Genetic Evaluation of A Nation-Wide Dutch Pediatric DCM Cohort:The Use of Genetic Testing in Risk Stratification

BACKGROUND: This study aimed to describe the current practice and results of genetic evaluation in Dutch children with dilated cardiomyopathy and to evaluate genotype-phenotype correlations that may guide prognosis. METHODS: We performed a multicenter observational study in children diagnosed with dilated cardiomyopathy, from 2010 to 2017. RESULTS: One hundred forty-four children were included. Initial diagnostic categories were idiopathic dilated cardiomyopathy in 67 children (47%), myocarditis in 23 (16%), neuromuscular in 7 (5%), familial in 18 (13%), inborn error of metabolism in 4 (3%), malformation syndrome in 2 (1%), and "other" in 23 (16%). Median follow-up time was 2.1 years [IQR 1.0-4.3]. Hundred-seven patients (74%) underwent genetic testing. We found a likely pathogenic or pathogenic variant in 38 children (36%), most often in MYH7 (n = 8). In 1 patient initially diagnosed with myocarditis, a pathogenic LMNA variant was found. During the study, 39 patients (27%) reached study endpoint (SE: all-cause death or heart transplantation). Patients with a likely pathogenic or pathogenic variant were more likely to reach SE compared with those without (hazard ratio 2.8; 95% CI 1.3-5.8, P = 0.007), while transplant-free survival was significantly lower (P = 0.006). Clinical characteristics at diagnosis did not differ between the 2 groups. CONCLUSIONS: Genetic testing is a valuable tool for predicting prognosis in children with dilated cardiomyopathy, with carriers of a likely pathogenic or pathogenic variant having a worse prognosis overall. Genetic testing should be incorporated in clinical work-up of all children with dilated cardiomyopathy regardless of presumed disease pathogenesis

Exercise capacity in children with isolated congenital complete atrioventricular block: does pacing make a difference?

Item does not contain fulltextThe management of patients with isolated congenital complete atrioventricular block (CCAVB) has changed during the last decades. The current policy is to pace the majority of patients based on a variety of criteria, among which is limited exercise capacity. Data regarding exercise capacity in this population stems from previous publications reporting small case series of unpaced patients. Therefore, we have investigated the exercise capacity of a group of contemporary children with CCAVB. Sixteen children (mean age 11.5 +/- 4; seven boys, nine girls) with CCAVB were tested. In 13 patients, a median number of three pacemakers were implanted, whereas in three patients no pacemaker was given. All patients had an echocardiogram and completed a cardiopulmonary cycle exercise test. Exercise parameters were determined and compared with reference values obtained from healthy Dutch peers. The peak oxygen uptake/body mass was reduced to 34.4 +/- 9.5 ml kg(-1) min(-1) (79 +/- 24% of predicted) and the ventilatory threshold was reduced to 52 +/- 17% of peak oxygen uptake (78 +/- 21% of predicted), whereas the peak work load/body mass was 2.8 +/- 0.6 W/kg (91 +/- 24% of predicted), which was similar to controls. Importantly, 25% of the paced patients showed upper rate restriction by the pacemaker. In conclusion, children with CCAVB show a reduced peak oxygen uptake and ventilatory threshold, whereas they show normal peak work rates. This indicates that they generate more energy during exercise from anaerobic energy sources. Paced children with CCAVB do not perform better than unpaced children.1 april 201

Distribution of strain patterns in children with dilated cardiomyopathy

Objectives: This study aimed to evaluate the predicting value of quantitative and qualitative dyssynchrony parameters as assessed by two-dimensional speckle tracking echocardiography (STE) on outcome in children with dilated cardiomyopathy (DCM). Furthermore, the reproducibility of these parameters was investigated. Background: In previous studies in adults with heart failure, several dyssynchrony parameters have been shown to be a valuable predictor of clinical outcome. Methods: This multicenter, prospective study included 75 children with DCM and 75 healthy age-matched controls. Using STE, quantitative (time to global peak strain and parameters describing intraventricular time differences) and qualitative dyssynchrony parameters (pattern analysis) of the apical four-chamber, three-chamber, two-chamber views, and the short axis of the left ventricle were assessed. Cox regression was used to identify risk factors for the primary endpoints of death or heart transplantation. Inter-observer and intra-observer variability were described. Results: During a median of 21 months follow-up, 10 patients (13%) reached an endpoint. Although quantitative dyssynchrony measures were higher in patients as compared to controls, the inter-observer and intra-observer variability were high. Pattern analysis showed mainly reduced strain, instead of dyssynchronous patterns. Conclusions: In this study, quantitative dyssynchrony parameters were not reproducible, precluding their use in children. Qualitative pattern analysis showed predominantly reduced strain, suggesting that in children with DCM dyssynchrony may be a minor proble

Usefulness of Serial N-terminal Pro-B-type Natriuretic Peptide Measurements to Predict Cardiac Death in Acute and Chronic Dilated Cardiomyopathy in Children

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is an important predictor of outcome in adults with heart failure. In children with heart failure secondary to dilated cardiomyopathy (DC) markers that reliably predict disease progression and outcome during follow-up are scarce. We investigated whether serial NT-proBNP measurements were predictive for outcome in children with DC. All available NT-proBNP measurements in children with DC were analyzed. Linear mixed-effect models and Cox regression were used to analyze the predictive value of NT-proBNP on the end point of cardiac death (death, heart transplantation, or mechanical circulatory support). During 7 years, 115 patients were included. At diagnosis, median NT-proBNP was high and not predictive for outcome. At any time during follow-up, a twofold higher NT-proBNP resulted in a 2.9 times higher risk in the first year (p 30 days HR 2.9; >1 year HR 6.4). In patients with idiopathic DC (IDC) at 30 days after diagnosis, NT-proBNP >= 7,990 pg/ml showed a 1- and 2-year eyent-free survival of 79% and 71% and >1 year after diagnosis NT-proBNP >= 924 pg/ml showed a 2- and 5-year event-free survival of 50% and 40%, whereas below both thresholds event-free survival was 100%. In non-IDC, these thresholds were not predictive for outcome. In conclusion, NT-proBNP at any time during follow-up and its change over time were significantly predictive for the risk of cardiac death in children with DC. In children with IDC >1 year after diagnosis, NTproBNP >924 pg/ml identified a subgroup with a poor outcome. (C) 2016 Published by Elsevier Inc

Parent reports of health-related quality of life and heart failure severity score independently predict outcome in children with dilated cardiomyopathy

Background: Dilated cardiomyopathy in children causes heart failure and has a poor prognosis. Health-related quality of life in this patient group is unknown. Moreover, results may provide detailed information of parents' sense of their child's functioning. We hypothesised that health-related quality of life, as rated by parents, and the paediatric heart failure score, as assessed by physicians, have both predictive value on outcome.  Methods and results: In this prospective study, health-related quality of life was assessed by parent reports: the Infant Toddler Quality of Life questionnaire (0-4 years) or Child Health Questionnaire-Parent Form 50 (4-18 years) at 3-6-month intervals. We included 90 children (median age 3.8 years, interquartile range (IQR) 0.9-12.3) whose parents completed 515 questionnaires. At the same visit, physicians completed the New York University Pediatric Heart Failure Index. Compared with Dutch normative data, quality of life was severely impaired at diagnosis (0-4 years: 7/10 subscales and 4-18 years: 8/11 subscales) and >= 1 year after diagnosis (3/10 and 6/11 subscales). Older children were more impaired (p <0.05). After a median follow-up of 3 years (IQR 2-4), 15 patients underwent transplantation. Using multivariable time-dependent Cox regression, "physical functioning" subscale and the Heart Failure Index were independently predictive of the risk of death and heart transplantation (hazard ratio 1.24 per 10% decrease of predicted, 95% confidence interval (CI) 1.06-1.47 and hazard ratio 1.38 per unit, 95% CI 1.19-1.61, respectively).  Conclusion: Physical impairment rated by parents and heart failure severity assessed by physicians independently predicted the risk of death or heart transplantation in children with dilated cardiomyopathy

Six-Minute Walk Test as a Predictor for Outcome in Children with Dilated Cardiomyopathy and Chronic Stable Heart Failure

Cardiopulmonary exercise testing is an important tool to predict prognosis in children and adults with heart failure. A much less sophisticated exercise test is the 6 min walk test, which has been shown an independent predictor for morbidity and mortality in adults with heart failure. Therefore, we hypothesized that the 6 min walk test could be predictive for outcome in children with dilated cardiomyopathy. We prospectively included 49 children with dilated cardiomyopathy ≥6 years who performed a 6 min walk test. Median age was 11.9 years (interquartile range [IQR] 7.4-15.1), median time after diagnosis was 3.6 years (IQR 0.6-7.4). The 6 min walk distance was transformed to a percentage of predicted, using age- and gender-specific norm values (6MWD%). For all patients, mean 6MWD% was 70 ± 21%. Median follow-up was 33 months (IQR 14-50). Ten patients reached the combined endpoint of death or heart transplantation. Using univariable Cox regression, a higher 6MWD% resulted in a lower risk of death or transplantation (hazard ratio 0.95 per percentage increase, p = 0.006). A receiver operating characteristic curve was generated to define the optimal threshold to identify patients at highest risk for an endpoint. Patients with a 6MWD% < 63% had a 2 year transplant-free survival of 73%, in contrast to a transplant-free survival of 92% in patients with a 6MWD% ≥ 63% (p = 0.003). In children with dilated cardiomyopathy, the 6 min walk test is a simple and feasible tool to identify children with a higher risk of death or heart transplantation