Cardiomyopathies in children and adolescents: aetiology, management, and outcomes in the European Society of Cardiology EURObservational Research Programme Cardiomyopathy and Myocarditis Registry.

BACKGROUND AND AIMS: Childhood-onset cardiomyopathies are rare and poorly characterized. This study examined the baseline characteristics and 1-year follow-up of children with cardiomyopathy in the first European Cardiomyopathy Registry. METHODS: Prospective data were collected on individuals aged 1-<18 years enrolled in the European Society of Cardiology EURObservational Research Programme Cardiomyopathy and Myocarditis long-term registry (June 2014-December 2016). RESULTS: A total of 633 individuals aged ≤18 years with hypertrophic [HCM; n = 388 (61.3%)], dilated [DCM; n = 206 (32.5%)], restrictive [RCM; n = 28 (4.4%)], and arrhythmogenic right ventricular cardiomyopathy [ARVC; n = 11 (1.7%)] were enrolled by 23 referral centres in 14 countries. Median age at diagnosis was 4.0 [interquartile range (IQR) 0-10] years, and there was a male predominance [n = 372 (58.8%)] across all subtypes, with the exception of DCM diagnosed <10 years of age; 621 (98.1%) patients were receiving cardiac medication and 80 (12.6%) had an implantable cardioverter-defibrillator. A total of 253 patients (253/535, 47.3%) had familial disease. Genetic testing was performed in 414 (67.8%) patients with a pathogenic or likely pathogenic variant reported in 250 (60.4%). Rare disease phenocopies were reported in 177 patients (28.0%) and were most frequent in patients under 10 years [142 (30.9%) vs. 35 (19.6%); P = .003]. Over a median follow-up of 12.5 months (IQR 11.3-15.3 months), 18 patients (3.3%) died [HCM n = 9 (2.6%), DCM n = 5 (3.0%), RCM n = 4 (16.0%)]. Heart failure events were most frequent in RCM patients (36.0%). CONCLUSIONS: The findings confirm the heterogeneous aetiology of childhood cardiomyopathies and show a high frequency of familial disease. Outcomes differed by cardiomyopathy subtype, highlighting a need for disease-specific evaluation and treatment.

Genome-wide association studies highlight novel risk loci for septal defects and left-sided congenital heart defects.

BACKGROUND: Congenital heart defects (CHD) are structural defects of the heart affecting approximately 1% of newborns. They exhibit low penetrance and non-Mendelian patterns of inheritance as varied and complex traits. While genetic factors are known to play an important role in the development of CHD, the specific genetics remain unknown for the majority of patients. To elucidate the underlying genetic risk, we performed a genome wide association study (GWAS) of CHDs in general and specific CHD subgroups using the FinnGen Release 10 (R10) (N > 393,000), followed by functional fine-mapping through eQTL and co-localization analyses using the GTEx database. RESULTS: We discovered three genome-wide significant loci associated with general CHD. Two of them were located in chromosome 17: 17q21.32 (rs2316327, intronic: LRRC37A2, Odds ratio (OR) [95% Confidence Interval (CI)] = 1.17[1.12-1.23], p = 1.5 × 10-9) and 17q25.3 (rs1293973611, nearest: BAHCC1, OR[95%CI] = 4.48[2.80-7.17], p = 7.0 × 10-10), respectively, and in addition to general CHD, the rs1293973611 locus was associated with the septal defect subtype. The third locus was in band 1p21.2 (rs35046143, nearest: PALMD, OR[95%CI] = 1.15[1.09-1.21], p = 7.1 × 10-9), and it was associated with general CHD and left-sided lesions. In the subgroup analysis, two additional loci were associated with septal defects (rs75230966 and rs6824295), and one with left-sided lesions (rs1305393195). In the eQTL analysis the variants rs2316327 (general CHD), and rs75230966 (septal defects) both located in 17q21.32 (with a LD r2 of 0.41) were both predicted to significantly associate with the expression of WNT9B in the atrial appendage tissue category. This effect was further confirmed by co-localization analysis, which also implicated WNT3 expression in the atrial appendage. A meta-analysis of general CHD together with the UK Biobank (combined N = 881,678) provided a different genome-wide significant locus in LRRC37A2; rs16941382 (OR[95%CI] = 1.15[1.11-1.20], p = 1.5 × 10-9) which is in significant LD with rs2316327. CONCLUSIONS: Our results of general CHD and different CHD subcategories identified a complex risk locus on chromosome 17 near BAHCC1 and LRRC37A2, interacting with the genes WNT9B, WNT3 and MYL4, may constitute potential novel CHD risk associated loci, warranting future experimental tests to determine their role.

High-sensitive troponinT, interleukin-8, and interleukin-6 link with post-surgery risk in infant heart surgery.

BACKGROUND: This study focuses on biomarkers in infants after open heart surgery, and examines the association of high-sensitive troponin T (hs-cTnT), interleukin-6 (IL-6), and interleukin-8 (IL-8) with postoperative acute kidney injury (AKI), ventilatory support time and need of vasoactive drugs. METHODS: Secondary exploratory study from a double-blinded clinical randomized trial (Mile-1) on 70 infants undergoing open heart surgery with cardiopulmonary bypass (CPB). In this sub-study, the entire study population was examined without considering the study drugs. The biomarkers' peak concentration (highest concentration at 2 or 6 h post-CPB) were used for statistical analyses. RESULTS: Peak IL-8, hs-cTnT, and IL-6 occurred at 2 h post-CPB for 96%, 79%, and 63% of the patients, respectively. The odds ratio of developing AKI2-3 for IL-6 > 293 pg/mL was 23.4 (95% CI 5.3;104.0), for IL-8 > 100 pg/mL it was 11.5 (3.0;44.2), and for hs-cTnT >5597 pg/mL it was 6.1 (1.5; 24.5). In more than two third of the patients with the highest peak concentrations of IL-8, IL-6, and hs-cTnT, there was a need for ventilatory support for >24 h and use of vasoactive drugs at 24 h post-CPB, while in less than one third of the patients with the lowest peak concentrations of IL-8 and hs-cTnT such requirements were observed. CONCLUSIONS: The peak biomarker concentrations and CPB-time strongly predicted AKI2-3, with IL-6 and IL-8 emerging as strongest predictors. Furthermore, our findings suggest that measuring hs-cTnT and IL-8 just 2 h post-CPB-weaning may assist in identifying infants suitable for early extubation and highlight those at risk of prolonged ventilation.

Organisation of paediatric echocardiography laboratories and governance of echocardiography services and training in Europe: current status, disparities, and potential solutions. A survey from the Association for European Paediatric and Congenital Cardiology (AEPC) imaging working group.

BACKGROUND: There is limited data on the organisation of paediatric echocardiography laboratories in Europe. METHODS: A structured and approved questionnaire was circulated across all 95 Association for European Paediatric and Congenital Cardiology affiliated centres. The aims were to evaluate: (1) facilities in paediatric echocardiography laboratories across Europe, (2) accredited laboratories, (3) medical/paramedical staff employed, (4) time for echocardiographic studies and reporting, and (5) training, teaching, quality improvement, and research programs. RESULTS: Respondents from forty-three centres (45%) in 22 countries completed the survey. Thirty-six centres (84%) have a dedicated paediatric echocardiography laboratory, only five (12%) of which reported they were European Association of Cardiovascular Imaging accredited. The median number of echocardiography rooms was three (range 1-12), and echocardiography machines was four (range 1-12). Only half of all the centres have dedicated imaging physiologists and/or nursing staff, while the majority (79%) have specialist imaging cardiologist(s). The median (range) duration of time for a new examination was 45 (20-60) minutes, and for repeat examination was 20 (5-30) minutes. More than half of respondents (58%) have dedicated time for reporting. An organised training program was present in most centres (78%), 44% undertake quality assurance, and 79% perform research. Guidelines for performing echocardiography were available in 32 centres (74%). CONCLUSION: Facilities, staffing levels, study times, standards in teaching/training, and quality assurance vary widely across paediatric echocardiography laboratories in Europe. Greater support and investment to facilitate improvements in staffing levels, equipment, and governance would potentially improve European paediatric echocardiography laboratories.

Institutional transition from invasive to non-invasive imaging in children with univentricular heart defects: safety and cost savings.

OBJECTIVES: Patients with univentricular heart defects require lifelong imaging surveillance. Recent advances in non-invasive imaging have enabled replacing these patients' routine catheterisation. Our objective was to describe the safety and cost savings of transition of a tertiary care children's hospital from routine invasive to routine non-invasive imaging of low-risk patients with univentricular heart defects. METHODS: This single-centre cohort study consists of 1) a retrospective analysis of the transition from cardiac catheterisation (n = 21) to CT angiography (n = 20) before bidirectional Glenn operation and 2) a prospective study (n = 89) describing cardiac magnetic resonance before and after the total cavopulmonary connection in low-risk patients with univentricular heart defects. RESULTS: Pre-Glenn: The total length of CT angiography was markedly shorter compared to the catheterisation: 30 min (range: 20-60) and 125 min (range: 70-220), respectively (p < 0.001). Catheterisation used more iodine contrast agents than CT angiography, 19 ± 3.9 ml, and 10 ± 2.4 ml, respectively (p < 0.001). Controlled ventilation was used for all catheterised and 3 (15%) CT angiography patients (p < 0.001). No complications occurred during CT angiography, while they emerged in 19% (4/21) catheterisation cases (p < 0.001). CT angiography and catheterisation showed no significant difference in the radiation exposure. Pre-/post-total cavopulmonary connection: All cardiac magnetic resonance studies were successful, and no complications occurred. In 60% of the cardiac magnetic resonance (53/89), no sedation was performed, and peripheral venous pressure was measured in all cases. Cost analysis suggests that moving to non-invasive imaging yielded cost savings of at least €2500-4000 per patient. CONCLUSION: Transition from routine invasive to routine non-invasive pre-and post-operative imaging is safely achievable with cost savings.

Levosimendan Versus Milrinone and Release of Myocardial Biomarkers After Pediatric Cardiac Surgery: Post Hoc Analysis of Clinical Trial Data.

OBJECTIVES: We compared the effect of two inodilators, levosimendan and milrinone, on the plasma levels of myocardial injury biomarkers, that is, high-sensitivity troponin T and heart-type fatty acid binding protein, and on N-terminal prohormone of brain natriuretic peptide as a biomarker of ventricular function. We hypothesized that levosimendan could attenuate the degree of myocardial injury when compared with milrinone. DESIGN: A post hoc, nonprespecified exploratory secondary analysis of the Milrinone versus Levosimendan-1 trial (ClinicalTrials.gov Identifier: NCT02232399). SETTING: Two pediatric tertiary university hospitals. PATIENTS: Infants 1-12 months old, diagnosed with ventricular septal defect, complete atrioventricular septal defect, or Tetralogy of Fallot undergoing corrective surgery with cardiopulmonary bypass. INTERVENTIONS: Seventy patients received a loading dose of either levosimendan or milrinone at the start of cardiopulmonary bypass followed by an infusion of the respective drug, which continued for 26 hours. MEASUREMENTS AND MAIN RESULTS: Plasma levels of the three cardiac biomarkers were measured prior to the initiation of cardiopulmonary bypass and 2, 6, and 24 hours after weaning from cardiopulmonary bypass. In both groups, the levels of high-sensitivity troponin T and heart-type fatty acid binding protein were highest at 2 hours post cardiopulmonary bypass, whereas the highest level of N-terminal prohormone of brain natriuretic peptide occurred at 24 hours post cardiopulmonary bypass. There was no significant difference in the biomarkers' plasma levels between the study groups over time. Neither was there a significant difference in the postoperative peak plasma levels of the cardiac biomarkers. CONCLUSIONS: In this post hoc analysis of the MiLe-1 trial, there was no demonstrable difference in the postoperative cardiac biomarker profile of myocardial injury and ventricular function when comparing infants managed in the perioperative period with levosimendan versus milrinone.

Loss of function, missense, and intronic variants in NOTCH1 confer different risks for left ventricular outflow tract obstructive heart defects in two European cohorts.

Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes.

Long-term renal prognosis and risk for hypertension after myeloablative therapies in survivors of childhood high-risk neuroblastoma: A nationwide study.

BACKGROUND: Patients with high-risk neuroblastoma (HR NBL) treated with myeloablative regimens are reported to be at risk for cardiovascular morbidity, and this risk may be increased by impaired renal function. PROCEDURE: Long-term renal function was assessed in a national cohort of 18 (age 22.4 ± 4.9 years) HR NBL survivors by plasma creatinine (P-Cr), urea, and cystatin C (P-Cys C) concentrations, urine albumin/creatinine ratio (ACR), and estimated glomerular filtration rate (eGFR). Ambulatory blood pressure was monitored, and common carotid intima-media thickness (CIMT) and left ventricular mass index (LVMI) were evaluated. RESULTS: No significant difference in P-Cr, P-Cys C, or eGFR was found between the NBL survivors and the age- and sex-matched 20 controls. P-Cys C-based eGFR (eGFRcysc) was significantly lower than the P-Cr-based eGFRcr (97 ± 17 mL/min/1.73 m2 vs 111 ± 19 mL/min/1.73 m2 , P < 0.001) among the NBL survivors. The eGFRcysc was below normal in 28%, and ACR was above normal in 22% of the NBL survivors. Abnormal blood pressure was found in 56% of the survivors, and an additional 17% were normotensive at daytime but had significant nocturnal hypertension. Both ACR and P-Cys C were associated with nighttime diastolic hypertension. CONCLUSIONS: Long-term survivors of childhood HR NBL showed signs of only mild renal dysfunction associated with diastolic hypertension. Elevated ACR and P-Cys C were the most sensitive indicators of glomerular renal dysfunction and hypertension in this patient cohort.

Perinatal and perioperative factors associated with mortality and an increased need for hospital care in infants with transposition of the great arteries: A nationwide 11-year population-based cohort.

INTRODUCTION: Newborn infants with transposition of the great arteries (d-TGA) need immediate care for an optimal outcome. This study comprised a nationwide 11-year population-based cohort of d-TGA infants, and assessed whether the implementation of a nationwide systematic fetal screening program, or other perinatal, or perioperative factors, are associated with mortality or an increased need for hospital care. MATERIAL AND METHODS: The national cohort consisted of all live-born infants with simple d-TGA (TGA ± small ventricular septal defect, n = 127) born in Finland during 2004-2014. Data were collected from six national registries. Prenatal diagnosis and perinatal and perioperative factors associated with mortality and length of hospitalization were evaluated. RESULTS: Preoperative mortality was 7.9%, and the total mortality was 8.7%. The prenatal detection rate increased after introducing systematic fetal anomaly screening from 5.0% to 37.7% during the study period (P < .0001), but the total mortality rate remained unchanged. All prenatally diagnosed infants (n = 27) survived. Lower gestational age (odds ratio 0.68, P = .012) and higher maternal age at birth (odds ratio 1.16, P = .036) were associated with increased mortality in multivariable analysis. Older infant age at time of operation (P = .002), longer aortic clamp time (P < .001), and higher maternal body mass index (P = .027) were associated with longer initial hospital stay. An extended need for hospital care during the first year of life was multi-factorial. CONCLUSIONS: In our cohort, none of the prenatally diagnosed d-TGA infants died. As a result of the limited prenatal detection rates, however, the sample size was insufficient to reach statistical significance. The d-TGA infants born with lower gestational age and to older mothers had increased mortality.

Levosimendan Versus Milrinone for Inotropic Support in Pediatric Cardiac Surgery: Results From a Randomized Trial.

OBJECTIVE: The present study aimed to determine the differential effects of intraoperative administration of milrinone versus levosimendan on myocardial function after pediatric cardiac surgery. Transthoracic echocardiography was used for myocardial function evaluation using biventricular longitudinal strain with 2-dimensional speckle tracking echocardiography in addition to conventional echocardiographic variables. DESIGN: A secondary analysis of a randomized, prospective, double-blinded clinical drug trial. SETTING: Two pediatric tertiary university hospitals. PARTICIPANTS: Infants between 1 and 12 months old diagnosed with ventricular septal defect, complete atrioventricular septal defect, or tetralogy of Fallot who were scheduled for corrective surgery with cardiopulmonary bypass. INTERVENTIONS: The patients were randomly assigned to receive an infusion of milrinone or levosimendan at the start of cardiopulmonary bypass and for 26 consecutive hours. MEASUREMENTS AND MAIN RESULTS: Biventricular longitudinal strain and conventional echocardiographic variables were measured preoperatively, on the first postoperative morning, and before hospital discharge. The association between perioperative parameters and postoperative myocardial function also was investigated. Images were analyzed for left ventricular (n = 67) and right ventricular (n = 44) function. The day after surgery, left ventricular longitudinal strain deteriorated in both the milrinone and levosimendan groups (33% and 39%, respectively). The difference was not significant. The corresponding deterioration in right ventricular longitudinal strain was 42% and 50% (nonsignificant difference). For both groups, biventricular longitudinal strain approached preoperative values at hospital discharge. Preoperative N-terminal pro-brain natriuretic peptide could predict the left ventricular strain on postoperative day 1 (p = 0.014). CONCLUSIONS: Levosimendan was comparable with milrinone for left and right ventricular inotropic support in pediatric cardiac surgery.

The effect of sildenafil on pleural and peritoneal effusions after the TCPC operation.

BACKGROUND: We evaluated whether the administration of sildenafil in children undergoing the TCPC operation shortened the interval from the operation to the removal of the pleural and peritoneal drains. METHODS: We retrospectively reviewed the data of 122 patients who had undergone the TCPC operation between 2004 and 2014. Patients were divided into two groups on the basis of their treatments. Sildenafil was orally administered pre-operatively in the morning of the procedure or within 24 hours after the TCPC operation to the sildenafil group (n = 48), which was compared to a control group (n = 60). Fourteen patients were excluded from the study. RESULTS: The primary outcome measure was the time from the operation to the removal of the drains. The study groups had similar demographics. The median [interquartile range] time for the removal of drains (sildenafil group 11 [8-19] vs control group 11 [7-16] d, P = .532) was comparable between the groups. The median [interquartile range] fluid balance on the first post-operative day was significantly higher (P = .001) in the sildenafil group compared with controls (47 [12-103] vs 7 [-6-67] mL kg-1 ). The first post-operative day fluid balance was a significant predictor for a prolonged need for drains in the multivariate analysis. CONCLUSIONS: Sildenafil administration, pre-operatively or within 24 hours after the TCPC operation, did not reduce the required time for pleural and peritoneal drains but was associated with a significantly higher positive fluid balance.

Congenital diaphragmatic hernia with heart defect has a high risk for hypoplastic left heart syndrome and major extra-cardiac malformations: 10-year national cohort from Finland.

INTRODUCTION: Congenital diaphragmatic hernia (CDH) has a well-known risk of congenital heart defects with poor prognosis. This study was conducted to determine the national total prevalence and prenatal detection rates of CDH with heart defects and its association with major extra-cardiac malformations and to further evaluate the impact of the heart defect severity on survival. MATERIAL AND METHODS: A 10-year national cohort was derived from four national registries, including live births, stillbirths, and terminations of pregnancy for fetal anomalies. The study cohort was sorted according to cardiac defect severity. RESULTS: The total prevalence of CDH with heart defects was 0.6/10 000 births and live birth prevalence 0.3/10 000 live births. Of 145 cases with CDH, 37 (26%) had a concurrent heart defect. The overall prenatal detection rate of heart defects was 41%. The total prevalence (483/10 000) and live birth prevalence (500/10 000) of hypoplastic left heart syndrome were 124 and 250 times higher than in the general population in Finland, respectively. Additional major extra-cardiac malformations were found in 68% of cases. The survival rate for CDH with major heart defects was 11 and 38% with minor heart defects. CONCLUSIONS: The total prevalence of hypoplastic left heart syndrome was significantly higher in CDH patients than in the general population in Finland. Prenatal detection rate for heart defects in CDH patients was 41%. Major extra-cardiac malformations were more common than previously reported. The prognosis of CDH with major heart defects remained poor.

Velocity vector imaging shows normal cardiac systolic function in survivors of severe bronchopulmonary dysplasia at six to 16 years of age.

AIM: This study evaluated global myocardial function and associations between cardiac function and lung function in very low birth weight (VLBW) children, with and without severe radiographic bronchopulmonary dysplasia (BPD), at six to 14 years of age. METHODS: We studied 34 VLBW and 19 term-born controls, and the VLBW group was further divided into a BPD group with severe radiographic BPD and those without radiographic BPD in infancy. Detailed right and left ventricular myocardial functions were analysed by velocity vector imaging, and the left ventricular mass was calculated. The associations between cardiac function and lung function were assessed by impulse oscillometry. RESULTS: The right and left ventricular myocardial systolic functions and the left ventricular mass were similar in the three groups. Lung function was not associated with cardiac systolic function. Neonatal exposure to dexamethasone treatment was negatively associated with right ventricular function, as measured by the automated fractional area change, with an odds ratio of 7.9 and 95% confidence interval of 1.9-33.5 (p = 0.005). CONCLUSION: Lung function measurements were not associated with cardiac systolic function in preterm infants at six to 14 years of age. Neonatal exposure to dexamethasone, used for weaning from the ventilator, was negatively associated with right ventricular function.

Right ventricular systolic function in hypoplastic left heart syndrome: A comparison of manual and automated software to measure fractional area change.

BACKGROUND: Quantitative echocardiographic assessment of right ventricular function is important in children with hypoplastic left heart syndrome (HLHS). The aim of this study was to examine the repeatability of different echocardiographic techniques, both manual and automated, to measure fractional area change (FAC) in patients with HLHS and to correlate these measurements with magnetic resonance imaging (MRI)-derived ejection fraction (EF). METHODS: Fifty-one children with HLHS underwent transthoracic echocardiography and cardiac MRI under the same general anesthetic as part of routine inter-stage assessment. FAC was measured from the apical four-chamber view using three different techniques: velocity vector imaging (VVI) (Syngo USWP 3.0; Siemens Healthineers), QLAB (Q-lab R 10.0; Philips Healthcare), and manual endocardial contour tracing (Xcelera, Philips Healthcare). Intra- and inter-observer variability was calculated using intra-class correlation coefficient (ICC). FAC was correlated with MRI EF calculated using a single standard method. RESULTS: Fractional area change had a good correlation with MRI-derived EF with an R value for VVI, QLAB, and manual methods of .7, .6, and .4, respectively. Intra- and inter-observer variability for FAC was good for automated echocardiographic methods (ICC>.85) but worse for manual method particularly inter-observer variability of FAC and end-systolic area. Both automated techniques tended to produce higher FAC values compared with manual measurements (P<.001). CONCLUSION: Automation improves the repeatability of FAC in HLHS. There are some differences between automated software in terms of correlation with MRI-derived EF. Measurement bias and wide limits of agreement mean that the same echocardiographic technique should be used during the follow-up of individual patients.

The rare Costello variant HRAS c.173C>T (p.T58I) with severe neonatal hypertrophic cardiomyopathy.

We report a 10-year-old girl presenting with severe neonatal hypertrophic cardiomyopathy (HCM), feeding difficulties, mildly abnormal facial features, and progressive skeletal muscle symptoms but with normal cognitive development. Targeted oligonucleotide-selective sequencing of 101 cardiomyopathy genes revealed the genetic diagnosis, and the mutation was verified by Sanger sequencing in the patient and her parents. To offer insights into the potential mechanism of patient mutation, protein structural analysis was performed using the resolved structure of human activated HRAS protein with bound GTP analogue (PDB id 5P21) in Discovery Studio 4.5 (Dassault Systèmes Biovia, San Diego, CA). The patient with hypertrophic cardiomyopathy and normal cognitive development was diagnosed with an HRAS mutation c.173C>T (p.T58I), a milder variant of Costello syndrome affecting a highly conserved amino acid, threonine 58. Our analysis suggests that the p.G12 mutations slow GTP hydrolysis rendering HRAS unresponsive to GTPase activating proteins, and resulting in permanently active state. The p.T58I mutation likely affects binding of guanidine-nucleotide-exchange factors, thereby promoting the active state but also allowing for slow inactivation. Patients with the HRAS mutation c.173C>T (p.T58I) might go undiagnosed because of the milder phenotype compared with other mutations causing Costello syndrome. We expand the clinical and molecular picture of the rare HRAS mutation by reporting the first case in Europe and the fourth case in the literature. Our protein structure analysis offers insights into the mechanism of the mildly activating p.T58I mutation. © 2016 Wiley Periodicals, Inc.

Cardiovascular magnetic resonance findings in patients with PRKAG2 gene mutations.

BACKGROUND: Autosomal dominantly inherited PRKAG2 cardiac syndrome is due to a unique defect of the cardiac cell metabolism and has a distinctive histopathology with excess intracellular glycogen, and prognosis different from sarcomeric hypertrophic cardiomyopathy. We aimed to define the distinct characteristics of PRKAG2 using cardiovascular magnetic resonance (CMR). METHODS: CMR (1.5 T) and genetic testing were performed in two families harboring PRKAG2 mutations. On CMR, segmental analysis of left ventricular (LV) hypertrophy (LVH), function, native T1 mapping, and late gadolinium enhancement (LGE) were performed. RESULTS: Six individuals (median age 23 years, range 16-48; two females) had a PRKAG2 mutation: five with an R302Q mutation (family 1), and one with a novel H344P mutation (family 2). Three of six mutation carriers had LV mass above age and gender limits (203 g/m2, 157 g/m2 and 68 g/m2) and others (with R302Q mutation) normal LV masses. All mutation carriers had LVH in at least one segment, with the median maximal wall thickness of 13 mm (range 11-37 mm). Two R302Q mutation carriers with markedly increased LV mass (203 g/m2 and 157 g/m2) showed a diffuse pattern of hypertrophy but predominantly in the interventricular septum, while other mutation carriers exhibited a non-symmetric mid-infero-lateral pattern of hypertrophy. In family 1, the mutation negative male had a mean T1 value of 963 ms, three males with the R302Q mutation, LVH and no LGE a mean value of 918 ± 11 ms, and the oldest male with the R302Q mutation, extensive hypertrophy and LGE a mean value of 973 ms. Of six mutations carriers, two with advanced disease had LGE with 11 and 22 % enhancement of total LV volume. CONCLUSIONS: PRKAG2 cardiac syndrome may present with eccentric distribution of LVH, involving focal mid-infero-lateral pattern in the early disease stage, and more diffuse pattern but focusing on interventricular septum in advanced cases. In patients at earlier stages of disease, without LGE, T1 values may be reduced, while in the advanced disease stage T1 mapping may result in higher values caused by fibrosis. CMR is a valuable tool in detecting diffuse and focal myocardial abnormalities in PRKAG2 cardiomyopathy.

Radiotherapy-related arterial intima thickening and plaque formation in childhood cancer survivors detected with very-high resolution ultrasound during young adulthood.

BACKGROUND: The aim of the study was to evaluate arterial morphology and function in a national cohort of long-term survivors of high-risk neuroblastoma (NBL) treated with high-dose chemotherapy and autologous hematopoietic stem cell transplantation with or without total body irradiation (TBI). METHODS AND RESULTS: Common carotid, femoral, brachial, and radial artery morphology were assessed with very-high-resolution vascular ultrasound (25-55 MHz), and carotid artery stiffness and brachial artery flow-mediated dilatation measured with conventional vascular ultrasound in 19 adult or pubertal (age 22.7 ± 4.9 years, range 16-30) NBL survivors transplanted during 1984-1999 at the mean age of 2.5 ± 1.0 years. Results were compared with 20 age- and sex-matched healthy controls. The cardiovascular risk assessment included history, body mass index, fasting plasma lipids, glucose, and 24-h ambulatory blood pressure (BP). The survivors had consistently smaller arterial lumens, increased carotid intima-media thickness (IMT), plaque formation (N = 3), and stiffness, as well as increased radial artery intima thickness (N = 5) compared with the control group. Survivors displayed higher plasma triglyceride and cholesterol levels, and increased heart rate, as well as increased systolic and diastolic BPs. TBI (N = 10) and a low body surface area were independent predictors for decreased arterial lumen size and increased IMT. Three out of five survivors with subclinical intima thickening had arterial plaques. Plaques occurred only among TBI-treated survivors. CONCLUSIONS: Long-term childhood cancer survivors treated with TBI during early childhood display significant signs of premature arterial aging during young adulthood.

Fetal left ventricular noncompaction cardiomyopathy and fatal outcome due to complete deficiency of mitochondrial trifunctional protein.

We report a fetal case with fatal outcome having a novel mutation in the HADHB gene, coding the beta-subunit of the mitochondrial trifunctional protein. Parents had a previous pregnancy loss due to fetal heart failure and hydrops. The next pregnancy led to left ventricular noncompaction and increasing pleural effusions after 29 gestational weeks. The fetus was small for gestational age, and long bones were abnormally short. The baby was born severely asphyxiated at 32 gestational weeks by cesarean section. Intensive care was withdrawn due to failure to thrive and suspicion of a severe mitochondrial disorder. Postmortem brain MRI suggested microcephaly with a simplified gyral pattern. The lateral cerebral ventricles were normal. Chromosome analysis was normal (46, XX). Fibroblasts cultured from a skin biopsy of the baby revealed the large homozygous deletion c.1109+243_1438-703del in the HADHB gene, and heterozygous mutations were detected in both parents. The deletion has not been reported earlier. CONCLUSION: It is important to differentiate systemic metabolic diseases from disorders that affect only the cardiac muscle. Trifunctional protein deficiency is a relatively rare disorder of the fatty acid ß-oxidation cycle. The mutation in the HADHB gene causes a systemic disease with early-onset cardiomyopathy. Understanding the molecular genetic defect of the patient allows appropriate genetic counseling of the family. WHAT IS KNOWN: • Mitochondrial disorders as a group are an important etiology for fetal cardiomyopathies including human trifunctional protein (TFP) disorders and several other mitochondrial diseases. WHAT IS NEW: • We report a fetal case with fatal outcome having a novel mitochondrial trifunctional protein mutation (c.1109+243_1438-703del in the HADHB gene).

Screening for congenital heart defects by transabdominal ultrasound - role of early gestational screening and importance of operator training.

The majority of congenital heart defects occur without identifiable risk factors. Detection rates are therefore highly dependent on the experience and expertise of the obstetrical screening operator. In the first trimester, the risk of congenital heart defects increases with increasing nuchal thickness (≥2.5 mm detects 44% of major congenital heart defects), but because of the number of false positives, the positive predictive value is only a few percent. The anatomy of major congenital heart defects may be delineated in less than half of the fetuses during early second trimester. The reported yield of congenital heart defects detection during the mid-gestational routine obstetrical screening has improved over time and detection rates up to 85% of major congenital heart defects have been reported when outflow tract and three-vessel views are included in conjunction with the four-chamber view. Improved detection rates have been achieved following screening operator training interventions combined with a low referral threshold to obtain a detailed fetal echocardiographic study.