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Background Methods Results Conclusions The survival rate of LVAD recipients may be improved by eliminating the infection failure mode at the percutaneous lead entry site. Wireless powering through a Transcutaneous Energy Transfer System (TETS) is a promising solution for achieving this. However, automatic controls need to be employed to compensate for the variations in efficiency and power transfer due to changes in load and coil‐to‐coil gaps.This article discusses the results of in vitro and animal models performance evaluation of an automatically controlled TETS for powering a Left Ventricular Assist Device.It was found that power up to 20 W could be transferred at an axial gap of 30 mm. A 5% variation in speed and a 2% change in flow rate are observed with the change in tissue thickness, in porcine carcass model.The LVAD could be operated at the required RPM irrespective of the change in axial positions. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion ShuttlePump is a novel total artificial heart (TAH) recently introduced to potentially overcome the limitations associated with the current state‐of‐the‐art mechanical circulatory support devices intended for adults. In this study, we adapted the outflow cannulation of the previously established ShuttlePump TAH and evaluated the anatomical compatibility using the virtual implantation technique.We retrospectively assessed the anatomical compatibility of the ShuttlePump using virtual implantation techniques within 3D‐reconstructed anatomies of adult heart failure patients. Additionally, we examined the impact of outflow cannula modification on the hemocompatibility of the ShuttlePump through computational fluid dynamic simulations.A successful virtual implantation in 9/11 patients was achieved. However, in 2 patients, pump interaction with the thoracic cage was observed and considered unsuccessful virtual implantation. A strong correlation (r <−0.78) observed between the measured anatomical parameters and the ShuttlePump volume exceeding pericardium highlights the importance of these measurements apart from body surface area. The numerical simulation revealed that the angled outflow cannulation resulted in a maximum pressure drop of 1.8 mmHg higher than that of the straight outflow cannulation. With comparable hemolysis index, the shear stress thresholds of angled outflow differ marginally (<5%) from the established pump model. Similar washout behavior between the pump models indicate that the curvature did not introduce stagnation zone.This study demonstrates the anatomic compatibility of the ShuttlePump in patients with biventricular failure, which was achieved by optimizing the outflow cannulation without compromising hemocompatibility. Nevertheless, clinical validation is critical to ensure the clinical applicability of these findings. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions The SynCardia® temporary total artificial heart (TAH) serves as a mechanical circulatory support device for patients suffering from irreversible biventricular failure.This retrospective study analyzed 196 consecutive patients who underwent TAH implantation at our center from 2001 to 2021. We assessed survival rates and all‐cause mortality during TAH support, including survival post‐heart transplantation.The median age of patients was 55 years, with 88% being male. The primary diagnoses included cardiomyopathy (43.9%), acute myocardial infarction (26.5%), and postcardiotomy heart failure (15.5%). At implantation, 87.2% of patients were classified as INTERMACS Profile 1. The median duration of support was 96 days (IQR: 23–227). Survival rates at 1, 6, and 12 months were 72%, 41%, and 34%, respectively. Postoperative rethoracotomy was necessary in 44.4% of patients; 39.3% experienced neurological events and 24.6% developed gastrointestinal bleeding. Overall, 64.8% of patients died while on support, primarily due to multiple organ failure (55.9%). Factors such as older age, higher bilirubin levels, postcardiotomy and specific underlying diagnoses were independent predictors of mortality during TAH support. On a positive note, 35.2% of patients underwent successful heart transplants, with 1‐, 5‐, and 10‐year posttransplant survival rates of 65%, 58%, and 51%, respectively.While high mortality rates persist among patients with biventricular failure, the SynCardia® TAH offers a viable interim solution for critically ill patients, particularly those who can be successfully bridged to heart transplantation. [ABSTRACT FROM AUTHOR]

Congestive heart failure (CHF) is a multifaceted clinical syndrome characterized by the inability of the heart to pump blood effectively, leading to inadequate oxygen and nutrient delivery to the body tissues. Despite advancements in treatment strategies, including guideline-directed medical treatment (GDMT), end-stage CHF remains a significant cause of morbidity and mortality worldwide. Heart transplantation is considered to be the gold standard treatment of end stage CHF but constrained by the lack of organ donors, lengthening waitlists, and the negative side effects of lifelong immunosuppressive medications. Mechanical circulatory support (MCS) has emerged as a pivotal intervention for patients with end-stage CHF, serving as a bridge to recovery, transplantation, or destination therapy. The aim of this narrative review is to highlight the historical development of MCS, to assess the recent status of MCS device technology and discuss current challenges associated with complications of MCS that need to be solved in the future by device development. The history of MCS dates back to pioneering efforts in the 1960s, with significant progress in device development and utilization over decades. MCS devices, including left ventricular assist devices (LVADs), extracorporeal membrane oxygenation (ECMO), and artificial hearts, play a crucial role in providing circulatory support to patients with end-stage CHF. Recent advancements in MCS technology aim to decrease the device size, enhance blood compatibility, reduce thrombo-embolic complications, and prolong device durability and battery life and improve physiological performance of MCS. Continued research and innovation are essential to address these challenges and improve outcomes in patients with end-stage CHF. Artificial intelligence (AI) has emerged as a valuable tool in cardiovascular medicine to facilitate risk prediction, patient selection, and treatment optimization for MCS and heart transplantation. Despite these advancements, challenges persist in MCS device selection, resource allocation, and integration of AI into clinical practice. Continued research and innovation are essential to address these challenges and improve outcomes in patients with advanced heart failure. [ABSTRACT FROM AUTHOR]

Mechanical circulatory support (MCS) devices can bridge the gap to transplant whilst awaiting a viable donor heart. The Realheart Total Artificial Heart is a novel positive-displacement MCS that generates pulsatile flow via bileaflet mechanical valves. This study developed a combined computational fluid dynamics and fluid-structure interaction (FSI) methodology for simulating positive displacement bileaflet valves. Overset meshing discretised the fluid domain, and a blended weak-strong coupling FSI algorithm was combined with variable time-stepping. Four operating conditions of relevant stroke lengths and rates were assessed. The results demonstrated this modelling strategy is stable and efficient for modelling positive-displacement artificial hearts. [ABSTRACT FROM AUTHOR]

The total artificial heart (TAH) has a long and rich history, being the product of decades of innovation, hard work, and dedication. This review examines the history of the TAH, a device that has revolutionized the treatment of end-stage biventricular heart failure. It reviews the development of the device from early concepts to the current state-of-the-art device, the SynCardia TAH, which has been implanted in over 2,000 patients worldwide. The article also discusses the challenges and successes experienced by researchers, clinicians, and patients throughout the development of TAH devices. Our focus will also be on discussing the hemostatic alterations in patients implanted with TAH and anticoagulation strategies to decrease associated thromboembolic risks. The article concludes with a look at other novel TAH devices and the future of TAH as an increasingly viable treatment for end-stage heart failure. [ABSTRACT FROM AUTHOR]

In cardiogenic shock various short-term mechanical assistances may be employed, including an Extra Corporeal Membrane Oxygenator and other non-dischargeable devices. Once hemodynamic stabilization is achieved and the patient evolves towards a persisting biventricular dysfunction or an underlying long-standing end-stage disease is present, aside from Orthotopic Heart Transplantation, a limited number of long-term therapeutic options may be offered. So far, only the Syncardia Total Artificial Heart and the Berlin Heart EXCOR (which is not approved for adult use in the United States unlike in Europe) are available for extensive implantation. In addition to this, the strategy providing two continuous-flow Left Ventricular Assist Devices is still off-label despite its widespread use. Nevertheless, every solution ensures at best a 70% survival rate (reflecting both the severity of the condition and the limits of mechanical support) with patients suffering from heavy complications and a poor quality of life. The aim of the present paper is to summarize the features, implantation techniques, and results of current devices used for adult Biventricular Mechanical Circulatory Support, as well as a glance to future options.

The Syncardia total artificial heart system is the only commercially approved durable device for treating biventricular heart failure patients awaiting heart transplantation. Conventionally, the Syncardia total artificial heart system is implanted based on the distance from the anterior aspect of the 10th thoracic vertebra to the sternum and the patient's body surface area. However, this criterion does not account for chest wall musculoskeletal deformities. This case report describes a patient with a pectus excavatum who developed compression of the inferior vena cava after Syncardia total artificial heart implantation and how transesophageal echocardiography guided chest wall surgery to accommodate the total artificial heart system. [ABSTRACT FROM AUTHOR]

Background: Hemolysis testing of new devices to treat heart failure is a regulatory requirement. The ASTM F1841–97 standard for hemolysis testing was developed for continuous flow pumps and does not specify test rig design. When research groups use different methodologies, results are difficult to compare. Pulsatile flow pump rigs require compliance chambers, and thus, the Aachen rig (Gräf et al) was developed for the pulsatile Reinheart TAH. The study objective was to use this rig to test the early Realheart TAH prototype V11C hemolysis performance compared to literature. Methods: The experimental control was the continuous flow pump BPX‐80 (Medtronic) and pooled heparinized porcine blood was used. Results: The mgNIH of BPX‐80 and V11C was 5.42 ± 1.47 and 25.20 ± 5.46 mg/100 L, respectively. The NIH ratio of V11C over BPX‐80 was 5.5. Conclusion: The absolute and the relative hemolysis of the V11C are lower compared to both the large and small Reinheart TAH devices published values. Pulsatile pumps create more hemolysis in the Aachen rig, and it is not known if this is because how the rig handles pulsatile flow or due to the devices. Future studies will, therefore, use a pulsatile pump such as the SynCardia as clinical comparator and human blood to test the performance of future Realheart TAH prototypes. [ABSTRACT FROM AUTHOR]

Background: In the total artificial heart (TAH), the inputs to the physiological control unit, preload, and afterload, are detected from intrinsic pump parameters (e.g., motor current). Within this study, their detection techniques are developed, and their reliability in pre‐ and afterload prediction is mapped for a broad range of cardiovascular system states. Methods: We used ReinHeart TAH which is a fully implantable TAH with a plunger coil drive that is alternately emptying the left and right chambers. From the coil currents we first derived a force generated by the piston with respect to its position and then analyzed its pattern to detect (1) preload—chamber filling, found as piston position at begin ejection and (2) afterload—mean outflow pressures, determined as linearly calibrated average piston force during ejection. TAH is then integrated into a mock loop circulation (MLC) which is set to 135 different steady operating points varying in chamber filling (0%–100%, five steps), mean outflow pressures (system circulation: 60–90–120 mm Hg, pulmonary circulation: 15–30‐45 mm Hg), and heart cycle duration (171–600 ms in seven non‐equidistant steps). The detected preload and afterload are compared to MLC set values, and the errors are mapped. Results: Respectively for the left and right chambers, the preload was detectable in 134 and 118 operating points and the mean error was ±3% and ±2%. The afterload was detectable in 135 and 87 operating points and the mean error was 37% and 30% respectively for left and right circulation. The operational points that are further away from homeostatic equilibrium values generally yielded larger errors. The largest errors were observed for right circulation at long cycle duration, low afterload, and low filling. Conclusions: The study yields reliable preload estimation in a broad range of physiological states, particularly for left circulation. Detection of afterload needs further improvements. The study revealed a need for piston movement optimization within the ReinHeart TAH during the early phase of systole. [ABSTRACT FROM AUTHOR]

BackgroundPost-infarction ventricular septal defects remain one of the most feared complications after myocardial infarction with high mortality rates. In special cases, surgical or interventional treatment strategies are technically not feasible and do not always lead to a good outcome.Case presentationA 58-year-old male patient in cardiogenic shock with a very large ventricular septal (VSD) defect (4.9 cm × 5 cm) due to myocardial infarction was presented in our department. Acute stabilization was achieved using peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) support. Neither surgical nor interventional therapy was considered as a sufficient option due to the unsuitable anatomy of the VSD and the patient was listed for heart transplantation. After 2 weeks on ECMO, bleeding and infectious complications occurred. Due to organ shortage, urgent implantation of the bioprosthetic total artificial heart (TAH) Aeson device (CARMAT) remained the only useful strategy to achieve a mid- or long-term bridge to transplantation. After successful implantation and good recovery with the Aeson device, the patient was transplanted 4 weeks after implantation.ConclusionPost-infarction ventricular septal defects are highly challenging and are commonly associated with a poor prognosis. The implantation of the new Aeson TAH device is a promising therapeutic option, allowing a safe and long-term bridging to heart transplantation.

Introduction: Primary cardiac tumors are very rare, with just 25% being malignant and 65% being sarcomas. The clinical expression of the disease is mostly determined by the tumor’s location; therefore, the range of symptoms is wide. The diagnosis is often established between the ages of 40 and 502, with a median survival time of 6 to 12 months. Case report: The purpose is to present the case of a healthy 35-year-old woman who was diagnosed with cardiac sarcoma in April of this year. The patient was admitted to the hospital for treatment of suspected pericarditis, and an echocardiogram was performed to identify the suspicious tumor in the right ventricle. In the context of the observations, a radiological examination was undertaken, which verified the tumor mass in the right ventricle, which is pushed into the lumen of the right atrium and shows no distant indications of the disease. A biopsy of the tumor reveals changes consistent with sarcoma. Considering the size of the formation, chemotherapy is initiated, with surgical treatment excluded as a possibility. Following three cycles of chemotherapy and repeated discussion of surgical treatment, the patient underwent a cardioectomy in June, with two HeartMate3 devices implanted in the configuration of a total artificial heart. After a complex surgery, the patient required prolonged mechanical ventilation due to respiratory complications and failed extubation attempts on the 5th and 7th postoperative days (POD). To facilitate long-term ventilation, a percutaneous tracheotomy was performed on the 13th POD, and bilateral pleural drains were placed to manage substantial pleural effusions. In the early stages, the patient was heavily dependent on ventilatory support, experiencing severe chest pain (VAS 10), cachexia, and left peroneal nerve paresis. Her physical condition was notably limited, with the ability to perform only active-assisted movements and sitting at the bed’s edge with support. Early mobilization and intensive respiratory physiotherapy were initiated to counteract muscle atrophy and improve respiratory function. Throughout July and August, the patient underwent a slow weaning process from mechanical ventilation, supported by CPAP and high-flow oxygen therapy, which provided crucial respiratory support and reduced the work of breathing. By the end of August, she was fully weaned from mechanical ventilation, marking a significant milestone in her recovery. By the 62nd POD, the patient was independently active within bed, could stand with walker support, and had achieved a 150-meter walking distance. With no evidence of residual or relapsing malignant disease, the patient was scheduled for ongoing oncological monitoring. Discharge occurred in early September, with partial dependence on assistance for daily activities and a continued need for home-based care. Conclusion: This case emphasizes the importance of a comprehensive, multidisciplinary approach in managing rare malignancies with complex postoperative needs. Early mobilization and targeted rehabilitation were pivotal in the patient’s recovery, and nursing care played a vital role in supporting device maintenance, wound care, and psychological well-being. Long-term outcomes remain uncertain due to the unique nature of the diagnosis, reinforcing the need for individualized care and lifetime follow-up. [ABSTRACT FROM AUTHOR]

ObjectiveSevere biventricular heart failure (BHF) can be remedied using a biventricular assist device (BVAD). Two devices are currently in development: a universal ventricular assist device (UVAD), which will be able to assist either the left, right, or both ventricles, and a continuous-flow total artificial heart (CFTAH), which replaces the entire heart. In this study, the in vitro hemodynamic performances of two UVADs are compared to a CFTAH acting as a BVAD.MethodsFor this experiment, a biventricular mock circulatory loop utilizes two pneumatic pumps (Abiomed AB5000™, Danvers, MA, USA), in conjunction with a dual-output driver, to create heart failure (HF) conditions (left, LHF; right, RHF; biventricular, BHF). Systolic BHF for four different situations were replicated. In each situation, CFTAH and UVAD devices were installed and operated at two distinct speeds, and cannulations for ventricular and atrial connections were evaluated.ResultsBoth CFTAH and UVAD setups achieved our recommended hemodynamic criteria. The dual-UVAD arrangement yielded a better atrial balance to alleviate LHF and RHF. For moderate and severe BHF scenarios, CFTAH and dual UVADs both created excellent atrial pressure balance. Conversely, when CFTAH was atrial cannulated for LHF and RHF, the needed atrial pressure balance was not met.ConclusionComprehensive in vitro testing of two different BVAD setups exhibited self-regulation and exceptional pump performance for both (single- and dual-device) BHF support scenarios. For treating moderate and severe BHF, UVAD and CFTAH both functioned well with respect to atrial pressure regulation and cardiac output. Though, the dual-UVAD setup yielded a better atrial pressure balance in all BHF testing scenarios.

There continues to be an unmet therapeutic need for an alternative treatment strategy for respiratory distress and lung disease. We are developing a portable cardiopulmonary support system that integrates an implantable oxygenator with a hybrid, dual‐support, continuous‐flow total artificial heart (TAH). The TAH has a centrifugal flow pump that is rotating about an axial flow pump. By attaching the hollow fiber bundle of the oxygenator to the base of the TAH, we establish a new cardiopulmonary support technology that permits a patient to be ambulatory during usage. In this study, we investigated the design and improvement of the blood flow pathway from the inflow‐to‐outflow of four oxygenators using a mathematical model and computational fluid dynamics (CFD). Pressure loss and gas transport through diffusion were examined to assess oxygenator design. The oxygenator designs led to a resistance‐driven pressure loss range of less than 35 mmHg for flow rates of 1–7 L/min. All of the designs met requirements. The configuration having an outside‐to‐inside blood flow direction was found to have higher oxygen transport. Based on this advantageous flow direction, two designs (Model 1 and 3) were then integrated with the axial‐flow impeller of the TAH for simulation. Flow rates of 1–7 L/min and speeds of 10,000–16,000 RPM were analyzed. Blood damage studies were performed, and Model 1 demonstrated the lowest potential for hemolysis. Future work will focus on developing and testing a physical prototype for integration into the new cardiopulmonary assist system. [ABSTRACT FROM AUTHOR]

Background: Data are limited on outcomes after heart transplantation in patients bridged‐to‐transplantation (BTT) with a total artificial heart (TAH‐t). Methods: The UNOS database was used to identify 392 adult patients undergoing heart transplantation after TAH‐t BTT between 2005 and 2020. They were compared with 11 014 durable left ventricular assist device (LVAD) BTT patients and 22 348 de novo heart transplants (without any durable VAD or TAH‐t BTT) during the same period. Results: TAH‐t BTT patients had increased dialysis dependence compared to LVAD BTT and de novo transplants (24.7% vs. 2.7% vs. 3.8%) and higher levels of baseline creatinine and total bilirubin (all p <.001). After transplantation, TAH‐t BTT patients were more likely to die from multiorgan failure in the first year (25.0% vs. 16.1% vs. 16.1%, p =.04). Ten‐year survival was inferior in TAH‐t BTT patients (TAH‐t BTT 53.1%, LVAD BTT 61.8%, De Novo 62.6%, p <.001), while 10‐year survival conditional on 1‐year survival was similar (TAH‐t BTT 66.8%, LVAD BTT 68.7%, De Novo 69.0%, all p >.20). Among TAH‐t BTT patients, predictors of 1‐year mortality included higher baseline creatinine and total bilirubin, mechanical ventilation, and cumulative center volume <20 cases of heart transplantation involving TAH‐t BTT (all p <.05). Conclusion: Survival after TAH‐t BTT is acceptable, and patients who survive the early postoperative phase experience similar hazards of mortality over time compared to de novo transplant patients and durable LVAD BTT patients. [ABSTRACT FROM AUTHOR]

Background The coronavirus disease 2019 (COVID-19) was first identified in December 2019 and is currently still a public health issue affecting millions of people worldwide. Heart failure patients are known to be at higher risk of morbidity and mortality in this case. Yet, few data exist concerning COVID-19 among patients with a left ventricular assistance device, and even less among those with a total artificial heart (TAH). Case summary A 27-year-old man with Marfan syndrome underwent prophylactic ascending aorta replacement. Shortly after surgery completion, he developed refractory cardiogenic shock with biventricular dysfunction leading to veno-arterial extracorporeal membrane oxygenation (VA-ECMO) implantation. In the context of no appropriate eligible donor during the following 10 days while waiting on the heart transplantation list, the patient was scheduled for a TAH as a bridge to transplantation. Meanwhile, he developed an acute respiratory distress syndrome secondary to SARS-CoV-2. The patient was successfully treated with corticosteroids, prone positioning and mechanical ventilation, and heart transplantation occurred 5 weeks after COVID-19 onset. Discussion Here, we report the first case of a patient presenting with COVID-19 infection following TAH implantation in a bridge to transplantation. We highlight that (i) cardiogenic shock patients simultaneously infected by COVID-19 should be treated instantly with all-time available technology to ensure best outcomes, including TAH and prone positioning, (ii) heart transplantation safety 5 weeks after COVID-19 onset. [ABSTRACT FROM AUTHOR]

Cardiac involvement occurs in light-chain (AL), transthyretin wild-type (wtATTR), and hereditary (hATTR) amyloidosis; other types of amyloidosis account for < 5% of all cardiac amyloidosis (CA). CA can present subclinically on screening, insidiously with symptoms such as exertional dyspnea, or abruptly as cardiogenic shock. Initially, CA patients were thought to be poor candidates for transplant due to short long-term survival; however, there is a marked improvement in heart and multi-organ transplant outcomes over the past 10 years with newer treatments and improvements in support with temporary and durable mechanical circulatory support while awaiting transplant. Patients with AL CA were reported to have worse post-OHT outcomes than patients with ATTR CA, but this gap is quickly closing with improved patient selection, novel chemotherapeutics, and perhaps with selected use of bone marrow transplantation. Waitlist mortality and transplantation rates have markedly improved for CA after the United Network for Organ Sharing (UNOS) policy change in October 2018. In this review, we will evaluate contemporary data from the last 5 years on advances in the field of transplantation and mechanical circulatory support in this patient population. [ABSTRACT FROM AUTHOR]

Background: The evaluation of pulsatile flow created by the new Cleveland Clinic continuous‐flow total artificial heart (CFTAH100), which has a re‐designed right impeller and motor, had not been tested in vivo. The purpose of this study was to evaluate the feasibility of pulsatility with the CFTAH100 during the application of pump speed modulation protocols in a chronic animal model. Methods: A 30‐day chronic animal experiment was conducted with a calf. Five pulsatile studies were performed on the alert animal. The mean pump speed was set at 2800 rpm, and modulated sinusoidally within a range of 0 to ± 35% of mean speed, in increments of 5% at 80 beats per minute (bpm). The pressures and pump flow were collected and a pulsatility index (PI) was calculated. Results: The calf was supported with the CFTAH100 without any major complications. The maximum and minimum pump flows changed significantly from baseline in all conditions, while the mean pump flow did not change. All flow pulsatility (FP) readings in all conditions significantly increased from baseline, and the percent modulation (%S) and FP had a strong positive correlation (r = 0.99, p < 0.01). The PI also increased significantly in all conditions (maximum at %S of 35%, 2.2 ± 0.05, p < 0.01), and a positive correlation between %S and PI (r = 0.99, p < 0.01) was observed. Conclusion: The CFTAH100 showed the feasibility of creating pulsatile circulation with sinusoidal pump speed modulation. [ABSTRACT FROM AUTHOR]

Background: Heart failure is a growing health problem worldwide. Due to the lack of donor hearts there is a need for alternative therapies, such as total artificial hearts (TAHs). The aim of this study is to evaluate the hemodynamic performance of the Realheart® TAH, a new 4‐chamber cardiac prosthesis device. Methods: The Realheart® TAH was connected to a hybrid cardiovascular simulator with inflow connections at the left/right atrium, and outflow connections at the ascending aorta/pulmonary artery. The Realheart® TAH was tested at different pumping rates and stroke volumes. Different systemic resistances (20.0‐16.7‐13.3‐10.0 Wood units), pulmonary resistances (6.7‐3.3‐1.7 Wood units), and pulmonary/systemic arterial compliances (1.4–0.6 ml/mm Hg) were simulated. Tests were also conducted in static conditions, by imposing predefined values of preload‐afterload across the artificial ventricle. Results: The Realheart® TAH allows the operator to finely tune the delivered flow by regulating the pumping rate and stroke volume of the artificial ventricles. For a systemic resistance of 16.7 Wood units, the TAH flow ranges from 2.7 ± 0.1 to 6.9 ± 0.1 L/min. For a pulmonary resistance of 3.3 Wood units, the TAH flow ranges from 3.1 ± 0.0 to 8.2 ± 0.3 L/min. The Realheart® TAH delivered a pulse pressure ranging between ~25 mm Hg and ~50 mm Hg for the tested conditions. Conclusions: The Realheart® TAH offers great flexibility to adjust the output flow and delivers good pressure pulsatility in the vessels. Low sensitivity of device flow to the pressure drop across it was identified and a new version is under development to counteract this. [ABSTRACT FROM AUTHOR]

Hundreds of thousands of Americans have advanced heart failure and experience severe symptoms (e. g., dyspnea) with minimal exertion or at rest despite optimal management. Although heart transplant is an effective treatment for advanced heart failure, the demand for organs far exceeds the supply. Another option for these patients is mechanical circulatory support (MCS) provided by devices such as the ventricular assist device and total artificial heart. MCS alleviates symptoms, prolongs life, and provides a “bridge to transplant” or a decision regarding future management such as “destination therapy,” in which the patient receives lifelong MCS. However, a patient receiving MCS, or his/her surrogate decision-maker, may conclude ongoing MCS is burdensome and no longer consistent with the patient's healthcare-related values, goals, and preferences and, as a result, request withdrawal of MCS. Likewise, the patient's clinician and care team may conclude ongoing MCS is medically ineffective and recommend its withdrawal. These scenarios raise ethical and legal concerns. In the U.S., it is ethically and legally permissible to carry out an informed patient's or surrogate's request to withdraw any treatment including life-sustaining treatment (LST) if the intent is to remove a treatment perceived by the patient as burdensome and not to terminate intentionally the patient's life. Under these circumstances, death that follows withdrawal of the LST is due to the underlying disease and not a form of physician-assisted suicide or euthanasia. In this article, frequently encountered ethical and legal concerns regarding requests to withdraw MCS are reviewed: the ethical and legal permissibility of withholding or withdrawing LSTs from patients who no longer want such treatments; what to do if the clinician concludes ongoing LST will not result in achieving clinical goals (i.e., medically ineffective); responding to requests to withdraw LST; the features of patients who undergo withdrawal of MCS; the rationale for advance care planning in patients being considered for, or receiving, MCS; and other related topics. Notably, this article reflects a U.S. perspective.

Introduction: Bridge to transplantation (BTT) with a SynCardia Total Artificial Heart (TAH) has been gaining momentum as a therapy for patients with biventricular heart failure. Recent transplant waitlist and posttransplant outcomes with this strategy have not been comprehensively characterized. We reviewed the United Network for Organ Sharing (UNOS) database to examine BTT outcomes for the TAH system since approval. Methods: Adult patients listed for heart transplantation in the UNOS system between 2004 and 2020 who underwent BTT therapy with a TAH were included in the study. Trends in utilization of TAH compared with other durable mechanical support strategies were examined. The primary outcome was 1‐year survival following heart transplantation following BTT with TAH. Secondary outcomes included waitlist deterioration and risk factors for waitlist or posttransplant mortality. Results: During the study 433 total patients underwent TAH implant as BTT therapy; 236 (54.4%) were listed with the TAH, while the remaining patients were upgraded to TAH support while on the waitlist. Waitlist mortality was 7.4%, with 375 patients (86.6%) ultimately being transplanted. Age, cerebrovascular disease, functional status, and ventilator dependence were risk factors for waitlist mortality. One‐year survival following successful BTT was 80%. Risk factors for mortality following BTT included age, body mass index, and underlying diagnosis. Conclusions: Patients undergoing BTT with TAH demonstrate acceptable waitlist survival and good 1‐year survival. While utilization initially increased as a BTT therapy, there has been a plateau in relative utilization. Individual patient and transplantation center factors deserve further investigation to determine the ideal population for this therapy. [ABSTRACT FROM AUTHOR]

Background: BiVACOR is a novel total artificial heart (TAH) utilizing a single centrifugal magnetically levitated rotor with the ability to modulate pulsatile flow. The device has been successfully tested in a bovine model. We undertook a multicenter anatomical and virtual fitting study of the BiVACOR in patients undergoing heart transplantation. Methods: 10 patients were recruited across two heart transplant centers. A sterilized 1:1 titanium model of the device was inserted into the patient's chest post heart explant, prior to implantation of the donor heart. Measurements were recorded in situ. The device was then removed. Following this, retrospective 3D reconstructions were created from computed tomography chest scans to simulate a virtual fitting. Results: Mean age was 53 years (range 38–67). Mean BMI was 28 (range 20–37). Heart failure etiology was varied—with ischemic cardiomyopathy being the most common. Mean spine‐to‐sternum distance at the tenth thoracic vertebrae (T10) was 14 cm (range 11–18). Mean aorta to aortic Port distance was 0.2 cm (range 0–0.5). Mean pulmonary artery to pulmonary artery port distance was 4.2 cm (range 1–7). The device fitted suitably in all patients without gross distortion to the geometry between native vessel/chamber and port. Conclusions: This study described the anatomical and virtual fitting of the BiVACOR TAH. The device fit well within the chest cavities of all 10 patients, who represented a variety of body morphologies and heart failure etiology. [ABSTRACT FROM AUTHOR]

Background: Patients with end‐stage, biventricular heart failure, and for whom heart transplantation is not an option, may be given a Total Artificial Heart (TAH). The Realheart® is a novel TAH which pumps blood by mimicking the native heart with translation of an atrioventricular plane. The aim of this work was to create a strategy for using Computational Fluid Dynamics (CFD) to simulate haemodynamics in the Realheart®, including motion of the atrioventricular plane and valves. Methods: The accuracies of four different computational methods for simulating fluid‐structure interaction of the prosthetic valves were assessed by comparison of chamber pressures and flow rates with experimental measurements. The four strategies were: prescribed motion of valves opening and closing at the atrioventricular plane extrema; simulation of fluid‐structure interaction of both valves; prescribed motion of the mitral valve with simulation of fluid‐structure interaction of the aortic valve; motion of both valves prescribed from video analysis of experiments. Results: The most accurate strategy (error in ventricular pressure of 6%, error in flow rate of 5%) used video‐prescribed motion. With the Realheart operating at 80 bpm, the power consumption was 1.03 W, maximum shear stress was 15 Pa, and washout of the ventricle chamber after 4 cycles was 87%. Conclusions: This study, the first CFD analysis of this novel TAH, demonstrates that good agreement between computational and experimental data can be achieved. This method will therefore enable future optimisation of the geometry and motion of the Realheart®. [ABSTRACT FROM AUTHOR]

The objective of this study is to identify the preload and afterload sensitivity of the ReinHeart TAH 2.0. For adequate left‐right flow balance, the concept of a reduced right stroke volume (by about 10%) and active adaption of the right diastole duration are evaluated concerning the controllability of the flow balance. This study used an active mock circulation loop to test a wide range of preload and afterload conditions. Preload sensitivity was tested at atrial pressures (APs) between 4 and 20 mm Hg. Left afterload was varied in a range of 60‐140 mm Hg mean aortic pressure (MAP), right afterload was simulated between 15 and 40 mm Hg. Four scenarios were developed to verify that the flow difference fully covers the defined target range of 0‐1.5 L/min. Although a positive correlation between inlet pressure and flow is identified for the right pump chamber, the left pump chamber already fills completely at an inlet pressure of 8‐10 mm Hg. With increasing afterload, both the left and right flow decrease. A positive flow balance (left flow exceeds right flow) is achieved over the full range of tested afterloads. At high APs, the flow difference is limited to a maximum of 0.7 L/min. The controllability of flow balance was successfully evaluated in four scenarios, revealing that a positive flow difference can be achieved over the full range of MAPs. Under physiological test conditions, the linear relationship between flow and heart rate was confirmed, ensuring good controllability of the TAH. [ABSTRACT FROM AUTHOR]

Objective: The need for safe and reliable mechanical circulatory support (MCS) for smaller children with severe heart failure (HF) is well defined. More specifically, in pediatric patients with advanced congenital HF, there is no implantable total artificial heart (TAH) device available for small patients. Herein, we report the development of the infant continuous-flow total artificial heart (I-CFTAH), a fully implantable in infants and newborns., Methods: After extensive engineering analysis, we performed an unprecedented effort: reducing the I-CFTAH's displacement volume to be 14% of the adult CFTAH pump while simultaneously decreasing pump diameter (6.2 cm to 2.6 cm) and axial length (9.8 cm to 4.8 cm). Facilitated by these proportional reductions, for the first time, a durable total artificial heart device was successfully fit in the chest of infants and newborns (height of ≥50 cm)., Results: The functional I-CFTAH prototype demonstrated capability to support stable hemodynamics and desired device performance. The pump flow range (0.5-1.5 L/min) was confirmed in a mock circulatory testing loop. Within the tested flow range, the I-CFTAH can support small patients that could benefit from the intended cardiac output., Conclusions: This successful effort demonstrated the feasibility of the miniature continuous-flow total artificial heart, intended for very small patient populations. I-CFTAH showed stable hemodynamics and could, therefore, become one of the few therapeutic options as a bridge to transplantation, aiming to enhance both the quality and duration of life for pediatric patients with advanced HF., Competing Interests: J.H.K., B.K., and K.F. and are coinventors of the I-CFTAH. All other authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (© 2024 The Author(s).)

The assessment and reduction of haemolysis within mechanical circulatory support (MCS) remains a concern with regard to device safety and regulatory approval. Numerical methods for predicting haemolysis have typically been applied to rotary MCS devices and the extent to which these methods apply to positive-displacement MCS is unclear. The aim of this study was to evaluate the suitability of these methods for assessing haemolysis in positive-displacement blood pumps. Eulerian scalar-transport and Lagrangian particle-tracking approaches derived from the shear-based power-law relationship were used to calculate haemolysis in a computational fluid dynamics model of the Realheart total artificial heart. A range of power-law constants and their effect on simulated haemolysis were also investigated. Both Eulerian and Lagrangian methods identified the same key mechanism of haemolysis: leakage flow through the bileaflet valves. Whilst the magnitude of haemolysis varied with different power-law constants, the method of haemolysis generation remained consistent. The Eulerian method was more robust and reliable at identifying sites of haemolysis generation, as it was able to capture the persistent leakage flow throughout the entire pumping cycle. This study paves the way for different positive-displacement MCS devices to be compared across different operating conditions, enabling the optimisation of these pumps for improved patient outcomes., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: S.F.Z, A.N., T.F. and I.L.P. are employees of or consultants to and/or shareholders of Scandinavian Real Heart AB. J.B., A.N.C. and K.H.F. declare no potential conflicts of interest.

The Aeson® total artificial heart (A-TAH) has been developed as a total heart replacement for patients at risk of death from biventricular failure. We previously described endothelialization of the hybrid membrane inside A-TAH probably at the origin of acquired hemocompatibility. We aimed to quantify vasculogenic stem cells in peripheral blood of patients with long-term A-TAH implantation. Four male adult patients were included in this study. Peripheral blood mononuclear cells were collected before A-TAH implantation (T0) and after implantation at one month (T1), between two and five months (T2), and then between six and twelve months (T3). Supervised analysis of flow cytometry data confirmed the presence of the previously identified Lin−CD133+CD45− and Lin−CD34+ with different CD45 level intensities. Lin−CD133+CD45−, Lin−CD34+CD45− and Lin−CD34+CD45+ were not modulated after A-TAH implantation. However, we demonstrated a significant mobilization of Lin−CD34+CD45dim (p = 0.01) one month after A-TAH implantation regardless of the expression of CD133 or c-Kit. We then visualized data for the resulting clusters on a uniform manifold approximation and projection (UMAP) plot showing all single cells of the live Lin− and CD34+ events selected from down sampled files concatenated at T0 and T1. The three clusters upregulated at T1 are CD45dim clusters, confirming our results. In conclusion, using a flow cytometry approach, we demonstrated in A-TAH-transplanted patients a significant mobilization of Lin−CD34+CD45dim in peripheral blood one month after A-TAH implantation. Using a flow cytometry approach, we demonstrated in A-TAH transplanted patients a significant mobilization of Lin−CD34+CD45dim in peripheral blood one month after A-TAH implantation. This cell population could be at the origin of newly formed endothelial cells on top of hybrid membrane in Carmat bioprosthetic total artificial heart. [ABSTRACT FROM AUTHOR]

• Qualitative online ethnography extracted device names from a social media group. • 28 codes were inductively generated and assigned to each relevant datapoint. • Consolidated under four themes of emotional relationship between patient and device. • Themes: grateful partnership; dependency reversal; preserving perceptions; coping via humour. Patients with mechanical circulatory support devices regularly experience positive and negative emotions which are reinforced through interactions with their device. We explored emotional relationships between patients and their MCS devices through the names they assign to those devices. We sought to characterise device naming and suggest future developments which might capitalise on the naming phenomenon to improve patient wellbeing. Qualitative online ethnography extracted comments on device names and emotions from a social media group. Thematic analysis grouped the comments according to their explicit or implied emotions, and their potential consequences for designing future MCS treatment. Thematic analysis identified 28 codes to characterise the names, from which we inferred 4 main themes for proposed emotional relationships. They centred on humour, coping, improving acceptance for family and friends, and reclaiming agency. We suggest that by deliberately considering these factors in future research and development, clinicians and device manufacturers have scope to improve patient wellbeing. [ABSTRACT FROM AUTHOR]

Introduction: Circulatory assistance from a SynCardia Total Artificial Heart (SynCardia-TAH) is a reliable bridge-to-transplant solution for patients with end-stage biventricular heart failure. Ischemic strokes affect about 10% of patients with a SynCardia-TAH. We report for the first time in the literature two successful thrombectomies to treat the acute phase of ischemic stroke in two patients treated with a SynCardia-TAH in the bridge-to-transplant (BTT). Case report: We follow two patients with circulatory support from a SynCardia-TAH in the bridge-to-transplant for terminal biventricular cardiac failure with ischemic stroke during the support period. An early in-hospital diagnosis enables the completion of a mechanical thrombectomy within the first 6 h of the onset of symptoms. There was no intracranial hemorrhagic complication during or after the procedure and the patients fully recovered from neurological deficits, allowing a successful heart transplant. Conclusion: This case report describes the possibility of treating ischemic strokes under a SynCardia-TAH by mechanical thrombectomy following the same recommendations as for the general population with excellent results and without any hemorrhagic complication during or after the procedure. [ABSTRACT FROM AUTHOR]

A patient with biventricular heart failure received a total artificial heart (TAH) as a bridge to transplant. He had a complicated hospital course including postoperative bleeding, subarachnoid hemorrhage, and adjustment disorder. After participating in 6 months of a rehabilitation program, his Berg balance score progressed from 8 to 41 and his endurance improved from ambulating 75 feet with a rolling walker and requiring moderate assistance in his activities of daily living on admission to ambulating several times up to 200 feet with modified independent and modified independent with setup for his basic activities of daily living. Since few patients have undergone inpatient rehabilitation with a TAH, this case illustrates significant functional gains that a comprehensive rehabilitation team can provide and major considerations to be aware of to optimize care when working with patients with TAH.

There continues to be limited, viable ventricular assist device technology options to support the dysfunctional states of pediatric heart failure. To address this need, we are developing a magnetically suspended, versatile pumping technology that uniquely integrates two blood pumps in a series configuration within a single device housing. This device enables operational switching from the usage of one pump to another as needed for clinical management or to support growth and development of the pediatric patient. Here, we present the initial design where we conducted a virtual fit study, the Taguchi Design Optimization Method, iterative design to develop pump geometries. Computational tools were used to estimate the pressure generation, capacity delivery, hydraulic efficiency, fluid stress levels, exposure time to stresses, blood damage index, and fluid forces on the impellers. Prototypes of the pumps were tested in a flow loop using a water‐glycerin solution. Both designs demonstrated the capability to generate target pressures and flows. Blood damage estimations were below threshold levels and achieved design requirements; however, maximum scalar stress levels were above the target limit. Radial and axial forces were less than 1 N and 10 N, respectively. The performance data trends for physical prototypes correlated with theoretical expectations. The centrifugal prototype was able to generate slightly higher pressure rises than numerical predictions. In contrast, the axial prototype outperformed the computational studies. Experimental data were both repeatable and reproducible. The findings from this research are promising, and development will continue. [ABSTRACT FROM AUTHOR]

• Extracted 225 statements on psychosocial considerations from 42 included articles. • 23 codes were inductively generated and assigned to each relevant statement. • Codes consolidated under four main themes, framed as pragmatic future design needs. • Themes: remote care; multidisciplinary tools; easier interactions; extended pathway. Biomedical engineers are developing new mechanical circulatory support pumps. Clinicians are generating and analysing new evidence for their prescription and management. Industrial designers are generating usable solutions for wearable components and controllers. However, psychosocial considerations may be falling between the cracks of the three disciplines because of their multi-faceted nature. This article seeks to identify psychosocial needs raised in previous work, re-frame them as needs for future products and services, and discuss routes to solutions. SLR extracted 225 statements on psychosocial considerations from 42 included articles. 23 codes were inductively generated and applied to relevant datapoints. Codes were consolidated under 4 main themes and re-framed as solvable problems. Identified themes: expanded remote care, improved multidisciplinary management tools, creating easier interactions; and extending patient engagement. Design-driven methods have been used to solve analogous problems in other contexts and can address the identified psychosocial problems if implemented fully. [ABSTRACT FROM AUTHOR]

A total artificial heart (TAH) must be designed to autonomously balance the flows of the systemic and pulmonary circulation to prevent potentially lethal lung damage. The flow difference between the systemic and pulmonary circulation is mainly caused by the bronchial (arteries) shunt flow and can change dynamically. The ReinHeart TAH consists of only one actuator that ejects blood alternately from the right and left pump chamber. This design entails a coupling of the right and left stroke and thus, complicates the independent adaptation of the right and left flow. In this experimental study on the ReinHeart TAH, four concepts to keep the flows well balanced were investigated using an active mock circulation loop for data acquisition. Three concepts are based on mechanical design changes (variation of pusher plate shape, flexible right pump chamber housing, and reduced right stroke volume) to achieve a static flow difference. In combination with these static concepts, a concept influencing the ratio of systole and diastole duration to respond to dynamic changes was studied. In total, four measurement series, each with 270 operating points, to investigate the influence of circulatory filling volume, heart rate, bronchial shunt flow, and lung resistance were recorded. In the course of this study, we introduce a concept deviation indicator, providing information about the efficiency of the concepts to balance the flows based on changes in lung's blood pressures. Furthermore, the distribution of the measured data was evaluated based on bubble plot visualizations. The investigated variation of the right pusher plate shape results in high lung pressures which will cause lethal lung damage. In comparison, a flexible right pump chamber housing shows lower lung pressures, but it still has the potential to damage the lungs. Reducing the stroke volume of the right pump chamber results in proper lung pressures. The flow balance can dynamically be influenced with a positive effect on the lung pressures by choosing a suitable systole‐diastole‐ratio. The results of this study suggest that an adequate right‐left flow balance can be achieved by combining the mechanical concept of a reduced right stroke volume with an active control of the systole‐diastole‐ratio. [ABSTRACT FROM AUTHOR]

Right ventricular failure (RVF) remains the main cause of morbidity and mortality following the implantation of continuous flow (CF) left ventricular assist devices. Apart from the difficulties inherent in assessing right ventricular function, other factors that may confound the prediction of RVF intraoperative events include concomitant surgical procedures, postoperative changes in pulmonary hemodynamics, evolving mechanical circulatory support (MCS) technology, shifts in the target population, and device settings. In this commentary, the role of concomitant tricuspid valve repair, early planned temporary or durable MCS have been discussed. A focus on the current modifications in CF ventricular assist devices designed for the left ventricle to make them suitable for right ventricular support has been set. [ABSTRACT FROM AUTHOR]