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.

Treatment Strategies for Cardiomyopathy in Children: A Scientific Statement From the American Heart Association.

This scientific statement from the American Heart Association focuses on treatment strategies and modalities for cardiomyopathy (heart muscle disease) in children and serves as a companion scientific statement for the recent statement on the classification and diagnosis of cardiomyopathy in children. We propose that the foundation of treatment of pediatric cardiomyopathies is based on these principles applied as personalized therapy for children with cardiomyopathy: (1) identification of the specific cardiac pathophysiology; (2) determination of the root cause of the cardiomyopathy so that, if applicable, cause-specific treatment can occur (precision medicine); and (3) application of therapies based on the associated clinical milieu of the patient. These clinical milieus include patients at risk for developing cardiomyopathy (cardiomyopathy phenotype negative), asymptomatic patients with cardiomyopathy (phenotype positive), patients with symptomatic cardiomyopathy, and patients with end-stage cardiomyopathy. This scientific statement focuses primarily on the most frequent phenotypes, dilated and hypertrophic, that occur in children. Other less frequent cardiomyopathies, including left ventricular noncompaction, restrictive cardiomyopathy, and arrhythmogenic cardiomyopathy, are discussed in less detail. Suggestions are based on previous clinical and investigational experience, extrapolating therapies for cardiomyopathies in adults to children and noting the problems and challenges that have arisen in this experience. These likely underscore the increasingly apparent differences in pathogenesis and even pathophysiology in childhood cardiomyopathies compared with adult disease. These differences will likely affect the utility of some adult therapy strategies. Therefore, special emphasis has been placed on cause-specific therapies in children for prevention and attenuation of their cardiomyopathy in addition to symptomatic treatments. Current investigational strategies and treatments not in wide clinical practice, including future direction for investigational management strategies, trial designs, and collaborative networks, are also discussed because they have the potential to further refine and improve the health and outcomes of children with cardiomyopathy in the future.

NT-proBNP for Predicting All-Cause Death and Heart Transplant in Children and Adults with Heart Failure.

Plasma N-terminal prohormone B-type natriuretic peptide (NT-proBNP) concentration is a heart failure (HF) biomarker in adults and children. Its prognostic value for HF-related events has been established only in adults. Therefore, we aimed to test the hypothesis that plasma NT-proBNP concentrations predicted the risk of heart transplantation or death in children with HF. We studied the medical records of 109 children with HF enrolled in the IBM Watson Explorys database and from 150 children enrolled in the Pediatric Cardiomyopathy Registry (PCMR). Nonlinear regression was used to assess the relationship between plasma NT-proBNP concentrations and the risk of events in the two cohorts. All children in the PCMR cohort had dilated cardiomyopathy. The Explorys cohort also included children with congenital cardiovascular malformations. Median plasma NT-proBNP concentrations were 1250 pg/mL and 184 pg/mL in the Explorys and PCMR cohorts, respectively. The percentage of deaths/heart transplantations was 7%/22%, over 2 years in the Explorys cohort and 3%/16% over 5 years in the PCMR cohort. Mean estimates of plasma NT-proBNP concentration indicative of half-maximum relative risk for events (EC50 values) at 2 and 5 years were 3730 pg/mL and 4199 pg/mL, respectively, values both close to the mean of 3880 pg/mL established for adults with HF. The plasma NT-proBNP concentration is suitable for estimating relative risk of mortality and heart transplantation in children with HF, independent of etiology and shows similar relations to clinical outcomes as in adults, indicating its likely value as a surrogate marker both for adult and pediatric HF.ClinicalTrials.gov Identifiers: NCT00005391 (May 26, 2000), NCT01873976 (June 10, 2013).

Genetic Testing Resources and Practice Patterns Among Pediatric Cardiomyopathy Programs.

The use of genetic testing has enhanced the diagnostic accuracy of heritable genetic cardiomyopathies. However, it remains unclear how genetic information is interpreted and incorporated into clinical practice for children with cardiomyopathy. The primary aim of this study was to understand how clinical practice differs regarding sequence variant classifications amongst pediatric cardiologists who treat children with cardiomyopathy. A secondary aim was to understand the availability of genetic testing and counseling resources across participating pediatric cardiomyopathy programs. An electronic survey was distributed to pediatric heart failure, cardiomyopathy, or heart transplantation physicians between August and September 2022. A total of 106 individual providers from 68 unique centers responded to the survey. Resources for genetic testing and genetic counseling vary among large pediatric cardiomyopathy programs. A minority of centers reported having a geneticist (N = 16, 23.5%) or a genetic counselor (N = 21, 31%) on faculty within the division of pediatric cardiology. A total of 9 centers reported having both (13%). Few centers (N = 13, 19%) have a formal process in place to re-engage patients who were previously discharged from cardiology follow-up if variant reclassification would alter clinical management. Clinical practice patterns were uniform in response to pathogenic or likely pathogenic variants but were more variable for variants of uncertain significance. Efforts to better incorporate genetic expertise and resources into the clinical practice of pediatric cardiomyopathy may help to standardize the interpretation of genetic information and better inform clinical decision-making surrounding heritable cardiomyopathies.

Cardiac imaging and biomarkers for assessing myocardial fibrosis in children with hypertrophic cardiomyopathy.

BACKGROUND: Myocardial fibrosis, as diagnosed on cardiac magnetic resonance imaging (cMRI) by late gadolinium enhancement (LGE), is associated with adverse outcomes in adults with hypertrophic cardiomyopathy (HCM), but its prevalence and magnitude in children with HCM have not been established. We investigated: (1) the prevalence and extent of myocardial fibrosis as detected by LGE cMRI; (2) the agreement between echocardiographic and cMRI measurements of cardiac structure; and (3) whether serum concentrations of N-terminal pro hormone B-type natriuretic peptide (NT-proBNP) and cardiac troponin-T are associated with cMRI measurements. METHODS: A cross-section of children with HCM from 9 tertiary-care pediatric heart centers in the U.S. and Canada were enrolled in this prospective NHLBI study of cardiac biomarkers in pediatric cardiomyopathy (ClinicalTrials.gov Identifier: NCT01873976). The median age of the 67 participants was 13.8 years (range 1-18 years). Core laboratories analyzed echocardiographic and cMRI measurements, and serum biomarker concentrations. RESULTS: In 52 children with non-obstructive HCM undergoing cMRI, overall low levels of myocardial fibrosis with LGE >2% of left ventricular (LV) mass were detected in 37 (71%) (median %LGE, 9.0%; IQR: 6.0%, 13.0%; range, 0% to 57%). Echocardiographic and cMRI measurements of LV dimensions, LV mass, and interventricular septal thickness showed good agreement using the Bland-Altman method. NT-proBNP concentrations were strongly and positively associated with LV mass and interventricular septal thickness (P < .001), but not LGE. CONCLUSIONS: Low levels of myocardial fibrosis are common in pediatric patients with HCM seen at referral centers. Longitudinal studies of myocardial fibrosis and serum biomarkers are warranted to determine their predictive value for adverse outcomes in pediatric patients with HCM.

Heart Failure with Preserved Ejection Fraction in Children.

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

Late health outcomes after dexrazoxane treatment: A report from the Children's Oncology Group.

BACKGROUND: The objective of this study was to examine long-term outcomes among children newly diagnosed with cancer who were treated in dexrazoxane-containing clinical trials. METHODS: P9404 (acute lymphoblastic leukemia/lymphoma [ALL]), P9425 and P9426 (Hodgkin lymphoma), P9754 (osteosarcoma), and Dana-Farber Cancer Institute 95-01 (ALL) enrolled 1308 patients between 1996 and 2001: 1066 were randomized (1:1) to doxorubicin with or without dexrazoxane, and 242 (from P9754) were nonrandomly assigned to receive dexrazoxane. Trial data were linked with the National Death Index, the Organ Procurement and Transplantation Network, the Pediatric Health Information System (PHIS), and Medicaid. Osteosarcoma survivors from the Childhood Cancer Survivor Study (CCSS; n = 495; no dexrazoxane) served as comparators in subanalyses. Follow-up events were assessed with cumulative incidence, Cox regression, and Fine-Gray methods. RESULTS: In randomized trials (cumulative prescribed doxorubicin dose, 100-360 mg/m2 ; median follow-up, 18.6 years), dexrazoxane was not associated with relapse (hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.63-1.13), second cancers (HR, 1.19; 95% CI, 0.62-2.30), all-cause mortality (HR, 1.07; 95% CI, 0.78-1.47), or cardiovascular mortality (HR, 1.45; 95% CI, 0.41-5.16). Among P9754 patients (all exposed to dexrazoxane; cumulative doxorubicin, 450-600 mg/m2 ; median follow-up, 16.6-18.4 years), no cardiovascular deaths or heart transplantation occurred. The 20-year heart transplantation rate among CCSS osteosarcoma survivors (mean doxorubicin, 377 ± 145 mg/m2 ) was 1.6% (vs 0% in P9754; P = .13). Among randomized patients, serious cardiovascular outcomes (cardiomyopathy, ischemic heart disease, and stroke) ascertained by PHIS/Medicaid occurred less commonly with dexrazoxane (5.6%) than without it (17.6%; P = .02), although cardiomyopathy rates alone did not differ (4.4% vs 8.1%; P = .35). CONCLUSIONS: Dexrazoxane did not appear to adversely affect long-term mortality, event-free survival, or second cancer risk.

Pediatric and adult dilated cardiomyopathy are distinguished by distinct biomarker profiles.

BACKGROUND: Emerging evidence suggests that pediatric and adult dilated cardiomyopathy (DCM) represent distinct diseases. Few diagnostic tools exist for pediatric cardiologists to assess clinical status and prognosis. We hypothesized that pediatric DCM would have a unique biomarker profile compared to adult DCM and controls. METHODS: We utilized a DNA aptamer array (SOMAScan) to compare biomarker profiles between pediatric and adult DCM. We simultaneously measured 1310 plasma proteins and peptides from 39 healthy children (mean age 3 years, interquartile range (IQR) 1-14), 39 ambulatory subjects with pediatric DCM (mean age 2.7 years, IQR 1-13), and 40 ambulatory adults with DCM (mean age 53 years, IQR 46-63). RESULTS: Pediatric and adult DCM patients displayed distinct biomarker profiles, despite similar clinical characteristics. We identified 20 plasma peptides and proteins that were increased in pediatric DCM compared to age- and sex-matched controls. Unbiased multidimensionality reduction analysis suggested previously unrecognized heterogeneity among pediatric DCM subjects. Biomarker profile analysis identified four subgroups of pediatric DCM with distinguishing clinical characteristics. CONCLUSIONS: These findings support the emerging concept that pediatric and adult DCM are distinct disease entities, signify the need to develop pediatric-specific biomarkers for disease prognostication, and challenge the paradigm that pediatric DCM should be viewed as a single disease. IMPACT: Pediatric and adult DCM patients displayed distinct biomarker profiles, despite similar clinical characteristics and outcomes. Our findings suggest that pediatric DCM may be a heterogeneous disease with various sub-phenotypes, including differing biomarker profiles and clinical findings. These data provide prerequisite information for future prospective studies that validate the identified pediatric DCM biomarkers, address their diagnostic accuracy and prognostic significance, and explore the full extent of heterogeneity amongst pediatric DCM patients.

Cardiovascular diseases in survivors of childhood cancer.

Over the past few decades, the diagnosis and management of children with various malignancies have improved tremendously. As a result, there are an increasing number of children who are long-term cancer survivors. With improved survival, however, has come an increased risk of treatment-related cardiovascular complications that can appear decades after treatment. These problems are serious enough that all caregivers of childhood cancer survivors, including oncologists, cardiologists, and other health care personnel, must pay close attention to the short- and long-term effects of chemotherapy and radiotherapy on these children. This review discusses the effects of treatment-related cardiovascular complications from anthracyclines and radiotherapy and the methods for preventing, screening, and treating these complications.

Cardiomyopathy in Children: Classification and Diagnosis: A Scientific Statement From the American Heart Association.

In this scientific statement from the American Heart Association, experts in the field of cardiomyopathy (heart muscle disease) in children address 2 issues: the most current understanding of the causes of cardiomyopathy in children and the optimal approaches to diagnosis cardiomyopathy in children. Cardiomyopathies result in some of the worst pediatric cardiology outcomes; nearly 40% of children who present with symptomatic cardiomyopathy undergo a heart transplantation or die within the first 2 years after diagnosis. The percentage of children with cardiomyopathy who underwent a heart transplantation has not declined over the past 10 years, and cardiomyopathy remains the leading cause of transplantation for children >1 year of age. Studies from the National Heart, Lung, and Blood Institute-funded Pediatric Cardiomyopathy Registry have shown that causes are established in very few children with cardiomyopathy, yet genetic causes are likely to be present in most. The incidence of pediatric cardiomyopathy is ≈1 per 100 000 children. This is comparable to the incidence of such childhood cancers as lymphoma, Wilms tumor, and neuroblastoma. However, the published research and scientific conferences focused on pediatric cardiomyopathy are sparcer than for those cancers. The aim of the statement is to focus on the diagnosis and classification of cardiomyopathy. We anticipate that this report will help shape the future research priorities in this set of diseases to achieve earlier diagnosis, improved clinical outcomes, and better quality of life for these children and their families.

Short- and long-term safety and efficacy of bariatric surgery for severely obese adolescents: a narrative review.

The selection criteria, safety, and efficacy of bariatric surgery are well established in adults but are less well defined for severely obese adolescents. The number of severely obese adolescents who could benefit from weight loss surgery is increasing, although referral rates have plateaued. Surgical options for these adolescents are controversial and raise several questions. Recent studies, including the prospective Teen-Longitudinal Assessment of Bariatric Surgery Study and the Adolescent Morbid Obesity Surgery Study, help answer these questions. Early bariatric surgical intervention improves body mass index but, more importantly, improves cardiovascular and metabolic co-morbidities of severe obesity. A review of the medical, psychosocial, and economic risks and benefits of bariatric surgery in severely obese adolescents is a step toward improving the management of a challenging and increasing population. We describe the current knowledge of eligibility criteria, preoperative evaluation, surgical options, outcomes, and referral barriers of adolescents for bariatric surgery.

Stakeholder perspectives on addressing adverse events from adjuvant cancer therapy: A qualitative study.

BACKGROUND: With increasing survival rates, a growing population of patients with cancer have received or will receive adjuvant therapy to prevent cancer recurrences. Patients and caregivers will confront the complexities of balancing the preventative benefits of adjuvant therapy with possible near-term or long-term adverse events (AEs). Adjuvant treatment-related AEs (from minimal to severe) can impact therapeutic adherence, quality of life, emotional and physical health, and survival. However, to the authors' knowledge, limited information is available regarding how stakeholders use or desire to use adjuvant-related AE information to inform the care of patients with cancer. METHODS: A qualitative, purposeful sampling approach was used to elicit stakeholder feedback via semistructured interviews (24 interviews). Drug development, drug regulatory, clinical, payer, and patient/patient advocacy stakeholders were questioned about the generation, dissemination, and use of adjuvant treatment-related AE information to inform the care of patients with cancer. Transcripts were coded independently by 2 senior health care researchers and reconciled to identify key themes. RESULTS: All stakeholder groups in the current study identified needed improvements in each of the following 4 areas: 1) improving the accessibility and relevance of AE-related information; 2) better integrating and implementing available information regarding AEs for decisions; 3) connecting contemporary cultural and economic value systems to the generation and use of information regarding adjuvant treatment-related AEs; and 4) addressing a lack of alignment and ownership of stakeholder efforts to improve the use of AE information in the adjuvant setting. CONCLUSIONS: Despite commonalities in the overall needs identified by the diverse stakeholders in the current study, broad systemic change has been stymied. The current study identified the lack of alignment and the absence of a central "owner" of these diffuse efforts as a previously unrecognized hurdle to realizing the desired systemic improvements. Future initiatives aimed at improving quality of life and outcomes for patients receiving adjuvant therapy through the improved use of AE information must address this challenge through innovative collectives and novel leadership strategies.

A randomized controlled laboratory study on the long-term effects of methylphenidate on cardiovascular function and structure in rhesus monkeys.

BACKGROUND: Whether long-term methylphenidate (MPH) results in any changes in cardiovascular function or structure can only be properly addressed through a randomized trial using an animal model which permits elevated dosing over an extended period of time. METHODS: We studied 28 male rhesus monkeys (Macaca mulatta) approximately 7 years of age that had been randomly assigned to one of three MPH dosages: vehicle control (0 mg/kg, b.i.d., n = 9), low dose (2.5 mg/kg, b.i.d., n = 9), or high dose (12.5 mg/kg, b.i.d., n = 10). Dosage groups were compared on serum cardiovascular and inflammatory biomarkers, electrocardiograms (ECGs), echocardiograms, myocardial biopsies, and clinical pathology parameters following 5 years of uninterrupted dosing. RESULTS: With the exception of serum myoglobin, there were no statistical differences or apparent dose-response trends in clinical pathology, cardiac inflammatory biomarkers, ECGs, echocardiograms, or myocardial biopsies. The high-dose MPH group had a lower serum myoglobin concentration (979 ng/mL) than either the low-dose group (1882 ng/mL) or the control group (2182 ng/mL). The dose response was inversely proportional to dosage (P = .0006). CONCLUSIONS: Although the findings cannot be directly generalized to humans, chronic MPH exposure is unlikely to be associated with increased cardiovascular risk in healthy children.

Pediatric Cardiomyopathies.

Pediatric cardiomyopathies are rare diseases with an annual incidence of 1.1 to 1.5 per 100 000. Dilated and hypertrophic cardiomyopathies are the most common; restrictive, noncompaction, and mixed cardiomyopathies occur infrequently; and arrhythmogenic right ventricular cardiomyopathy is rare. Pediatric cardiomyopathies can result from coronary artery abnormalities, tachyarrhythmias, exposure to infection or toxins, or secondary to other underlying disorders. Increasingly, the importance of genetic mutations in the pathogenesis of isolated or syndromic pediatric cardiomyopathies is becoming apparent. Pediatric cardiomyopathies often occur in the absence of comorbidities, such as atherosclerosis, hypertension, renal dysfunction, and diabetes mellitus; as a result, they offer insights into the primary pathogenesis of myocardial dysfunction. Large international registries have characterized the epidemiology, cause, and outcomes of pediatric cardiomyopathies. Although adult and pediatric cardiomyopathies have similar morphological and clinical manifestations, their outcomes differ significantly. Within 2 years of presentation, normalization of function occurs in 20% of children with dilated cardiomyopathy, and 40% die or undergo transplantation. Infants with hypertrophic cardiomyopathy have a 2-year mortality of 30%, whereas death is rare in older children. Sudden death is rare. Molecular evidence indicates that gene expression differs between adult and pediatric cardiomyopathies, suggesting that treatment response may differ as well. Clinical trials to support evidence-based treatments and the development of disease-specific therapies for pediatric cardiomyopathies are in their infancy. This compendium summarizes current knowledge of the genetic and molecular origins, clinical course, and outcomes of the most common phenotypic presentations of pediatric cardiomyopathies and highlights key areas where additional research is required. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02549664 and NCT01912534.

Left ventricle segmental function in childhood cancer survivors using speckle-tracking echocardiography.

AIM: Anthracycline-associated cardiotoxicity in childhood cancer survivors may relate to global or segmental left ventricular abnormalities from associated thromboembolic events and myocardial microinfarcts. We characterized left ventricular segmental changes by two-dimensional speckle-tracking echocardiography in anthracycline-treated asymptomatic childhood cancer survivors. METHODS AND RESULTS: Childhood cancer survivors' echocardiograms with normal left ventricular fractional shortening >1 year after anthracycline chemotherapy were studied. Cancer-free control children had normal echocardiograms. Apical two-, three-, and four-chamber peak systolic left ventricular longitudinal and global longitudinal strain, and peak systolic left ventricular radial and circumferential strain at papillary muscle levels were analyzed. The mean (standard deviation) age was 12.7 (3.8) years in 41 childhood cancer survivors. The median (interquartile range) follow-up after anthracycline chemotherapy was 4.73 (2.15-8) years. The median (range) cumulative anthracycline dose was 160.2 (60-396.9) mg/m2. In childhood cancer survivors, the mean (standard deviation) left ventricular longitudinal strain was lower in two- (-18.6 [3.2] versus -21.3 [2.5], p < 0.001), three- (-16.3 [6.0] versus -21.7 [3.0], p < 0.001), and four- (-17.6 [2.7] versus -20.8 [2.0], p < 0.001) chamber views compared to controls. The left ventricular global longitudinal strain (-17.6 [2.7] versus -21.3 [2.0]) and circumferential strain (-20.8 [4.3] versus -23.5 [2.6], p < 0.001) were lower in childhood cancer survivors. Among childhood cancer survivors, 12 out of 16 left ventricular segments had significantly lower longitudinal strain than controls. CONCLUSIONS: Asymptomatic anthracycline-treated childhood cancer survivors with normal left ventricular fractional shortening had lower global longitudinal and circumferential strain. The left ventricular longitudinal strain was lower in majority of the segments, suggesting that anthracycline cardiotoxicity is more global than regional.

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.

Cardiovascular disease in survivors of childhood cancer.

PURPOSE OF REVIEW: We review the cardiotoxic chemotherapeutic agents, the clinical and subclinical presentations and progression of their cardiotoxicity, and the management of the subsequent cardiovascular disease in survivors of childhood cancer. We discuss various preventive measures, especially the cardioprotectant, dexrazoxane, whose use with anthracycline chemotherapy, including doxorubicin, is based on strong evidence. Most treatment recommendations for this unique population are based on expert opinion, not on empirical evidence. RECENT FINDINGS: As patients with childhood cancers live longer, morbidity from the cardiac side effects of chemotherapy is increasing. Treatment-related cardiac damage is irreversible and often progressive. It is imperative that such damage be prevented with strategies such as limiting the cumulative anthracycline dose, the use of anthracycline structural analogues and the use of cardioprotective agents. SUMMARY: A deeper understanding of the mechanisms of their cardiotoxicity reveals that there is no 'safe' dose of anthracyclines. However, certain risk factors, such as higher lifetime anthracycline cumulative doses, higher anthracycline dose rates, female sex, longer follow-up, younger age at anthracycline treatment and cardiac irradiation, are associated with more severe cardiotoxicity. We advocate the use of dexrazoxane to limit the cardiotoxic effects of anthracycline chemotherapy.

Cardiovascular disease in adult survivors of childhood cancer.

Treatment advances have increased survival in children with cancer, but subclinical, progressive, irreversible, and sometimes fatal treatment-related cardiovascular effects may appear years later. Cardio-oncologists have identified promising preventive and treatment strategies. Dexrazoxane provides long-term cardioprotection from doxorubicin-associated cardiotoxicity without compromising the efficacy of anticancer treatment. Continuous infusion of doxorubicin is as effective as bolus administration in leukemia treatment, but no evidence has indicated that it provides long-term cardioprotection; continuous infusions should be eliminated from pediatric cancer treatment. Angiotensin-converting enzyme inhibitors can delay the progression of subclinical and clinical cardiotoxicity. All survivors, regardless of whether they were treated with anthracyclines or radiation, should be monitored for systemic inflammation and the risk of premature cardiovascular disease. Echocardiographic screening must be supplemented with screening for biomarkers of cardiotoxicity and perhaps by identification of genetic susceptibilities to cardiovascular diseases; optimal strategies need to be identified. The health burden related to cancer treatment will increase as this population expands and ages.

The Design of the Valsartan for Attenuating Disease Evolution in Early Sarcomeric Hypertrophic Cardiomyopathy (VANISH) Trial.

Hypertrophic cardiomyopathy (HCM) is often caused by sarcomere gene mutations, resulting in left ventricular hypertrophy (LVH), myocardial fibrosis, and increased risk of sudden cardiac death and heart failure. Studies in mouse models of sarcomeric HCM demonstrated that early treatment with an angiotensin receptor blocker (ARB) reduced development of LVH and fibrosis. In contrast, prior human studies using ARBs for HCM have targeted heterogeneous adult cohorts with well-established disease. The VANISH trial is testing the safety and feasibility of disease-modifying therapy with an ARB in genotyped HCM patients with early disease. METHODS: A randomized, placebo-controlled, double-blind clinical trial is being conducted in sarcomere mutation carriers, 8 to 45 years old, with HCM and no/minimal symptoms, or those with early phenotypic manifestations but no LVH. Participants are randomly assigned to receive valsartan 80 to 320 mg daily (depending on age and weight) or placebo. The primary endpoint is a composite of 9 z-scores in domains representing myocardial injury/hemodynamic stress, cardiac morphology, and function. Total z-scores reflecting change from baseline to final visits will be compared between treatment groups. Secondary endpoints will assess the impact of treatment on mutation carriers without LVH, and analyze the influence of age, sex, and genotype. CONCLUSIONS: The VANISH trial is testing a new strategy of disease modification for treating sarcomere mutation carriers with early HCM, and those at risk for its development. In addition, further insight into disease mechanisms, response to therapy, and phenotypic evolution will be gained.

Prevention of cardiotoxicity among survivors of childhood cancer.

LINKED ARTICLES: This article is part of a joint Themed section with the British Journal of Pharmacology on Cardiotoxicity. The rest of the Themed section will appear in a future issue of BJP and will be available at http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1476-5381 The number of survivors of childhood cancers has increased exponentially over the past few decades. However, these survivors are also at substantially increased long-term risk of morbidity and mortality, especially from treatment-related cardiotoxicity. Preventing these risks is now a priority when treating children and adolescents with cancer. Dexrazoxane reduces the risk of anthracycline-induced cardiotoxicity among adults and children with cancer without reducing its antineoplastic effects or event-free survival. Thus, it should be strongly considered as a part of therapy for children and adolescents treated with anthracyclines.