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Synopsis Cardiomyopathy is a serious disorder of the heart muscle and, although rare, is a common cause of heart failure in children and the most common cause for heart transplantation in children older than 1 year of age. Funded by the National Heart Lung and Blood Institute since 1994, the Pediatric Cardiomyopathy Registry (PCMR) has followed more than 3500 North American children with cardiomyopathy. Early analyses determined estimates for the incidence of pediatric cardiomyopathy (1.13 cases per 100,000 children per year), risk factors for cardiomyopathy (age less than 1 year, male sex, black race, and living in New England as opposed to the Central Southwestern states), the prevalence of heart failure at diagnosis (6%–84% depending on cause), and 10-year survival (29%–94% depending on cause). More recent analyses explored cause-specific functional status, survival and transplant outcomes, and risk factors in greater detail. For many topics these analyses are based on the largest and best-documented samples of children with disease such as the muscular dystrophies, mitochondrial disorders, and Noonan’s syndrome. Data from the PCMR continue to provide valuable information that guides clinical management and the use of life-saving therapies, such as cardiac transplantation and approaches to treating heart failure, and that prepares children, their families, and their caregivers for dealing with this serious condition.

A B S T R A C T PurposeTo determine whether cardiovascular abnormalities in childhood cancer survivors are restricted to patients exposed to cardiotoxic anthracyclines and cardiac irradiation and how risk factors for atherosclerotic disease and systemic inflammation contribute to global cardiovascular status. MethodsWe assessed echocardiographic characteristics and atherosclerotic disease risk in 201 survivors of childhood cancer with and without exposure to cardiotoxic treatments at a median of 11 years after diagnosis (range, 3 to 32 years) and in 76 sibling controls. ResultsThe 156 exposed survivors had below normal left ventricular (LV) mass, wall thickness, contractility, and fractional shortening and above normal LV afterload. The 45 unexposed survivors also had below normal LV mass overall, and females had below normal LV wall thickness. Exposed and unexposed survivors, compared with siblings, had higher levels of N-terminal pro-brain natriuretic peptide (81.7 and 69.0 pg/mL, respectively, v 39.4 pg/mL), higher mean fasting serum levels of non-high-density lipoprotein cholesterol (126.5 and 121.1 mg/dL, respectively, v 109.8 mg/dL), higher insulin levels (10.4 and 10.5 U/mL, respectively, v 8.2 U/mL), and higher levels of high-sensitivity C-reactive protein (2.7 and 3.1 mg/L, respectively, v 0.9 mg/L; P Ͻ .001 for all comparisons). Age-adjusted, predicted-to-ideal 30-year risk of myocardial infarction, stroke, or coronary death was also higher for exposed and unexposed survivors compared with siblings (2.16 and 2.12, respectively, v 1.70; P Ͻ .01 for both comparisons). ConclusionChildhood cancer survivors not receiving cardiotoxic treatments nevertheless have cardiovascular abnormalities, systemic inflammation, and an increased risk of atherosclerotic disease. Survivorship guidelines should address cardiovascular concerns, including the risk of atherosclerotic disease and systemic inflammation, in exposed and unexposed survivors.

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Anthracycline chemotherapeutic agents are widely used to treat childhood cancers, helping to create an increasing population of childhood cancer survivors. Cardiac complications can occur years after exposure to anthracyclines and are a leading cause of noncancerous morbidity and mortality in this population. The mechanism of its cardiotoxicity is not completely known, although oxidative stress is believed to play a significant role. This pathway and other nonoxidative mechanisms are reviewed. Several risk factors such as age, dose, female gender, and concomitant radiation therapy are known, but the relative risks of many comorbidities such as diabetes and hypertension are not well studied. No standard, evidence-based guidelines for appropriate screening methods to detect cardiotoxicity exist. Periodic imaging with echocardiography or radionuclide angiography is appropriately recommended for long-term survivors but is of limited use during therapy. Biomarkers such as cardiac troponins and brain natriuretic peptides may aid in detecting cardiotoxicity. Studies investigating the use of agents such as angiotensin-converting enzyme (ACE)-inhibitors and beta-blockers to treat anthracycline cardiotoxicity have shown promise, but more data are needed. Structural analogs such as epirubicin were developed to minimize cardiotoxicity but have not sufficiently reduced it. Liposome-encapsulated anthracyclines have shown a considerable decrease of cardiotoxicity in adults without sacrificing efficacy, but the data related to children are sparse. The only agent proven to be cardioprotective is the iron chelator, dexrazoxane. Studies have shown that dexrazoxane is safe and significantly reduces the incidence of cardiotoxicity. Dexrazoxane should be considered for pediatric oncology protocols using anthracyclines that include longitudinal assessment.

Childhood cancer survivors are at increased risk of cardiovascular disease, in part because of adiposity. Whether survivors have healthy diets and whether dietary quality is associated with adiposity among survivors are not known. Survivors and siblings from the Cardiac Risk Factors in Childhood Cancer Survivors Study completed 3-day food records that were used to estimate daily caloric intake relative to recommended and dietary quality using the Healthy Eating Index-2005 (HEI). Medical records were reviewed for cancer therapies. Body composition was measured by dual-energy x-ray absorptiometry. Of 91 childhood cancer survivors and 30 sibling controls, there were no marked differences in mean daily caloric intakes (98% vs. 100% of recommended) or HEI total scores (55.5 vs. 53.3), respectively, with both groups scoring worst for the consumption of dark green vegetables and whole grains. Survivors exposed to cranial irradiation had lower total HEI scores (-6.4, P = 0.01). Among survivors, better dietary quality, as reflected by the total HEI score, was associated with decreasing percent body fat (β = -0.19, P = 0.04). Survivors consume diets similar to their siblings although these diets are only moderately adherent to current guidelines. Decreased dietary quality is associated with higher body fat and receipt of cranial irradiation in survivors.

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