Self-management with the therapeutic regimen in patients with ventricular assist device (VAD) support - a scoping review

BACKGROUND

Ventricular assist device (VAD) implantation has become an established treatment strategy for the increasing number of patients with advanced heart failure. Adequate patient self-management becomes essential to prevent adverse events, which could diminish expected outcomes and survival for patients on VAD support.

OBJECTIVES

The aim of this study was to provide an overview of the current state of evidence concerning self-management in VAD patients through a systematized search and mapping of the literature.

METHODS

Following the scoping review process, a comprehensive literature search (PubMed, PsychInfo), tabular synthesis of included articles, and data analysis of synthesized findings were performed.

RESULTS

Overall, twenty articles were included. Results describe the complexity of regular self-management tasks and give direction for specific self-management training.

CONCLUSIONS

This article represents the first comprehensive overview of available evidence suggesting the need for development and implementation of evidence-based, patient self-management curricula with therapeutic regimen for VAD patients.

Using existing technology better: Improving outcomes with the HeartWare left ventricular assist device

BACKGROUND

The HeartWare left ventricular assist device has been in use for over 12 years. We sought to determine how outcomes at our centre have improved over time.

METHODS

Review of electronic hospital records at the Freeman Hospital, Newcastle upon Tyne, United Kingdom.

RESULTS

A total of 255 first time adult implants were divided into 2 eras: Era 1: 2009-2015 (N = 154) and Era 2: 2016-2020 (N = 101). We prospectively aimed to avoid higher risk Intermacs Classifications in Era 2, which resulted in significant changes in Intermacs class to lower risk in Era 2 (P < 0.001). There was a significant improvement in survival in Era 2, with 1 year survival increasing from 70 to 80% (P < 0.05). This was particularly associated with lower 30 day mortality in Era 2 (1.7 ± 2.3 vs 15.5 ± 7%, P < 0.005). This was associated with better right ventricular function in Era 2, and there was a trend to more temporary right ventricular assist devices used in Era 2 (28 ± 13 vs 12 ± 14%, P = 0.06). Deaths from intracranial haemorrhage, sepsis and right heart failure were unchanged between eras, though there was a trend towards less deaths in Era 2 from combined thromboses deaths (stroke and device thrombosis; 3.3 ± 5.4 vs 11.1 ± 7.4%, P = 0.07).

CONCLUSIONS

Better patient selection in association with more use of temporary right ventricular assist support has resulted in a significant improvement in survival. Intracranial haemorrhage, sepsis and right heart failure remain significant problems.

Role of Cardiac Rehabilitation After Ventricular Assist Device Implantation

Patients with heart failure suffered by a complex syndrome, where the filling of the ventricle or ejection of the blood is impaired. In this setting, the exercise capacity decreases for many reasons, one of them being the insufficient oxygen transfer due to reduced cardiac output and anemia. Ventricular assist device has emerged as a durable and safe therapy for patients with end-stage heart failure. The benefits of cardiac rehabilitation in ventricular assist device patients are enormous: the first aim is to progressively reduce the physical and functional impairments of these patients, so that they will be able to resume meaningful daily activities.

Extracorporeal membrane oxygenation-assisted emergency percutaneous treatment of left ventricular assist device graft occlusion

End‐stage heart failure is more often treated with Implantable left ventricular assist device (LVAD), even if the prolonged use may increase the risk of complications. In this case, a 51‐year‐old male patient presented to our emergency department showing acute heart failure signs and symptoms and a dramatic reduction of LVAD flow. Laboratory tests ruled out significant haemolysis, usually associated with pump thrombosis. The echocardiogram and the computed tomography were not able to clarify the correct diagnosis. We immediately placed a veno‐arterial extracorporeal membrane oxygenation, followed by a selective retrograde angiography of the pump. The images showed stenosis of the LVAD‐outflow graft, suggesting a twist. Through a hand‐made J‐tip guidewire, we performed multiple dilatations of the occlusion using peripheral balloons. Finally, we implanted an aortic coarctation covered‐stent, re‐establishing an adequate cardiac output to the patient. Our case indicates that catheter‐based approach in extracorporeal membrane oxygenation assistance provides an important therapeutic alternative to treat outflow graft stenosis, especially in the case of acutely unstable patient.

Device-based treatment options for heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a syndrome with an unfavorable prognosis, and the number of the patients continues to grow. Because there is no effective therapy established as a standard, including pharmacological treatments, a movement to develop and evaluate device-based therapies is an important emerging area in the treatment of HFpEF patients. Many devices have set their target to reduce the left atrial pressure or pulmonary capillary wedge pressure because they are strongly related to the symptoms and prognosis of HFpEF, but the methodology to achieve it varies based on the devices. In this review, we summarize and categorize these devices into the following: (1) interatrial shunt devices, (2) left ventricle expander, (3) electrical therapy, (4) left ventricular assist devices, and (5) mechanical circulatory support devices under development. Here, we describe the features and specifications of device-based therapies currently under development and those at more advanced stages of preclinical testing. Advantages and limitations of these technologies, with insights on their safety and feasibility for HFpEF patients, are described.

Production of erythrocyte microparticles in a sub-hemolytic environment

Microparticles are produced by various cells due to a number of different stimuli in the circulatory system. Shear stress has been shown to injure red blood cells resulting in hemolysis or non-reversible sub-hemolytic damage. We hypothesized that, in the sub-hemolytic shear range, there exist sufficient mechanical stimuli for red blood cells to respond with production of microparticles. Red blood cells isolated from blood of healthy volunteers were exposed to high shear stress in a microfluidic channel to mimic mechanical trauma similar to that occurring in ventricular assist devices. Utilizing flow cytometry techniques, both an increase of shear rate and exposure time showed higher concentrations of red blood cell microparticles. Controlled shear rate exposure shows that red blood cell microparticle concentration may be indicative of sub-hemolytic damage to red blood cells. In addition, properties of these red blood cell microparticles produced by shear suggest that mechanical trauma may underlie some complications for cardiovascular patients.

Clinical Outcomes, Trends in Weight, and Weight Loss Strategies in Patients With Obesity After Durable Ventricular Assist Device Implantation

PURPOSE OF REVIEW

To discuss clinical outcomes, changes in weight, and weight loss strategies of patients with obesity post left ventricular assist device (LVAD) implantation.

RECENT FINDINGS

Despite increased complications in patients with obesity after LVAD implantation, survival is comparable to patients without obesity. A minority of patients with obesity lose significant weight and become eligible for heart transplantation after LVAD implantation. In fact, a great majority of such patients gain weight post-implantation. Obesity by itself should not be considered prohibitive for LVAD therapy but, rather, should be incorporated into the overall risk assessment for LVAD implantation. Concerted strategies should be developed to promote sustainable weight loss in patients with obesity and LVAD to improve quality of life, eligibility, and outcomes after heart transplantation. Investigation of the long-term impact of weight loss on patients with obesity with LVAD is warranted.

Emergent Percutaneous Closure of a Free-Wall Perforation During Impella Implantation

Free wall perforation during percutaneous manipulation of devices and wires into the ventricular cavities is an uncommon but life-threatening complication that should be managed with emergent surgery whenever possible. However, the number of patients with prohibitive surgical risk that undergo complex percutaneous cardiac procedures is increasing. Some cases of ventricle perforation during Impella® (Abiomed; Danvers, MA) implantation have been previously reported but in all previous reported cases the patient underwent emergent surgery. We present a case of iatrogenic perforation during Impella® implantation that was emergently treated using an Amplatzer® Duct Occluder II device (Abbott Vascular; Santa Clara, CA).

Switch from minimally invasive biventricular mechanical support to cardiopulmonary bypass during heart transplant

An easily reproducible surgical technique to switch from percutaneous minimally invasive biventricular mechanical support to cardiopulmonary bypass during heart transplantation is illustrated. After cannulation of the distal ascending aorta with a standard arterial cannula, the ProtekDuo® cannula and the ProtekSolo® Transseptal cannula were partially retracted to reach the superior and inferior vena cava, respectively, and connected to the pump circuit for the venous drainage. With this cardiopulmonary bypass configuration, orthotopic heart transplantation was routinely performed and, at the end of the procedure, the 2 cannulas were uneventfully removed.

Successful papillary muscle approximation for severe mitral regurgitation via apical cuff hole in HeartMate 3 implantation via left anterior thoracotomy

We herein report a case of successful papillary muscle approximation for severe mitral regurgitation and HeartMate 3 left ventricular assist device implantation via left anterior thoracotomy in a 39-year-old man diagnosed with dilated cardiomyopathy. He underwent papillary muscle approximation in the mitral valve for severe functional regurgitation via the apical cuff hole. The postoperative course was uneventful. Echocardiography revealed that mitral regurgitation has disappeared. He was awaiting heart transplantation while working.

Neurologic complications of implantable devices

Technologies for repairing cardiac structures or sustaining cardiac function with implantable devices have helped patients with an ever-expanding array of cardiac conditions. Patients are surviving and thriving with cardiac conditions that would formerly have been disabling or fatal. With the implantation of devices in the heart, however, comes the inevitable risk of neurological complications. This chapter focuses on devices implanted in the chambers or valves of the heart itself, including prosthetic heart valves, closure devices for patent foramen ovale, atrial appendage occluder devices, short-term implantable circulatory assist devices, and long-term ventricular assist devices, but excluding coronary artery stents or extracardiac devices. Further, it considers the procedural and postprocedural risks of the devices, leaving the discussion of clinical effectiveness of the devices to other chapters of this book.

Mechanical Support for The Failing Single Ventricle at Pre-Fontan Stage: Current State of The Field and Future Directions

With the substantial growth of pediatric ventricular assist device (VAD) support, there has been an expansion of the target population towards more complex patients, including congenital heart disease (CHD) with single ventricle (SV) physiology. The outcomes of Stage I and Stage II SV-CHD patients on VAD support from the Pedimacs database are poor, with less than 50% survival on VAD by the 3-month mark in both. The primary objective of this article is to describe the current state of VAD support for the failing Stage I and II SV-CHD circulation, to provide insight into potential areas of outcome improvement. We reviewed the published literature in the form of database and registry reports as well as single-center studies to discuss the outcomes of Stage I and Stage II SV-CHD patients on VAD support. Registry-based studies suggest that VAD support for the failing Stage I and Stage II SV-CHD circulations is challenging. However, the more promising outcomes in several single-institutional reports for both Stage I and Stage II SV-VAD indicate that the grim picture from the databases does not reflect the best outcomes that are possible to be achieved, potentially at experienced centers with higher volumes. Areas of future study and potential improvement including timely initiation of VAD support in the cohort of patients expected to not be a candidate for standard SV palliations, pump selection and the benefits of continuous-flow devices, and the decision-making for setting up the optimum circulation for VAD support, be it Fontan completion if feasible or takedown to shunt physiology.

Mechanical Circulatory Support for the Failing Sub-Aortic Right Ventricle in Adults

Patients with ccTGA or d-TGA managed via atrial switch (Mustard or Senning operations) have biventricular circulations with a sub-aortic right ventricle (2V-RV). Other than in a tiny percentage of ccTGA patients, premature heart failure (HF) is common, driven by chronic RV dilatation and dysfunction and/or tricuspid regurgitation. These patients are different from the general HF population in that they are younger, more heterogeneous, are predisposed to pulmonary hypertension and present unique and complex surgical challenges. Despite their young age, they experience disproportionately poor access to advanced therapies and are often disqualified for transplant by pulmonary hypertension, HLA sensitization, program risk-tolerance and psychosocial issues. Mechanical support of the subaortic RV with ventricular assist device (subaortic RVAD, also known as SVAD), although technically challenging, can be an effective alternative to palliative care and offers high likelihood of bridging patients to heart transplant candidacy. In addition, temporary trans-catheter SVAD Impella support has been advantageous for stabilization of decompensated 2V-RV patients or as bridge to durable SVAD support. Improved awareness of and access to specialist ACHD-HF teams offering mechanical support (and transplantation) for 2V-RV patients is increasingly urgent for this aging population, and will improve options and outcomes for these patients as HF emerges.

The Human Explanted Heart Program: A translational bridge for cardiovascular medicine

The progression of cardiovascular research is often impeded by the lack of reliable disease models that fully recapitulate the pathogenesis in humans. These limitations apply to both in vitro models such as cell-based cultures and in vivo animal models which invariably are limited to simulate the complexity of cardiovascular disease in humans. Implementing human heart tissue in cardiovascular research complements our research strategy using preclinical models. We established the Human Explanted Heart Program (HELP) which integrates clinical, tissue and molecular phenotyping thereby providing a comprehensive evaluation into human heart disease. Our collection and storage of biospecimens allow them to retain key pathogenic findings while providing novel insights into human heart failure. The use of human non-failing control explanted hearts provides a valuable comparison group for the diseased explanted hearts. Using HELP we have been able to create a tissue repository which have been used for genetic, molecular, cellular, and histological studies. This review describes the process of collection and use of explanted human heart specimens encompassing a spectrum of pediatric and adult heart diseases, while highlighting the role of these invaluable specimens in translational research. Furthermore, we highlight the efficient procurement and bio-preservation approaches ensuring analytical quality of heart specimens acquired in the context of heart donation and transplantation.

Insertion of a biventricular assist device

This video tutorial demonstrates the insertion of a temporary biventricular assist device as a bridge to a heart transplant in a patient with end-stage heart failure with decompensation and increasing pulmonary pressure . This technique utilizes cardiopulmonary bypass to maintain hemodynamic stability throughout the procedure. Transesophageal echocardiography is used to guide the correct positioning of the ventricular cannulae. The cannulation sites include the right ventricle and the pulmonary artery for the right ventricular assist device and the left ventricular apex and the ascending aorta for the left ventricular assist device. The patient is weaned off cardiopulmonary bypass as the biventricular assist device flows are increased to the desired level. Following chest closure, the patient can be ambulatory with the device in situ.

Financial implications of using extracorporeal membrane oxygenation following heart transplantation

OBJECTIVES

Primary graft dysfunction after heart transplant is associated with high morbidity and mortality. Extracorporeal membrane oxygenation (ECMO) can be used to wean patients from cardiopulmonary bypass. This study retrospectively reviews a single-centre experience of post-transplant ECMO in regard to outcomes and associated costs.

METHODS

Between May 2006 and May 2019, a total of 267 adult heart transplants were performed. We compared donor and recipient variables, ECMO duration and the incidence of renal failure, bleeding, infection and cost analysis between ECMO and non-ECMO groups.

RESULTS

ECMO support was required postoperatively to manage primary graft dysfunction in 72 (27%) patients. The mean duration of ECMO support was 6 ± 3.2 days. Mean ischaemic times were similar between the groups. There was a significantly higher proportion of ventricular assist device explant to transplant in the ECMO group versus non-ECMO (38.2% vs 14.1%; P < 0.0001). ECMO patients had a longer duration of stay in the intensive care unit (P < 0.0001) and total hospital stay (P < 0.0001). Greater mortality was observed in the ECMO group (P < 0.0001). The median cost of providing ECMO was £18 000 [interquartile range (IQR): £12 750-£24 000] per patient with an additional median £35 225 (IQR: £21 487.25-£51 780.75) for ITU stay whilst on ECMO. The total median cost per patient inclusive of hospital stay, ECMO and dialysis costs was £65 737.50 (IQR: £52 566.50-£95 221.75) in the non-ECMO group compared to £145 415.71 (IQR: £102 523.21-£200 618.96) per patient in the ECMO group (P < 0.0001).

CONCLUSIONS

Patients with primary graft dysfunction following heart transplantation who require ECMO are frequently bridged to a recovery; however, the medium and longer-term survival for these patients is poorer than for patients who do not require ECMO.

Ultrasound-based prediction of interventricular septum positioning during left ventricular support-an experimental study

The implantation of left ventricular assist devices (LVADs) is often complicated by arrhythmias and right ventricular failure (RVF). Today, the pump speed is titrated to optimize device support using single observations of interventricular septum (IVS) positioning with echocardiographic ultrasound (US). The study demonstrates the applicability of three integrated US transducers in the LVAD cannula to monitor IVS positioning continuously and robustly in real time. In vitro, the predictor of the IVS shift shows an overall prediction error for all volume states of less than 20% and provides a continuous assessment for 99% of cases in four differently sized heart phantoms. The prediction of IVS shift depending on the cannula position is robust for azimuthal and polar deviations of ± 20° and ± 8°, respectively. This intracardiac US concept results in a viable predictor for IVS positioning and represents a promising approach to continuously monitor the IVS and ventricular loading in LVAD patients. Graphical abstract.

"BAX602" in Preventing Surgical Adhesion after Extracorporeal Ventricular Assist Device Implantation for Refractory Congestive Heart Failure: Study Protocol for a Multicenter Randomized Clinical Trial

BACKGROUND

The high surgical risk in redo cardiac surgery is largely attributed to adhesions around the epicardium and the great vessels. BAX602 is an adhesion prevention reagent composed of two synthetic polyethylene glycols. Spraying BAX602 over the epicardium and the great vessels reportedly contributes to adhesion prevention after pediatric cardiac surgery. The present study aims to evaluate the safety and effectiveness of BAX602 spray in patients undergoing extracorporeal ventricular assist device implantation surgery to treat refractory congestive heart failure.

METHODS AND DESIGN

This investigator-initiated, multicenter, pivotal, two-arm, open-label, randomized trial will include a total of 30 patients. The primary outcome measure is the severity of adhesions, which will be evaluated during re-sternotomy surgery performed 2-12 weeks after the primary extracorporeal ventricular assist device implantation surgery. The adhesion severity will be evaluated at five predefined sites using a four-grade adhesion evaluation score (0 = no adhesion; 1 = filmy and avascular adhesion; 2 = dense/vascular adhesion; 3 = cohesive adhesion). This measure will be summarized in two ways to evaluate the effect of BAX602: (1) the total score of the severity of adhesions at all five sites (ranging from 0 to 15), and (2) the total number of sites with dense/vascular or cohesive adhesions (ranging from 0 to 5).

ETHICS AND DISSEMINATION

The study findings will be disseminated at regional, national, and international conferences and through peer-reviewed scientific journals.

TRIAL REGISTRATION

The trial was registered in the UMIN Clinical Trials Registry (UMIN-CTR: UMIN000038998) on 6 January 2020.

Effects of left ventricular assist device on pulmonary functions and pulmonary hemodynamics: A meta-analysis

BACKGROUND

Given current evidence, the effect of left ventricular assist device (LVAD) implantation on pulmonary function tests remains controversial.

AIM

To better understand the factors contributing to the changes seen on pulmonary function testing and the correlation with pulmonary hemodynamics after LVAD implantation.

METHODS

Electronic databases were queried to identify relevant articles. The summary effect size was estimated as a difference of overall means and standard deviation on a random-effects model.

RESULTS

A total of four studies comprising 219 patients were included. The overall mean forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and diffusion lung capacity of carbon monoxide (DLCO) after LVAD implantation were significantly lower by 0.23 L (95%CI: 0.11-0.34, P = 00002), 0.18 L (95%CI: 0.03-0.34, P = 0.02), and 3.16 mmol/min (95%CI: 2.17-4.14, P < 0.00001), respectively. The net post-LVAD mean value of the cardiac index was significantly higher by 0.49 L/min/m² (95%CI: 0.31-0.66, P < 0.00001) compared to pre-LVAD value. The pulmonary capillary wedge pressure and pulmonary vascular resistance were significantly reduced after LVAD implantation by 8.56 mmHg (95%CI: 3.78-13.35, P = 0.0004), and 0.83 Woods U (95%CI: 0.11-1.55, P = 0.02), respectively. There was no significant difference observed in the right atrial pressure after LVAD implantation (0.61 mmHg, 95%CI: -2.00 to 3.32, P = 0.65). Overall findings appear to be driven by studies using HeartMateII devices.

CONCLUSION

LVAD implantation might be associated with a significant reduction of the spirometric measures, including FEV1, FVC, and DLCO, and an overall improvement of pulmonary hemodynamics.

Impact of bridge-to-bridge strategies from paracorporeal to implantable left ventricular assist devices on the pre-heart transplant outcome: A single-center analysis of 134 cases

BACKGROUND

In Japan, patients with heart failure who have a paracorporeal left ventricular assist device (pLVAD) and cannot be weaned from the VAD may undergo conversion to implantable continuous-flow LVAD (iLVAD) via a bridge-to-bridge (BTB) strategy for bridge-to-transplantation (BTT). This study aimed to evaluate the real-world clinical status of BTB strategies.

METHODS

Among 134 patients who underwent iLVAD implantation for BTT, 34 patients underwent conversion from pLVAD to iLVAD (BTB group) and 100 patients underwent iLVAD implantation primarily (primary iLVAD group). The clinical characteristics and outcomes were compared between the two groups.

RESULTS

No significant difference was found in the overall survival between the two groups (p = 0.26; log-rank test). However, the 1-year survival rate and the 1-year freedom from the composite events of death, stroke, systemic infection, and bleeding rate were lower in the BTB group than in the primary iLVAD group (survival rate, 88.2% vs. 99.0%, p = 0.0040; composite event-free survival rate, 26.1% vs. 49.8%, p = 0.030; log-rank test). Multivariate analysis indicated that the BTB strategy [hazard ratio (HR) 1.70, 95% confidence intervals (CI) 1.03-2.72; p=0.036] and serum total bilirubin levels at iLVAD implantation [HR 1.31, 95% CI 1.00-1.65; p=0.043] were independent predictors of 1-year composite events.

CONCLUSIONS

The BTB strategy is useful in providing long-term survival in patients with acute critical diseases. However, the early mortality rate after conversion is higher in patients who underwent the BTB strategy.

Durable ventricular assist device implantation for systemic right ventricle: a case series

Background

A systemic right ventricle (RV) after atrial switch in transposition of the great arteries (TGA) or congenitally corrected TGA (ccTGA) often results in advanced heart failure in adulthood.

Case summary

Four patients with INTERMACS Class III underwent durable ventricular assist device (VAD) implantation for a systemic RV. Two patients were diagnosed with ccTGA and underwent tricuspid valve replacement, and two were diagnosed with TGA in childhood and underwent Mustard repair. The two patients with ccTGA received an EVAHEART (Sun Medical, Nagano, Japan) and HeartMate 3 (Abbott Laboratories, Abbott Park, IL, USA) at the age of 56 years and 34 years, respectively. Of the patients with TGA, one received a Heartmate II at age 40 years, and one received a HeartMate 3 at age 40 years. All patients were weaned from cardiopulmonary bypass without subpulmonic VAD support and transferred to the intensive care unit with optimum VAD support. No in-hospital deaths, cerebrovascular accidents, or other major complications occurred. The post-VAD right heart catheter study showed a remarkable reduction in pulmonary capillary wedge pressure in all patients.

Discussion

The indications for and surgical technique of durable VAD implantation for a systemic RV after atrial switch of TGA or ccTGA have not been fully established. A durable VAD, including the HeartMate 3, was successfully implanted in four such patients in this study. Pre-operative three-dimensional computed tomography images and intraoperative transoesophageal echocardiography guidance helped to determine the positions of the inflow and pump.

Accuracy of Doppler blood pressure measurement in HeartMate 3 ventricular assist device patients

Aims

Optimal blood pressure (BP) control is imperative to reduce complications, especially strokes, in continuous flow ventricular assist device (VAD) patients. Doppler BP has been shown to be an accurate and reliable non‐invasive BP measurement method in HeartMate II and HVAD patients. We examined whether Doppler BP is also accurate in patients with the HeartMate 3 VAD.

Methods and results

In a prospective, longitudinal cohort of HeartMate 3 patients, arterial line BP and simultaneously measured Doppler opening pressure were obtained. Correlation and agreement between Doppler opening pressure and arterial line mean arterial pressure (MAP) versus systolic blood pressure (SBP) were analysed, as well as the effect of pulse pressure on the accuracy of Doppler opening pressure.

A total of 589 pairs of simultaneous Doppler opening pressure and arterial line pressure readings were obtained in 43 patients. Doppler opening pressure had good correlation with intra‐arterial MAP (r = 0.754) and more closely approximated MAP than SBP (mean error 2.0 vs. −8.6 mmHg). Pulse pressure did not have a clinically significant impact on the accuracy of the Doppler BP method. These results in HeartMate 3 patients are very similar to previous results in HeartMate II and HVAD patients.

Conclusions

Doppler BP method should be the default non‐invasive BP measurement method in continuous flow VAD patients including patients implanted with the HeartMate 3.

Mechanical Support of the Failing Fontan Circulation

The Fontan is the final common pathway for most single ventricle lesions. It is not a durable circulation and many Fontan patients eventually present for advanced heart failure therapies including mechanical circulatory support. While there have been advancements in available durable devices, many pediatric patients have size, anatomical, and physiologic constraints that make placement of adult ventricular assist devices challenging. And, Fontan failure comes in different varieties, including failure with preserved systolic function. This subset of patients requires either a subpulmonary assist device or a total artificial heart. Unique operative maneuvers, including atrial cannulation and atrioventricular valve manipulation have allowed many failing Fontan patients to be bridged to transplant after recovery of end-organ dysfunction and improved nutrition. The Advanced Cardiac Therapies Improving Outcomes Network is a multicenter learning network of pediatric hospitals implanting, managing, and studying ventricular assist devices in children and adults with congenital heart disease. This network is advancing the knowledge of outcomes and approaches to mechanical circulatory support in those with congenital heart disease, including Fontans. The congenital heart disease community continues to work toward and hope for a smaller durable device that will help this complex cohort of patients.

Pathophysiology and molecular signalling in pediatric heart failure and VAD therapy

Heart Failure (HF) is a progressive clinical syndrome characterized by molecular and structural abnormalities that result in impaired ventricular filling and a reduced blood ejection. In pediatric patients, HF represents an important cause of morbidity and mortality, but underlying cause, presentation and disease course remains unclear in many cases. It is evident that a child is not a "small adult" and findings are not comparable. The adoption of a standardized clinical and surgical tools as well as increased biomolecular research and therapeutic trials targeting pediatric patients with HF would greatly improve the management of this special class of patients. This review examines the most current information about the pathophysiology and molecular mechanisms related to HF in children to identify gaps in our knowledge base to further improve clinical care and outcomes.