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Aims: Myocardial calcification is an unusual condition in which excess calcium is deposited in the myocardium. Herein, we report two cases of myocardial calcification from our clinical experience. Furthermore, we conduct a systematic review to examine the clinical course and associated pathologies of myocardial calcification., Methods and Results: This systematic review was registered in PROSPERO (CRD42023463285). PubMed and Scopus were searched according to the following inclusion criteria: (i) case reports or case series describing patients with myocardial calcification; (ii) diagnosis of myocardial calcification by computed tomography (CT); (iii) adequate description of patients, including their chief complaint, medical history, evaluations, and treatments; and (iv) publication in English. Among the 75 patients, 24 had sepsis, 14 had myocarditis, and 37 had other pathologies. The mortality rate was 33% for patients with sepsis, 14% for patients with myocarditis, and 11% for patients with other pathologies. Follow-up CT findings beyond 2 years were reported in six patients, showing that the CT findings of myocardial calcification persisted but subsided over time. Autopsy was performed in seven patients, and extensive interstitial fibrosis and collection of inflammatory cells were observed in patients with myocarditis, sepsis, and ischaemic heart disease., Conclusion: While various medical conditions can cause myocardial calcification, accompanying conditions commonly reported with myocardial calcification were sepsis and myocarditis. The CT findings of myocardial calcification tend to regress over time if the underlying disease can be treated., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Ventricular-assist device therapy for small patients with congenital heart disease is challenging due to its complex anatomy and hemodynamics. We describe a 3-year-old patient with heart failure with truncus arteriosus in the palliative stage. The patient underwent palliative right ventricular outflow tract reconstruction following bilateral pulmonary artery banding. At 6 months of age, the patient developed severe truncal valve regurgitation and left ventricular dysfunction. Emergent truncal valve replacement with a mechanical valve was performed, but left ventricular dysfunction persisted. At 3 years of age, the patient developed acute progression of heart failure triggered by influenza infection. The patient was intubated and transferred to our center to determine the indication for heart transplantation. On the second day after admission, signs of multiorgan failure appeared. Emergent ventricular-assist device implantation for both ventricles was performed with truncal valve closure, ventricular septal defect closure, atrial septal defect closure, and re-right ventricular outflow tract reconstruction. The right ventricular-assist device was successfully removed on the seventh postoperative day. Due to the small pulmonary arteries, severe pulmonary stenosis persisted after ventricular-assist device implantation, but it gradually improved with multiple pulmonary angioplasties. The patient was registered in the Japanese organ transplant network and is awaiting a donor organ in a stable condition., (© 2024. The Author(s).)

This open-label, extension study assessed long-term safety, tolerability, and efficacy of ambrisentan in a pediatric population (age 8- < 18 years) with pulmonary arterial hypertension (PAH). Following completion of a 6-month, randomized study, participants entered the long-term extension at individualized ambrisentan dosages (2.5/5/7.5 or 10 mg/day). Safety assessments included adverse events (AEs), AEs of special interest, and serious AEs (SAEs); efficacy outcomes included 6-min walking distance (6MWD) and World Health Organization functional class (WHO FC). Thirty-eight of 41 (93%) randomized study participants entered the extension; 21 (55%) completed (reaching age 18 years). Most participants received concomitant phosphodiesterase-5 inhibitors (n = 25/38, 66%). Median ambrisentan exposure was 3.5 years. Most participants experienced ≥ 1 AE (n = 34/38, 89%), and 21 (55%) experienced SAEs, most commonly worsening PAH (n = 3/38, 8%), acute cardiac failure, pneumonia, or anemia (n = 2/38; 5% each); none considered ambrisentan-related. Seven participants (18%) died, with recorded reasons (MedDRA preferred term): cardiac failure (n = 2), PAH (n = 2), COVID-19 (n = 1), acute right ventricular failure (n = 1), and failure to thrive (n = 1); median time to death: 5.2 years. Anemia and hepatotoxicity AEs were generally mild to moderate and did not require ambrisentan dose adjustment. Assessed at study end in 29 participants (76%), mean 6MWD improved by 17% (standard deviation: 34.3%), and all (29/29, 100%) had improved or unchanged WHO FC.    Conclusion: Long-term weight-based ambrisentan dosing, alone or combined with other PAH therapies in children with PAH aged 8- < 18 years, exhibited tolerability and clinical improvements consistent with prior randomized study results.    Trial registration: NCT01342952, April 27, 2011. What is Known: • The endothelin receptor antagonist, ambrisentan, is indicated for treatment of pulmonary arterial hypertension (PAH). Previous studies have shown similar efficacy and tolerability in pediatric patients as in adults. What is New: • This open-label extension study assessed the long-term use of ambrisentan in pediatric patients (8-<18 years) with PAH, most of whom were also receiving recommended background PAH treatment. • Weight-based dosing of ambrisentan, given alone or in combination with other PAH therapies, was well tolerated with clinical improvements consistent with prior randomized study results., (© 2024. The Author(s).)

Background: Restrictive cardiomyopathy (RCM) is characterized by impaired diastolic function with preserved ventricular contraction. Several pathogenic variants in sarcomere genes, including TNNI3 , are reported to cause Ca 2+ hypersensitivity in cardiomyocytes in overexpression models; however, the pathophysiology of induced pluripotent stem cell (iPSC)-derived cardiomyocytes specific to a patient with RCM remains unknown., Methods and Results: We established an iPSC line from a pediatric patient with RCM and a heterozygous TNNI3 missense variant, c.508C>T (p.Arg170Trp; R170W). We conducted genome editing via CRISPR/Cas9 technology to establish an isogenic correction line harboring wild type TNNI3 as well as a homozygous TNNI3 -R170W. iPSCs were then differentiated to cardiomyocytes to compare their cellular physiological, structural, and transcriptomic features. Cardiomyocytes differentiated from heterozygous and homozygous TNNI3 -R170W iPSC lines demonstrated impaired diastolic function in cell motion analyses as compared with that in cardiomyocytes derived from isogenic-corrected iPSCs and 3 independent healthy iPSC lines. The intracellular Ca 2+ oscillation and immunocytochemistry of troponin I were not significantly affected in RCM-cardiomyocytes with either heterozygous or homozygous TNNI3 -R170W. Electron microscopy showed that the myofibril and mitochondrial structures appeared to be unaffected. RNA sequencing revealed that pathways associated with cardiac muscle development and contraction, extracellular matrix-receptor interaction, and transforming growth factor-β were altered in RCM-iPSC-derived cardiomyocytes., Conclusions: Patient-specific iPSC-derived cardiomyocytes could effectively represent the diastolic dysfunction of RCM. Myofibril structures including troponin I remained unaffected in the monolayer culture system, although gene expression profiles associated with cardiac muscle functions were altered.

Background: Anti-α6β4 integrin autoantibodies can be observed in some patients with mucous membrane pemphigoid. We have previously identified anti-α6β4 integrin extracellular domain autoantibodies together with anti-BP180 NC16A antibodies in a patient with DPP-4 inhibitor-induced bullous pemphigoid. However, the significance and impact of anti-α6β4 integrin antibodies are unknown., Objectives: To characterize anti-α6β4 integrin extracellular domain autoantibodies in pemphigoid patients, to determine whether these antibodies inhibit laminin-α6β4 integrin binding and to observe their systemic effects., Methods: Anti-α6β4 integrin autoantibodies were analysed by staining cells expressing the extracellular region of α6β4 integrin with sera from 20 patients with pemphigoid. The anti-α6β4 integrin autoantibodies were characterized using different transfectants. The binding of laminins to α6β4 integrin was studied using cells expressing the activated conformation of α6β4 integrin and the inhibitory effect of the autoantibodies on the binding of laminins to α6β4 integrin was tested. Trends in antibody titres and clinical symptoms were quantified and analysed., Results: IgG autoantibodies against the extracellular domain of anti-α6β4 integrin were found in some patients with pemphigoid. Laminin binding to α6β4 integrin was observed in the active conformation of α6β4 integrin, and serum from a patient with a high titre of anti-α6β4 integrin antibodies inhibited the binding of both laminin-511 and laminin-332 to α6β4 integrin. α6β4 integrin is expressed on the basement membrane of both skin and small intestine, and exfoliation was observed in the patient's epidermis and small intestinal epithelium. A reduction in the titre of the anti-α6β4 integrin antibody was associated with improvement in both skin and gastrointestinal symptoms., Conclusions: This study demonstrated the presence of anti-α6β4 integrin extracellular domain-specific autoantibodies in some patients with pemphigoid. In addition, these autoantibodies showed inhibitory activity on α6β4 integrin-laminin binding. Anti-α6β4 integrin antibodies can affect the gastrointestinal tract as well as the skin and oral mucosa., (© 2023 European Academy of Dermatology and Venereology.)

Down syndrome (DS) is the most prevalent chromosomal disorder associated with a higher incidence of pulmonary arterial hypertension (PAH). The dysfunction of vascular endothelial cells (ECs) is known to cause pulmonary arterial remodeling in PAH, although the physiological characteristics of ECs harboring trisomy 21 (T21) are still unknown. In this study, we analyzed the human vascular ECs by utilizing the isogenic pairs of T21-induced pluripotent stem cells (iPSCs) and corrected disomy 21 (cDi21)-iPSCs. In T21-iPSC-derived ECs, apoptosis and mitochondrial reactive oxygen species (mROS) were significantly increased, and angiogenesis and oxygen consumption rate (OCR) were significantly impaired as compared with cDi21-iPSC-derived ECs. The RNA-sequencing identified that EGR1 on chromosome 5 was significantly upregulated in T21-ECs. Both EGR1 suppression by siRNA and pharmacological inhibitor could recover the apoptosis, mROS, angiogenesis, and OCR in T21-ECs. Alternately, the study also revealed that DYRK1A was responsible to increase EGR1 expression via PPARG suppression, and that chemical inhibition of DYRK1A could restore the apoptosis, mROS, angiogenesis, and OCR in T21-ECs. Finally, we demonstrated that EGR1 was significantly upregulated in the pulmonary arterial ECs from lung specimens of a patient with DS and PAH. In conclusion, DYRK1A/PPARG/EGR1 pathway could play a central role for the pulmonary EC functions and thus be associated with the pathogenesis of PAH in DS., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Impella is a device effective for the treatment of cardiogenic shock. However, among small children, its application has limitations due to left ventricle size and vasculature and the turning diameter of the aortic arch. Herein, we report an 11-year-old girl with fulminant myocarditis who was successfully managed with Impella CP implantation via the right subclavian artery using a polyethylene terephthalate chimney graft. Compared with insertion via the femoral artery, this method has several advantages. That is, it can address limitations in aortic arch diameter and facilitate equable fixation of the Impella device in small pediatric patients., (© 2022. The Japanese Society for Artificial Organs.)

Microbubbles have potential applications as drug and gene carriers, and drug release can be triggered by externally applied ultrasound irradiation while inside blood vessels. Desorption of molecules forming the microbubble shell can be observed under ultrasound irradiation of a single isolated microbubble, and the volume of desorbed molecules can be quantitatively estimated from the contact angle between the bubble and a glass plate. Microbubbles composed of a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) shell and a poorly-soluble gas are created. When the microbubbles are exposed to a pulsed ultrasound, the contact angles increase dramatically; the percentage of DMPC molecules desorbed from the bubble surface reaches 70%. Vibration of a single bubble in the radial direction is measured using a laser Doppler vibrometer. The relationship between the vibrational characteristics and the amount of molecular desorption reveals that a larger vibrational amplitude of the bubble around the resonance size induces a larger amount of molecular desorption. These results support the possibility of controlling molecular desorption with pulsed ultrasound., (© 2023. Springer Nature Limited.)

Background: Restrictive cardiomyopathy in children is rare and outcomes are very poor. However, little information is available concerning genotype-outcome correlations., Methods: We analyzed the clinical characteristics and genetic testing, including whole exome sequencing, of 28 pediatric restrictive cardiomyopathy patients who were diagnosed from 1998 to 2021 at Osaka University Hospital in Japan., Results: The median age at diagnosis (interquartile range) was 6 (2.25-8.5) years. Eighteen patients received heart transplantations and 5 patients were on the waiting list. One patient died while waiting for transplantation. Pathologic or likely-pathogenic variants were identified in 14 of the 28 (50%) patients, including heterozygous TNNI3 missense variants in 8 patients. TNNT2 , MYL2 , and FLNC missense variants were also identified. No significant differences in clinical manifestations and hemodynamic parameters between positive and negative pathogenic variants were detected. However, 2- and 5-year survival rates were significantly lower in patients with pathogenic variants (50% and 22%) compared with survival in patients without pathogenic variants (62% and 54%; P =0.0496, log-rank test). No significant differences were detected in the ratio of patients diagnosed at nationwide school heart disease screening program between positive and negative pathogenic variants. Patients diagnosed by school screening showed better transplant-free survival compared with patients diagnosed by heart failure symptoms ( P =0.0027 in log-rank test)., Conclusions: In this study, 50% of pediatric restrictive cardiomyopathy patients had pathogenic or likely-pathogenic gene variants, and TNNI3 missense variants were the most frequent. Patients with pathogenic variants showed significantly lower transplant-free survival compared with patients without pathogenic variants., Competing Interests: Disclosures None.

Background: In adult patients, after a Fontan procedure, high central venous pressure (CVP) is a hemodynamic risk factor associated with poor prognosis. High liver stiffness (LS) on transient elastography (TE) is associated with high CVP in patients with heart failure without liver disease. Here, we investigated whether LS assessment using TE is a reliable method to noninvasively evaluate CVP in adult patients after a Fontan procedure, who can present varying degrees of liver fibrosis as a complication., Methods: We measured LS using TE and CVP by cardiac catheterization in 24 adult patients who had undergone a Fontan procedure. The estimated CVP was calculated using the previously reported formula: -5.8 + 6.7 × ln[LS]. We examined the correlation between LS and CVP, and degree of agreement between the estimated and measured CVPs. Patients were divided into two groups, with or without suspected liver cirrhosis, based on abdominal imaging studies., Results: The median patient age was 35 years (interquartile range 25, 39). Overall, there was a strong correlation between LS and CVP (ρ = 0.83, p < 0.001). The estimated CVP based on LS and the CVP measured using cardiac catheterization were positively correlated; however, the estimated CVP tended to be higher than the measured CVP (mean difference 0.9 mmHg [95% limits of agreement: -2.8 to 4.6 mmHg]). These results were consistent across all groups., Conclusions: In adult patients after a Fontan procedure, LS measured by TE showed a positive correlation with CVP by cardiac catheterization. TE can be useful as a noninvasive estimation of CVP., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (© 2023 The Authors.)

Background Dilated cardiomyopathy (DCM) is a major cause of heart failure in children. Despite intensive genetic analyses, pathogenic gene variants have not been identified in most patients with DCM, which suggests that cardiomyocytes are not solely responsible for DCM. Cardiac fibroblasts (CFs) are the most abundant cell type in the heart. They have several roles in maintaining cardiac function; however, the pathological role of CFs in DCM remains unknown. Methods and Results Four primary cultured CF cell lines were established from pediatric patients with DCM and compared with 3 CF lines from healthy controls. There were no significant differences in cellular proliferation, adhesion, migration, apoptosis, or myofibroblast activation between DCM CFs compared with healthy CFs. Atomic force microscopy revealed that cellular stiffness, fluidity, and viscosity were not significantly changed in DCM CFs. However, when DCM CFs were cocultured with healthy cardiomyocytes, they deteriorated the contractile and diastolic functions of cardiomyocytes. RNA sequencing revealed markedly different comprehensive gene expression profiles in DCM CFs compared with healthy CFs. Several humoral factors and the extracellular matrix were significantly upregulated or downregulated in DCM CFs. The pathway analysis revealed that extracellular matrix receptor interactions, focal adhesion signaling, Hippo signaling, and transforming growth factor-β signaling pathways were significantly affected in DCM CFs. In contrast, single-cell RNA sequencing revealed that there was no specific subpopulation in the DCM CFs that contributed to the alterations in gene expression. Conclusions Although cellular physiological behavior was not altered in DCM CFs, they deteriorated the contractile and diastolic functions of healthy cardiomyocytes through humoral factors and direct cell-cell contact.

Objectives: The goal of this study was to identify the clinical significance of the deoxyribonucleic acid (DNA) damage response marker, phosphorylated H2A histone variant X, on the bridge to recovery in low-weight paediatric patients with dilated cardiomyopathy (DCM) after having a Berlin Heart EXCOR implanted., Methods: Consecutive paediatric patients with DCM who had an EXCOR implanted for DCM at our hospital between 2013 and 2021 were reviewed. Patients were classified into 2 groups according to the degree of DNA damage in the left ventricular cardiomyocytes-the low DNA damage group and the high DNA damage group-using the median value as the threshold. We examined and compared the preoperative factors and histologic findings associated with cardiac functional recovery following the explant procedure in the 2 groups., Results: Competing outcome analysis of 18 patients (median body weight, 6.1 kg) showed that the incidence of an EXCOR explant was 40% at 1 year after the implant procedure. Serial echocardiography revealed significant left ventricular functional recovery in the low DNA damage group 3 months after the implant. The univariable Cox proportional hazards model revealed that the percentage of phosphorylated H2A histone variant X-positive cardiomyocytes was the significant factor associated with cardiac recovery and the EXCOR explant (hazard ratio, 0.16; 95% confidence interval, 0.027-0.51; P = 0.0096)., Conclusions: The degree of DNA damage response to the EXCOR implant may aid in predicting the bridge to recovery with EXCOR among low-weight paediatric patients with DCM., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Cardiac allograft vasculopathy (CAV) sometimes leads to restenosis, even after percutaneous transcatheter intervention. Recently, drug-coated balloons (DCBs) have been successfully used to treat coronary artery disease, especially CAVs, in adults. However, no studies have used DCBs in pediatric CAVs. We encountered a patient with CAV who underwent cardiac transplantation for restrictive cardiomyopathy at the age of 2 years. Nine years after the transplantation, severe stenosis of the proximal left anterior descending branch was observed. Considering the patient's young age and the possibility of restenosis, we performed an intervention with DCB. Follow-up conducted 7 months after the intervention showed no restenosis. Cardiac coronary artery lesions following transplantation are more likely to result in restenosis earlier than arteriosclerotic lesions. In pediatric patients, restenosis might require multiple stents and prolonged antiplatelet therapy. Our findings provide evidence supporting the possibility of an effective treatment of CAV in children., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Annals of Pediatric Cardiology.)

Restrictive cardiomyopathy (RCM) is a rare disease characterized by increased ventricular stiffness and preserved ventricular contraction. Various sarcomere gene variants are known to cause RCM; however, more than a half of patients do not harbor such pathogenic variants. We recently demonstrated that cardiac fibroblasts (CFs) play important roles in inhibiting the diastolic function of cardiomyocytes via humoral factors and direct cell-cell contact regardless of sarcomere gene mutations. However, the mechanical properties of CFs that are crucial for intercellular communication and the cardiomyocyte microenvironment remain less understood. In this study, we evaluated the rheological properties of CFs derived from pediatric patients with RCM and healthy control CFs via atomic force microscopy. Then, we estimated the cellular modulus scale factor related to the cell stiffness, fluidity, and Newtonian viscosity of single cells based on the single power-law rheology model and analyzed the comprehensive gene expression profiles via RNA-sequencing. RCM-derived CFs showed significantly higher stiffness and viscosity and lower fluidity compared to healthy control CFs. Furthermore, RNA-sequencing revealed that the signaling pathways associated with cytoskeleton elements were affected in RCM CFs; specifically, cytoskeletal actin-associated genes (ACTN1, ACTA2, and PALLD) were highly expressed in RCM CFs, whereas several tubulin genes (TUBB3, TUBB, TUBA1C, and TUBA1B) were down-regulated. These results implies that the signaling pathways associated with cytoskeletal elements alter the rheological properties of RCM CFs, particularly those related to CF-cardiomyocyte interactions, thereby leading to diastolic cardiac dysfunction in RCM., Competing Interests: The authors have declared that no competing interests exist.

Pulmonary atresia and ventricular septal defect (PA/VSD) demonstrate a wide variety of pulmonary and coronary artery abnormalities; additionally, coronary-to-pulmonary artery fistula (CPAF) is a rare manifestation of PA/VSD and is seldom detected during pregnancy. In this report, we present a case of prenatal diagnosis of CPAF in PA/VSD and impactful images in a neonate, which were obtained using fetal echocardiography and postnatal electrocardiography-gated 320-row CT. Prenatal diagnosis of CPAF can facilitate the provision of better therapeutic strategies after birth., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

A 92-year-old woman diagnosed with dementia and end-stage gastric cancer received end-of-life care on the island where she lived. Informed consent concerning remote death certification based on the Japanese government's guidelines was obtained from a family member in case a physician was unavailable. A physical examination after cardiopulmonary arrest was conducted, supported by telemedicine and a well-trained registered nurse under remote supervision of the physician who last saw the deceased directly. Death certification was provided accordingly. To our knowledge, this was the first case of remote death certification using telemedicine in Japan.

Flowering plant species and their nectar-feeding vertebrates exemplify some of the most remarkable biotic interactions in the Neotropics. In the Brazilian Atlantic Forest, several species of birds (especially hummingbirds), bats, and non-flying mammals, as well as one lizard feed on nectar, often act as pollinators and contribute to seed output of flowering plants. We present a dataset containing information on flowering plants visited by nectar-feeding vertebrates and sampled at 166 localities in the Brazilian Atlantic Forest. This dataset provides information on 1902 unique interactions among 515 species of flowering plants and 129 species of potential vertebrate pollinators and the patterns of species diversity across latitudes. All plant-vertebrate interactions compiled were recorded through direct observations of visits, and no inferences of pollinators based on floral syndromes were included. We also provide information on the most common plant traits used to understand the interactions between flowers and nectar-feeding vertebrates: plant growth form, corolla length, rate of nectar production per hour in bagged flowers, nectar concentration, flower color and shape, time of anthesis, presence or absence of perceptible fragrance by human, and flowering phenology as well as the plant's threat status by International Union for Conservation of Nature (IUCN) classification. For the vertebrates, status of threat by IUCN classification, body mass, bill or rostrum size are provided. Information on the frequency of visits and pollen deposition on the vertebrate's body is provided from the original source when available. The highest number of unique interactions is recorded for birds (1771) followed by bats (110). For plants, Bromeliaceae contains the highest number of unique interactions (606), followed by Fabaceae (242) and Gesneriaceae (104). It is evident that there was geographical bias of the studies throughout the southeast of the Brazilian Atlantic Forest and that most effort was directed to flower-hummingbird interactions. However, it reflects a worldwide tendency of more plants interacting with birds compared with other vertebrate species. The lack of similar protocols among studies to collect basic data limits the comparisons among areas and generalizations. Nevertheless, this dataset represents a notable effort to organize and highlight the importance of vertebrate pollinators in this hotspot of biodiversity on Earth and represents the data currently available. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or scientific events., (© 2022 The Ecological Society of America.)

Background: Although widely reported to affect older adults more, coronavirus disease 2019 (COVID-19) also affects adolescents, especially those with co-morbidities, including heart diseases. The safety and efficacy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines has been established in healthy adolescents, yet there are few data for humoral and cellular immunogenicity in adolescents with cardiac diseases., Methods: We evaluated anti-spike antibodies, neutralizing activities, and interferon-gamma production prior to and after SARS-CoV-2 vaccination in adolescents with cardiac diseases and healthy controls., Results: Five healthy adolescents and 26 patients with cardiac diseases, including congenital heart disease (CHD, n = 10), dilated cardiomyopathy (DCM, n = 4), idiopathic pulmonary arterial hypertension (IPAH, n = 4), and those post-heart transplantation (post-HTx, n = 8) were enrolled. No severe adverse events, including myocarditis and pericarditis, were noted, even in patients with severe heart failure. Febrile events were noted after 21 of 62 injections (34%). All the healthy adolescents and 21 of the 26 patients (81%) showed sufficient elevation of neutralizing antibodies after the second dose of vaccination. Neutralizing antibodies and cellular immunity were absent in four of the eight post-HTx patients and one with single ventricle CHD. There was no correlation between the anti-spike and neutralizing antibody titers and interferon-gamma levels. When comparing the clinical characteristics of the patients post-HTx who did or did not acquire antibodies, there was no significant difference in the immunosuppressant types and trough levels., Conclusions: SARS-CoV-2 mRNA vaccine has efficient immunogenicity for adolescents with CHD, IPAH, and DCM. Half of post-HTx patients could not acquire sufficient humoral immunity., (© 2022 Japan Pediatric Society.)