RESULTS: Of the 153 cases, 28% had atrial flutter (AF), 63% had atrioventricular reentrant tachycardia (AVRT) and 9% had other mechanisms. Hydrops was present in 45, less frequently in AF than in AVRT. Transplacental treatment was commenced in 99 and the rhythm normalised in two-thirds, without any significant difference in cardioversion rates between AF and AVRT cases or nonhydropic and hydropic foetuses. Sotalol treatment had a higher cardioversion rate than digoxin in AVRT (63% versus 33%, p < 0.05) but not in AF (57% versus 56%). Two or more drugs were used in 38%. Neonatal survival was 100% in nonhydropic and 84% in hydropic cases. After a median of eight years, 11/134 patients still had arrhythmias, one had died due to arrhythmia and another had undergone cardiac transplantation. CONCLUSION: Transplacental treatment was frequently insufficient to obtain cardioversion in nonhydropic and hydropic foetuses, but all nonhydropic cases had favourable outcomes. Larger prospective studies are needed to optimise the treatment of cases with hydrops.

Warfarin dose prediction in children using pharmacometric bridging--comparison with published pharmacogenetic dosing algorithms.

PURPOSE: Numerous studies have investigated causes of warfarin dose variability in adults, whereas studies in children are limited both in numbers and size. Mechanism-based population modelling provides an opportunity to condense and propagate prior knowledge from one population to another. The main objectives with this study were to evaluate the predictive performance of a theoretically bridged adult warfarin model in children, and to compare accuracy in dose prediction relative to published warfarin algorithms for children. METHOD: An adult population pharmacokinetic/pharmacodynamic (PK/PD) model for warfarin, with CYP2C9 and VKORC1 genotype, age and target international normalized ratio (INR) as dose predictors, was bridged to children using allometric scaling methods. Its predictive properties were evaluated in an external data set of children 0-18 years old, including comparison of dose prediction accuracy with three pharmacogenetics-based algorithms for children. RESULTS: Overall, the bridged model predicted INR response well in 64 warfarin-treated Swedish children (median age 4.3 years), but with a tendency to overpredict INR in children ≤2 years old. The bridged model predicted 20 of 49 children (41 %) within ± 20 % of actual maintenance dose (median age 7.2 years). In comparison, the published dosing algorithms predicted 33-41 % of the children within ±20 % of actual dose. Dose optimization with the bridged model based on up to three individual INR observations increased the proportion within ±20 % of actual dose to 70 %. CONCLUSION: A mechanism-based population model developed on adult data provides a promising first step towards more individualized warfarin therapy in children.

Exercise performance after surgery for pulmonary atresia and intact ventricular septum.

The objective of this study was to assess exercise performance in subjects born in Sweden between 1980 and 1995 and undergoing surgery for pulmonary atresia and intact ventricular septum and to identify determinants of exercise performance. Twenty-seven subjects, 16 with biventricular repair and 11 with univentricular palliation, and 28 age- and sex-matched controls completed cardiopulmonary exercise and lung function testing. Peak oxygen uptake was determined using a symptom-limited ramp bicycle exercise protocol. Regression analysis was performed to identify predictors of peak oxygen uptake (V'O(2)), The index group had lower peak V'O(2) (1.4 [median 0.8; range 2.5] l/min) than controls (1.9 [0.7; 3.1]; p < 0.05). Subjects without ventriculocoronary arterial communications (VCAC), corrected to biventricular circulation, had higher peak V'O(2), than the remaining index subjects. Decreased total lung capacity, low minute ventilation, and high physiologic dead space measured at peak exercise were all independent determinants of low peak V'O(2) Exercise capacity is generally decreased in subjects with pulmonary atresia and intact ventricular septum, although there are marked interindividual differences. Good exercise capacity was found in subjects without VCAC who had undergone biventricular repair. Decreased lung function was an unfavourable predictor of exercise capacity.

Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns.

OBJECTIVE: To evaluate the use of pulse oximetry to screen for early detection of life threatening congenital heart disease. DESIGN: Prospective screening study with a new generation pulse oximeter before discharge from well baby nurseries in West Götaland. Cohort study comparing the detection rate of duct dependent circulation in West Götaland with that in other regions not using pulse oximetry screening. Deaths at home with undetected duct dependent circulation were included. SETTING: All 5 maternity units in West Götaland and the supraregional referral centre for neonatal cardiac surgery. PARTICIPANTS: 39,821 screened babies born between 1 July 2004 and 31 March 2007. Total duct dependent circulation cohorts: West Götaland n=60, other referring regions n=100. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values, and likelihood ratio for pulse oximetry screening and for neonatal physical examination alone. RESULTS: In West Götaland 29 babies in well baby nurseries had duct dependent circulation undetected before neonatal discharge examination. In 13 cases, pulse oximetry showed oxygen saturations

Functional analysis of the novel TBX5 c.1333delC mutation resulting in an extended TBX5 protein.

BACKGROUND: Autosomal dominant Holt-Oram syndrome (HOS) is caused by mutations in the TBX5 gene and is characterized by congenital heart and preaxial radial ray upper limb defects. Most of the TBX5 mutations found in patients with HOS cause premature truncation of the primary TBX5 transcript. TBX5 missense mutations alter the three-dimensional structure of the protein and result in failed nuclear localization or reduced binding to target DNA. In this study we present our functional analyses of the novel and unusual c.1333delC mutation found in a patient with classical HOS. METHODS: The functional impact of this novel mutation was assessed by investigating the intracellular localization of the resulting TBX5 protein and its ability to activate the expression of its downstream target ANF. RESULTS: The deletion of the cytosine is the first TBX5 frameshift mutation predicted to result in an elongated TBX5 protein with 74 miscoding amino acids and 62 supernumerary C-terminal amino acids. The c.1333delC mutation affects neither the nuclear localization, nor its colocalization with SALL4, but severely affects the activation of the ANF promoter. CONCLUSION: The mutation c.1333delC does not locate within functional domains, but impairs the activation of the downstream target. This suggests that misfolding of the protein prevents its biological function.

Abnormalities in myocardial perfusion after surgical correction of pulmonary atresia with intact ventricular septum.

We describe the results of myocardial perfusion scintigraphy performed 4 to 15 years after surgery in 12 patients with pulmonary atresia and intact ventricular septum. We used single photon emission computed tomography after injection of technetium Tc-99m tetrofosmin at submaximal exercise test. The patients, 7 girls and 5 boys, with a mean age of 11 years, and a range from 6 to 19 years, had either undergone biventricular repair, in 5 cases, or univentricular palliation in the remaining 7. This second group included 4 patients with ventriculo-coronary arterial communications. Of the children, 3 with biventricular repair and 6 with univentricular palliation had perfusion defects. Children with biventricular repair had perfusion defects in the ventricular septum, while those having univentricular palliation also had defects located to the left ventricular free wall. All children with ventriculo-coronary arterial communications had perfusion defects both in the ventricular septum and in the left ventricular free wall.

CHARGE association in Sweden: malformations and functional deficits.

CHARGE association (CA) consists of a non-random association of ocular coloboma (C), heart anomaly (H), atresia of choanae (A), retarded growth and/or development (R), genital hypoplasia (G), and ear anomalies and/or hearing impairment (E). A prospective multidisciplinary study of 31 Swedish patients with CA was undertaken in order to describe the associated malformations and functional deficits, find possible etiological factors and identify critical time periods for the maldevelopment. The clinical files were analyzed, the mothers answered a questionnaire on history of prenatal events, and a clinical evaluation of systemic findings, vision, hearing, balance, speech, oral and swallowing function, and neuro-psychiatric function, especially autism, was performed. The most frequent physical abnormalities affected ears (90%), eyes (90%), brain (61%), heart (52%), retarded growth (48%), genitals (38%), choanae (35%), and facial nerve (32%). Sixty-one percent of the patients were visually impaired or blind, and 74% had hearing loss or deafness. Problems in balance, speech, and eating were common. Forty percent of the patients had autism/atypical autism, and 82% had developmental delay. Three children were born following assisted fertilization and two mothers had diabetes. The mothers reported infections, bleedings, and drug use during pregnancy. Analysis of possible critical time periods suggested that most malformations were produced early in pregnancy, mainly during post conceptual weeks 4, 5, and 6. A multidisciplinary approach is essential in the assessment and management of CA.

Quality of life in children with pulmonary atresia and intact ventricular septum.

OBJECTIVE: To measure quality of life in children with pulmonary atresia and intact ventricular septum, and make comparisons with a healthy group of children from the general Swedish population. An additional aim was to compare quality of life in two subgroups, children undergoing biventricular and univentricular repair, the latter by establishment of the Fontan circulation. METHODS: Quality of life was measured using a mailed questionnaire, taking into consideration the three spheres of personal, interpersonal, and external living conditions. In all, 52 children received the questionnaire, and the answers were compared with those of a random sample of 1856 healthy Swedish children. RESULTS: We received responses from 42 children and parents. The overall differences between groups were small, and no difference was found when comparing the children undergoing univentricular as opposed to biventricular surgical repair. In terms of personal quality of life, we found a higher level of psychosomatic complaints, and lower satisfaction with their own and parent-child activities, in those with the congenital anomaly than in their normal peers. In terms of the interpersonal sphere, more time was available for those with malformed hearts, but the experience of support from the relatives was significantly lower. CONCLUSIONS: Overall, quality of life was equal between children with pulmonary atresia and intact ventricular septum and the children in the reference group. The personal psychological conditions were less favourable for children with pulmonary atresia and intact ventricular septum. The perceived lack of support from relatives was also higher in these families. No difference was found when comparing the children undergoing univentricular and biventricular surgical repair.