Predictors of long-term mortality among perioperative survivors of Fontan operation.

AIMS: The criteria for 'good' Fontan haemodynamics have been poorly defined in relation to long-term outcomes. The aim of this study was to identify the risk factors for mortality among haemodynamic parameters obtained early after the Fontan operation. METHODS AND RESULTS: Clinical data of all perioperative survivors of the Fontan operation performed before 2011, from nine institutions, were collected through a retrospective chart review. In total, 1260 patients were included. The median age at the time of Fontan operation was 3.6 years. Post-operative cardiac catheterization was conducted in 1117 patients at a median period of 1.0 years after the operation. During the median follow-up period of 10.2 years, 107 patients died. The mortality rates at 10, 20, and 25 years after the operation were 5%, 12%, and 22%, respectively. On multivariable analysis, older age at the time of the operation {≥15 years, hazard ratio (HR) [95% confidence interval (CI)]: 3.2 (1.7-5.9)} and haemodynamic parameters obtained at post-operative catheterization, such as low ejection fraction [<30%, HR (95% CI): 7.5 (3.2-18)], low systemic oxygen saturation [<80%, HR (95% CI): 3.8 (1.6-9.1)], high central venous pressure [≥16 mmHg, HR (95% CI): 2.3 (1.3-3.9)], and low mean systemic arterial pressure [<60 mmHg, HR (95% CI): 3.0 (1.4-6.2)] were identified as independent predictors of mortality. The predictive model based on these parameters had a c-index of 0.75 at 10 years. CONCLUSIONS: Haemodynamic parameters obtained at a median period of 1.0 years, post-operatively, can accurately identify patients with a high mortality risk, who may need intensive management to improve long-term outcomes.

G0S2 regulates innate immunity in Kawasaki disease via lncRNA HSD11B1-AS1.

BACKGROUND: Kawasaki disease (KD) is a systemic vasculitis that is currently the most common cause of acquired heart disease in children. However, its etiology remains unknown. Long non-coding RNAs (lncRNAs) contribute to the pathophysiology of various diseases. Few studies have reported the role of lncRNAs in KD inflammation; thus, we investigated the role of lncRNA in KD inflammation. METHODS: A total of 50 patients with KD (median age, 19 months; 29 males and 21 females) were enrolled. We conducted cap analysis gene expression sequencing to determine differentially expressed genes in monocytes of the peripheral blood of the subjects. RESULTS: About 21 candidate lncRNA transcripts were identified. The analyses of transcriptome and gene ontology revealed that the immune system was involved in KD. Among these genes, G0/G1 switch gene 2 (G0S2) and its antisense lncRNA, HSD11B1-AS1, were upregulated during the acute phase of KD (P < 0.0001 and <0.0001, respectively). Moreover, G0S2 increased when lipopolysaccharides induced inflammation in THP-1 monocytes, and silencing of G0S2 suppressed the expression of HSD11B1-AS1 and tumor necrosis factor-α. CONCLUSIONS: This study uncovered the crucial role of lncRNAs in innate immunity in acute KD. LncRNA may be a novel target for the diagnosis of KD. IMPACT: This study revealed the whole aspect of the gene expression profile of monocytes of patients with Kawasaki disease (KD) using cap analysis gene expression sequencing and identified KD-specific molecules: G0/G1 switch gene 2 (G0S2) and long non-coding RNA (lncRNA) HSD11B1-AS1. We demonstrated that G0S2 and its antisense HSD11B1-AS1 were associated with inflammation of innate immunity in KD. lncRNA may be a novel key target for the diagnosis of patients with KD.

Pathological and Comprehensive Genetic Investigation of Autopsy Cases of Idiopathic Bradyarrhythmia.

BACKGROUND: Idiopathic bradyarrhythmia is considered to be due to pathological degeneration of the cardiac conduction system (CCS) during aging. There appears to have been no comprehensive genetic investigations in patients with idiopathic bradyarrhythmia.Methods and Results: Ten autopsy cases with advanced bradyarrhythmia (6 men and 4 women; age: 70-94 years, 81.5±6.9 years; 5 cases each of sinus node dysfunction [SND] and complete atrioventricular block [CAVB]) were genetically investigated by using whole-exome sequencing. Morphometric analysis of the CCS was performed with sex-, age- and comorbidity-matched control cases. As a result, severe loss of nodal cells and distal atrioventricular conduction system were found in SND and CAVB, respectively. However, the conduction tissue loss was not significant in either the atrioventricular node or the proximal bundle of His in CAVB cases. A total of 13 heterozygous potential variants were found in 3 CAVB and 2 SND cases. Of these 13 variants, 4 were missense in the known progressive cardiac conduction disease-related genes: GATA4 and RYR2. In the remaining 9 variants, 5 were loss-of-function mutation with highly possible pathogenicity. CONCLUSIONS: In addition to degenerative changes of selectively vulnerable areas in the heart during advancing age, the vulnerability of the CCS, which may be associated with "rare variants of small effect," may also be a contributing factor to the degeneration of CCS, leading to "idiopathic" bradyarrhythmia.

Effects of Concomitant Administration of PXR Ligand Drugs on the Anticoagulant Effects of Warfarin.

We encountered cases in which the anticoagulant effects of warfarin (CYP2C9 substrate) were reversibly attenuated by the concomitant administration of rifampicin or bosentan, which are potent pregnane X receptor (PXR) ligands. The purpose of the present study is to report the previous case with rifampicin, and to evaluate the changes in the warfarin anticoagulant effects when withdrawing or switching bosentan treatment. The former is a case study of a 4-year-old girl undergoing warfarin treatment. The latter is a longitudinal study of 20 pediatric patients receiving stable warfarin treatment. The prothrombin time and international normalized ratio (PT-INR) values were extracted from the medical records and normalized by the daily-dose per body size as an index for the warfarin anticoagulant effects. Rifampicin treatment resulted in a 52.0% decrease in the anticoagulant index. On the other hand, 10 of 20 patients started bosentan and their anticoagulant index was reduced by a median of 2.00. Bosentan was withdrawn in 4 of 20 patients and their anticoagulant index increased by a median of 3.67. Six of 20 patients switched from bosentan to macitentan, which is considered not to activate PXR in clinical settings. However, switching from bosentan to macitentan resulted in a median of 2.25 reduction of the anticoagulant index rather than recovery of the response to warfarin. This study suggests not only the possibility of heterogeneity in the response to PXR activation and deactivation, but also the importance of long-term monitoring of drug-drug interactions when switching from bosentan to macitentan.

Clinical significance of chronic myocarditis: systematic review and meta-analysis.

Chronic myocarditis is a prolonged inflammatory condition in the myocardium and its histological manifestation is defined by the presence of an inflammatory infiltrate. Chronic myocarditis has not been well known and its treatment of chronic myocarditis has not been established. Primary outcome of this study was to assess the efficacy of immunomodulatory treatment in addition to conventional treatment, and secondary outcomes were to clarity the prognosis of natural history of chronic myocarditis and incidence of chronic myocarditis in patients with dilated cardiomyopathy (DCM). We searched for studies in Medline, Embase, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi published between January 1946 and June 2020. Sixteen studies met the inclusion criteria. A meta-analysis revealed that patients receiving immunomodulatory treatment showed an improvement in left ventricular ejection fraction after immunomodulatory treatment compared to the control group (hazard ratio, 16.65; confidence interval, 4.55-28.74; p = 0.007). Five-year survival rate of the patients with inflammatory DCM (iDCM) and DCM was 52.7-70.3% and 51.9-91.1%, respectively. Moreover, 51.5%-62.7% of patients with DCM met the criteria of iDCM. Our systematic review revealed that patients with chronic myocarditis had poor prognosis and immunomodulatory treatment was significantly effective in addition to conventional treatment.

Outcomes of hypertrophic cardiomyopathy in Japanese children: a retrospective cohort study.

There has been no multicenter study on the prognosis of pediatric hypertrophic cardiomyopathy (HCM) in Japan. Therefore, we conducted a retrospective multicenter observational study on the long-term survival rate in patients diagnosed with HCM under the age of 18 between 1990 and 2014. Twenty institutions participated. A total of 180 patients were identified. The median age at diagnosis was 5.8 years old and median duration of observation was 8.3 years. Although six patients (3%) deteriorated into the dilated phase of HCM, no patient received heart transplantation. Freedom from death at 1, 5, 10, and 20 years were 97%, 92%, 84%, and 80%, respectively. There were 26 deaths. Among them, 11 patients died suddenly, presumably due to arrhythmia, and 15 patients died of heart failure. The presence of heart failure symptoms and a greater cardiothoracic ratio were significant risk factors for heart failure-related death. There were no significant risk factors identified for arrhythmia-related death. In conclusion, the prognosis of pediatric HCM in Japan is good and similar to those reported in population-based studies in the United States and Australia. Significant risk factors for heart failure-related death were identified in pediatric patients with HCM in Japan.

Identification of a de novo mutation of the elastin gene by targeted exome sequencing in autosomal dominant cutis laxa.

Cutis laxa (CL) comprises a heterogeneous group of entities mainly classified as X-linked, autosomal dominant and recessive forms, which differ in severity. We encountered a CL baby with no familial history. We performed targeted exome sequencing, and detected a de novo heterozygous frameshift mutation in the elastin gene of the baby.

Clinical Characteristics and Prognosis of Fetal Left Ventricular Noncompaction in Japan.

BACKGROUND: Left ventricular noncompaction (LVNC) is morphologically characterized by numerous prominent trabeculations and a severely thickened, two-layered myocardium. The fetal onset of LVNC has rarely been described.Methods and Results:We conducted nationwide retrospective surveys on fetal cardiomyopathy (CM) in Japan from 2010 to 2016, from which 38 fetal patients with CM were enrolled, including 16 patients with LVNC. The rate of diagnostic concordance was 56.3% between fetal and postnatal visits in LVNC patients. The increase in the ratio of noncompacted to compacted (N/C) myocardium was time-dependent throughout the fetal period till birth (LV lateral: 1.6±0.1 to 2.8±0.2; LV apex: 2.0±0.1 to 3.2±0.2). Of all fetuses, 16 (42.1%) died or underwent heart transplantation (HT), with 3 intrauterine deaths. Lower fetal cardiovascular profile score (odds ratio, 26.9; P=0.0266) was a risk factor for death or HT. N/C ratio ≥1.6 at the apex at the first visit was a significant predictor of LVNC (odds ratio, 47.8; P=0.0113). CONCLUSIONS: This is the first study to reveal the etiology of fetal CM based on results from a nationwide survey in Japan, highlighting the difficulty of diagnosing LVNC in fetal patients. To better understand and manage fetal CM, novel diagnostic criteria of LVNC in fetus should be established.

Electrocardiographic Diagnosis of Hypertrophic Cardiomyopathy in the Pre- and Post-Diagnostic Phases in Children and Adolescents.

BACKGROUND: The usefulness of electrocardiographic (ECG) voltage criteria for diagnosing hypertrophic cardiomyopathy (HCM) in pediatric patients is poorly defined.Methods and Results:ECGs at the 1st grade (mean [±SD] age 6.6±0.3 years) were available for 11 patients diagnosed with HCM at around the 7th grade (13.2±0.3 years). ECGs were available for another 64 patients diagnosed with HCM in the 1st (n=15), 7th (n=32), and 10th (n=17) grades. Fifty-one voltage criteria were developed by grade and sex using 62,841 ECGs from the general population. Voltage criteria were set at the 99.95th percentile (1/2,000) point based on the estimated prevalence of childhood HCM (2.9 per 100,000 [1/34,483]) to decrease false negatives. Conventional criteria were from guidelines for school-aged children in Japan. Of 11 patients before diagnosis, 2 satisfied conventional criteria in 1st grade; 5 (56%) of the remaining 9 patients fulfilled 2 voltage criteria (R wave in limb-lead I [RI]+S wave in lead V3 [SV3] and R wave in lead V3 [RV3]+SV3). Robustness analysis for sensitivity showed RV3+SV3 was superior to RI+SV3. For all patients after diagnosis, RI+SV4 was the main candidate. However, conventional criteria were more useful than voltage criteria. CONCLUSIONS: Early HCM prediction was possible using RV3+SV3 in >50% of patients in 1st grade. Voltage criteria may help diagnose prediagnostic or early HCM, and prevent tragic accidents, although further prospective studies are required.

Reversible left ventricular noncompaction caused by hypertensive hydrocephalus: a pediatric case report.

BACKGROUND: Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by prominent ventricular trabeculations on cardiovascular imaging. Acquired reversible LVNC has not been reported in pediatrics without a genetic background. CASE PRESENTATION: A 9-year-old girl with a ventriculoperitoneal (VP) shunt for neonatal posthemorrhagic hydrocephalus was referred due to exacerbation of hydrocephalus caused by VP shunt dysfunction. Transthoracic echocardiography (TTE) revealed depressed left ventricular (LV) systolic function and thick prominent trabeculae in the LV, predominantly in the apex, suggesting LVNC. Following treatment with extraventricular drainage for hydrocephalus, prominent trabeculation of the LV was diminished on TTE within 3 months. Genetic testing using next-generation sequencing was performed, and no significant variants were identified. CONCLUSIONS: We revealed for the first time a pediatric case of reversible LVNC without genetic predisposition. This case report provides valuable information on the pathogenesis of acquired LVNC and suggests that detailed evaluation is required to elucidate the diagnosis of this wide spectrum of etiologic-pathogenetic disorders.

Poor Myocardial Compaction in a Patient with Recessive MYL2 Myopathy.

Recessive mutations in the Myosin regulatory light chain 2 (MYL2) gene are the cause of an infantile-onset myopathy, associated with fatal myocardial disease of variable macromorphology. We here present the first Japanese family affected with recessive MYL2 myopathy. Affected siblings manifested typical features and the proband's autopsy findings were compatible with the diagnosis of noncompaction cardiomyopathy. The rapidly progressive clinical course of this recessive MYL2 cardiomyopathy highlights the crucial role of c-terminal tails in MYL2 protein in maintaining cardiac morphology and function.

Efficacy of primary treatment with immunoglobulin plus ciclosporin for prevention of coronary artery abnormalities in patients with Kawasaki disease predicted to be at increased risk of non-response to intravenous immunoglobulin (KAICA): a randomised controlled, open-label, blinded-endpoints, phase 3 trial.

BACKGROUND: Genetic studies have indicated possible involvement of the upregulated calcium-nuclear factor of activated T cells pathway in the pathogenesis of Kawasaki disease. We aimed to assess safety and efficacy of ciclosporin, an immunosuppressant targeting this pathway, for protection of patients with Kawasaki disease against coronary artery abnormalities. METHODS: We did a randomised, open-label, blinded endpoints trial involving 22 hospitals in Japan between May 29, 2014, and Dec 27, 2016. Eligible patients predicted to be at higher risk for intravenous immunoglobulin (IVIG) resistance were randomly assigned to IVIG plus ciclosporin (5 mg/kg per day for 5 days; study treatment) or IVIG (conventional treatment) groups, stratified by risk score, age, and sex. The primary endpoint was incidence of coronary artery abnormalities using Japanese criteria during the 12-week trial, assessed in participants who received at least one dose of study drug and who visited the study institution at least once during treatment. This trial is registered to Center for Clinical Trials, Japan Medical Association, number JMA-IIA00174. FINDINGS: We enrolled 175 participants. One patient withdrew consent after enrolment and was excluded and one patient (in the study treatment group) was excluded from analysis because of lost echocardiography data. Incidence of coronary artery abnormalities was lower in the study treatment group than in the conventional treatment group (12 [14%] of 86 patients vs 27 [31%] of 87 patients; risk ratio 0·46; 95% CI 0·25-0·86; p=0·010). No difference was found in the incidence of adverse events between the groups (9% vs 7%; p=0·78). INTERPRETATION: Combined primary therapy with IVIG and ciclosporin was safe and effective for favourable coronary artery outcomes in Kawasaki disease patients who were predicted to be unresponsive to IVIG. FUNDING: Japan Agency for Medical Research and Development (grant CCT-B-2503).

CYP2C9, VKORC1, and CYP4F2 polymorphisms and pediatric warfarin maintenance dose: a systematic review and meta-analysis.

Studies on the effect of cytochrome P450 2C9 (CYP2C9), vitamin K epoxide reductase complex subunit 1 (VKORC1), and cytochrome P450 4F2 (CYP4F2) polymorphisms on warfarin maintenance dose in children are conflicting. We conducted a systematic review and meta-analysis to evaluate the effect of these polymorphisms on warfarin maintenance dose in children. We searched relevant literature using the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trial libraries without any language restrictions from their inception to 23 July 2017. Dose differences are expressed as standardized mean difference (SMD) or mean difference (MD) with 95% confidence intervals (CI). This review was registered in the PROSPERO prospective register of systematic reviews (CRD42015016172). We included a total of nine studies (745 participants) in the meta-analysis. Patients with CYP2C9 *1/*2, *1/*3, *2/*2, *2/*3, or *3/*3 required a lower warfarin maintenance dose compared with patients with CYP2C9 *1/*1 (SMD = -0.610, 95% CI: -0.802 to -0.419, I2 = 0%). Patients with VKORC1-1639GA or AA required a lower warfarin maintenance dose compared with patients with VKORC1-1639GG (SMD = -0.666, 95% CI: -0.887 to -0.445, I2 = 33%). However, no associations were observed between CYP4F2 polymorphisms and warfarin maintenance dose (MD = 0.005 mg/kg/day, 95% CI: -0.006 to 0.015, I2 = 0%). These results were not affected by a sensitivity analysis. Our meta-analysis provides evidence that CYP2C9 and VKORC1 variant statuses affect warfarin maintenance dose in children, but not CYP4F2.

The Pharmacokinetics of Sildenafil May Be Affected by Intestinal Absorption Rate in Children Admitted to the Intensive Care Unit.

This study was performed for a better understanding of the pharmacokinetics of sildenafil (SIL) and N-desmethyl sildenafil (DMS) in 13 children treated in the intensive care unit (ICU). Blood samples were taken periodically after the first oral administration of SIL (0.5 mg/kg). Plasma concentrations were analyzed by tandem LC/MS. Of the 13 patients, apparent peaks in the plasma concentration of SIL were observed in four patients, with the other nine patients showing reduced or delayed drug absorption of SIL. The maximum plasma concentrations of SIL after administration varied in range from 7.8 to 101.0 ng/mL. The parent drug-to-metabolite (SIL/DMS) ratios of the nine patients with reduced or delayed drug absorption of SIL were relatively lower than those in the four patients with rapid absorption of the drug. These observations suggested that the inter-individual variability of intestinal absorption and/or first-pass extraction of SIL was involved in the pharmacokinetic variability of the drug. Next, we evaluated the impact of changes in the gastrointestinal absorption rate on the pharmacokinetics of the drug. That is, SIL (2.5 mg/body) was administered at two different rates in the duodenum of rats. When SIL was administered for 10 min, the Cmax and bioavailability were 3.46 ± 1.65 µg/mL and 23.2 ± 11.1%, respectively. When SIL was administered for 60 min, the Cmax and bioavailability were 0.990 ± 0.352 µg/mL and 9.91 ± 3.79%, respectively. These findings suggest that the drug absorption rate was at least partly responsible for the pharmacokinetic variability of SIL in the ICU children.

The combination of the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios as a novel predictor of intravenous immunoglobulin resistance in patients with Kawasaki disease: a multicenter study.

INTRODUCTION: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been reported to be a predictor for intravenous immunoglobulin (IVIG) resistance in patients with Kawasaki disease (KD) recently. The objective of the present study was to elucidate the predictive validity of this new marker in a multicenter study. MATERIALS AND METHODS: We retrospectively reviewed the clinical records of 520 consecutive KD patients (development data set) and 332 subsequent patients (validation data set) at 7 hospitals in Japan. RESULTS: Both NLR and PLR were significantly higher in the IVIG-resistant group than in the IVIG-responsive group. When we set the cut-off point as NLR ≥ 4.11 and PLR ≥ 119, multiple logistic regression analyses showed that a high NLR and PLR before initial IVIG were independent predictors of IVIG resistance, and their combination was a stronger predictor than either alone. The sensitivity and specificity of the combination of NLR ≥ 4.11 and PLR ≥ 119 were 0.58 and 0.73 in the development data set. Validated using an independent data set, they were 0.54 and 0.72 in the validation data set. On comparing the AUC of this predictor with those of the Gunma and Kurume scores, the AUC was highest for this predictor, followed by the Gunma score and Kurume score (0.70, 0.68, and 0.64, respectively). DISCUSSION: The predictive validity of the combination of a high NLR and PLR, which is a simple and convenient indicator, was equal to or better than that of the existing scoring systems. The new predictive marker may be a suitable indicator for predicting IVIG resistance in KD patients.

A significance of school screening electrocardiogram in the patients with ventricular noncompaction.

Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy and is associated with high morbidity and mortality. However, the role and significance of school screening for LVNC have not been fully elucidated. In this multicenter, retrospective cohort study, a total of 105 children with LVNC were included from 2000 to 2017. At the initial presentation, 44 patients (41.9%) were diagnosed by school screening. One (1.0%) patient underwent heart transplantation and four (3.8%) patients died during the study. Electrocardiogram data showed a high prevalence of fragmented QRS (33.4%) and J wave (15.7%). Treatments were needed in eight (18.2%) patients who were detected by school screening. The multivariable proportional hazards model showed T-wave abnormality on electrocardiogram in first graders was independent risk factors for major adverse cardiac events (odds ratio 4.94, p value = 0.0007). Moreover, dilation of the left atrium on chest X-ray and low ejection fraction on echocardiogram at the initial treatment were independent risk factors for treatment (odds ratio 1.7 × 107 and 22.3, p = 0.0362 and 0.0028, respectively). This study is the first report focusing on school screening in a large pediatric cohort with LVNC. With the use of abnormalities in electrocardiogram, school screening may be a good detector of and predictor for LVNC.

Neurodevelopmental outcomes at 3 years for infants with congenital heart disease and very-low birthweight.

BACKGROUND: Both congenital heart disease (CHD) and very-low birthweight (VLBW) infants are at a very high risk of neurodevelopmental delay. We investigated neurological development at 3 years in pediatric patients with CHD after surgical intervention, those of VLBW, and healthy controls. METHODS: We enrolled pediatric patients with CHD (n = 67), VLBW (n = 67), and healthy controls (n = 81). Infants with CHD were grouped into those with single ventricle and two ventricles, and infants with VLBW were grouped into those with birthweights of <1000 and 1000-1499 g. Neurodevelopmental outcomes at 3 years were evaluated using the Bayley Scales of Infant and Toddler Development, Third Edition. RESULTS: Compared with healthy controls, a significant deficit in the language, cognition, and motor skills scores were observed in infants with CHD and VLBW. Infants with a single ventricle exhibited significantly low scores in language and gross motor skills. No statistically significant difference was observed between the birthweight groups of <1000 and 1000-1499 g. CONCLUSION: Neurodevelopmental outcomes for infants with both CHD and VLBW showed impairment. Notably, neurodevelopmental delays in infants with a single ventricle were remarkable. Thus, because infants with both CHD and VLBW are at high risk of neurodevelopmental disorders, periodic developmental screenings and support are warranted for these children.

Minimal inflammatory foci of unknown etiology may be a tentative sign of early stage inherited cardiomyopathy.

Although relatively uncommon, pathologists may encounter minimal inflammatory foci in the absence of typical structural heart disease; however, the clinicopathological significance of minimal inflammatory foci, including correlation with sudden unexpected death, is unexplored. From 1072 serial autopsy subjects, cases with unexplained minimal inflammatory foci, the extent of which was under 1% of the whole examined ventricle, were extracted to exclude cases with borderline/focal myocarditis resulting from local, systemic infection, or autoimmune mechanisms. Immunohistochemistry and genetic analysis targeting viral genomes and heart disease-related genes using next generation sequencing were performed. We detected 10 cases with unexplained minimal inflammatory foci (five males, five females, aged 15-68 years). The cause and/or manner of death were sudden unexpected death (6 cases, 60%), sudden unexpected death with epilepsy (1 case, 10%), drowning in a hot bath (1 case, 10%), and suicide (2 cases, 20%). In none of these cases was pathogen-derived DNA or RNA detected. In 8 of the 10 cases (80%), 17 possible pathogenic genetic variants causative for arrhythmogenic right ventricular cardiomyopathy or dilated cardiomyopathy; DSP was the most frequently involved gene (three cases with two different variants), followed by LAMA4 and MYBPC3 (two cases, two variants for each gene), LDB3 (two cases, one variant), and the remaining 10 variants occurred in seven cases (DSC2, RYR2, SOS1, SCN5A, SGCD, LPL, PKP2, MYH11, GATA6, and DSG2). All mutations were missense mutations. DSP_Lys1581Glu and DSC2_p.Thr275Met were classified according to American College of Medical Genetics and Genomics consensus statement guidelines as pathogenic or likely pathogenic for arrhythmogenic cardiomyopathy in three patients (30%). The remaining 15 variants were classified as potentially pathogenic variants. Unexplained minimal inflammatory foci may be an early sign of inherited cardiomyopathy, and such cases might already have arrhythmogenic potential that can lead to sudden unexpected death. Detection of minimal inflammatory foci by careful pathological examination may indicate the value of conducting comprehensive genetic analysis, even if significant structural abnormalities are not evident.

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.

Evaluation of the effects of ontogenetic or maturation functions and chronic heart failure on the model analysis for the dose-response relationship of warfarin in Japanese children.

PURPOSE: We previously demonstrated that the rational pediatric dosage of warfarin can be well-described by a SIZE parameter that includes an allometry exponent of weight. On the other hand, allometry alone is considered to be insufficient to predict drug clearance in neonates and infants. The primary purpose of the present study was to evaluate the effects of incorporation of the maturation process into the analysis model for the dose-response relationship of warfarin in Japanese children. In addition, we evaluated the effect of chronic heart failure (CHF) on the response to warfarin as an independent risk factor for increased anticoagulant effects. METHODS: Thirty-eight patients with stable anticoagulation by warfarin were enrolled. During a mean follow-up period of 4.74 ± 3.51 years, 1092 data points including prothrombin time-international normalized ratio (PT-INR) were obtained. The data were subjected to multiple regression analysis to identify covariates related to the anticoagulant effects. RESULTS: Two different models describing the maturation process did not improve the predictive performance for the dose-response relationship in pediatric patients. In addition to the SIZE-normalized daily dose, the vitamin K epoxide reductase complex 1 (VKORC1) genotype, and concomitant use of bosentan, CHF was identified as a covariate increasing the anticoagulant effects of warfarin to 118%. CONCLUSION: The SIZE parameter was useful even without incorporation of maturation models to describe the response to warfarin in pediatric patients, and our longitudinal follow-up study design with multiple observations was beneficial to detect changes within individual subjects.