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Background Peripheral pulmonary stenosis (PPS) is a condition characterized by the narrowing of the pulmonary arteries, which impairs blood flow to the lung. The mechanisms underlying PPS pathogenesis remain unclear. Thus, the aim of this study was to investigate the genetic background of patients with severe PPS to elucidate the pathogenesis of this condition. Methods and Results We performed genetic testing and functional analyses on a pediatric patient with PPS and Williams syndrome (WS), followed by genetic testing on 12 patients with WS and mild‐to‐severe PPS, 50 patients with WS but not PPS, and 21 patients with severe PPS but not WS. Whole‐exome sequencing identified a rare PTGIS nonsense variant (p.E314X) in a patient with WS and severe PPS. Prostaglandin I2 synthase (PTGIS) expression was significantly downregulated and cell proliferation and migration rates were significantly increased in cells transfected with the PTGIS p.E314X variant‐encoding construct when compared with that in cells transfected with the wild‐type PTGIS‐encoding construct. p.E314X reduced the tube formation ability in human pulmonary artery endothelial cells and caspase 3/7 activity in both human pulmonary artery endothelial cells and human pulmonary artery smooth muscle cells. Compared with healthy controls, patients with PPS exhibited downregulated pulmonary artery endothelial prostaglandin I2 synthase levels and urinary prostaglandin I metabolite levels. We identified another PTGIS rare splice‐site variant (c.1358+2T>C) in another pediatric patient with WS and severe PPS. Conclusions In total, 2 rare nonsense/splice‐site PTGIS variants were identified in 2 pediatric patients with WS and severe PPS. PTGIS variants may be involved in PPS pathogenesis, and PTGIS represents an effective therapeutic target.

Abstract We used 4D-flow MRI to investigate circulation, an area integral of vorticity, in the main pulmonary artery (MPA) as a new hemodynamic parameter for assessing patients with a repaired Tetralogy of Fallot (TOF). We evaluated the relationship between circulation, right ventricular (RV) function and the pulmonary regurgitant fraction (PRF). Twenty patients with a repaired TOF underwent cardiac MRI. Flow-sensitive 3D-gradient sequences were used to obtain 4D-flow images. Vortex formation in the MPA was visualized, with short-axis and longitudinal vorticities calculated by software specialized for 4D flow. The RV indexed end-diastolic/end-systolic volumes (RVEDVi/RVESVi) and RV ejection fraction (RVEF) were measured by cine MRI. The PR fraction (PRF) and MPA area were measured by 2D phase-contrast MRI. Spearman ρ values were determined to assess the relationships between circulation, RV function, and PRF. Vortex formation in the MPA occurred in 15 of 20 patients (75%). The longitudinal circulation (11.7 ± 5.1 m2/s) was correlated with the RVEF (ρ = − 0.85, p = 0.0002), RVEDVi (ρ = 0.62, p = 0.03), and RVESVi (ρ = 0.76, p = 0.003) after adjusting for the MPA size. The short-axis circulation (9.4 ± 3.4 m2/s) in the proximal MPA was positively correlated with the MPA area (ρ = 0.61, p = 0.004). The relationships between the PRF and circulation or RV function were not significant. Increased longitudinal circulation in the MPA, as demonstrated by circulation analysis using 4D flow MRI, was related to RV dysfunction in patients with a repaired TOF.

AimsThe incidence of hepatocellular carcinoma (HCC) in patients with Fontan-associated liver disease (i.e., FALD-HCC) has increased over time. However, the risk factors for HCC development remain unclear. Here, we compared the levels of non-invasive markers to the survival rate of FALD-HCC patients.MethodsFrom 2003 to 2021, 154 patients (66 men, 42.9%) developed liver disease after undergoing Fontan procedures. HCC was diagnosed in 15 (9.7%) (8 men, 53.3%) at a median age of 34 years (range, 21-45 years). We compared FALD-HCC and non-HCC cases; we generated marker level cutoffs using receiver operating characteristic curves. We sought to identify risk factors for HCC and mortality.ResultsThe incidence of HCC was 4.9% in FALD patients within 20 years after the Fontan procedure. Compared with non-HCC patients, FALD-HCC patients exhibited higher incidences of polysplenia and esophageal varices. At the time of HCC development, the hyaluronic acid (HA) level (p = 0.04) and the fibrosis-4 index (p = 0.02) were significantly higher in FALD-HCC patients than in non-HCC patients; the total bilirubin (T-BIL) level (p = 0.07) and the model for end-stage liver disease score [excluding the international normalized ratio (MELD-XI)] (p = 0.06) tended to be higher in FALD-HCC patients. Within approximately 20 years of the Fontan procedure, 10 patients died (survival rate, 96.9%). Kaplan-Meier curve analysis indicated that patients with T-BIL levels ≥ 2.2 mg/dL, HA levels ≥ 55.5 ng/mL, and MELD-XI scores ≥ 18.7 were at high risk of HCC, a generally poor prognosis, and both polysplenia and esophageal varices. Multivariate Cox regression analyses indicated that the complication of polysplenia [Hazard ratio (HR): 10.915] and a higher MELD-XI score (HR: 1.148, both p < 0.01) were independent risk factors for FALD-HCC.ConclusionsThe complication of polysplenia and a MELD-XI score may predict HCC development and mortality in FALD patients.

The SCN5A R1623Q mutation is one of the most common genetic variants associated with severe congenital long QT syndrome 3 (LQT3) in fetal and neonatal patients. To investigate the properties of the R1623Q mutation, we established an induced pluripotent stem cell (iPSC) cardiomyocyte (CM) model from a patient with LQTS harboring a heterozygous R1623Q mutation. The properties and pharmacological responses of iPSC-CMs were characterized using a multi-electrode array system. The biophysical characteristic analysis revealed that R1623Q increased open probability and persistent currents of sodium channel, indicating a gain-of-function mutation. In the pharmacological study, mexiletine shortened FPDcF in R1623Q-iPSC-CMs, which exhibited prolonged field potential duration corrected by Fridericia’s formula (FPDcF, analogous to QTcF). Meanwhile, E4031, a specific inhibitor of human ether-a-go-go-related gene (hERG) channel, significantly increased the frequency of arrhythmia-like early after depolarization (EAD) events. These characteristics partly reflect the patient phenotypes. To further analyze the effect of neonatal isoform, which is predominantly expressed in the fetal period, on the R1623Q mutant properties, we transfected adult form and neonatal isoform SCN5A of control and R1623Q mutant SCN5A genes to 293T cells. Whole-cell automated patch-clamp recordings revealed that R1623Q increased persistent Na+ currents, indicating a gain-of-function mutation. Our findings demonstrate the utility of LQT3-associated R1623Q mutation-harboring iPSC-CMs for assessing pharmacological responses to therapeutic drugs and improving treatment efficacy. Furthermore, developmental switching of neonatal/adult Nav1.5 isoforms may be involved in the pathological mechanisms underlying severe long QT syndrome in fetuses and neonates.

Although mutations in several genes have been reported in pulmonary arterial hypertension (PAH), most of PAH cases do not carry these mutations. This study aimed to identify a novel cause of PAH. To determine the disease-causing variants, direct sequencing and multiplex ligation-dependent probe amplification were performed to analyze 18 families with multiple affected family members with PAH. In one of the 18 families with PAH, no disease-causing variants were found in any of BMPR2, ACVRL1, ENG, SMAD1/4/8, BMPR1B, NOTCH3, CAV1, or KCNK3. In this family, a female proband and her paternal aunt developed PAH in their childhood. Whole-exome next-generation sequencing was performed in the 2 PAH patients and the proband's healthy mother, and a BRCA1-associated protein (BRAP) gene variant, p.Arg554Leu, was identified in the 2 family members with PAH, but not in the proband's mother without PAH. Functional analyses were performed using human pulmonary arterial smooth muscle cells (hPASMCs). Knockdown of BRAP via small interfering RNA in hPASMCs induced p53 signaling pathway activation and decreased cell proliferation. Overexpression of either wild-type BRAP or p.Arg554Leu-BRAP cDNA constructs caused cell death confounding these studies, however we observed higher levels of p53 signaling inactivation and hPASMC proliferation in cells expressing p.Arg554Leu-BRAP compared to wild-type BRAP. In addition, p.Arg554Leu-BRAP induced decreased apoptosis of hPASMCs compared with wild-type BRAP. In conclusion, we have identified a novel variant of BRAP in a Japanese family with PAH and our results suggest it could have a gain-of-function. This study sheds light on new mechanism of PAH pathogenesis.

Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV) valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM) components, versican and hyaluronan (HA), and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH) stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC) aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions.

Purpose: Dilated aortic root and ascending aorta (AAO) with progressive aortic regurgitation is a wellknown sequela after arterial switch operation (ASO) in adults with transposition of the great arteries (TGA). We aimed to quantitatively assess aortic flow profiles in adults with TGA after ASO (Jatene procedure with LeCompte maneuver) using echo planar imaging (EPI) 4D flow MRI. Methods: Prospectively, 9 consecutive adults (30.2 ± 6.6 years) after ASO (Jatene operation with LeCompte technique), 13 consecutive adults (34.3 ± 7.2 years) after the atrial switch operation with Senning procedure, and 8 age-matched control patients, who underwent turbo field echo (TFE) EPI 4D flow MRI (average scan time of approximately 4 min), were enrolled. Results: TGA after ASO showed a markedly dilated sinus of Valsalva, compared to TGA after atrial switch operation (26.6. ± 4.9 vs. 18.6. ± 1.5 mm/cm2). Vorticity, helicity, wall share stress (WSS), and energy loss (EL) in the aortic root and the AAO in TGA were greater than in the controls. Vorticity, helicity, WSS, and EL in the aortic root and the AAO were also greater in TGA after ASO than after atrial switch operation. More acute aortic arch angle correlated with greater vorticity of the aortic root, and the significant diameter ratio of the sinus of Valsalva and the AAO was relevant to greater vorticity, helicity, and EL in TGA after ASO. Conclusion: A non-physiological blood flow pattern of the aortic root was identified in TGA adults after the ASO (Jatene procedure with LeCompte maneuver). Missing spiral looping of the great arteries and the unique structure after the Jatene procedure may play an adjunctive role in promoting aortopathy. The evaluation of aortic flow profile using EPI 4D flow MRI may be useful for risk stratification for aortopathy in this population. [ABSTRACT FROM AUTHOR]

Purpose: The native T1 value at 3T MRI is a sensitive marker for diffuse fibrosis or damage in various organs including the heart, liver, and pancreas. Despite the fact that Fontan-associated liver disease (FALD) is a crucial issue in adults with Fontan circulation, there are only a few studies with liver T1 mapping in children and adolescents. We investigated the potential of the liver native T1 mapping in detecting FALD in adult patients. Methods: We prospectively enrolled 16 consecutive adults with Fontan circulation (age 31.3 ± 8.5 years), who were in New York Heart Association Functional class II-IV. Twenty with tetralogy of Fallot (TOF), and 20 age-matched controls also underwent cardiac magnetic resonance (CMR) imaging at 3T. Myocardial T1 mapping with a Modified Look-Locker Inversion recovery sequence was applied to liver T1 mapping. Patients in the Fontan group underwent the right heart catheter and liver function tests, including those for fibrotic markers. Results: Liver native T1 values in the Fontan group were significantly higher than that in TOF and controls (P < 0.001). In the Fontan group, the liver native T1 value was significantly correlated with age, g -glutamyltransferase, model for end-stage liver disease XI score, and albumin-bilirubin score (P = 0.01, 0.01, 0.044, 0.001). However, it demonstrated no correlation with central venous pressure, pulmonary vessel resistance, or fibrotic markers. Conclusion: Liver native T1 value derived from CMR may be a non-invasive adjunctive and/or screening marker to detect FALD. [ABSTRACT FROM AUTHOR]

Background: A high incidence of cardiovascular (CV) risk factors has been reported in adults with Williams-Beuren syndrome (WS). However, the prevalence of these factors in children and adolescents with WS is unknown. Therefore, the purpose of this study was to evaluate the prevalence of CV risk factors in these patients.Methods: Thirty-two WS patients aged <18 years were enrolled in the study. Oxidized low-density lipoprotein levels (n = 32), oral glucose tolerance test results (n = 20), plasma renin and aldosterone levels (n = 31), 24-h ambulatory blood pressure (ABP; n = 24), carotid artery intima-media thickness (IMT; n = 15), and brachial artery flow-mediated dilatation (FMD; n = 15) were measured and analyzed.Results: The lipid profile revealed hypercholesterolemia in 22% and elevated oxidized low-density lipoprotein levels in 94% of the patients. Glucose metabolism abnormalities were found in 70% of the patients. Insulin resistance was observed in 40% of the patients. High plasma renin and aldosterone levels were detected in 45 and 39% of the patients, respectively. A mean systolic blood pressure above the 90th percentile was noted in 29% of patients. High IMT (>0.65 mm) and low FMD (<9%) were detected in 80 and 73% of patients, respectively.Conclusion: In patients with WS, CV risk factors are frequently present from childhood. In children with WS, screening tests for the early detection of CV risk factors and long-term follow-up are required to determine whether long-term exposure to these factors increases the risk for CV events in adulthood. [ABSTRACT FROM AUTHOR]

Background: The management of Eisenmenger syndrome (ES) has dramatically changed since the advent of disease-targeted therapy (DTT). However, guidelines for ES management, including DTT, have not been established. We aimed to clarify the current incidence, underlying disease, and management of ES in Japan, using a nationwide survey. Methods: A written questionnaire was sent to members of the Japanese Society for Adult Congenital Heart Disease, through which information was obtained from 86 institutions. Results: A total of 251 patients with ES (80.5% cases ≥ 20 years of age) were followed as of February 2012; DTT was performed in 124 (49.4%) patients. Unrepaired simple anatomy was reported as an underlying condition in 165 patients (65.7%). Among patients with ES, 55 (21.9%), 128 (51%), 53 (21.1%), and 12 (4.8%) were classified into functional classes I, II, III, and IV, respectively. DTT was routinely performed at 52 (60.5%) institutions, but there were variations in the DTT therapeutic strategy at these institutions. Combined therapy was more often used than monotherapy; an endothelin receptor antagonist was the most frequently prescribed medication. There were institutional differences regarding heart failure treatment and indications for anticoagulation. Digitalis and angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers were widely used, but beta-blockers were infrequently used to manage heart failure. Conclusions: This survey describes the current status, including prevalence and underlying disease, and variations in the practical management of ES in Japan. The results will help in the creation of future guidelines for ES management. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to determine whether morphine-HCl or pethidine-HCl differ as pre-medication to prevent anoxic spell in patients with tetralogy of Fallot (TOF) at catheterization. Methods: A 3 year retrospective case notes review study of 46 consecutive patients who underwent cardiac catheterization from 1998 to 2001 was conducted. In a prospective 1 year randomized control study, 10 patients diagnosed as TOF and admitted to Tokyo Women's Medical University, The Heart Institute of Japan, Tokyo, in 2002 were randomized to receive morphine or pethidine as pre-medication for cardiac catheterization. The incidence of anoxic spell before and after cardiac catheterization was investigated in both studies. Results: In the case notes review, a total of 10 out of the 46 patients showed anoxic spell study: eight out of 24 patients in the morphine group and two out of 22 in the pethidine group. The difference in the incidence was statistically significant ( P < 0.05, Fisher's exact test). Four patients in the prospective study showed anoxic spell: three out of six in the morphine group and one out of four in the pethidine group (odds ratio = 3.0). Overall, 14 out of 56 patients had anoxic spell: 11 out of 30 in the morphine group and three out of 26 in the pethidine group ( P = 0.03). Conclusion: The incidence of hypoxic spells in patients with TOF undergoing cardiac catheterization is reduced by the use of pethidine-HCl as pre-medication compared to morphine. This has important clinical implications. [ABSTRACT FROM AUTHOR]

In our previous work, we found that BMP-2 was expressed in atrioventricular (AV) cushion mesenchymal (CM) cells at post-epithelial-mesenchymal-transformation (EMT) stages. In the present study, we localized type 1 BMP receptors in AV CM cells by in situ hybridization at post-EMT stages in the chick. To test our hypothesis that BMP-2 regulates differentiation and maturation of post-EMT CM cells, we examined CM cell-aggregates from stage-24 chick AV cushions and cultured them on collagen gels. Exogenous BMP-2 treatments induced expression of a BMP signaling marker, phospho-Smad 1/5/8; migration of the CM cells into the collagen gels; and expression of a valvulogenic extracellular matrix protein, periostin, both at mRNA and protein levels. Noggin, an antagonist of BMPs, inhibited the effect of BMP-2 in the CM cell aggregates. Furthermore, experiments with RCAS-virus encoding dominant negative (dn)- or constitutively active (ca)- BMP receptor (BMPR)-1B revealed that BMP signaling induced cell-migration and periostin expression both in cultured CM cell-aggregates and whole chick embryo cultures in ovo. These results strongly suggest that BMP-2 plays essential roles in post-EMT cardiac valvulogenesis. [ABSTRACT FROM AUTHOR]