A review of cardiac transplantation

Myocardial protection: a forgotten modality

The goals of a cardiac surgical procedure are both technical excellence and complete protection of cardiac function. Cardioplegia is used almost universally to protect the heart and provide a quiet bloodless field for surgical accuracy. Yet, despite the importance of myocardial protection in cardiac surgery, manuscripts or dedicated sessions at major meetings on this subject have become relatively rare, as though contemporary techniques now make them unnecessary. Nevertheless, septal dysfunction and haemodynamic support (inotropes, intra-aortic balloon pump, assist devices) are common in postoperative patients, indicating that myocardial damage following cardiac surgery is still prevalent with current cardioplegic techniques and solutions. This article first describes why cardiac enzymes and septal function are the ideal markers for determining the adequacy of myocardial protection. It also describes the underappreciated consequences of postoperative cardiac enzyme release or septal dysfunction (which currently occurs in 40-80% of patients) from inadequate protection, and how they directly correlate with early and especially late mortality. Finally, it reviews the various myocardial protection techniques available to provide a detailed understanding of the cardioplegic methods that can be utilized to protect the heart. This will allow surgeons to critically assess their current method of protection and, if needed, make necessary changes to provide their patients with optimal protection.

Enhanced Piezoelectric Fibered Extracellular Matrix to Promote Cardiomyocyte Maturation and Tissue Formation: A 3D Computational Model

Mechanical and electrical stimuli play a key role in tissue formation, guiding cell processes such as cell migration, differentiation, maturation, and apoptosis. Monitoring and controlling these stimuli on in vitro experiments is not straightforward due to the coupling of these different stimuli. In addition, active and reciprocal cell-cell and cell-extracellular matrix interactions are essential to be considered during formation of complex tissue such as myocardial tissue. In this sense, computational models can offer new perspectives and key information on the cell microenvironment. Thus, we present a new computational 3D model, based on the Finite Element Method, where a complex extracellular matrix with piezoelectric properties interacts with cardiac muscle cells during the first steps of tissue formation. This model includes collective behavior and cell processes such as cell migration, maturation, differentiation, proliferation, and apoptosis. The model has employed to study the initial stages of in vitro cardiac aggregate formation, considering cell-cell junctions, under different extracellular matrix configurations. Three different cases have been purposed to evaluate cell behavior in fibered, mechanically stimulated fibered, and mechanically stimulated piezoelectric fibered extra-cellular matrix. In this last case, the cells are guided by the coupling of mechanical and electrical stimuli. Accordingly, the obtained results show the formation of more elongated groups and enhancement in cell proliferation.

Blocking the IL-1 receptor reduces cardiac transplant ischemia and reperfusion injury and mitigates CMV-accelerated chronic rejection

Ischemia-reperfusion injury (IRI) is an important risk factor for accelerated cardiac allograft rejection and graft dysfunction . Utilizing a rat heart isogeneic transplant model, we identified inflammatory pathways involved in IRI in order to identify therapeutic targets involved in disease. Pathway analyses identified several relevant targets, including cytokine signaling by the IL-1 receptor (IL-1R) pathway and inflammasome activation. To investigate the role of IL-1R signaling pathways during IRI, we treated syngeneic cardiac transplant recipients at 1-hour posttransplant with Anakinra, a US Food and Drug Administration (FDA)-approved IL-1R antagonist; or parthenolide, a caspase-1 and nuclear factor kappa-light-chain-enhancer of activated B cells inhibitor that blocks IL-1β maturation. Both Anakinra and parthenolide significantly reduced graft inflammation and cellular recruitment in the treated recipients relative to nontreated controls. Anakinra treatment administered at 1-hour posttransplant to recipients of cardiac allografts from CMV-infected donors significantly increased the time to rejection and reduced viral loads at rejection. Our results indicate that reducing IRI by blocking IL-1Rsignaling pathways with Anakinra or inflammasome activity with parthenolide provides a promising approach for extending survival of cardiac allografts from CMV-infected donors.

Controversies in the Postoperative Management of the Critically Ill Heart Transplant Patient

Heart transplant recipients are susceptible to a number of complications in the immediate postoperative period. Despite advances in surgical techniques, mechanical circulatory support (MCS), and immunosuppression, evidence supporting optimal management strategies of the critically ill transplant patient is lacking on many fronts. This review identifies some of these controversies with the aim of stimulating further discussion and development into these gray areas.

Anesthetic management of the patient undergoing heart transplantation

Cardiac transplantation is the treatment of choice for patients with end-stage heart failure. Over the years, significant advances in patient selection, donor optimization and selection, and optimization of immunosuppression strategies have markedly improved outcomes. In this review, we highlight patient selection, donor management and procurement, heart transplantation procedure, and intraoperative and postoperative management of heart transplants.

Anesthesia for Heart Transplantation

This article seeks to evaluate current practices in heart transplantation. The goals of this article were to review current practices for heart transplantation and its anesthesia management. The article reviews current demographics and discusses the current criteria for candidacy for heart transplantation. The process for donor and receipt selection is reviewed. This is followed by a review of mechanical circulatory support devices as they pertain to heart transplantation. The preanesthesia and intraoperative considerations are also discussed. Finally, management after transplantation is also reviewed.

The Perceptions of Important Elements of Caregiving for a Left Ventricular Assist Device Patient: A Qualitative Meta-Synthesis

BACKGROUND

The use of a left ventricular assist device (LVAD) is becoming increasingly common in patients with end-stage heart failure. Many LVAD programs require patients to have a caregiver before receiving a device. There are few studies exploring the experience, burden, and impacts on caregivers of patients with LVADs.

OBJECTIVES

The aim of this study was to synthesize the qualitative literature regarding caregiver's perceptions about caring for an adult LVAD patient.

METHODS

We searched MEDLINE, CINAHL, PsychInfo, and Web of Science to find English articles on the topic of LVAD caregiver's perceptions. The articles were then synthesized using a formal process of qualitative meta-synthesis.

RESULTS

Eight articles met criteria for inclusion. The meta-synthesis across the articles resulted in 8 themes categorized under 3 domains. Many of the articles suggested a longitudinal process of caregiving with perceptions largely dependent upon the time of interview in relation to the LVAD. The first domain of caregiving is the "early" stage, covering the life before the LVAD through the procedure. This phase is characterized by the pre-LVAD "emotional rollercoaster," the decision seen as "no option," and the thought of "leave it [the LVAD] at the hospital." The second domain is the "middle" stage, covering the time frame after discharge from the hospital. This phase is characterized by fragility of the patient, recognition of a need to adapt, and a transformed life. The final domain is "late LVAD" and describes how late in the LVAD process the LVAD indication (bridge to transplant or destination therapy) brings in to focus what is important to caregivers.

CONCLUSIONS

Existing literature indicates that the LVAD caregiver experience is intense as well as burdensome and entails the need to adapt to a new life. Given the burdens caregivers experience, clinicians and future research should explore strategies to support these important individuals.

Extracorporeal Membrane Oxygenation Applications in Cardiac Critical Care

The use of extracorporeal membrane oxygenation therapy (ECMO) in cardiac critical care has steadily increased over the past decade. Significant improvements in the technology associated with ECMO have propagated this recent resurgence and contributed to improved patient outcomes in the fields of cardiac and transplant (heart and lung) surgery. Specifically, ECMO is being increasingly utilized as a bridge to heart and lung transplantation, as well as to ventricular assist device placement. ECMO is also employed during the administration of cardiopulmonary resuscitation, known as extracorporeal life support. In this review, we examine the recent literature regarding the applications of ECMO and also describe emerging topics involving current ECMO management strategies.

Cardiac Transplantation: Considerations for the Intensive Care Unit Nurse

Heart transplantation is a recommended and curative treatment option for patients with advanced heart failure symptoms despite receiving optimal medical and device therapy. The availability of donor organs limits the number of patients able to receive a heart transplant. The overall outcome of patients able to receive a heart transplant is determined by the successful delivery of essential nursing care. Understanding the specific interventions and therapies unique to this patient population is critical to their care. This article reviews considerations for the intensive care unit clinician in the management of heart transplant patients in this setting.

Novel therapeutic strategies for cardioprotection

The morbidity and mortality from ischemic heart disease (IHD) remain significant worldwide. The treatment for acute myocardial infarction has improved over the past decades, including early reperfusion of occluded coronary arteries. Although it is essential to re-open the artery as soon as possible, paradoxically this leads to additional myocardial injury, called acute ischemia-reperfusion injury (IRI), for which currently no effective therapy is available. Therefore, novel therapeutic strategies are required to protect the heart from acute IRI in order to reduce myocardial infarction size, preserve cardiac function and improve clinical outcomes in patients with IHD. In this review article, we will first outline the pathophysiology of acute IRI and review promising therapeutic strategies for cardioprotection. These include novel aspects of mitochondrial function, epigenetics, circadian clocks, the immune system, microvesicles, growth factors, stem cell therapy and gene therapy. We discuss the therapeutic potential of these novel cardioprotective strategies in terms of pharmacological targeting and clinical application.

Factors contributing to poor sleep quality as perceived by heart transplant recipients in Taiwan

BACKGROUND

The aims of this project were to explore the factors contributing to poor sleep quality at 1 to 3 years after heart transplantation (post-HT), and to explore economic problems and social support for HT recipients (HTRs).

METHODS

This study used a cross-sectional retrospective triangulation approach combining qualitative and quantitative research method designs. Quantitative data included data from the visual analog scale and the Taiwanese version of the World Health Organization Quality of Life questionnaire. Qualitative data were derived from questions that explored physiological, psychological, and economic factors contributing to poor sleep quality postprocedure for HTRs.

RESULTS

Sixty-four subjects (81% male, 19% female) participated in this research. Their ages ranged from 20 to 70 (M = 46.88 ± 12.12) years old. Their post-HT timeframe ranged from 1 to 4.10 years; 33% received preoperative extracorporeal membrane oxygenation support. Sleeping disturbances were reported by 72.7% of subjects after HT. Poor sleeping quality at 2 to 3 years post-HT (P = .028) was a complaint, and was worse than at 1 to 2 years post-HT (P = .008). Six physiological (62.5%) and 3 psychological (37.5%) contributing factors were further identified in qualitative interviews. Physiological factors were the major causes affecting their sleep quality 2 to 3 years after HT, whereas psychological factors arose from various family roles, responsibilities, and economic-related pressures.

CONCLUSIONS

Medical teams should find the causes that lead to sleep disturbances and use the findings to improve HTR sleep quality. When the family financial status is affected, these teams should offer assistance and suggestions for patients who are unable to work due to post-HT physical decline. Establishing and providing good family support systems or patient support groups may allow patients to obtain physical, psychological, and spiritual comfort.