Biallelic PKP2 loss of function variants are associated with a lethal perinatal-onset biventricular dilated cardiomyopathy with excessive trabeculations and ventricular septal defects.

Homozygous plakophilin-2 (PKP2) variants have been identified as a cause of a lethal form of dilated cardiomyopathy with excessive trabeculations (DCM-ET) in three cases. We report three more cases from two families with homozygous pathogenic PKP2 variants and perinatal-onset, lethal DCM-ET. Identification of the genetic abnormalities played a key role in decision-making and family counselling in these cases. This case series supports the published evidence that biallelic loss of function PKP2 variants cause a lethal, perinatal-onset cardiomyopathy.

Indications and management of implantable cardioverter-defibrillator therapy in childhood hypertrophic cardiomyopathy.

Sudden cardiac death is the most common mode of death during childhood and adolescence in hypertrophic cardiomyopathy, and identifying those individuals at highest risk is a major aspect of clinical care. The mainstay of preventative therapy is the implantable cardioverter-defibrillator, which has been shown to be effective at terminating malignant ventricular arrhythmias in children with hypertrophic cardiomyopathy but can be associated with substantial morbidity. Accurate identification of those children at highest risk who would benefit most from implantable cardioverter-defibrillator implantation while minimising the risk of complications is, therefore, essential. This position statement, on behalf of the Association for European Paediatric and Congenital Cardiology (AEPC), reviews the currently available data on established and proposed risk factors for sudden cardiac death in childhood-onset hypertrophic cardiomyopathy and current approaches for risk stratification in this population. It also provides guidance on identification of individuals at risk of sudden cardiac death and optimal management of implantable cardioverter-defibrillators in children and adolescents with hypertrophic cardiomyopathy.

The heart in RASopathies.

The cardiovascular phenotype associated with RASopathies has expanded far beyond the original descriptions of pulmonary valve stenosis by Dr Jaqueline Noonan in 1968 and hypertrophic cardiomyopathy by Hirsch et al. in 1975. Because of the common underlying RAS/MAPK pathway dysregulation, RASopathy syndromes usually present with a typical spectrum of overlapping cardiovascular anomalies, although less common cardiac defects can occur. The identification of the causative genetic variants has enabled the recognition of specific correlations between genotype and cardiac phenotype. Characterization and understanding of genotype-phenotype associations is not only important for counseling a family of an infant with a new diagnosis of a RASopathy condition but is also critical for their clinical prognosis with respect to cardiac disease, neurodevelopment and other organ system involvement over the lifetime of the patient. This review will focus on the cardiac manifestations of the most common RASopathy syndromes, the relationship between cardiac defects and causal genetic variation, the contribution of cardiovascular abnormalities to morbidity and mortality and the most relevant follow-up issues for patients affected by RAS/MAPK pathway diseases, with respect to cardiac clinical outcomes and management, in children and in the adult population.

Cardiovascular safety of growth hormone treatment in Noonan syndrome: real-world evidence.

Objective: The study aims to assess the cardiovascular safety of growth hormone (GH) treatment in patients with Noonan syndrome (NS) in clinical practice. Design: The study design involves two observational, multicentre studies (NordiNet® IOS and the ANSWER Program) evaluating the long-term effectiveness and safety of GH in >38,000 paediatric patients, of which 421 had NS. Methods: Serious adverse events, serious adverse reactions (SARs) and non-serious adverse reactions (NSARs) were reported by the treating physicians. Cardiovascular comorbidities at baseline and throughout the studies were also recorded. Results: The safety analysis set comprised 412 children with NS (29.1% females), with a mean (s.d.) baseline age of 9.29 (3.88) years, treated with an average GH dose of 0.047 (0.014) mg/kg/day during childhood. Cardiovascular comorbidities at baseline were reported in 48 (11.7%), most commonly pulmonary valve stenosis (PVS) and atrial septal defects. Overall, 22 (5.3%) patients experienced 34 safety events. The most common were the NSARs: headache (eight events in seven patients) and arthralgia (five events in three patients). Two SARs occurred in one patient (brain neoplasm and metastases to spine). No cardiovascular safety events were recorded in patients with NS. Five cardiovascular comorbidities in five patients were reported after initiation of GH treatment: three cases of unspecified cardiovascular disease, one ruptured abdominal aortic aneurysm and one PVS. Conclusions: GH treatment had a favourable safety profile in patients with NS, including those with cardiovascular comorbidities. Prospective studies are warranted to systematically assess the safety of GH treatment in patients with NS and cardiovascular disease.

Somatic mutations of GNA11 and GNAQ in CTNNB1-mutant aldosterone-producing adenomas presenting in puberty, pregnancy or menopause.

Most aldosterone-producing adenomas (APAs) have gain-of-function somatic mutations of ion channels or transporters. However, their frequency in aldosterone-producing cell clusters of normal adrenal gland suggests a requirement for codriver mutations in APAs. Here we identified gain-of-function mutations in both CTNNB1 and GNA11 by whole-exome sequencing of 3/41 APAs. Further sequencing of known CTNNB1-mutant APAs led to a total of 16 of 27 (59%) with a somatic p.Gln209His, p.Gln209Pro or p.Gln209Leu mutation of GNA11 or GNAQ. Solitary GNA11 mutations were found in hyperplastic zona glomerulosa adjacent to double-mutant APAs. Nine of ten patients in our UK/Irish cohort presented in puberty, pregnancy or menopause. Among multiple transcripts upregulated more than tenfold in double-mutant APAs was LHCGR, the receptor for luteinizing or pregnancy hormone (human chorionic gonadotropin). Transfections of adrenocortical cells demonstrated additive effects of GNA11 and CTNNB1 mutations on aldosterone secretion and expression of genes upregulated in double-mutant APAs. In adrenal cortex, GNA11/Q mutations appear clinically silent without a codriver mutation of CTNNB1.

Multidisciplinary evaluation and management of obstructive hypertrophic cardiomyopathy in 2020: Towards the HCM Heart Team.

Patients with hypertrophic cardiomyopathy (HCM) exhibit a variable phenotype with ventricular hypertrophy as the cardinal manifestation and left ventricular (LV) outflow tract obstruction (LVOTO) as a key pathophysiologic determinant. Patients with severe LVOTO usually present with exertional dyspnea, exertional syncope, and heart failure symptoms, while successful relief of LVOTO by pharmacological or invasive interventions leads to a dramatic improvement in clinical status. Proper management of obstructive HCM remains challenging and poses numerous clinical dilemmas. Since the development of surgical myectomy over half a century ago, progress in the management of LVOTO in HCM has paralleled technological advances in genetic testing, cardiac imaging, arrhythmic prophylaxis, cardiac surgery and interventional cardiology. These changes have been incorporated in dedicated scientific guidelines on both sides of the Atlantic. However, either the 2011 American guidelines or the 2014 European guidelines remain largely based on expert consensus for lack of recommendations with level of evidence A regarding any of the treatment options commonly employed in HCM. Consequently, management of obstructive HCM patients remains largely subjective and dependent on clinical judgment, local expertise, and patient preference. Following the trend that has emerged for other cardiac diseases amenable to invasive interventions, adequate evaluation and management of obstruction in HCM today requires a multidisciplinary team capable of optimizing referral, choosing the best available options, minimizing complications and ensuring state-of-the-art results. The concept of an HCM Heart Team is coming of age. This review aims to provide an update of available pharmacologic and invasive options for the management of LVOTO in HCM, either in adulthood or in childhood, highlighting areas for multidisciplinary integration and future development.

Incidence and Progression of Echocardiographic Abnormalities in Older Children with Human Immunodeficiency Virus and Adolescents Taking Antiretroviral Therapy: A Prospective Cohort Study.

BACKGROUND: A high prevalence of cardiac abnormalities has been reported in children with human immunodeficiency virus (HIV) taking antiretroviral therapy (ART) in sub-Saharan Africa. We investigated the incidence and progression of cardiac abnormalities among children taking ART in Zimbabwe. METHODS: A prospective cohort study was conducted at a pediatric HIV clinic from 2014 to 2017. Children with HIV aged between 6 and 16 years and taking ART ≥6 months were enrolled. Transthoracic echocardiography was performed at baseline and after 18 months. RESULTS: Of 197 participants recruited at baseline, 175 (89%; 48% female; median age 12 years, interquartile range 10-14 years) were followed up. The incidences of left and right heart abnormalities were 3.52 and 5.64 per 100 person-years, respectively. Stunting was associated with the development of any cardiac abnormality (adjusted odds ratio 2.59, 95% confidence interval 1.03-6.49; P = .043). Right ventricular (RV) dilatation persisted at follow-up in 92% of participants and left ventricular (LV) diastolic dysfunction in 88%. Cardiac abnormalities present at baseline reverted to normal over the follow-up period in 11 (6%). There was an overall increase in mean z scores for LV, left atrium (LA), RV, interventricular septum, and LV posterior wall diameters at 18 months (P < .001). CONCLUSIONS: Despite ART, children with HIV have a high incidence of cardiac abnormalities, with only a minority being transient. Mean z scores for LV, LA, RV, interventricular septum, and LV posterior wall diameters increased over a relatively short follow-up period, suggesting the potential for progression of cardiac abnormalities. Longer follow-up is required to understand the clinical implications of these abnormalities.

Yield of Clinical Screening for Hypertrophic Cardiomyopathy in Child First-Degree Relatives.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a heritable myocardial disease with age-related penetrance. Current guidelines recommend clinical screening of relatives beginning at 10 years of age, but the clinical value of this approach has not been systematically evaluated. METHODS: Anonymized clinical data were collected from children referred for family screening between 1994 and 2017 after diagnosis of HCM in a first-degree relative. RESULTS: Of 1198 consecutive children (≤18 years of age) from 594 families who underwent serial evaluation (median, 3.5 years; interquartile range, 1.2-7), 32 individuals met diagnostic criteria at baseline (median maximal left ventricular wall thickness, 13 mm; interquartile range, 8-21 mm), and 25 additional patients developed HCM during follow-up. Median age at diagnosis was 10 years (interquartile range, 4-13 years); 44 (72%) were ≤12 years of age. Median age of affected patients at the last follow-up was 14 years (interquartile range, 9.5-18.2 years). A family history of childhood HCM was more common in those patients diagnosed with HCM (n=32 [56%] versus n=257 [23%]; P<0.001). Eighteen patients (32%) were started on medication for symptoms; 2 (4%) underwent a septal myectomy; 14 (25%) received an implantable cardioverter-defibrillator; 1 underwent cardiac transplantation; 2 had a resuscitated cardiac arrest; and 1 died after a cerebrovascular accident. CONCLUSIONS: Almost 5% of first-degree child relatives undergoing screening meet diagnostic criteria for HCM at first or subsequent evaluations, with the majority presenting as preadolescents; a diagnosis in a child first-degree relative is made in 8% of families screened. The phenotype of familial HCM in childhood is varied and includes severe disease, suggesting that clinical screening should begin at a younger age.

The Cardiomyopathy Registry of the EURObservational Research Programme of the European Society of Cardiology: baseline data and contemporary management of adult patients with cardiomyopathies.

Aims: The Cardiomyopathy Registry of the EURObservational Research Programme is a prospective, observational, and multinational registry of consecutive patients with four cardiomyopathy subtypes: hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), and restrictive cardiomyopathy (RCM). We report the baseline characteristics and management of adults enrolled in the registry. Methods and results: A total of 3208 patients were enrolled by 69 centres in 18 countries [HCM (n = 1739); DCM (n = 1260); ARVC (n = 143); and RCM (n = 66)]. Differences between cardiomyopathy subtypes (P < 0.001) were observed for age at diagnosis, history of familial disease, history of sustained ventricular arrhythmia, use of magnetic resonance imaging or genetic testing, and implantation of defibrillators. When compared with probands, relatives had a lower age at diagnosis (P < 0.001), but a similar rate of symptoms and defibrillators. When compared with the Long-Term phase, patients of the Pilot phase (enrolled in more expert centres) had a more frequent rate of familial disease (P < 0.001), were more frequently diagnosed with a rare underlying disease (P < 0.001), and more frequently implanted with a defibrillator (P = 0.023). Comparing four geographical areas, patients from Southern Europe had a familial disease more frequently (P < 0.001), were more frequently diagnosed in the context of a family screening (P < 0.001), and more frequently diagnosed with a rare underlying disease (P < 0.001). Conclusion: By providing contemporary observational data on characteristics and management of patients with cardiomyopathies, the registry provides a platform for the evaluation of guideline implementation. Potential gaps with existing recommendations are discussed as well as some suggestions for improvement of health care provision in Europe.

Pigmentary hypertrichosis and non-autoimmune insulin-dependent diabetes mellitus (PHID) syndrome is associated with severe chronic inflammation and cardiomyopathy, and represents a new monogenic autoinflammatory syndrome.

Mutations in SLC29A3 lead to pigmentary hypertrichosis and non-autoimmune insulin-dependent diabetes mellitus (PHID) and H syndromes, familial Rosai-Dorfman disease, and histiocytosis-lymphadenopathy plus syndrome. We report a new association of PHID syndrome with severe systemic inflammation, scleroderma-like changes, and cardiomyopathy. A 12-year-old girl with PHID syndrome presented with shortness of breath, hepatosplenomegaly, and raised erythrocyte sedimentation rate and C-reactive protein. An echocardiogram showed biventricular myocardial hypertrophy, and cardiac magnetic resonance imaging showed circumferential late gadolinium enhancement of the myocardium. No systemic amyloid deposits were observed on a whole-body serum amyloid P scintigraphy scan. Abdominal ultrasound revealed intra-abdominal fat surrounding the solid organs, suggesting a possibility of evolving lipodystrophy with visceral adiposity. PHID syndrome is a novel monogenic autoinflammatory syndrome (AIS) associated with severe elevation of serum amyloid. Lipodystrophy, cutaneous sclerodermatous changes, and cardiomyopathy were also present in this case. In contrast to other AIS, blockade of interleukin-1 and tumor necrosis-α was ineffective.

Mutations in the cardiac Troponin C gene are a cause of idiopathic dilated cardiomyopathy in childhood.

The role of familial disease in childhood dilated cardiomyopathy is unknown. A novel mutation in the cardiac Troponin C gene has been identified recently in a family with dilated cardiomyopathy. Here we present a subsequent case of dilated cardiomyopathy occurring in a child from the same family, and emphasise the implications for future screening and counselling.