Pediatric Ventricular Assist Device Research Articles

Predicting Stroke For Pediatric Patients Supported With Ventricular Assist Devices:A PEDIMACS Report

PEDIMACS provides detailed understanding on pediatric patients supported with ventricular assist devices (VADs). We sought to identify important variables affecting the incidence of stroke in pediatric VADs. Between 2012-2022, 1,463 devices in 1,219 patients were reported to PEDIMACS s from 40 Centers in patients<19yrs at their first VAD implantation. Multiphase parametric hazard modeling was used to identify risk factors for stroke among all device types. Of the 1,219 patients, the most common devices were implantable continuous (472 [39%]), followed by paracorporeal pulsatile (342 [28%]), paracorporeal continuous (327 [27%]). Overall freedom from stroke at 6 months was higher in the recent era (2012-2016; 80.2% [77.1%-82.9%] vs 2017-2023; 87.9% [86.2%-89.4%], p=0.009). Implantable Continuous had the highest freedom from stroke at 3 (92.7% [91.1%-93.9%]) and 6 (91.1% [89.3%-92.6%]) months, followed by Paracorporeal Pulsatile (87.0% [84.8%-88.9%] and 82.8% [79.8%-85.5%]), and Paracoporeal Continuous (76.0% [71.8%-79.5%] and 69.5% [63.4%-74.8%]). Parametric modeling identified risk factors for stoke early post implant and later. Overall, and particularly for Paracorporal Pulsatile devices, early stroke risk has decreased in the most recent era (HR 5.01). Among Implantable Continuous devices, cardiogenic shock was the major risk factor. For patients<10kg, early hazard was only seen in previous era. For congentail patients, early hazard was seen in non-implantable device use and use of ECMO. Overall stroke rate has decreased from 20% to 15% at 6 months, with particular improvement among PP devices. Risk factor analyses offer insights for identification of higher stroke risk subsets and further management refinements.

Impact of inflammation and steroids on anti-coagulation in children supported on a ventricular assist device.

Critically ill pediatric patients supported on ventricular assist devices (VADs) are increasingly being anticoagulated on bivalirudin, but with difficulty monitoring anticoagulation. Activated partial thromboplastin time (aPTT) has recently been shown to poorly correlate with bivalirudin plasma concentrations, while dTT had excellent correlation. However, aPTT is the more common monitoring test and dTT testing is rarely used. In addition, effects of frequent clinical VAD scenarios (such as inflammation) on the accuracy of aPTT and dTT testing remains uncertain. We reviewed the effects of clinical scenarios (infection/inflammation, chylothorax, and steroids administration) on anticoagulation monitoring in 10 pediatric VAD patients less than 3years at Cincinnati Children's Hospital Medical Center from 10/27/2020 to 5/6/2022 using bivalirudin for anticoagulation. There were 16 inflammation/infection, 3 chylothorax, and 6 steroids events. Correlation between dTT and aPTT was significantly lower after infection/inflammation, with dTT increasing prior to inflammation/infection while aPTT remained unchanged. In addition, steroids are administered to VAD patients to reduce inflammation and thus additionally stabilize anticoagulation. However, this anticoagulation stabilization effect was reflected more accurately by dTT compared to aPTT. In children requiring VAD support utilizing bivalirudin anticoagulation, inflammation/infection is a common occurrence resulting in anticoagulation changes that may be more accurately reflected by dTT as opposed to aPTT.

(127) - External Validation of a Risk Score Assessment for Pediatric Ventricular Assist Device Mortality

(127) - External Validation of a Risk Score Assessment for Pediatric Ventricular Assist Device Mortality

(332) - Clinical Outcomes and Complications in Pediatric Ventricular Assist Devices Implanted as Bridge to Candidacy

(332) - Clinical Outcomes and Complications in Pediatric Ventricular Assist Devices Implanted as Bridge to Candidacy

(1367) - Influence of Steroid Administration on Inflammatory and Hematologic Parameters in Pediatric VAD Inflammation

(1367) - Influence of Steroid Administration on Inflammatory and Hematologic Parameters in Pediatric VAD Inflammation

(1333) - Patient-Reported Outcomes in Pediatric VAD Recipients: ACTION Findings Stratified by Device

(1333) - Patient-Reported Outcomes in Pediatric VAD Recipients: ACTION Findings Stratified by Device

Current status and future directions in pediatric ventricular assist device.

A ventricular assist device (VAD) is a form of mechanical circulatory support that uses a mechanical pump to partially or fully take over the function of a failed heart. In recent decades, the VAD has become a crucial option in the treatment of end-stage heart failure in adult patients. However, due to the lack of suitable devices and more complicated patient profiles, this therapeutic approach is still not widely used for pediatric populations. This article reviews the clinically available devices, adverse events, and future directions of design and implementation in pediatric VADs.

Exploring Liposomal Systems for Gallic Acid and Tannic Acid Delivery: Potential Strategies to Address Inflammation and Infections in Pediatric Ventricular Assist Device Recipients

Exploring Liposomal Systems for Gallic Acid and Tannic Acid Delivery: Potential Strategies to Address Inflammation and Infections in Pediatric Ventricular Assist Device Recipients

Abstract 12339: Erythropoietin Use in Pediatric Ventricular Assist Device Patients

Background: Anemia is common in pediatric ventricular assist device (VAD) patients. Erythropoietin (EPO) has been used to reduce blood transfusions in children after VAD placement. A study in adults showed EPO use after left VAD implantation was associated with higher rates of suspected pump thrombosis. No studies have evaluated the use of EPO in pediatric patients receiving VAD support. Objectives: We aim to assess EPO use in all pediatric patients who underwent placement of a VAD and to assess outcomes for children who received EPO compared to those who did not. Methods: We identified patients from the Pediatric Health Information System who underwent VAD placement from 2010-2020. Use of EPO was described across all sites. Cohorts were compared to assess differences in blood transfusions received post-VAD, incidence of stroke and pump-exchange. Multivariable Cox proportional hazard and logistic regression models were constructed to adjust for confounding factors for outcomes of VAD exchange and stroke, respectively. Results: A total of 1260 patients were included, of which 336 (27%) received EPO. Patients who received EPO were younger (median 3.5y vs. 9y, p&lt;0.001) and more likely to have congenital heart disease (55% vs. 45%, p=0.002). Patients on EPO received fewer blood transfusions compared to those not on EPO [median 0/month (IQR 0-0.9) vs. 0/month (IQR 0-2.3), p&lt;0.001]. VAD exchange and stroke were more common in patients on EPO (10.1% vs. 5.5%, p=0.004 and 37.8% vs. 25%, p&lt;0.001, respectively). After adjusting for confounding factors, the use of EPO was not independently associated with the need for VAD exchange (adjusted hazard ratio 1.2, 95% confidence 0.78 - 1.9, p=0.378). However, EPO remained independently associated with stroke during the hospitalization (adjusted hazard ratio 1.6, 95% confidence 1.2 - 2.1, p=0.002). Conclusion: EPO was used in approximately 1 out of 4 pediatric VAD patients. Those who received EPO were younger and more likely to have congenital heart disease. The use of EPO is associated with fewer post-VAD blood transfusions. EPO was not independently associated with VAD exchange but remained independently associated with stroke during the VAD hospitalization.

Magnetically Levitated Pediatric Ventricular Assist Device with Compact Self-Bearing Motor

Magnetically Levitated Pediatric Ventricular Assist Device with Compact Self-Bearing Motor

One Size Does Not Fit All: The Story of Pediatric Ventricular Assist Devices!

One Size Does Not Fit All: The Story of Pediatric Ventricular Assist Devices!

Starting Pediatric VAD Program: Transforming Challenges into Opportunities; A Case Series of a Single Center

Background: The prevalence of heart failure is constantly increasing in both children and adults. End-stage heart failure in children unresponsive to medical therapy has limited treatment options. Surgical options include heart transplantation or implantation of durable ventricular assist devices (VADs). To start the VAD program, it was necessary to train core team members, invite experienced proctors and adjust the organizational approach. Methods: We present our first seven pediatric patients who underwent a VAD implantation with primary indication end-stage dilated cardiomyopathy. Results: The median age on implant was four and a half years and the median duration of VAD support was 39 days with long term survival achieved in three patients. The causes of death were multiorgan failure, thromboembolic events, sepsis, and low cardiac output syndrome. Ischemic stroke was the reason for successful neurointervention during VAD support in two patients. Conclusions: To establish a VAD program, numerous specialties must be included with adequate training and learning for all team members.

Effect of Hematocrit and Elevated Beat Rate on the 12cc Penn State Pediatric Ventricular Assist Device.

Congenital heart disease affects approximately 40,000 infants annually in the United States with 25% requiring invasive treatment. Due to limited number of donor hearts and treatment options available for children, pediatric ventricular assist devices (PVADs) are used as a bridge to transplant. The 12cc pneumatic Penn State PVAD is optimized to prevent platelet adhesion and thrombus formation at patient nominal conditions; however, children demonstrate variable blood hematocrit and elevated heart rates. Therefore, with pediatric patients exhibiting greater variability, particle image velocimetry is used to evaluate the PVAD with three non-Newtonian hematocrit blood analogs (20%, 40%, and 60%) and at two beat rates (75 and 120 bpm) to understand the device's performance. The flow fields demonstrate a strong inlet jet that transitions to a solid body rotation during diastole. During systole, the rotation dissipates and reorganizes into an outlet jet. This flow field is consistent across all hematocrits and beat rates but at a higher velocity magnitude during 120 bpm. There are also minor differences in flow field timing and surface washing due to hematocrit. Therefore, despite patient differences in hematocrit or required pumping output, thorough surface washing can be achieved in the PVAD by altering operating conditions, thus reducing platelet adhesion potential.

Survival in Pediatric Patients With Ventricular Assist Devices: A Special Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Report

BackgroundThe Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) provides detailed understanding on pediatric patients supported with ventricular assist devices (VADs). We sought to identify important variables affecting mortality in pediatric VADs. MethodsPatients aged <19 years, from 2012 to 2021, were included. Survival analyses were performed using Kaplan-Meier. Parametric hazard modeling was used to identify risk factors for death. ResultsOf the 1109 patients, the most common devices were implantable continuous (IC, 448 [40%]), followed by paracorporeal pulsatile (PP, 306 [28%]), paracorporeal continuous (PC, 293 [26%]), and percutaneous (58 [5%]). Patients with percutaneous device, infants, congenital heart disease, biventricular support, and Interagency Registry for Mechanically Assisted Circulatory Support profile 1 had worse overall survival at 6 months. Positive outcome was 83% at 6 months. Consistent with their cohort composition, device type positive outcomes at 6 months were IC, 92%; PP, 84%; and PC, 69%. Parametric hazard modeling for overall survival showed an early hazard for death with biventricular support, congenital heart disease (CHD), intubation before implantation, PC device, and renal impairment, whereas a constant hazard was associated with ascites. For patients <10 kg, parametric modeling showed an early hazard for CHD, intubation, and renal impairment. Modeling in CHD patients showed an early hazard for biventricular support, renal impairment, and use of PC/PP devices. ConclusionsThis multivariable analysis of the complete Pedimacs database demonstrates that illness at VAD implantation, diagnosis, and strategy of support affect survival and differ by device type. We hope this is the first step in creating a predictive tool to help providers and families have informed expectations.

Prospective examination of HLA sensitization after VAD implantation in children and adults

BackgroundVentricular assist devices (VADs) have improved survival to heart transplantation (HTx). However, VADs have been associated with development of antibodies against human leukocyte antigen (HLA-Ab) which may limit the donor pool and decrease survival post-HTx. Since HLA-Ab development after VAD insertion is poorly understood, the purpose of this prospective single-center study was to quantify the incidence of and evaluate risk factors for HLA-Ab development across the age spectrum following VAD implantation. MethodsAdult and pediatric patients undergoing VAD placement as bridge to transplant or transplant candidacy between 5/2016 and 7/2020 were enrolled. HLA-Ab were assessed pre-VAD and at 1-, 3-, and 12-months post-implant. Factors associated with HLA-Ab development post-VAD implant were explored using univariate and multivariate logistic regression. Results15/41 (37%) adults and 7/17 (41%) children developed new HLA-Ab post-VAD. The majority of patients (19/22) developed HLA-Ab within two months of implant. New class I HLA-Ab were more common (87% adult, 86% pediatric). Prior pregnancy was strongly associated with HLA-Ab development in adults post-VAD (HR 16.7, 95% CI 1.8–158, p = 0.01). Of the patients who developed new HLA-Ab post-VAD, in 45% (10/22) the HLA-Ab resolved while in 55% (12/22) the HLA-Ab persisted. ConclusionMore than one-third of adult and pediatric VAD patients developed new HLA-Ab early after VAD implant with the majority having class I antibodies. Prior pregnancy was strongly associated with post-VAD HLA-Ab development. Further studies are needed to predict regression or persistence of HLA-Ab developed post-VAD, to understand modulation of individuals' immune responses to sensitizing events, and to determine whether transiently detected HLA-Ab post-VAD recur and have long-term clinical impact post-heart transplantation.

BIO19: Patient-Specific Econotherapeutic Closed-Clinician/Engineer-in-the-loop Framework for VAD Physiological Control

Background: Mechanical circulatory support therapy essentially restricts patients to the hospital. Numerous clinical publications and national/international presentations indicate the need for early patient discharge, both from a quality of life and economic viewpoint. An alternative strategy is to look at providing time-appropriate VAD support to temporize patients for transplantation or other definitive therapy. However, current VAD systems do not possess high-level feedback control targeting therapy-specific objectives. Current Controllers (i) operate in open-loop fixed-average-speed mode (do not adjust to match physiological demand or cardiac function) and (ii) have minimal ability to assess and respond to adverse events. Therefore, our group is embarking on developing an Intelligent VAD ControllerTM (iVC™) with advanced, modern features that address the deficits of prevailing technologies. Methods: As an initial step towards the design of an Intelligent VAD ControllerTM (iVC™), we developed an Econotherapeutic framework based on concepts of modern control theory, inter-operator communication (Kanban Method), and industrial supply-demand management (Tanpin-Kanri System). The design inputs included considerations for 1. collaboration of clinician and engineer; 2. patient-specific therapeutic goals; 3. fusion of multiple control objectives; 4. non-invasive monitoring of the patient and hardware, and 5. considerations of the financial/resource cost. From the perspective of a control problem, we extend the engineering theory behind its implementation by including, in our framework, the therapy and healthcare protocols to the control problem as constraints. Results: The resulting Econotherapeutic framework is depicted schematically in Figures 1 and 2 below. Figure 1 outlines the framework’s architecture, which includes two sub-frameworks: Therapeutic and Economical. The outlines of the framework’s functions are provided to optimize patient-specific therapy and follow-up and the economic burden of care and control. Figure 2 outlines the inter-operator communication (inspired by Kanban Methods) protocols that form the basis for the framework in terms of roles and responsibilities, design aspects of the control, and implementation steps (including support). The framework addresses the design inputs with the outlines mentioned in Figure 1 as to what the framework addresses, with the implementation of the framework specific to a patient carried out by the protocols outlined in Figure 2. Conclusion: A VAD closed-loop physiological control is, in essence, a multi-disciplinary optimization problem driven by both medical and engineering considerations. The econotherapeutic framework derived above provides a framework for developing an iVC. We will now proceed to develop, in conjunction with clinicians, the possible details of the framework and, using The PediaFlowTM Pediatric VAD, conduct feasibility studies of the iVC that tests the framework.Figure 1. Architecture of the Econotherapeutic FrameworkFigure 2. The Design, Management and Monitoring Communication protocols of the Econotherapeutic Framework for iVC for every individual patient.

Taking ACTION: A Prognostic Tool for Pediatric Ventricular Assist Device Mortality.

We sought to develop a contemporary risk assessment tool for use in pediatric ventricular assist device (VAD) candidates to estimate risk for mortality on the device using readily available preimplantation clinical data. Training and testing datasets were created from Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry data on patients supported with a VAD from 2012 to 2021. Potential risk factors for mortality were assessed and incorporated into a simplified risk prediction model utilizing an open-source, gradient-boosted decision tree machine learning library, known as random forest. Predictive performance was assessed by the area under the receiver operating characteristic curve in the testing dataset. Nine significant risk factors were included in the final predictive model which demonstrated excellent discrimination with an area under the curve of 0.95. In addition to providing a framework for establishing pediatric-specific risk profiles, our model can help inform team expectations, guide optimal patient selection, and ultimately improve patient outcomes.

(94) Social Determinants of Heath and Outcomes after Pediatric Ventricular Assist Device Implantation

(94) Social Determinants of Heath and Outcomes after Pediatric Ventricular Assist Device Implantation

(1036) Through the "Chimney": Berlin Heart Excor Pediatric Ventricular Assist Device Inflow Stenting via a Novel Direct Access to Inflow Tubing

(1036) Through the "Chimney": Berlin Heart Excor Pediatric Ventricular Assist Device Inflow Stenting via a Novel Direct Access to Inflow Tubing

Cost-effectiveness of bivalirudin in pediatric ventricular assist devices.

Despite recent data suggesting improved outcomes with bivalirudin vs heparin in pediatric Ventricular assist devices (VAD), higher costs remain a barrier. This study quantified trends in bivalirudin use and compared outcomes, resource utilization, and cost-effectiveness associated with bivalirudin vs heparin. Children age 0 to 6 year who received VAD from 2009 to 2021 were identified in Pediatric Health Information System. Bivalirudin use was evaluated using trend analysis and outcomes were compared using Fine-Gray subdistrubtion hazard ratios (SHR). Daily-level hospital costs were compared due to differences in length of stay. Cost-effectiveness was evaluated using incremental cost-effectiveness ratio (ICER). Of 691 pediatric VAD recipients (median age 1 year, IQR 0-2), 304 (44%) received bivalirudin with 90% receiving bivalirudin in 2021 (trend p-value <0.01). Bivalirudin had lower hospital mortality (26% vs 32%; adjusted SHR 0.57, 95% CI 0.40-0.83) driven by lower VAD mortality (20% vs 27%; adjusted SHR 0.46, 95% CI 0.32-0.77) after adjusting for year, age, diagnosis, and center VAD volume. Post-VAD length of stay was longer for bivalirudin than heparin (median 91 vs 64 days, respectively, p < 0.001). Median daily-level costs were lower among bivalirudin (cost ratio 0.87, 95% CI 0.79-0.96) with higher pharmacy costs offset by lower imaging, laboratory, supply, and room/board costs. Estimated ICER for bivalirudin vs heparin was $61,192 per quality-adjusted life year gained with a range of $27,673 to $131,243. Bivalirudin use significantly increased over the past decade and is now used in 90% young pediatric VAD recipients. Bivalirudin was associated with significantly lower hospital mortality and an ICER <$65,000, making it a cost-effective therapy for pediatric VAD recipients.