Evaluation and Management of Chronic Heart Failure in Children and Adolescents With Congenital Heart Disease: A Scientific Statement From the American Heart Association.

With continued medical and surgical advancements, most children and adolescents with congenital heart disease are expected to survive to adulthood. Chronic heart failure is increasingly being recognized as a major contributor to ongoing morbidity and mortality in this population as it ages, and treatment strategies to prevent and treat heart failure in the pediatric population are needed. In addition to primary myocardial dysfunction, anatomical and pathophysiological abnormalities specific to various congenital heart disease lesions contribute to the development of heart failure and affect potential strategies commonly used to treat adult patients with heart failure. This scientific statement highlights the significant knowledge gaps in understanding the epidemiology, pathophysiology, staging, and outcomes of chronic heart failure in children and adolescents with congenital heart disease not amenable to catheter-based or surgical interventions. Efforts to harmonize the definitions, staging, follow-up, and approach to heart failure in children with congenital heart disease are critical to enable the conduct of rigorous scientific studies to advance our understanding of the actual burden of heart failure in this population and to allow the development of evidence-based heart failure therapies that can improve outcomes for this high-risk cohort.

Masked Hypertension in Pediatric Heart Transplant Recipients.

BACKGROUND: Masked hypertension (HTN), especially, isolated nocturnal HTN (INH) has been shown to be a risk factor for cardiovascular disease (CVD) but is not studied well in pediatric heart transplant (PHT) patients. Ambulatory blood pressure monitoring (ABPM) is known to identify patients with HTN but is not used routinely in PHT. METHODS: A single-center, prospective, cross-sectional study of PHT recipients was performed to observe the incidence of masked HTN using 24-h ABPM. The relationship between ABPM parameters and clinical variables was assessed using Spearman correlation coefficient. p value < 0.05 was considered significant. RESULTS: ABPM was performed in 34 patients, mean age 14 ± 5 years, median 5.5 years post-PHT. All patients had normal cardiac function, left ventricular mass index and blood pressure measurements in the clinic. Four patients had known prior HTN and on medications, one of them was uncontrolled. Of the remaining 30 patients, 18 new patients were diagnosed with masked HTN, of which 14 had INH. Diurnal variation was abnormal in 82% (28/34) patients. 24-h diastolic blood pressure (DBP) index correlated with glomerular filtration rate (GFR) (r = - 0.44, p = 0.01). There was no correlation between other ABPM parameters with tacrolimus trough levels. CONCLUSIONS: ABPM identified masked HTN in 60% of patients, with majority being INH. Abnormal circadian BP patterns were present in 82% and an association was found between GFR and DBP parameters. HTN, especially INH, is under-recognized in PHT recipients and ABPM has a role in their long-term care.

Waitlist and Posttransplant Outcomes of Children and Young Adults With Hypertrophic Cardiomyopathy.

BACKGROUND: Heart transplantation (HT) is standard therapy for end-stage hypertrophic cardiomyopathy (HCM); however, few studies have described outcomes of older children and young adults with HCM listed for HT. Our objective was to compare waitlist and post-HT outcomes among pediatric and young adult patients with HCM and dilated cardiomyopathy (DCM). METHODS: The Scientific Registry of Transplant Recipients was queried for patients with HCM and DCM listed at ≤25 years of age. Patient characteristics, waitlist and post-HT survival were compared between younger (≤5 years of age) and older (>5 to ≤25 years of age) HCM patients and between HCM and DCM patients. RESULTS: Among 6252 patients listed for HT at ≤25 years of age with DCM and HCM, 3926 and 250 were in the older cohort and 1944 and 132 were in the younger cohort, respectively. Older HCM patients were less likely to be critically ill at listing compared with younger HCM patients (P = .0001). Waitlist mortality was similar between HCM and DCM patients in both age cohorts. Post-HT survival in HCM patients was similar between the age cohorts. In the younger cohort, early post-HT survival was worse in HCM compared with DCM (P = .009), with no difference in long-term survival. Survival was similar between the older cohorts. CONCLUSIONS: Older children and young adults with HCM are less critically ill than the younger cohort and show waitlist and post-HT survival similar to DCM patients. The young children with HCM had worse early posttransplantation survival, though long-term survival was same as DCM.

The genetic architecture of pediatric cardiomyopathy.

To understand the genetic contribution to primary pediatric cardiomyopathy, we performed exome sequencing in a large cohort of 528 children with cardiomyopathy. Using clinical interpretation guidelines and targeting genes implicated in cardiomyopathy, we identified a genetic cause in 32% of affected individuals. Cardiomyopathy sub-phenotypes differed by ancestry, age at diagnosis, and family history. Infants < 1 year were less likely to have a molecular diagnosis (p < 0.001). Using a discovery set of 1,703 candidate genes and informatic tools, we identified rare and damaging variants in 56% of affected individuals. We see an excess burden of damaging variants in affected individuals as compared to two independent control sets, 1000 Genomes Project (p < 0.001) and SPARK parental controls (p < 1 × 10-16). Cardiomyopathy variant burden remained enriched when stratified by ancestry, variant type, and sub-phenotype, emphasizing the importance of understanding the contribution of these factors to genetic architecture. Enrichment in this discovery candidate gene set suggests multigenic mechanisms underlie sub-phenotype-specific causes and presentations of cardiomyopathy. These results identify important information about the genetic architecture of pediatric cardiomyopathy and support recommendations for clinical genetic testing in children while illustrating differences in genetic architecture by age, ancestry, and sub-phenotype and providing rationale for larger studies to investigate multigenic contributions.

COVID-19 infection in pediatric solid organ transplant patients.

BACKGROUND: Adult SOT recipients with COVID-19 have higher mortality rates when compared to general population. There is paucity of data on outcomes in pediatric SOT recipients. METHODS: This is a cross-sectional study investigating the prevalence of COVID-19 infection and outcomes in pediatric SOT (heart, liver, and kidney) recipients. We extracted demographic and clinical characteristics and COVID-19 testing (PCR or [Ab] test) results from medical records. Clinical characteristics were compared between patients who were positive for COVID-19 (PCR or Ab) and those who did not, using Mann-Whitney, Student's t test, or chi-square test. p value <.05 was statistically significant. RESULTS: A total of 108 SOT recipients with a median age of 13.1 (8.4, 17.8) years and median 4.2 (2.7, 7.9) years from transplant were checked for COVID-19 via a PCR or Ab test. A positive PCR was confirmed in 10 patients (9.3%), while 12 patients (11.1%) were positive for COVID-19 Ab. The patients who tested positive in our cohort were 9/50 (18%) heart, 6/68 (8.8%) kidney, and 7/50 (14%) liver transplant recipients. There were no differences in the clinical characteristics between patients with and without COVID-19 infection. All patients were either asymptomatic (50%) or had self-limiting symptoms. No changes were made to the immunosuppressive regimen. Only one patient was hospitalized and none had an oxygen requirement. CONCLUSIONS: In our cohort of pediatric SOT recipients, COVID-19 infection was asymptomatic or mild. This data may aid clinicians in counseling patients and families in this increased-risk population.

Early Improvement in Clinical Status Following Ventricular Assist Device Implantation in Children: A Marker for Survival.

While clinical status at the time of ventricular assist device (VAD) implant can negatively affect outcomes, it is unclear if early improvement after implant can have a positive effect. Therefore, the objectives of this study were to describe the clinical status of pediatric patients supported with a VAD and determine the impact of clinical status on the 1-month follow-up form on survival and ability to discharge. This was a retrospective analysis of data collected prospectively by the Pediatric Interagency Registry for Mechanical Circulatory Support Registry (Pedimacs) Registry. The Pedimacs database was queried for patients implanted between September 19, 2012, and September 30, 2019, who were alive on VAD support at 1-month postimplant on either a paracorporeal pulsatile or intracorporeal continuous device. Four factors on the 1-month follow-up were the focus of this study: mechanical ventilation, supplemental nutritional support, inotropic support, and ambulatory status. These factors were regarded as present if detected between 1-week and 1-month postimplant and were analyzed to determine their impact on survival following 1 month of VAD support and on successful discharge from hospital in patients with implantable continuous-flow devices. The eligible study cohort consisted of 414 patients with a mean age of 9.6 ± 6.2 years, weight of 40.8 ± 32.3 kg with the majority being male (56.7%) and having cardiomyopathy (68%). An isolated left ventricular assist device (LVAD) was the most common implant (85.5%). At implant, 40% were ventilated, 57% required nutritional support, 93% were on inotropes, and 58% were nonambulating. On the 1-month postimplant form, there were significant improvements in all four categories (14% ventilator support, 46% nutritional support, 53% on inotropes, and 25% nonambulating). However, there was no significant early change in the percentage of patients requiring supplemental nutrition in the paracorporeal pulsatile devices (88% vs. 82%; p = 0.2). Presence of these clinical parameters in early follow-up postimplant had a significant negative impact on survival and on the ability of patients with continuous-flow devices to be discharged. Presence of four specific clinical parameters early after VAD placement is associated with worse overall survival and an inability to discharge patients on VAD support. Ongoing work is needed for optimization of patients before implant and aggressive rehabilitation after implant to help improve long-term outcomes.

Impact of Z score system on the management of coronary artery lesions in Kawasaki disease.

BACKGROUND: Coronary artery aneurysms are well-described in Kawasaki disease and the Multisystem Inflammatory Syndrome in Children and are graded using Z scores. Three Z score systems (Boston, Montreal, and DC) are widely used in North America. The recent Pediatric Heart Network Z score system is derived from the largest diverse sample to-date. The impact of Z score system on the rate of coronary dilation and management was assessed in a large real-world dataset. METHODS: Using a combined dataset of patients with acute Kawasaki disease from the Children's Hospital at Montefiore and the National Heart, Lung, and Blood Institute Kawasaki Disease Study, coronary Z scores and the rate of coronary lesions (Z ≥ 2.0) and aneurysms (Z ≥ 2.5) were determined using four Z score systems. Agreement among Z scores and the effect on Kawasaki management were assessed. RESULTS: Of 333 patients analysed, 136 were from Montefiore and 197 from the Kawasaki Disease Study. Age, sex, body surface area, and rate of coronary lesions did not differ between the samples. Among the four Z score systems, the rate of acute coronary lesions varied from 24 to 55%. The mean left anterior descending Z scores from Pediatric Heart Network and Boston had a large uniform discrepancy of 1.3. Differences in Z scores among the four systems may change anticoagulation management in up to 22% of a Kawasaki population. CONCLUSIONS: Choice of Z score system alone may impact Kawasaki disease diagnosis and management. Further research is necessary to determine the ideal coronary Z score system.

Genetic Causes of Cardiomyopathy in Children: First Results From the Pediatric Cardiomyopathy Genes Study.

Background Pediatric cardiomyopathy is a genetically heterogeneous disease with substantial morbidity and mortality. Current guidelines recommend genetic testing in children with hypertrophic, dilated, or restrictive cardiomyopathy, but practice variations exist. Robust data on clinical testing practices and diagnostic yield in children are lacking. This study aimed to identify the genetic causes of cardiomyopathy in children and to investigate clinical genetic testing practices. Methods and Results Children with familial or idiopathic cardiomyopathy were enrolled from 14 institutions in North America. Probands underwent exome sequencing. Rare sequence variants in 37 known cardiomyopathy genes were assessed for pathogenicity using consensus clinical interpretation guidelines. Of the 152 enrolled probands, 41% had a family history of cardiomyopathy. Of 81 (53%) who had undergone clinical genetic testing for cardiomyopathy before enrollment, 39 (48%) had a positive result. Genetic testing rates varied from 0% to 97% between sites. A positive family history and hypertrophic cardiomyopathy subtype were associated with increased likelihood of genetic testing (P=0.005 and P=0.03, respectively). A molecular cause was identified in an additional 21% of the 63 children who did not undergo clinical testing, with positive results identified in both familial and idiopathic cases and across all phenotypic subtypes. Conclusions A definitive molecular genetic diagnosis can be made in a substantial proportion of children for whom the cause and heritable nature of their cardiomyopathy was previously unknown. Practice variations in genetic testing are great and should be reduced. Improvements can be made in comprehensive cardiac screening and predictive genetic testing in first-degree relatives. Overall, our results support use of routine genetic testing in cases of both familial and idiopathic cardiomyopathy. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01873963.

Angiotensin-converting enzyme inhibition and pre-superior cavopulmonary connection haemodynamics in infants with single-ventricle physiology.

INTRODUCTION: Preliminary animal and human data suggest that angiotensin-converting enzyme inhibition has a role in pulmonary vascular remodelling. We sought to assess the effect of ACEi versus placebo on pulmonary artery pressure and transpulmonary gradient amongst infants undergoing single-ventricle palliation. MATERIALS AND METHODS: Using the publicly available Pediatric Heart Network Infant Single-Ventricle trial dataset, we compared mean PA pressure at pre-superior cavopulmonary connection catheterisation (primary outcome), transpulmonary gradient, pulmonary-to-systemic flow ratio, and post-SCPC oxygen saturation (secondary outcomes) in infants receiving enalapril versus placebo. RESULTS: A total of 179 infants underwent pre-SCPC catheterisation, of which 85 (47%) received enalapril. There was no difference between the enalapril and placebo group in the primary and the secondary outcomes. Mean PA pressure in the enalapril group was 13.1 ± 2.9 compared to 13.7 ± 3.4 mmHg in the placebo group. The transpulmonary gradient was 6.7 ± 2.5 versus 6.9 ± 3.2 mmHg in the enalapril and placebo groups, respectively. The pulmonary-to-systemic flow ratio was 1.1 ± 0.5 in the enalapril group versus 1.0 ± 0.5 in the placebo group and the post-SCPC saturation was 83.1 ± 5.0% in the enalapril group versus 82.2 ± 5.3% in the placebo group. In the pre-specified subgroup analyses comparing enalapril and placebo according to ventricular morphology and shunt type, there was no difference in the primary and secondary outcomes. CONCLUSION: ACEi did not impact mean pulmonary artery pressure or transpulmonary gradient amongst infants with single-ventricle physiology prior to SCPC palliation.

Inpatient admissions and costs for adolescents and young adults with congenital heart defects in New York, 2009-2013.

OBJECTIVES: Most individuals born with congenital heart defects (CHDs) survive to adulthood, but healthcare utilization patterns for adolescents and adults with CHDs have not been well described. We sought to characterize the healthcare utilization patterns and associated costs for adolescents and young adults with CHDs. METHODS: We examined 2009-2013 New York State inpatient admissions of individuals ages 11-30 years with ≥1 CHD diagnosis codes recorded during any admission. We conducted multivariate linear regression using generalized estimating equations to examine associations between inpatient costs and sociodemographic and clinical variables. RESULTS: We identified 5,100 unique individuals with 9,593 corresponding hospitalizations over the study period. Median inpatient cost and length of stay (LOS) were $10,720 and 3.0 days per admission, respectively; 55.1% were emergency admissions. Admission volume increased 48.7% from 2009 (1,538 admissions) to 2013 (2,287 admissions), while total inpatient costs increased 91.8% from 2009 ($27.2 million) to 2013 ($52.2 million). Inpatient admissions and costs rose more sharply over the study period for those with nonsevere CHDs compared to severe CHDs. Characteristics associated with higher costs were longer LOS, severe CHD, cardiac/vascular hospitalization classification, surgical procedures, greater severity of illness, and admission in New York City. CONCLUSION: This study provides an informative baseline of health care utilization patterns and associated costs among adolescents and young adults with CHDs in New York State. Structured transition programs may aid in keeping this population in appropriate cardiac care as they move to adulthood.

Reversible Myocardial Injury Associated With SARS-CoV-2 in an Infant.

Coronavirus disease-2019 is caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and has been associated with myocardial dysfunction and heart failure in adult patients. We report a case of reversible myocardial injury and heart failure in an infant with SARS-CoV-2 infection. (Level of Difficulty: Intermediate.).

Cardiac Abnormalities Seen in Pediatric Patients During the SARS-CoV2 Pandemic: An International Experience.

Background During the SARS-CoV2 pandemic, there has been increase in hyperinflammatory presentation in previously healthy children with a variety of cardiac manifestations. Our objective is to describe the cardiac manifestations found in an international cohort of 55 pediatric cases with multi-system inflammatory syndrome (MIS-C) during the SARS-CoV2 pandemic. Methods and Results We reviewed data on previously healthy pediatric patients (≤18 years) with structurally normal hearts who presented at hospitals in the United States, United Kingdom, Spain and Pakistan with MIS-C and had consultation with a pediatric cardiologist. Data collected included demographics, clinical presentation, laboratory values, electrocardiographic abnormalities, echocardiographic findings and initial therapies. A total of 55 patients presented with MIS-C. Thirty-five patients (64%) had evidence of decreased left ventricular function, 17 (31%) had valvulitis, 12 (22%) with pericardial effusion and 11 (20%) with coronary abnormalities. Twenty-seven (49%) required ICU admission and 24 (44%) had evidence of shock. Eleven patients (20%) fulfilled complete Kawasaki disease criteria and had lower NT pro-BNP, D-dimer and ferritin levels compared with those who did not fulfill criteria. Electrophysiologic abnormalities occurred in 6 patients and included complete atrioventricular (AV) block, transient AV block and ventricular tachycardia. Conclusions We describe the first international cohort of pediatric patients with MIS-C during the SARS-CoV2 pandemic with a range of cardiac manifestations. This paper brings awareness and alertness to the global medical community to recognize these children during the pandemic and understand the need for early cardiology evaluation and follow-up.

Safety of Enalapril in Infants: Data from the Pediatric Heart Network Infant Single Ventricle Trial.

OBJECTIVE: To assess the safety profile of angiotensin-converting enzyme inhibitor therapy in infants with single ventricle. STUDY DESIGN: The Pediatric Heart Network conducted a double-blind trial involving infants with single ventricle physiology randomized to receive enalapril or placebo and followed to 14 months of age. Data including demographics, drug administration, hemodynamic monitoring, laboratory measurements, adverse events, and survival were extracted from the public use data set and compared between the placebo and enalapril-treated groups. RESULTS: The Infant Single Ventricle trial randomized 230 patients, with 115 patients in each group. Initial enalapril dose was 0.10 mg/kg/d and median maximal dose was 0.38 mg/kg/d. There was no significant difference in change in blood pressure at study drug initiation or when resuming study drug after Glenn surgery. The incidence of hyperkalemia and neutropenia did not differ between groups. Renal dysfunction occurred in 3% of the enalapril group and none of the placebo patients, which was not statistically significant. There was a high frequency of serious adverse events in both groups. There was no difference in the frequency of heart transplant or death between groups. CONCLUSIONS: Enalapril did not have sustained hemodynamic effects at initiation or up-titration of drug. Creatinine and potassium were not different between groups, although renal dysfunction occurred more often in the patients on enalapril. Although efficacy of enalapril in neonates with single ventricle has not been demonstrated, the safety profile of angiotensin-converting enzyme inhibitors appears to be low risk in infants and children with significant heart disease.

Use of bivalirudin as a primary anticoagulant in a child during Berlin Heart EXCOR ventricular assist device support.

We describe our experience of bivalirudin use, a newer direct thrombin inhibitor, in an infant who was supported with Berlin Heart EXCOR VAD (Berlin VAD) as bridge to transplant for 122 days without complications and without need for pump exchange. An 11-month-old girl with dilated cardiomyopathy with acute heart failure was awaiting cardiac transplant. Lack of improvement despite maximizing medical therapy and anticipating a prolonged waitlist time, she was supported with Berlin LVAD as a bridge to transplant. Anticoagulation with bivalirudin was started and titrated with a goal partial thromboplastin time of 60-90 seconds. Therapeutic anticoagulation was achieved with bivalirudin for 50% of the days (61/122 days) on a dose of 2.1 mg/kg/hour and in a narrow dose range of 1.9 to 2.3 mg/kg/hour for 80% of the days (98/122 days). Antiplatelet regimen was started initially with aspirin and clopidogrel added later. She was supported for 122 days on a single pump without any evidence of thrombus or need for pump change. Berlin VAD explant and orthotopic heart transplant with biatrial anastomosis were performed uneventfully. Explanted Berlin VAD had no evidence of clot/fibrin or thrombus formation. The child was discharged to home uneventfully 15 days after cardiac transplant.

Cardiac Biomarkers in Pediatric Cardiomyopathy: Study Design and Recruitment Results from the Pediatric Cardiomyopathy Registry.

BACKGROUND: Cardiomyopathies are a rare cause of pediatric heart disease, but they are one of the leading causes of heart failure admissions, sudden death, and need for heart transplant in childhood. Reports from the Pediatric Cardiomyopathy Registry (PCMR) have shown that almost 40% of children presenting with symptomatic cardiomyopathy either die or undergo heart transplant within 2 years of presentation. Little is known regarding circulating biomarkers as predictors of outcome in pediatric cardiomyopathy. STUDY DESIGN: The Cardiac Biomarkers in Pediatric Cardiomyopathy (PCM Biomarkers) study is a multi-center prospective study conducted by the PCMR investigators to identify serum biomarkers for predicting outcome in children with dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). Patients less than 21 years of age with either DCM or HCM were eligible. Those with DCM were enrolled into cohorts based on time from cardiomyopathy diagnosis: categorized as new onset or chronic. Clinical endpoints included sudden death and progressive heart failure. RESULTS: There were 288 children diagnosed at a mean age of 7.2±6.3 years who enrolled in the PCM Biomarkers Study at a median time from diagnosis to enrollment of 1.9 years. There were 80 children enrolled in the new onset DCM cohort, defined as diagnosis at or 12 months prior to enrollment. The median age at diagnosis for the new onset DCM was 1.7 years and median time from diagnosis to enrollment was 0.1 years. There were 141 children enrolled with either chronic DCM or chronic HCM, defined as children ≥2 years from diagnosis to enrollment. Among children with chronic cardiomyopathy, median age at diagnosis was 3.4 years and median time from diagnosis to enrollment was 4.8 years. CONCLUSION: The PCM Biomarkers study is evaluating the predictive value of serum biomarkers to aid in the prognosis and management of children with DCM and HCM. The results will provide valuable information where data are lacking in children. CLINICAL TRIAL REGISTRATION NCT01873976: https://clinicaltrials.gov/ct2/show/NCT01873976?term=PCM+Biomarker&rank=1.

Comparison of echocardiographic measurements to invasive measurements of diastolic function in infants with single ventricle physiology: a report from the Pediatric Heart Network Infant Single Ventricle Trial.

BACKGROUND: While echocardiographic parameters are used to quantify ventricular function in infants with single ventricle physiology, there are few data comparing these to invasive measurements. This study correlates echocardiographic measures of diastolic function with ventricular end-diastolic pressure in infants with single ventricle physiology prior to superior cavopulmonary anastomosis. METHODS: Data from 173 patients enrolled in the Pediatric Heart Network Infant Single Ventricle enalapril trial were analysed. Those with mixed ventricular types (n = 17) and one outlier (end-diastolic pressure = 32 mmHg) were excluded from the analysis, leaving a total sample size of 155 patients. Echocardiographic measurements were correlated to end-diastolic pressure using Spearman's test. RESULTS: Median age at echocardiogram was 4.6 (range 2.5-7.4) months. Median ventricular end-diastolic pressure was 7 (range 3-19) mmHg. Median time difference between the echocardiogram and catheterisation was 0 days (range -35 to 59 days). Examining the entire cohort of 155 patients, no echocardiographic diastolic function variable correlated with ventricular end-diastolic pressure. When the analysis was limited to the 86 patients who had similar sedation for both studies, the systolic:diastolic duration ratio had a significant but weak negative correlation with end-diastolic pressure (r = -0.3, p = 0.004). The remaining echocardiographic variables did not correlate with ventricular end-diastolic pressure. CONCLUSION: In this cohort of infants with single ventricle physiology prior to superior cavopulmonary anastomosis, most conventional echocardiographic measures of diastolic function did not correlate with ventricular end-diastolic pressure at cardiac catheterisation. These limitations should be factored into the interpretation of quantitative echo data in this patient population.