PATHFINDER-CHD: prospective registry on adults with congenital heart disease, abnormal ventricular function, and/or heart failure as a foundation for establishing rehabilitative, prehabilitative, preventive, and health-promoting measures: rationale, aims, design and methods.

BACKGROUND: Adults with congenital heart defects (ACHD) globally constitute a notably medically underserved patient population. Despite therapeutic advancements, these individuals often confront substantial physical and psychosocial residua or sequelae, requiring specialized, integrative cardiological care throughout their lifespan. Heart failure (HF) is a critical challenge in this population, markedly impacting morbidity and mortality. AIMS: The primary aim of this study is to establish a comprehensive, prospective registry to enhance understanding and management of HF in ACHD. Named PATHFINDER-CHD, this registry aims to establish foundational data for treatment strategies as well as the development of rehabilitative, prehabilitative, preventive, and health-promoting interventions, ultimately aiming to mitigate the elevated morbidity and mortality rates associated with congenital heart defects (CHD). METHODS: This multicenter survey will be conducted across various German university facilities with expertise in ACHD. Data collection will encompass real-world treatment scenarios and clinical trajectories in ACHD with manifest HF or at risk for its development, including those undergoing medical or interventional cardiac therapies, cardiac surgery, inclusive of pacemaker or ICD implantation, resynchronization therapy, assist devices, and those on solid organ transplantation. DESIGN: The study adopts an observational, exploratory design, prospectively gathering data from participating centers, with a focus on patient management and outcomes. The study is non-confirmatory, aiming to accumulate a broad spectrum of data to inform future hypotheses and studies. PROCESSES: Regular follow-ups will be conducted, systematically collecting data during routine clinical visits or hospital admissions, encompassing alterations in therapy or CHD-related complications, with visit schedules tailored to individual clinical needs. ASSESSMENTS: Baseline assessments and regular follow-ups will entail comprehensive assessments of medical history, ongoing treatments, and outcomes, with a focus on HF symptoms, cardiac function, and overall health status. DISCUSSION OF THE DESIGN: The design of the PATHFINDER-CHD Registry is tailored to capture a wide range of data, prioritizing real-world HF management in ACHD. Its prospective nature facilitates longitudinal data acquisition, pivotal for comprehending for disease progression and treatment impacts. CONCLUSION: The PATHFINDER-CHD Registry is poised to offer valuable insights into HF management in ACHD, bridging current knowledge gaps, enhancing patient care, and shaping future research endeavors in this domain.

Thymic Atrophy and Immune Dysregulation in Infants with Complex Congenital Heart Disease.

Congenital heart disease (CHD) is the most common birth defect, and up to 50% of infants with CHD require cardiovascular surgery early in life. Current clinical practice often involves thymus resection during cardiac surgery, detrimentally affecting T-cell immunity. However, epidemiological data indicate that CHD patients face an elevated risk for infections and immune-mediated diseases, independent of thymectomy. Hence, we examined whether the cardiac defect impacts thymus function in individuals with CHD. We investigated thymocyte development in 58 infants categorized by CHD complexity. To assess the relationship between CHD complexity and thymic function, we analyzed T-cell development, thymic output, and biomarkers linked to cardiac defects, stress, or inflammation. Patients with highly complex CHD exhibit thymic atrophy, resulting in low frequencies of recent thymic emigrants in peripheral blood, even prior to thymectomy. Elevated plasma cortisol levels were detected in all CHD patients, while high NT-proBNP and IL-6 levels were associated with thymic atrophy. Our findings reveal an association between complex CHD and thymic atrophy, resulting in reduced thymic output. Consequently, thymus preservation during cardiovascular surgery could significantly enhance immune function and the long-term health of CHD patients.

Anatomical Compliance of Cavopulmonary Assist Device Designs: A Virtual Fitting Study in Fontan Patients.

Several device designs for cavopulmonary mechanical circulatory support (MCS) are under investigation, however, challenged by the Fontan population's heterogeneity in size, cardiovascular and thoracic anatomy. This study aimed to preclinically assess the anatomical compliance of proposed device designs in silico. Representative double- and single-outlet cavopulmonary assist device (CPAD) designs were virtually implanted into CT imaging data of 10 patients previously palliated with total cavopulmonary connection (TCPC) for functionally univentricular hearts. Anatomical device compatibility was characterized concerning pump proximity to cardiovascular, respiratory and thoracic structures, as well as pump in- and outflow graft configuration. In 10 Fontan patients with a median age of 10.4 years (interquartile range [IQR] 5.0-15.3 years) and a median body surface area of 1.09 m2 (IQR 0.76-1.28 m2), implantation of a double-outlet CPAD was feasible in 1 patient (10%). In all other, adverse device intersection with the trachea and (neo-)aorta, or posterior pulmonary artery outflow graft kinking were observed. A single-outlet design permitted enhanced device mobilization adapting to individual anatomical conditions, resulting in device fit in nine of 10 patients (90%). Despite vast anatomical variations among single ventricle patients, a single-outlet device design may provide intracorporeal cavopulmonary MCS to a broad spectrum of failing Fontan patients.

Feasibility of an Animal Model for Cavopulmonary Support With a Double-Outflow Pump.

Both single- and double-outflow cavopulmonary assist devices (CPADs) were recently proposed for the Fontan population, whereas single-outflow configurations were evaluated in large animal trials and double-outflow concepts are lacking an equivalent in vivo assessment. The aim of this study was to test the hemodynamic properties of a double-outflow CPAD device in an acute sheep model. The two inflow cannulae of a CPAD were anastomosed to the caval veins. Outflow graft connection was performed via end-to-side anastomosis to the right (RPA) and main pulmonary artery (MPA). Speed ramp protocols were conducted, and hemodynamic effects were monitored in terms of caval flows, cardiac output (CO), central venous pressure (CVP), pulmonary artery pressure (PAP), and left atrial pressure (LAP). Six experiments were conducted (53.35 ± 5.1 kg). In three experiments, the animal model was established, the CPAD was examined, and restoration of biventricular equivalency in terms of venous return was achieved. Venous pressures (CVP) declined linearly with increasing pump speed (r > 0.879), whereas caval flow (r > 0.973), CO (r > 0.993), PAP (r > 0.973), and LAP (r > 0.408) increased. Despite the considerable complexity of the sheep model caused by the sheep pulmonary arterial anatomy that requires substantial graft bending, the CPAD was evaluated in three acute experiments and showed the potential to completely substitute a subpulmonary ventricle.

Treatment of advanced heart failure in adults with congenital heart disease: a narrative review and clinical cases.

Background and Objective: The number of adults with congenital heart disease (ACHD) is increasing worldwide. Almost all congenital cardiac lesions can be successfully treated due to the progress in neonatal surgery and pediatric cardiology with a high likelihood of surviving until adulthood. However, ACHD frequently develop sequelae related to the initial cardiac anomaly. Heart failure (HF) is one of the most common complications associated with a high morbidity and mortality. Methods: The authors did search the PubMed database regarding relevant content covering publications up to March 2022. Relevant manuscripts were classified according to the impact factor of the journal, being a guideline manuscript, a position paper by a society or a comprehensive review of the current literature. Key Content and Findings: Optimal HF treatment remains an unmet need in ACHD. In particular, advanced HF therapy with cardiac resynchronization therapy, ventricular assist devices or organ transplantation is still very different and more specific in ACHD compared to non-ACHD. This review aims to compile international views and evidence from the literatures on the treatment of advanced HF in ACHD. Current challenges, but also the success of different treatment strategies in ACHD are illustrated by clinical cases. Conclusions: The main finding of the review is that data is still scarce regarding ACHD with advanced HF and international efforts to collect data regarding these patients needed to improve the current standard of care.

Antimicrobial effects of inhaled sphingosine against Pseudomonas aeruginosa in isolated ventilated and perfused pig lungs.

BACKGROUND: Ex-vivo lung perfusion (EVLP) is a save way to verify performance of donor lungs prior to implantation. A major problem of lung transplantation is a donor-to-recipient-transmission of bacterial cultures. Thus, a broadspectrum anti-infective treatment with sphingosine in EVLP might be a novel way to prevent such infections. Sphingosine inhalation might provide a reliable anti-infective treatment option in EVLP. Here, antimicrobial potency of inhalative sphingosine in an infection EVLP model was tested. METHODS: A 3-hour EVLP run using pig lungs was performed. Bacterial infection was initiated 1-hour before sphingosine inhalation. Biopsies were obtained 60 and 120 min after infection with Pseudomonas aeruginosa. Aliquots of broncho-alveolar lavage (BAL) before and after inhalation of sphingosine were plated and counted, tissue samples were fixed in paraformaldehyde, embedded in paraffin and sectioned. Immunostainings were performed. RESULTS: Sphingosine inhalation in the setting of EVLP rapidly resulted in a 6-fold decrease of P. aeruginosa CFU in the lung (p = 0.016). We did not observe any negative side effects of sphingosine. CONCLUSION: Inhalation of sphingosine induced a significant decrease of Pseudomonas aeruginosa at the epithelial layer of tracheal and bronchial cells. The inhalation has no local side effects in ex-vivo perfused and ventilated pig lungs.

Anatomic Repair of Congenitally Corrected Transposition: Reappraisal of Eligibility Criteria.

Several criteria to identify suitable candidates for anatomic repair in congenitally corrected transposition (cc-TGA) have been proposed. The purpose of this study was to critically re-evaluate adequacy of these recommendations in our patient cohort. All cc-TGA patients undergoing anatomic repair between 2010 and 2019 were reviewed. Evaluated eligibility criteria for repair included age ≤ 15 years, LV mass index ≥ 45-50 g/m2, LV mass/volume ratio > 0.9-1.5 and systolic LV to right ventricle pressure ratio > 70-90% among others. Repair failure was defined as postoperative early mortality or LV dysfunction requiring mechanical circulatory support. Twenty-five patients were included (median [interquartile range] age at surgery 1.8 years [0.7;6.6]; median postoperative follow-up 3.2 years [0.7;6.3]). Median preoperative LV ejection fraction was 60% [56;64], indexed LV mass 48.5 g/m2 [43.7;58.1] and LV mass/volume ratio 1.5 [1.1;1.6], respectively. A total of 12 patients (48%) did not meet at least one of the previously recommended criteria, however, all but two patients (92%) experienced favorable early outcome. Of 7 patients (28%) with indexed LV mass < 45 g/m2, 6 were successfully operated. There were two early repair failures (8%) with LV dysfunction: one patient died and one required mechanical circulatory support but recovered well. Surgery was performed successfully in patients with LV mass and volume Z-scores as low as - 2 and - 2.5, respectively. Anatomic correction for cc-TGA can be performed with excellent early outcome and is feasible even in patients with LV mass below previously recommended cut-offs. The use of LV mass and volume Z-scores might help to refine eligibility criteria.

A potential future Fontan modification: preliminary in vitro data of a pressure-generating tube from engineered heart tissue.

OBJECTIVES: Univentricular malformations are severe cardiac lesions with limited therapeutic options and a poor long-term outcome. The staged surgical palliation (Fontan principle) results in a circulation in which venous return is conducted to the pulmonary arteries via passive laminar flow. We aimed to generate a contractile subpulmonary neo-ventricle from engineered heart tissue (EHT) to drive pulmonary flow actively. METHODS: A three-dimensional tubular EHT (1.8-cm length, 6-mm inner diameter, ca. 1-mm wall thickness) was created by casting human-induced pluripotent stem cell-derived cardiomyocytes (0.9 ml, 18 mio/ml) embedded in a fibrin-based hydrogel around a silicone tube. EHTs were cultured under continuous, pulsatile flow through the silicone tube for 23 days. RESULTS: The constructs started to beat macroscopically at days 8-14 and remained stable in size and shape over the whole culture period. Tubular EHTs showed a coherent beating pattern after 23 days in culture, and isovolumetric pressure measurements demonstrated a coherent pulsatile wave formation with an average frequency of 77 ± 5 beats/min and an average pressure of 0.2 mmHg. Histological analysis revealed cardiomyocytes mainly localized along the inner and outer curvature of the tubular wall with mainly longitudinal alignment. Cell density in the center of the tubular wall was lower. CONCLUSIONS: A simple tube-shaped contractile EHT was generated from human-induced pluripotent stem cells and developed a synchronous beating pattern. Further steps need to focus on optimizing support materials, flow rates and geometry to obtain a construct that creates sufficient pressures to support a directed and pulsatile blood flow.

Using three-dimensional visualization as an optimal tool to plan and validate an aortopexy in a congenital heart disease patient with severe tracheal stenosis.

We present a patient with severe tracheal stenosis resulting from a compression by the innominate artery 6 months after an arterial switch operation in a dextro-transposition of the great arteries. Segmentation and three-dimensional (3D) visualization were derived from a contrast-enhanced dual-source computed tomography and post-processing was performed using a dedicated open-source platform (3D Slicer). Post-processing allowed a comprehensible visualization of the relationship of the innominate artery to the trachea when compared to standard computer tomography reformations. Finally, the surgical approach to move the innominate artery anteriorly in order to relieve the tracheal obstruction was emphasized based on the improved 3D visualization of the actual pathology. An effective aortopexy could be performed and the postoperative result was confirmed by a second 3D visualization. About 3 months of follow-up, the patient is completely asymptomatic. Three-dimensional visualization offers excellent opportunities for diagnosis, treatment planning and follow-up in patients with a vascular-related tracheal stenosis in the context of congenital heart disease.

A Cavopulmonary Assist Device for Long-Term Therapy of Fontan Patients.

Treatment of univentricular hearts remains restricted to palliative surgical corrections (Fontan pathway). The established Fontan circulation lacks a subpulmonary pressure source and is commonly accompanied by progressively declining hemodynamics. A novel cavopulmonary assist device (CPAD) may hold the potential for improved therapeutic management of Fontan patients by chronic restoration of biventricular equivalency. This study aimed at translating clinical objectives toward a functional CPAD with preclinical proof regarding hydraulic performance, hemocompatibility and electric power consumption. A prototype composed of hemocompatible titanium components, ceramic bearings, electric motors, and corresponding drive unit was manufactured for preclinical benchtop analysis: hydraulic performance in general and hemocompatibility characteristics in particular were analyzed in-silico (computational fluid dynamics) and validated in-vitro. The CPAD's power consumption was recorded across the entire operational range. The CPAD delivered pressure step-ups across a comprehensive operational range (0-10 L/min, 0-50 mm Hg) with electric power consumption below 1.5 W within the main operating range. In-vitro hemolysis experiments (N = 3) indicated a normalized index of hemolysis of 3.8 ± 1.6 mg/100 L during design point operation (2500 rpm, 4 L/min). Preclinical investigations revealed the CPAD's potential for low traumatic and thrombogenic support of a heterogeneous Fontan population (pediatric and adult) with potentially accompanying secondary disorders (e.g., elevated pulmonary vascular resistance or systemic ventricular insufficiency) at distinct physical activities. The low power consumption implied adequate settings for a small, fully implantable system with transcutaneous energy transfer. The successful preclinical proof provides the rationale for acute and chronic in-vivo trials aiming at the confirmation of laboratory findings and verification of hemodynamic benefit.

Norwood-I in a hypoplastic left heart variant and right aortic arch.

Even though preoperative diagnostics have improved significantly, intraoperative surprises may still occur especially in the case of complex congenital heart disease. An instance of such a complex congenital heart disease is a hypoplastic left heart syndrome with a right-sided aortic arch. In this case report, we present 1 patient with such a complex and unexpected anatomy, as well as a possible way to overcome the obstacles.

Can smart policies solve the sand mining problem?

While sand has become a scarce essential resource for construction and land reclamation worldwide, its extraction causes severe ecological damage and high social costs. To derive policy solutions to this paramount global challenge with broad applicability, this model-based analysis exemplarily studies sand trade from Southeast Asia to Singapore. Accordingly, a coordinated transboundary sand output tax reduces sand mining to a large extent, while the economic costs are small for the sand importer and slightly positive for the exporters. As a novel policy implementation approach, a "Sand Extraction Allowances Trading Scheme" is proposed, which helps sustainably balance the importer's economic growth with the exporters' economic development.

Single coronary artery arising from an atretic pulmonary trunk.

Coronary artery anomalies are a diverse group of disorders with highly variable manifestations and pathophysiological mechanisms. The origin of a single coronary artery from an atretic pulmonary trunk is a rare anomaly. We encountered this in an 8-day-old female newborn. This report should alert the cardiac surgical community to this fatal coronary malformation. Surgeons should bear this anomaly in mind when they face unusual myocardial behavior intraoperatively.

Intracorporeal Biventricular Assist Devices Using the Heartware Ventricular Assist Device in Children.

We describe the experience with biventricular HeartWare VAD (HVAD) support in the pediatric population. As of May 2017, using the Heartware database, 11 centers were identified. Seven centers participated providing information for 10 patients (four females, six males). Median age at the time of implantation was 12.7 ± 4.6years (5.3-6.9), median body surface area was 1.56. The indications for biventricular assist device (BiVAD) support included: myocarditis (n = 1), cardiomyopathy (n = 8), and one posttransplant heart failure. Six patients had a primary BiVAD implantation. Out of 10 patients with BiVAD, five were transplanted, one is ongoing (postoperatively day 207), and none were weaned from the device. Two patients (20%) were discharged from hospital on BiVAD support. Median support time was 52 days (16-235). The overall success rate was 60% surviving to transplant (median support time: 51 days) or are ongoing. Reasons for death included bleeding (n = 2), intracerebral hemorrhage (n = 1), and multisystem organ failure (n = 1). Eight out of 10 patients had at least one major complication, that is, major bleeding requiring re-operation (n = 6), severe neurologic injury (n = 1), and pump thrombosis in two patients requiring device exchange (n = 1) or thrombolysis therapy (n = 1). BiVAD HVAD implantation in children is a rare procedure, with high mortality and low discharge rates. Bleeding requiring re-operation was the most common postoperative complication, despite fresh sternotomies in the majority of patients. The risk and benefit ratio of such an approach should be carefully reviewed, and compared with the standard strategy using the Berlin EXCOR.

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): second EUROMACS Paediatric (Paedi-EUROMACS) report.

OBJECTIVES: A second paediatric report has been generated from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). The purpose of EUROMACS, which is operated by the European Association for Cardio-Thoracic Surgery, is to gather data related to durable mechanical circulatory support for scientific purposes and to publish reports with respect to the course of mechanical circulatory support therapy. Since the first report issued, efforts to increase compliance and participation have been extended. Additionally, the data provided the opportunity to analyse patients of younger age and lower weight. METHODS: Participating hospitals contributed pre-, peri- and long-term postoperative data on mechanical circulatory support implants to the registry. Data for all implants in paediatric patients (≤19 years of age) performed from 1 January 2000 to 1 July 2019 were analysed. This report includes updates of patient characteristics, implant frequency, outcome (including mortality rates, transplants and recovery rates) as well as adverse events including neurological dysfunction, device malfunction, major infection and bleeding. RESULTS: Twenty-nine hospitals contributed 398 registered implants in 353 patients (150 female, 203 male) to the registry. The most frequent aetiology of heart failure was any form of cardiomyopathy (61%), followed by congenital heart disease and myocarditis (16.4% and 16.1%, respectively). Competing outcomes analysis revealed that a total of 80% survived to transplant or recovery or are ongoing; at the 2-year follow-up examination, 20% died while on support. At 12 months, 46.7% received transplants, 8.7% were weaned from their device and 18.5% died. The 3-month adverse events rate was 1.69 per patient-year for device malfunction including pump exchange, 0.48 for major bleeding, 0.64 for major infection and 0.78 for neurological events. CONCLUSIONS: The overall survival rate was 81.5% at 12 months following ventricular assist device implant. The comparison of survival rates of the early and later eras shows no significant difference. A focus on specific subgroups showed that survival was less in patients of younger age (<1 year of age) (P = 0.01) and lower weight (<20 kg) (P = 0.015). Transplant rates at 6 months continue to be low (33.2%) The fact that the EUROMACS registry is embedded within the European Association for Cardio-Thoracic Surgery Quality Improvement Programme offers opportunities to focus on improving outcomes.

Early results from a prospective, single-arm European trial on decellularized allografts for aortic valve replacement: the ARISE study and ARISE Registry data.

OBJECTIVES: Decellularized aortic homografts (DAH) may provide an additional aortic valve replacement option for young patients due to their potential to overcome the high early failure rate of conventional allogenic and xenogenic aortic valve prostheses. METHODS: A prospective, European Union-funded, single-arm, multicentre, safety study was conducted in 8 centres evaluating non-cryopreserved DAH for aortic valve replacement. RESULTS: One hundred and forty-four patients (99 male) were prospectively enrolled between October 2015 and October 2018, mean age 33.6 ± 20.8 years; 45% had undergone previous cardiac operations. Mean implanted DAH diameter 22.6 ± 2.4 mm and mean durations for the operation, cardiopulmonary bypass and cross-clamp were 341 ± 140, 174 ± 80 and 126 ± 43 min, respectively. There were 2 early deaths (1 LCA thrombus on day 3 and 1 ventricular arrhythmia 5 h postop) and 1 late death due to endocarditis 4 months postoperatively, resulting in a total mortality of 2.08%. One pacemaker implantation was necessary and 1 DAH was successfully repaired after 6 weeks for early regurgitation following subcoronary implantation. All other DAH were implanted as a free-standing root. After a mean follow-up of 1.54 ± 0.81 years, the primary efficacy end points peak gradient (mean 11.8 ± 7.5 mmHg) and regurgitation (mean 0.42 ± 0.49, grade 0-3) were excellent. At 2.5 years, freedom from explantation/endocarditis/bleeding/stroke was 98.4 ± 1.1%/99.4 ± 0.6%/99.1 ± 0.9%/99.2 ± 0.8%, respectively, with results almost identical to those in an age-matched Ross operation cohort of 212 patients (mean age 34 years) despite DAH patients having undergone >2× more previous procedures. CONCLUSIONS: The initial results of the prospective multicentre ARISE trial show DAH to be safe for aortic valve replacement with excellent haemodynamics in the short follow-up period.

Establishing a pre-clinical growing animal model to test a tissue engineered valved pulmonary conduit.

BACKGROUND: Many valvular pathologies of the heart may be only sufficiently treated by replacement of the valve if a reconstruction is not feasible. However, structural deterioration, thrombosis with thromboembolic events and infective endocarditis are commonly encountered complications over time and often demand a re-operation. In congenital heart disease the lack of small diameter valves with the potential to grow poses additional challenges and limits treatment options to homo- or xenograft implants. METHODS: In this study, a chronic sheep model (24 months follow-up), a self-constructed valved conduit was created out of a tissue engineered (TE) patch (CorMatrix® Cardiovascular, Inc, USA) and implanted in orthotopic right ventricular (RV)-pulmonary artery (PA) position. Thereafter, the sheep were regularly monitored by clinical, laboratory and echocardiographic examinations to evaluate cardiac function and the implanted RV-PA-conduit. DISCUSSION: Here, we summarize the study protocol and our experiences during the perioperative phase and the follow up period and explain how we constructed a valved conduit out of a commercially available TE patch. TRIAL REGISTRATION: License number: ZH 284/14.

A Valveless Pulsatile Pump for Heart Failure with Preserved Ejection Fraction: Hemo- and Fluid Dynamic Feasibility.

Treatment of heart failure with preserved ejection fraction (HFpEF) remains a major unmet medical need. An implantable valveless pulsatile pump with a single cannula-the CoPulse pump-may provide beneficial hemodynamic support for select HFpEF patients when connected to the failing ventricle. We aimed to demonstrate hemodynamic efficacy and hemocompatible design feasibility for this novel assist device. The hemodynamic effect of the pump was investigated with an in vitro circulatory mock loop and an ex vivo isolated porcine heart model. The hydraulic design was optimized using computational fluid dynamics (CFD), and validated by 4D-flow magnetic resonance imaging (MRI). The pump reduced left atrial pressure (> 27%) and increased cardiac output (> 14%) in vitro. Ex vivo experiments revealed elevated total stroke volume at increased end-systolic volume during pump support. Asymmetric cannula positioning indicated superior washout, decreased stagnation (8.06 mm2 vs. 31.42 mm2), and marginal blood trauma potential with moderate shear stresses (< 24 Pa) in silico. Good agreement in flow velocities was evident among CFD and 4D-flow MRI data (r > 0.76). The CoPulse pump proved hemodynamically effective. Hemocompatibility metrics were comparable to those of a previously reported, typical pulsatile pump with two cannulae. The encouraging in vitro, ex vivo, and hemocompatibility results substantiate further development of the CoPulse pump.