Dyslipidemia and cardiovascular disease among childhood cancer survivors: a St. Jude Lifetime Cohort report.

BACKGROUND: Childhood cancer survivors have increased risk of dyslipidemia and atherosclerotic cardiovascular disease (CVD). The aim of this study was to evaluate the prevalence and associated cardiovascular risks of specific lipid abnormalities among childhood cancer survivors. METHODS: Comprehensive lipid panel measurements were obtained from 4115 5-year survivors, with 3406 (mean age at evaluation = 35.2 years, SD = 10.4 years) not having previous dyslipidemia diagnosis, as well as 624 age, sex, and race and ethnicity matched community controls. RESULTS: Previously undiagnosed dyslipidemia with abnormal low-density lipoprotein (LDL) cholesterol (>160 mg/dL), non-high density lipoprotein (HDL) cholesterol (>190 mg/dL), HDL cholesterol (<40 mg/dL for men, <50 mg/dL for women), and triglycerides (>150 mg/dL) were identified in 4%, 6%, 30%, and 17%, respectively. Survivors without previous dyslipidemia diagnosis had higher LDL cholesterol and non-HDL cholesterol and lower HDL cholesterol than community controls. Cranial radiotherapy (relative risk [RR] = 2.2, 95% confidence interval [CI] = 1.6 to 3.0 for non-HDL cholesterol) and total body irradiation for hematopoietic cell transplantation (RR = 6.7, 95% CI = 3.5 to 13.0 for non-HDL cholesterol; RR = 9.9, 95% CI = 6.0 to 16.3 for triglycerides) were associated with greater risk of dyslipidemia. Diagnoses of low HDL cholesterol (hazard ratio [HR] = 2.9, 95% CI = 1.8 to 4.7) and elevated triglycerides (HR = 3.1, 95% CI = 1.9 to 5.1) were associated with increased risk for myocardial infarction, and diagnoses of high LDL cholesterol (HR = 2.2, 95% CI = 1.3 to 3.7), high non-HDL cholesterol (HR = 2.2, 95% CI = 1.3 to 3.7), low HDL cholesterol (HR = 3.9, 95% CI = 2.8 to 5.4), and elevated triglycerides (HR = 3.8, 95% CI = 2.7 to 5.5) were associated with increased risk for cardiomyopathy. CONCLUSIONS: Previously undiagnosed dyslipidemia among childhood cancer survivors was associated with increased risk for myocardial infarction and cardiomyopathy. Comprehensive dyslipidemia evaluation and treatment are needed to reduce cardiovascular morbidity in this population.

Utility of Left and Right Ventricular Strain in Arrhythmogenic Right Ventricular Cardiomyopathy: A Prospective Multicenter Registry.

BACKGROUND: Imaging evaluation of arrhythmogenic right ventricular cardiomyopathy (ARVC) remains challenging. Myocardial strain assessment by echocardiography is an increasingly utilized technique for detecting subclinical left ventricular (LV) and right ventricular (RV) dysfunction. We aimed to evaluate the diagnostic and prognostic utility of LV and RV strain in ARVC. METHODS: Patients with suspected ARVC (n = 109) from a multicenter registry were clinically phenotyped using the 2010 ARVC Revised Task Force Criteria and underwent baseline strain echocardiography. Diagnostic performance of LV and RV strain was evaluated using the area under the receiver operating characteristic curve analysis against the 2010 ARVC Revised Task Force Criteria, and the prognostic value was assessed using the Kaplan-Meier analysis. RESULTS: Mean age was 45.3±14.7 years, and 48% of patients were female. Estimation of RV strain was feasible in 99/109 (91%), and LV strain was feasible in 85/109 (78%) patients. ARVC prevalence by 2010 ARVC Revised Task Force Criteria is 91/109 (83%) and 83/99 (84%) in those with RV strain measurements. RV global longitudinal strain and RV free wall strain had diagnostic area under the receiver operating characteristic curve of 0.76 and 0.77, respectively (both P<0.001; difference NS). Abnormal RV global longitudinal strain phenotype (RV global longitudinal strain > -17.9%) and RV free wall strain phenotype (RV free wall strain > -21.2%) were identified in 41/69 (59%) and 56/69 (81%) of subjects, respectively, who were not identified by conventional echocardiographic criteria but still met the overall 2010 ARVC Revised Task Force Criteria for ARVC. LV global longitudinal strain did not add diagnostic value but was prognostic for composite end points of death, heart transplantation, or ventricular arrhythmia (log-rank P=0.04). CONCLUSIONS: In a prospective, multicenter registry of ARVC, RV strain assessment added diagnostic value to current echocardiographic criteria by identifying patients who are missed by current echocardiographic criteria yet still fulfill the diagnosis of ARVC. LV strain, by contrast, did not add incremental diagnostic value but was prognostic for identification of high-risk patients.

The TMEM43 S358L mutation affects cardiac, small intestine, and metabolic homeostasis in a knock-in mouse model.

The transmembrane protein 43 (TMEM43/LUMA) p.S358L mutation causes arrhythmogenic cardiomyopathy named as ARVC5, a fully penetrant disease with high risk of ventricular arrhythmias, sudden death, and heart failure. Male gender and vigorous exercise independently predicted deleterious outcome. Our systems genetics analysis revealed the importance of Tmem43 for cardiac and metabolic pathways associated with elevated lipid absorption from small intestine. This study sought to delineate gender-specific cardiac, intestinal, and metabolic phenotypes in vivo and investigate underlying pathophysiological mechanisms of S358L mutation. Serial echocardiography, surface electrocardiography (ECG), treadmill running, and body EchoMRI have been used in knock-in heterozygous (Tmem43WT/S358L), homozygous (Tmem43S358L), and wildtype (Tmem43WT) littermate mice. Electron microscopy, histology, immunohistochemistry, transcriptome, and protein analysis have been performed in cardiac and intestinal tissues. Systolic dysfunction was apparent in 3-mo-old Tmem43S358L and 6-mo-old Tmem43WT/S358L mutants. Both mutant lines displayed intolerance to acute stress at 6 mo of age, arrhythmias, fibro-fatty infiltration, and subcellular abnormalities in the myocardium. Microarray analysis found significantly differentially expressed genes between left ventricular (LV) and right ventricular (RV) myocardium. Mutants displayed diminished PPARG activities and significantly reduced TMEM43 and ß-catenin expression in the heart, whereas junctional plakoglobin (JUP) translocated into nuclei of mutant cardiomyocytes. Conversely, elongated villi, fatty infiltration, and overexpression of gut epithelial proliferation markers, ß-catenin and Ki-67, were evident in small intestine of mutants. We defined Tmem43 S358L-induced pathological effects on cardiac and intestinal homeostasis via distinctly disturbed WNT-ß-catenin and PPARG signaling thereby contributing to ARVC5 pathophysiology. Results suggest that cardiometabolic assessment in mutation carriers may be important for predictive and personalized care.NEW & NOTEWORTHY This manuscript describes the findings of our investigation of cardiac, small intestine, and metabolic features of Tmem43-S358L mouse model. By investigating interorgan pathologies, we uncovered multiple mechanisms of the S358L-induced disease, and these unique mechanisms likely appear to contribute to the disease pathogenesis. We hope our findings are important and novel and open new avenues in the hunting for additional diagnostic and therapeutic targets in subjects carrying TMEM43 mutation.

Progressive Reduction in Right Ventricular Contractile Function Attributable to Altered Actin Expression in an Aging Mouse Model of Arrhythmogenic Cardiomyopathy.

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is an inherited genetic disorder of desmosomal dysfunction, and PKP2 (plakophilin-2) has been reported to be the most common disease-causing gene when mutation-positive. In the early concealed phase, the ACM heart is at high risk of sudden cardiac death before cardiac remodeling occurs because of mistargeted ion channels and altered Ca2+ handling. However, the results of pathogenic PKP2 variants on myocyte contraction in ACM pathogenesis remain unknown. METHODS: We studied the outcomes of a human truncating variant of PKP2 on myocyte contraction using a novel knock-in mouse model with insertion of thymidine in exon 5 of Pkp2, which mimics a familial case of ACM (PKP2-L404fsX5). We used serial echocardiography, electrocardiography, blood pressure measurements, histology, cardiomyocyte contraction, intracellular calcium measurements, and gene and protein expression studies. RESULTS: Serial echocardiography of Pkp2 heterozygous (Pkp2-Het) mice revealed progressive failure of the right ventricle (RV) in animals older than 3 months. By contrast, left ventricular function remained normal. ECGs of 6-month-old anesthetized Pkp2-Het mice showed normal baseline heart rates and QRS complexes. Cardiac responses to ß-adrenergic agonist isoproterenol (2 mg/kg) plus caffeine (120 mg/kg) were also normal. However, adrenergic stimulation enhanced the susceptibility of Pkp2-Het hearts to tachyarrhythmia and sudden cardiac death. Histological staining showed no significant fibrosis or adipocyte infiltration in the RVs and left ventricles of 6- and 12-month-old Pkp2-Het hearts. Contractility assessment of isolated myocytes demonstrated progressively reduced Pkp2-Het RV cardiomyocyte function consistent with RV failure measured by echocardiography. However, aging Pkp2-Het and control RV myocytes loaded with intracellular Ca2+ indicator Fura-2 showed comparable Ca2+ transients. Western blotting of Pkp2-RV homogenates revealed a 40% decrease in actin, whereas actin immunoprecipitation followed by a 2,4-dinitrophenylhydrazine staining showed doubled oxidation level. This correlated with a 39% increase in troponin-I phosphorylation. In contrast, Pkp2-Het left ventricular myocytes had normal contraction, actin expression and oxidation, and troponin-I phosphorylation. Last, Western blotting of cardiac biopsies revealed that actin expression was 40% decreased in RVs of patients with end-stage ACM. CONCLUSIONS: During the early concealed phase of ACM, reduced actin expression drives loss of RV myocyte contraction, contributing to progressive RV dysfunction.

Restrictive cardiomyopathy: from genetics and clinical overview to animal modeling.

Restrictive cardiomyopathy (RCM), a potentially devastating heart muscle disorder, is characterized by diastolic dysfunction due to abnormal muscle relaxation and myocardial stiffness resulting in restrictive filling of the ventricles. Diastolic dysfunction is often accompanied by left atrial or bi-atrial enlargement and normal ventricular size and systolic function. RCM is the rarest form of cardiomyopathy, accounting for 2-5% of pediatric cardiomyopathy cases, however, survival rates have been reported to be 82%, 80%, and 68% at 1-, 2-, and 5-years after diagnosis, respectively. RCM can be idiopathic, familial, or secondary to a systemic disorder, such as amyloidosis, sarcoidosis, and hereditary hemochromatosis. Approximately 30% of cases are familial RCM, and the genes that have been linked to RCM are cTnT, cTnI, MyBP-C, MYH7, MYL2, MYL3, DES, MYPN, TTN, BAG3, DCBLD2, LNMA, and FLNC. Increased Ca2+ sensitivity, sarcomere disruption, and protein aggregates are some of the few mechanisms of pathogenesis that have been revealed by studies utilizing cell lines and animal models. Additional exploration into the pathogenesis of RCM is necessary to create novel therapeutic strategies to reverse restrictive cardiomyopathic phenotypes.

Management of Hypertrophic Cardiomyopathy: JACC State-of-the-Art Review.

Hypertrophic cardiomyopathy (HCM), a relatively common, globally distributed, and often inherited primary cardiac disease, has now transformed into a contemporary highly treatable condition with effective options that alter natural history along specific personalized adverse pathways at all ages. HCM patients with disease-related complications benefit from: matured risk stratification in which major markers reliably select patients for prophylactic defibrillators and prevention of arrhythmic sudden death; low risk to high benefit surgical myectomy (with percutaneous alcohol ablation a selective alternative) that reverses progressive heart failure caused by outflow obstruction; anticoagulation prophylaxis that prevents atrial fibrillation-related embolic stroke and ablation techniques that decrease the frequency of paroxysmal episodes; and occasionally, heart transplant for end-stage nonobstructive patients. Those innovations have substantially improved outcomes by significantly reducing morbidity and HCM-related mortality to 0.5%/y. Palliative pharmacological strategies with currently available negative inotropic drugs can control symptoms over the short-term in some patients, but generally do not alter long-term clinical course. Notably, a substantial proportion of HCM patients (largely those identified without outflow obstruction) experience a stable/benign course without major interventions. The expert panel has critically appraised all available data and presented management insights and recommendations with concise principles for clinical decision-making.

Systems genetics analysis defines importance of TMEM43/LUMA for cardiac- and metabolic-related pathways.

Broad cellular functions and diseases including muscular dystrophy, arrhythmogenic right ventricular cardiomyopathy (ARVC5) and cancer are associated with transmembrane protein43 (TMEM43/LUMA). The study aimed to investigate biological roles of TMEM43 through genetic regulation, gene pathways and gene networks, candidate interacting genes, and up- or downstream regulators. Cardiac transcriptomes from 40 strains of recombinant inbred BXD mice and two parental strains representing murine genetic reference population (GRP) were applied for genetic correlation, functional enrichment, and coexpression network analysis using systems genetics approach. The results were validated in a newly created knock-in Tmem43-S358L mutation mouse model (Tmem43S358L) that displayed signs of cardiac dysfunction, resembling ARVC5 phenotype seen in humans. We found high Tmem43 levels among BXDs with broad variability in expression. Expression of Tmem43 highly negatively correlated with heart mass and heart rate among BXDs, whereas levels of Tmem43 highly positively correlated with plasma high-density lipoproteins (HDL). Through finding differentially expressed genes (DEGs) between Tmem43S358L mutant and wild-type (Tmem43WT) lines, 18 pathways (out of 42 found in BXDs GRP) that are involved in ARVC, hypertrophic cardiomyopathy, dilated cardiomyopathy, nonalcoholic fatty liver disease, Alzheimer's disease, Parkinson's disease, and Huntington's disease were verified. We further constructed Tmem43-mediated gene network, in which Ctnna1, Adcy6, Gnas, Ndufs6, and Uqcrc2 were significantly altered in Tmem43S358L mice versus Tmem43WT controls. Our study defined the importance of Tmem43 for cardiac- and metabolism-related pathways, suggesting that cardiovascular disease-relevant risk factors may also increase risk of metabolic and neurodegenerative diseases via TMEM43-mediated pathways.

Pediatric Cardio-Oncology Medicine: A New Approach in Cardiovascular Care.

Survival for pediatric patients diagnosed with cancer has improved significantly. This achievement has been made possible due to new treatment modalities and the incorporation of a systematic multidisciplinary approach for supportive care. Understanding the distinctive cardiovascular characteristics of children undergoing cancer therapies has set the underpinnings to provide comprehensive care before, during, and after the management of cancer. Nonetheless, we acknowledge the challenge to understand the rapid expansion of oncology disciplines. The limited guidelines in pediatric cardio-oncology have motivated us to develop risk-stratification systems to institute surveillance and therapeutic support for this patient population. Here, we describe a collaborative approach to provide wide-ranging cardiovascular care to children and young adults with oncology diseases. Promoting collaboration in pediatric cardio-oncology medicine will ultimately provide excellent quality of care for future generations of patients.

Cardiac remodeling after anthracycline and radiotherapy exposure in adult survivors of childhood cancer: A report from the St Jude Lifetime Cohort Study.

BACKGROUND: Limited data exist regarding left ventricular remodeling patterns observed in adult survivors of childhood cancer after therapy. METHODS: Among 1190 adult survivors diagnosed with childhood cancer (median age at diagnosis, 9 years [interquartile range (IQR), 3.8-14.4 years]; age at evaluation, 35.6 years [IQR, 29.5-42.8 years]), treatment exposures included anthracyclines (n = 346), chest radiotherapy (n = 174), both (n = 245), or neither (n = 425). Prospective echocardiographic assessment compared survivors with 449 noncancer controls classified according to left ventricle geometric patterns. Associations between left ventricle geometric patterns and decreased exercise tolerance were assessed. RESULTS: Overall, 28.2% of survivors (95% confidence interval [CI], 25.6%-30.8%) exhibited concentric remodeling, 2.4% (95% CI, 1.6%-3.5%) exhibited eccentric hypertrophy, and 1.1% (95% CI, 0.6%-1.9%) exhibited concentric hypertrophy. A greater proportion of survivors who received only chest radiotherapy (41%) had concentric remodeling compared with those who received only anthracyclines (24%), both (27%), or neither (27%; all P < .001), and all were greater than the proportions in noncancer controls (18%; all P < .05). Concentric remodeling was associated with radiation exposure, but not with anthracycline exposure, in multivariable models. Survivors who had concentric remodeling were more likely to have a maximal oxygen uptake peak <85% compared with those who had normal geometry (81.0% vs 66.3%; odds ratio, 1.75; 95% CI, 1.15-2.68). CONCLUSIONS: Chest radiation therapy, but not anthracycline therapy, increased the risk for concentric remodeling in survivors of childhood cancer. The presence of concentric remodeling was associated with increased exercise intolerance.

Diagnosis and Management of Myocarditis in Children: A Scientific Statement From the American Heart Association.

Myocarditis remains a clinical challenge in pediatrics. Originally, it was recognized at autopsy before the application of endomyocardial biopsy, which led to a histopathology-based diagnosis such as in the Dallas criteria. Given the invasive and low-sensitivity nature of endomyocardial biopsy, its diagnostic focus shifted to a reliance on clinical suspicion. With the advances of cardiac magnetic resonance, an examination of the whole heart in vivo has gained acceptance in the pursuit of a diagnosis of myocarditis. The presentation may vary from minimal symptoms to heart failure, life-threatening arrhythmias, or cardiogenic shock. Outcomes span full resolution to chronic heart failure and the need for heart transplantation with inadequate clues to predict the disease trajectory. The American Heart Association commissioned this writing group to explore the current knowledge and management within the field of pediatric myocarditis. This statement highlights advances in our understanding of the immunopathogenesis, new and shifting dominant pathogeneses, modern laboratory testing, and use of mechanical circulatory support, with a special emphasis on innovations in cardiac magnetic resonance imaging. Despite these strides forward, we struggle without a universally accepted definition of myocarditis, which impedes progress in disease-targeted therapy.

Association of persistent tachycardia with early myocardial dysfunction in children undergoing allogeneic hematopoietic cell transplantation.

Cancer survivors who have undergone hematopoietic cell transplantation (HCT) are at risk for myocardial dysfunction. Children who receive allogenic HCT encounter systemic inflammation resulting in tachycardia and hypertension. The effect of these abnormalities on myocardial function is not known. The aim of this study was to determine whether cardiac dysfunction early after HCT can be predicted by tachycardia or hypertension, within a retrospective single-center sample of pediatric HCT recipients. Early tachycardia or hypertension was defined as a majority of values taken from infusion date to 90 days post-infusion being abnormal. Ejection fraction <53% determined systolic dysfunction. A composite score of accepted pediatric diastolic abnormalities determined diastolic dysfunction. Among 80 subjects (median age 8 years), early tachycardia, systolic dysfunction, and diastolic dysfunction were present in 64%, 25%, and 48% of the sample, respectively. In multivariable models, early tachycardia was an independent predictor of early systolic dysfunction (OR = 12.6 [1.4-112.8], p = 0.024) and diastolic dysfunction (OR = 3.9 [1.3-11.5], p = 0.013). Tachycardia and cardiac dysfunction are common and associated with one another in the early period after pediatric HCT. Future studies may elucidate the role of tachycardia and myocardial dysfunction early after HCT as important predictors of future cardiovascular dysfunction.

Acquired and modifiable cardiovascular risk factors in patients treated for cancer.

Cardiac mortality is the leading cause of death secondary to malignancy in survivors of cancer. The field of cardio-oncology is dedicated to identifying and, if possible, modifying risk factors that contribute to significant cardiac morbidity and mortality. Many risk factors for the development of cancer-related cardiotoxicity overlap with risk factors in cardiovascular disease such as hypertension, obesity, dyslipidemia, and diabetes among others. These risk factors are usually modifiable while others such as genetics, type of malignancy, and need for chemotherapy are less modifiable. This article summarizes acquired and modifiable risk factors in both pediatric and adult patients treated for cancer.

Cardiovascular Family History Increases Risk for Late-Onset Adverse Cardiovascular Outcomes in Childhood Cancer Survivors: A St. Jude Lifetime Cohort Report.

BACKGROUND: Survivors of childhood cancer have an increased risk of therapy-related cardiovascular disease. It is not known whether family history of cardiovascular disease further increases risk of adverse cardiovascular outcomes among survivors. METHODS: Family history of cardiovascular disease was collected from 1,260 survivors [median age at diagnosis, 8 years (range, 0-23); age at last follow-up, 35 years (range, 18-66)] of childhood cancer in the St. Jude Lifetime Cohort Study. Multivariable risk models evaluated associations with cardiovascular disease (Common Terminology Criteria for Adverse Events grade 2-4 events) and cardiovascular risk factors. RESULTS: Among survivors exposed to chest-directed radiation and/or anthracycline chemotherapy (n = 824), 7% reported a first-degree family history of heart failure, 19% myocardial infarction, 11% stroke, 26% atherosclerotic disease (myocardial infarction and/or stroke), 62% hypertension, and 31% diabetes mellitus. Eighteen percent of exposed survivors developed heart failure, 9% myocardial infarction, 3% stroke, 11% atherosclerotic disease, 30% hypertension, and 9% diabetes mellitus. Having a first-degree family history of atherosclerotic disease was independently associated with development of treatment-related heart failure [RR, 1.38; 95% confidence interval (CI), 1.01-1.88; P = 0.04] among exposed survivors. Risk for hypertension was increased among exposed survivors with a first-degree family history of hypertension (RR, 1.55; 95% CI, 1.26-1.92; P < 0.0001) or of any cardiovascular disease [myocardial infarction, stroke, or heart failure (RR, 1.30; 95% CI, 1.06-1.59; P = 0.01)]. CONCLUSIONS: Family history of cardiovascular disease and cardiovascular risk factors independently increased risk of heart failure and hypertension among survivors of childhood cancer exposed to cardiotoxic therapies. IMPACT: These data show the importance of cardiovascular family history as a risk factor for cardiovascular disease in survivors of childhood cancer.

Novel use of cangrelor in pediatrics: A pilot cohort study demonstrating use in ventricular assist devices.

Thromboembolic events and bleeding are major sources of morbidity among pediatric patients supported on a ventricular assist device (VAD). Pharmacokinetics and pharmacodynamics of enteral antiplatelet agents are affected and variable due to erratic enteral absorption in end-stage heart failure and VAD circulation. Additionally, 20%-40% of the population are poor metabolizers of clopidogrel, a prodrug, making cangrelor an alternative when antiplatelet therapy is crucial. Cangrelor has been used effectively and safely for short durations in adults during percutaneous coronary interventions, but the use of cangrelor is still under investigation in pediatrics. This case series utilized cangrelor, a novel short-acting, reversible, intravenous P2Y12 platelet inhibitor in managing pediatric patients supported with a VAD. We performed a retrospective, single-center review of patients admitted to a tertiary medical center with end-stage heart failure requiring mechanical circulatory support and concomitant cangrelor administration between January 2019 and March 2020. Platelet function testing, cangrelor dose, bleeding complications, thromboembolic events, and frequency of circuit interventions during the use of cangrelor were recorded. Optimal platelet reactivity, defined as P2Y12 < 180 platelet reaction units (PRU), was measured with serial point-of-care testing (VerifyNow). Seven patients, median age of 4.9 years, met the above criteria. Three patients had a diagnosis of complex congenital heart disease. Four patients had dilated or restrictive cardiomyopathy. All patients were on continuous flow VADs. The median VAD duration was 84.5 days (IQR 61.5-103). The median duration on cangrelor was 43 days (IQR 8-70). The median cangrelor dose to reach the therapeutic threshold was 0.75 µg/kg/min with the mean P2Y12 , while on cangrelor of 164.75 PRU. Bleeding complications included mild gastrointestinal bleeding and hematuria. There was one patient with pump thrombosis requiring intervention. There were no cerebrovascular events while on cangrelor. We report the first successful long-term use of cangrelor in pediatric patients. The reversibility and short half-life of cangrelor make it a feasible antiplatelet agent in selected patients. This data supports the use of cangrelor in children as a viable antiplatelet option; with minimal bleeding complications and no cerebrovascular events demonstrated in this cohort.

2019 HRS expert consensus statement on evaluation, risk stratification, and management of arrhythmogenic cardiomyopathy: Executive summary.

Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

Familial Left Ventricular Non-Compaction Is Associated With a Rare p.V407I Variant in Bone Morphogenetic Protein 10.

BACKGROUND: Left ventricular non-compaction (LVNC) is a heritable cardiomyopathy characterized by hypertrabeculation, inter-trabecular recesses and thin compact myocardium, but the genetic basis and mechanisms remain unclear. This study identified novel LVNC-associated mutations inNOTCH-dependent genes and investigated their mutational effects.Methods and Results:High-resolution melting screening was performed in 230 individuals with LVNC, followed by whole exome and Sanger sequencing of available family members. Dimerization of bone morphogenetic protein 10 (BMP10) and its binding to BMP receptors (BMPRs) were evaluated. Cellular differentiation, proliferation and tolerance to mechanical stretch were assessed in H9C2 cardiomyoblasts, expressing wild-type (WT) or mutant BMP10 delivered by adenoviral vectors. Rare variants, p.W143*-NRG1and p.V407I-BMP10, were identified in 2 unrelated probands and their affected family members. Although dimerization of mutant V407I-BMP10 was preserved like WT-BMP10, V407I-BMP10 pulled BMPR1a and BMPR2 receptors more weakly compared with WT-BMP10. On comparative gene expression and siRNA analysis, expressed BMPR1a and BMPR2 receptors were responsive to BMP10 treatment in H9C2 cardiomyoblasts. Expression of V407I-BMP10 resulted in a significantly lower rate of proliferation in H9C2 cells compared with WT-BMP10. Cyclic stretch resulted in destruction and death of V407I-BMP10 cells. CONCLUSIONS: The W143*-NRG1and V470I-BMP10variants are associated with LVNC. Impaired BMPR-binding ability, perturbed proliferation and differentiation processes and intolerance to stretch in V407I-BMP10 mutant cardiomyoblasts may underlie myocardial non-compaction.

Concurrent Use of Calcium Chloride and Arginine Vasopressin Infusions in Pediatric Patients with Acute Cardiocirculatory Failure.

Acute heart failure (AHF) can cause low cardiac output and poor end-organ perfusion. Inotropic agents along with vasodilators can improve organ perfusion. Arginine vasopressin (AVP) and calcium chloride (CaCl) infusions are increasingly being used in low cardiac output states in pediatric AHF. We retrospectively reviewed 77 patients (0-18 years) with AHF admitted between January 2014 and May 2017 who received concurrent AVP and CaCl infusions. Surrogates of cardiac output and organ perfusion included hemodynamic vital signs, laboratory parameters, and urine output (UO). Organ dysfunction and vasopressor inotropic scores were also calculated. Median (IQR) age was 0.88 years (0, 3.75), and median weight was 6.62 kg (3.5, 13.7). Congenital heart disease was present in 70% (46/77) patients. Univentricular physiology was present in 25% (25/77) patients. None of the patients were in the immediate postoperative period. Median durations of AVP and CaCl were 2 days (1, 3) and 3 days (2, 6), respectively. Using Wilcoxon-signed rank test and Bonferroni correction, post hoc comparison showed that at 8 h post infusion, all systolic blood pressure (SBP) and diastolic blood pressure (DBP) results, and UO were greater than those 1 h prior to infusion. Median SBP increased from 79 mm Hg (71, 92) 1 h prior to 97 mm Hg (84, 107) 8 h post. Median DBP increased from 44 mm Hg (35, 52) 1 h prior to 54 mm Hg (44, 62) 8 h post. Heart rate showed a decrease between measurements 1 h prior to infusion and 8 h post, with median scores 146 (127, 162) and 136 (114, 150) beats per minute, respectively. Within first 8 h, median UO continuously increased from 6 mL/h. (0, 25) at 1 h post infusion to 20 mL/h. (2, 62) at 8 h post infusion. Median pediatric logarithmic organ dysfunction scores on days 4 through 7 post infusion were lower compared to day 1; median vasopressor inotropic scores on day 2 through 7 post infusion were lower compared to day 1. Serum lactate level, arterial pH, and base excess all showed favorable trend. Concurrent use of AVP and CaCl infusions may improve surrogates of cardiac output, and intensive care outcomes, and prevent organ dysfunction in children with AHF.

2019 HRS expert consensus statement on evaluation, risk stratification, and management of arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.

The landscape of cardiovascular care in pediatric cancer patients and survivors: a survey by the ACC Pediatric Cardio-Oncology Work Group.

OBJECTIVE: To enhance the understanding of cardiovascular care delivery in childhood cancer patients and survivors. STUDY DESIGN: A 20-question survey was created by the Pediatric Cardio-oncology Work Group of the American College of Cardiology (ACC) Cardio-oncology Section to assess the care, management, and surveillance tools utilized to manage pediatric/young adult cardio-oncology patients. The survey distribution was a collaborative effort between Cardio-oncology Section and membership of the Adult Congenital and Pediatric Cardiology Section (ACPC) of the ACC. RESULTS: Sixty-five individuals, all self-identified as physicians, responded to the survey. Most respondents (n = 58,89%) indicated childhood cancer patients are regularly screened prior to and during cancer therapy at their centers, predominantly by electrocardiogram (75%), standard echocardiogram (58%) and advanced echocardiogram (50%) (i.e. strain, stress echo). Evaluation by a cardiologist prior to/during therapy was reported by only 8(12%) respondents, as compared to post-therapy which was reported by 28 (43%, p < 0.01). The most common indications for referral to cardiology at pediatric centers were abnormal test results (n = 31,48%) and history of chemotherapy exposure (n = 27,42%). Of note, during post-treatment counseling, common cardiovascular risk-factors like blood pressure (31,48%), lipid control (22,34%), obesity & smoking (30,46%) and diet/exercise/weight loss (30,46%) were addressed by fewer respondents than was LV function (72%). CONCLUSIONS: The survey data demonstrates that pediatric cancer patients are being screened by EKG and/or imaging prior to/during therapy at most centers. Our data, however, highlight the potential for greater involvement of a cardiovascular specialist for pre-treatment evaluation process, and for more systematic cardiac risk factor counseling in posttreatment cancer survivors.