Current Role of the Total Artificial Heart in the Management of Advanced Heart Failure

Postoperative management and nursing care after implantation of a total artificial heart: Scoping review

INTRODUCTION

End-stage heart failure (HF) is a condition whose only successful long-term treatment, with a survival of more than 10 years, is heart transplantation. However, limited organ availability and the progressive increase in the number of patients with advanced HF have served as an impetus for the development of implantable mechanical assistive devices.

AIM

To provide an overview of postoperative management and nursing care after the implementation of a Total Artificial Heart (TAH).

METHODS

A scoping review was carried out by consulting the PUBMED, CINAHL, and COCHRANE databases. From all the documents located, information was extracted on the date of publication, country of publication, type of study, and results of interest to answer the research question. In addition, the degree of recommendation was identified.

RESULTS

Twenty-three documents were included in the scoping review. Results were classified in relation to: 1) description of the CAT SynCardia®; 2) nursing care in the immediate postoperative period (management of the device and management of hematological, infectious, nephrological, nutritional complications, related to immobilization, sleep-rest disturbances, psychological disorders, and patient and family education); and 3) follow-up at home.

CONCLUSIONS

The complexity of implantation of the TAH, the multiple related complications that can arise during this process, both in the immediate post-operative and late, require a standardised and multidisciplinary management. The absence of standardised protocols raises the need for future studies to measure the effectiveness of care in patients with TAH. A multidisciplinary approach is crucial. Nurses must acquire autonomy and involvement in decision-making and develop competencies to address the patient's and family's physiological and psychosocial needs.

Overset meshing in combination with novel blended weak-strong fluid-structure interactions for simulations of a translating valve in series with a second valve

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.

Impact of Temporary Preoperative Mechanical Support on Heart Transplant Outcomes

We sought to assess the impact of temporary preoperative mechanical circulatory support (TPMCS) on heart transplantation outcomes. A total of 4,060 adult heart transplants from June 1, 2006, to December 31, 2019, were identified in the Scientific Registry of Transplant Recipients database as having TPMCS. Recipients were divided into groups based on their type of TPMCS: intra-aortic balloon pump (IABP), temporary ventricular assist device (VAD), biventricular assist device (BIVAD), and extracorporeal membrane oxygenation (ECMO). Perioperative outcomes and survival were compared among groups. Recipients with IABP were associated with older age, a smoking history, and a significantly shorter wait list time ( p < 0.01). Recipients with ECMO had a significantly increased in-hospital mortality as well as an increased incidence of dialysis ( p < 0.01). Kaplan-Meier analysis revealed worse 1 and 5 year survival for recipients with ECMO. Cox model demonstrated a significantly increased risk of mortality with BIVAD (hazard ratio [HR], 1.33; 95% CI, 1.12-1.57; p < 0.01) and ECMO (HR, 1.64; 95% CI, 1.33-2.03; p < 0.01). While patients with IABP have a survival comparable to patients without TPMCS or durable left VAD, outcomes for BIVADs and ECMO are not as favorable. Transplantation centers must continue to make careful choices about the type of TPMCS utilized before heart transplant.

A retrospective chart review evaluating pre-operative dental extractions on patients with end-stage heart failure undergoing advanced surgical cardiac therapies

OBJECTIVES

End-stage heart failure patients are functionally compromised by multiple physiologic mechanisms, placing them at increased risk of peri- and post-operative complications. This study aimed to evaluate if dental treatment performed before advanced cardiac interventions, including orthotopic heart transplant and mechanical circulatory support, increases the risk of adverse events.

STUDY DESIGN

A retrospective chart review spanning January 2011 to December 2020 was performed. Inpatients with end-stage heart disease were evaluated by the hospital dentistry service at UCLA Ronald Reagan Medical Center. Three hundred and five consults met the inclusion criteria. The patients were divided into 2 groups: those who underwent dental treatment and those who did not require dental treatment. The wait time from dental consultation to cardiac intervention (days), dental complications, medical adverse events, and deaths were evaluated.

RESULTS

Dental complications were only experienced in the form of intraoral bleeding. There was no significant difference in the number of medical adverse events or deaths between groups.

CONCLUSIONS

The elimination of oral infection before advanced cardiac interventions does not increase the risk of morbidity or mortality.

Concomitant or late aortic valve intervention and its efficacy for aortic insufficiency associated with continuous-flow left ventricular assist device implantation

Moderate to severe aortic insufficiency (AI) in patients who underwent continuous-flow left ventricular assist device (CF-LVAD) implantation is a significant complication. According to the INTERMACS registry analysis, at least mild AI occurs in 55% of patients at 6 months after CF-LVAD implantation and moderate to severe AI is significantly associated with higher rates of re-hospitalization and mortality. The clinical implications of these data may underscore consideration of prophylactic aortic valve replacement, or repair, at the time of CF-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AI that is more than mild. More crucially, even if a native aortic valve is seemingly competent at the time of VAD implantation, we frequently find de novo AI as time goes by, potentially due to commissural fusion in the setting of inconsistent aortic valve opening or persistent valve closure caused by CF-LVAD support, that alters morphological and functional properties of innately competent aortic valves. Therefore, close monitoring of AI is mandatory, as the prognostic nature of its longitudinal progression is still unclear. Clearly, significant AI during VAD support warrants surgical intervention at the appropriate timing, especially in patients of destination therapy. Nonetheless, such an uncertainty in the progression of AI translates to a lack of consensus regarding the management of this untoward complication. In practice, proposed surgical options are aortic valve replacement, repair, closure, and more recently transcatheter aortic valve implantation or closure. Transcatheter approach is of course less invasive, however, its efficacy in terms of long-term outcome is limited. In this review, we summarize the recent evidence related to the pathophysiology and surgical treatment of AI associated with CF-LVAD implantation.

Exploring the misalignment on the value of further research between payers and manufacturers. A case study on a novel total artificial heart

Payers and manufacturers can disagree on the appropriate level of evidence that is required for new medical devices, resulting in high societal costs due to decisions taken with sub-optimal information. A cost-effectiveness model of a hypothetical total artificial heart was built using data from the literature and the (simulated) results of a pivotal study. The expected value of perfect information (EVPI) was calculated from both the payer and manufacturer perspectives, using net monetary benefit and the company's return on investment respectively. A function was also defined, linking effectiveness to market shares. Additional constraints such as a minimum clinical difference or maximum budget impact were introduced into the company's decisions to simulate additional barriers to adoption. The difference in the EVPI between manufacturers and payers varied greatly depending on the underlying decision rules and constraints. The manufacturer's EVPI depends on the probability of being reimbursed, the uncertainty on the (cost-)effectiveness of the technology, as well as other parameters relating to initial investments, operating costs and market dynamics. The use of Value of information for both perspectives can outline potential misalignments and can be particularly useful to inform early dialogs between manufacturers and payers, or negotiations on conditional reimbursement schemes.

Mechanical Circulatory Support: Primer for Consultant Specialists

Mechanical life support therapies exist in many forms to temporarily replace the function of vital organs. Generally speaking, these tools are supportive therapy to allow for organ recovery but, at times, require transition to long-term mechanical support. This review will examine nonrenal extracorporeal life support for cardiac and pulmonary support as well as other mechanical circulatory support options. This is intended as a general primer and overview to assist nephrologist consultants participating in the care of these critically ill patients who often experience acute renal injury as a result of cardiopulmonary shock and from their exposure to mechanical circulatory support.

Left Ventricular Assist Device: Indication, Timing, and Management

Left ventricular assist devices (LVADs) are indicated in inotrope-dependent heart failure (HF) patients with pure or predominant LV dysfunction. Survival benefit is less clear in ambulatory, advanced HF. Timing is crucial: early, unnecessary exposure to the risks of surgery, and device-related complications (infections, stroke, and bleeding) should be weighed against the probability of dying or developing irreversible right ventricular and/or end-organ dysfunction while deferring implant. The interplay between LVAD and heart transplantation depends largely on donor availability and allocation rules. Postoperatively, quality of life depends on patients' expectations and is influenced by complications. Patients' preferences, prognosis, and alternative options-including palliation-should be openly discussed and reviewed before and after the operation.

Replacement of the right SynCardia® ventricle due to membrane rupture

Biventricular heart failure remains a major challenge and total artificial heart (TAH) (SynCardia Systems Inc., Tucson, AZ, USA) bear hurdles, in particular in long-term application. Ventricular membrane rupture of a TAH is a feared complication and often implies a fatal outcome. Hereby we present the first case of successful and effective replacement of a TAH right ventricle due to the membrane rupture.

Troubleshooting Total Artificial Heart: Novel Use of Implantable Hemodynamic Monitor

Accurate device optimization of the Syncardia temporary total artificial heart is difficult while waiting for heart transplantation. In this challenging clinical cohort, using an implantable hemodynamic monitor (CardioMEMS HF system) can assist in volume and hemodynamic assessments. (Level of Difficulty: Advanced.)

Surgery for heart failure: Treatment options and implications

Heart failure is considered one of the leading causes of death worldwide. Over the years, etiological risk factors, diagnostic criteria, and classifications have been revised to create guide management needed to alleviate the global health burden caused by heart failure. Pharmacological treatments have progressed over time but are insufficient in reducing mortality. This leads to many patients developing advanced heart failure who will require surgical intervention often in the form of the gold standard, a heart transplant. However, the number of patients requiring a transplant far exceeds the number of donors. Other surgical inventions have been utilized, yet the rate of patients being diagnosed with heart failure is still increasing. Future developments in the surgical field of heart failure include the 77SyncCardia and atrial shunting but long-term clinical trials involving larger cohorts of patients have not yet taken place to view how effective these approaches can be.

Current situation and future of stem cells in cardiovascular medicine

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. Currently, many methods have been proposed by researchers for the prevention and treatment of CVD; among them, stem cell-based therapies are the most promising. As the cells of origin for various mature cells, stem cells have the ability to self-renew and differentiate. Stem cells have a powerful ability to regenerate biologically, self-repair, and enhance damaged functional tissues or organs. Allogeneic stem cells and somatic stem cells are two types of cells that can be used for cardiac repair. Theoretically, dilated cardiomyopathy and acute myocardial infarction can be treated with such cells. In addition, stem cell transplantation procedures, including intravenous, epicardial, cardiac, and endocardial injections, have been reported to provide significant benefits in clinical practice; however, there are still a number of issues that need further study and consideration, such as the form and quantity of transplanted cells and post-transplantation health. The goal of this analysis was to summarize the recent advances in stem cell-based therapies and their efficacy in cardiovascular regenerative medicine.

Pig-to-human heart transplantation: Who goes first?

Cardiac xenotransplantation has recently taken an important step towards clinical reality. In anticipation of the "first-in-human" heart xenotransplantation trial, we propose a set of patient characteristics that define potential candidates. Our premise is that, to be ethically justified, the risks posed by current state-of-the-art options must outweigh the anticipated risks of a pioneering xenotransplant procedure. Suitable candidates include patients who are at high immunologic risk because of sensitization to alloantigens, including those who have exhibited early onset or accelerated cardiac allograft vasculopathy. In addition, patients should be considered (1) for whom mechanical circulatory support would be prohibitively risky due to a hypercoagulable state, a contraindication to anticoagulation, or restrictive physiology; (2) with severe biventricular dysfunction predicting unsuccessful univentricular left heart support; and (3) adults with complex congenital heart disease. In conclusion, because the published preclinical benchmark for clinical translation of heart xenotransplantation appears within reach, carefully and deliberately defining appropriate trial participants is timely as the basis for ethical clinical trial design.

Long-term biventricular circulatory support with POLVAD-MEV paracorporeal pulsatile pumps. Single-centre experience

Introduction

Severe heart failure decompensation requires circulatory mechanical support in emergency situations. Polish paracorporeal pulsatile pumps, POLVAD-MEV, are designed for biventricular end-stage heart dysfunction.

Aim

To evaluate long-term POLVAD-MEV therapy by multiple pump exchange in patients on a transplant list.

Material and methods

There were 3 patients in INTERMACS level 1 referred for emergency POLVAD-MED implantation due to acute heart failure deterioration. The paracorporeal pulsatile mechanical support was applied due to severe biventricular dysfunction.

Results

They were supported by paracorporeal biventricular POLVAD-MEV pumps for 438, 473 and 394 days until heart transplantation. During the hospitalisation the pumps required multiple pumps exchanges within 29 ±10 (4–49) day intervals.

Conclusions

POLVAD-MEV paracorporeal pulsatile pumps present a safe option for long-term circulatory support in a selected group of patients. Therapy requires pump exchange but enables survival while awaiting a heart transplant.

Right Ventricular Function in Chronic Heart Failure: From the Diagnosis to the Therapeutic Approach

There is growing attention for the study of the right ventricle in cardiovascular disease and in particular in heart failure. In this clinical setting, right ventricle dysfunction is a significant marker of poor prognosis, regardless of the degree of left ventricular dysfunction. Novel echocardiographic methods allow for obtaining a more complete evaluation of the right ventricle anatomy and function as well as of the related abnormalities in filling pressures. Specific and effective therapies for the right ventricle dysfunction are still not well defined and this represents the most difficult and important challenge. This article focuses on available diagnostic techniques for studying right ventricle dysfunction as well as on the therapies for right ventricle dysfunction.