Despite the range of body sizes in children, few ventricular assist devices (VAD) exist to support pediatric patients with end-stage heart failure. Large registry data identified weight < 20 kg to be associated with higher rates of VAD-related stroke, compared to > 40 kg. Moreover, patients < 1 years of age experience the highest post-implant mortality, with 1-year survival improving in an age-dependent manner. Within different VAD types, intracorporeal continuous (IC) devices confer the greatest clinical benefit and quality of life compared to paracorporeal alternatives. The major limitation of IC VADs is the technical challenge of implantation into patients of small body size, thus the majority of patients with IC devices are pre-adolescents or older. However, since 2021, the use of HeartMate 3™ (HM3) has expanded to patients as small as 17.7 kg. Although HM3 offers equally favorable survival outcomes irrespective of body size, patients of low body surface area are more likely to experience non-device-related major infections and renal dysfunction, with suggestion for elevated risk of major bleeding and stroke. Innovative imaging strategies have emerged to assess the feasibility of HM3 implantation and facilitate preoperative planning in small children. Moreover, the unmet need for an IC device in the infant population has revived interest in the axial pump, with a pivotal clinical trial currently underway. VAD outcomes in the pediatric population are not equivalent across all ages and body sizes, thus size-stratified analyses and device development to serve the full spectrum of body habitus are key considerations as this field rapidly evolves.

A blood turbine-pump system (iATVA), resembling a turbocharger was proposed as a mechanical right-heart assist device without external drive power. In this study, the iATVA system is investigated with particular emphasis on the blood turbine flow dynamics. A time-resolved 2D particle image velocimetry (PIV) set-up equipped with a beam splitter and two high speed cameras, allowed simultaneous recordings from both the turbine and pump impellers at 7 different phased-locked instances. The iATVA prototype is 3D printed using an optically clear resin following our earlier PIV protocols. Results showed that magnetically coupled impellers operated synchronously. As the turbine flow rate increased from 1.6 to 2.4 LPM, the rotational speed and relative inlet flow angle increase from 630 to 900 rpm, and 38 to 55% respectively. At the trailing edges, backflow region spanned 3/5 of the total passage outlet flow, and an extra leakage flow was observed at the leading edge. For this early turbine design, approximately, 75% of the turbine blade passage was not contributing to the impulse operation mode. The maximum non-wall shear rate was ~ 2288 s-1 near to the inlet exit, which is significantly lower than the commercial blood pumps, encouraging further research and blood experiments of this novel concept. Experimental results will improve the hydrodynamic design of the turbine impeller and volute regions and will be useful in computational fluid dynamics validation studies of similar passive devices.

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Mechanical circulatory support devices have profoundly transformed the management of severe cardiothoracic disorders. While heart transplantation is the gold standard therapy for end-stage heart disease, long-term mechanical support devices are a viable alternative for those ineligible and/or those awaiting organ availability. Major technological advancements were made over first 5 decades of development, resulting in improved durability and survival with reduced adverse events. However, gains have tapered recently for various complications (e.g., internal bleeding, multisystem organ failure), which collectively represent a significant proportion of disability and/or mortality. Further, in light of mature ventricular assist devices failing during clinical trials or even after clinical approval (class I withdrawals), it is timely to consider: Are our preclinical assessment protocols vital in the design and development of mechanical circulatory support devices, providing a realistic and reliable profile of future clinical performance? This commentary explores this question and analyses development pathways through the lens of the various disciplines involved in the preclinical assessment of mechanical circulatory support technologies: Limitations in approaches to benchtop blood testing, computational design and simulation, and animal testing are discussed as likely contributors to some of the common hemocompatibility-related adverse events (HRAEs). While it is acknowledged that some shortcomings are pragmatic in nature, possible solutions are presented that will only be realized through truly transdisciplinary and open approaches that challenge the current nature of medical device development. We suggest that these can and must be overcome to diminish HRAEs and will potentially demarcate the fourth generation of cardiac assist devices.

BACKGROUND: A significant proportion of patients with heart failure (HF) progress to an advanced stage, which is associated with a substantial increase in morbidity and mortality. These patients may be eligible for advanced treatment strategies such as mechanical circulatory support with ventricular assist devices (VAD). Vascular dysfunction is a hallmark of heart failure pathophysiology and prognosis. However, whether and to what degree the hemodynamic benefits of VADs influence vascular function remain unknown.
RESULTS: In this study, we evaluated endothelial vascular function with flow-mediated vasodilatation (FMD) and with flicker-light induced retinal vasodilatation (FID). 34 patients with a VAD (age 58 ± 10 years, 85% male, 74% ischemic heart disease, 26 continuous-flow (CF)-LVAD, and 8 pulsatile biventricular (bi)-VAD) were compared to 34 propensity-matched patients (mean age 62 ± 9 years, 68% male, 59% ischemic heart disease) with advanced HF (AdvHF). Endothelial function of larger arteries (FMD) was significantly better in patients after VAD implantation compared to matched AdvHF patients (7.2 ± 4.6% vs. 5.0 ± 3.2%, p = 0.03), whereas microvascular arteriolar function (FIDart) did not differ (0.99 ± 1.43% vs. 1.1 ± 1.7%, p = 0.78). The arterio-venous ratio (AVR) was higher in the VAD group (0.90 ± 0.06 vs 0.85 ± 0.09, p = 0.01), reflecting wider retinal arteriolar and narrower venular diameters. There was no difference in vascular function between patients with CF-LVAD and pulsatile Bi-VAD.
CONCLUSIONS: In patients with advanced heart failure, VAD implantation was associated with better endothelial function at the level of large arteries, but not in the microcirculation.

BACKGROUND: Implantation of a left ventricular assist device (LVAD) requires extensive aftercare. It is largely unclear how aftercare should be designed from the patients\' perspective. Implications can be developed based on an examination of the healthcare context. Its main components are mapped on five tiers in the Human Factors of Home Health Care Model by Henriksen, Joseph, and Zayas-Caban (2009). Using this model, the present study explores the patient perspective on the context of healthcare after an LVAD implantation.
METHODS: We employed a qualitative cross-sectional study, in which LVAD patients participated in semi-structured interviews. The transcribed interviews were analyzed using content analysis. First, relevant meaning units were identified and deductively categorized into the model. Then, categories of care-related aspects were developed inductively within each of the model tiers.
RESULTS: We interviewed 18 patients aged 33 to 78 years who had been living with the LVAD between a few weeks and more than 10 years. Twenty-eight categories related to care aspects were developed within the model tiers: 3 categories on patient characteristics (e.g., self-management skills), 3 on caregiver characteristics (e.g., professionalism), 11 healthcare-related tasks and requirements (e.g., wound management), 8 on factors of the physical environment (e.g., controllability), medical devices and technologies (e.g., carrying systems for external components), and cultural, social and community environment (e.g., interaction with peers), as well as 3 on external environmental factors (e.g., healthcare infrastructure).
CONCLUSIONS: The present study represents the first investigation focusing on aspects of the healthcare context influencing healthcare quality and safety from the perspective of LVAD patients in Germany. LVAD aftercare covers a broad and complex range of tasks. For this, patients, caregivers and healthcare professionals need specific knowledge, which is lacking in various respects. In the first place, this is compensated by the patients\' own initiative and the personal care provided by the VAD outpatient clinics.
CONCLUSIONS: Three key recommendations to optimize aftercare from the patient perspective are derived: Patients would benefit from a more flexible and decentralized aftercare concept, to which telemedicine could contribute. LVAD-specific expertise among general healthcare providers is perceived as insufficient by patients and could be strengthened through training and counseling services. The broad scope of tasks and the high level of responsibilities in LVAD aftercare pose challenges for patients and their families, which could be addressed through continuous information and training programs.

This study aimed to evaluate thrombosis and bleeding events in the children implanted with two types of ventricular assist devices (VAD). A total of 26 paediatric end-stage heart failure patients with the mean age of 11.32 ± 4.17 years, 15 were boys, implanted with a VAD, either the Berlin Heart EXCOR (BHE group; n = 9) or the HeartWare (HW group, n = 17), were included in this retrospective study. Follow up data on bleeding events, thrombosis events, bridge-to-transplantation rates and survival outcome were recorded. Overall, 16(33.3%) bleeding events and 32(66.7%) thrombosis events occurred, while 14(53.8%) patients had at least one thrombotic event and 8(30.8%) patients had at least one bleeding event. BHE and HW groups were similar in terms of number of patients with at least one thrombotic (33.3% vs. 64.7%, p = .218) or bleeding (22.2% vs.35.3%, p = .399) event. Mortality occurred in 9(34.6%) patients and 13(50.0%) patients achieved bridge-to-transplantation, similarly in BHE and HW groups (mortality: 44.4% vs. 29.4%, p = .667 and transplantation: 77.8% vs. 35.3%, p = .097). In conclusion, our findings revealed that VAD application in children with heart failure enables successful heart transplantation achievement with an acceptable risk of bleeding/thromboembolic events in most of cases. More advanced VAD technologies and more successful management for haematologic complications are necessary to improve the transplantation rates in children.

Cardiogenic shock (CS) caused by acute myocardial infarction (AMI) accounts for most deaths in the population with AMI and continues to be associated with high short-term mortality. Several temporary mechanical circulatory support (MCS) devices have been developed to treat CS and studied in randomized controlled trials (RCTs) of patients with AMI-CS. Unfortunately, none of these RCTs has demonstrated an improvement in survival with temporary MCS in AMI-CS. Potential reasons for these negative results in RCTs are numerous and reflect the challenges of enrolling critically ill patients with CS. Researchers have used observational study designs to provide insights about outcomes associated with the use of temporary MCS in AMI-CS. These observational studies have yielded conflicting results, in some cases contrary to the results of RCTs. Several limitations pertinent to both RCTs and observational analyses, mostly relating to selection bias and failure to consider unmeasured confounding variables and population heterogeneity, preclude drawing strong inferences regarding the effects of temporary MCS on survival in populations with AMI-CS. Understanding these limitations is essential to correctly interpreting the literature regarding temporary MCS to treat AMI-CS and is necessary to inform the design of future studies that will potentially provide stronger evidence. Optimally matching temporary MCS devices to the needs of individual patients with AMI-CS will presumably be more successful than indiscriminate application in unselected patients. In this review, we discuss the existing literature on temporary MCS to treat AMI-CS and describe the specific challenges that must be overcome to develop an improved evidence base for guiding clinical practice.

BACKGROUND: Von Willebrand factor (VWF) is a critical glycoprotein in hemostasis and is an important factor in diagnosing bleeding disorders. Albeit the analysis of VWF is often compromised by inconsistent methodologies and challenges quantifying multimeric size. Current VWF multimer analysis methods are costly, time-consuming, and often inconsistent; thus, demanding skilled professionals. This study aimed to streamline and optimize the VWF multimer analysis technique, making it more efficient and reproducible, particularly for identifying or predicting mechanical circulatory support (MCS) induced bleeding disorders.
METHODS: Blood samples from healthy volunteers were exposed to high shear forces via a Medtronic HeartWare ventricular assist device. VWF multimers were analyzed using vertical-gel agarose electrophoresis and Western blotting. Differences in VWF distribution were determined using densitometry, and two methods of densitometric analysis were compared: proprietary software against open-source software.
RESULTS: Using the developed method: (i) protocol duration was accelerated from three days (in classical methods) to ~ eight hours; (ii) the resolution of the high molecular weight (HMW) VWF multimers were substantially improved; and (iii) densitometric analysis tools were validated. Additionally, the densitometry analysis using two software types showed a strong correlation between results, with the proprietary software reporting slightly higher HMW VWF percentages.
CONCLUSIONS: This methodology is recommended for affordable, accurate, and reproducible VWF multimer evaluations during MCS use and testing. Further research comparing this method with semi-automated methods would provide additional insight and improve inter-laboratory comparisons.

UNASSIGNED: In view of the role of mechanical circulatory support in patients with severe cardiac insufficiency during perioperative period, we searched the relevant articles on mechanical circulatory support at Fuwai Hospital, and analyzed the indications and complications of different mechanical circulatory support methods.
UNASSIGNED: Relevant studies were identified by computerized searches of PubMed, Ovid, Embase, Cochrane Library, Wanfang Data, VIP Data, Chinese BioMedical Literature & Retrieval System (SinoMed), and China National Knowledge Infrastructure (CNKI), using search words (\"intra-aortic balloon counter pulsation\" OR \"IABP\" OR \"extracorporeal membrane oxygenation\" OR \"ECMO\" OR \"ventricular assist device\" OR \"VAD\") AND (\"Fuwai\" OR \"fuwai\"). All studies concerning the application of IABP, ECMO, and VAD at Fuwai Hospital were included, exclusion criteria included: (1) studies published as review, case report or abstract; (2) animal or cell studies; (3) duplicate publications; (4) studies lacking information about outcomes of interest.
UNASSIGNED: A total of 36 literatures were selected for analysis. The specific mechanical circulatory support methods of ECMO and VAD retrieved from the studies were VA-ECMO and LVAD. The number of cases using IABP, ECMO, LVAD was 1968, 972, 67; and the survival rate was 80.4%, 54.9%, 56.7%, respectively. The major complications of IABP, ECMO and LVAD were hemorrhage (1.2%, 35.9% and 14.5%), infection (3.7%, 12.7% and 9.7%), acute kidney injury (9.1%, 29.6% and 6.5%), the secondary complications were limb ischemia, neurological events, cardiovascular events and thrombosis.
UNASSIGNED: The present study suggested that, IABP, ECMO and VAD, either alone or in combination, were effective and safe mechanical circulation support when managing cardiovascular surgical patients with severe hemodynamic instability at Fuwai Hospital.