Persistent anemia after implantation of the total artificial heart

Blood Volume Analysis of Total Artificial Heart Recipients: A Case Series

Blood volume analysis provides a quantitative volume assessment in patients with equivocal or discordant clinical findings. Reports on its use in mechanical circulatory support are limited and it has never been described in patients with a total artificial heart. Our series demonstrates that patients supported with total artificial heart as a bridge to transplant have significant reductions in red blood cell volume and heterogeneous adaptations in their total blood volume and plasma volume. Pathologic derangements in our patient's total blood volume were targeted to restore euvolemia.

Assessment of plasma catecholamines in patients with dysmetabolic iron overload syndrome

BACKGROUND

Dysmetabolic iron overload syndrome (DIOS) is characterized by hyperferritinemia and normal transferrin saturation level with components of metabolic syndrome (MS). Among cases of MS, we determined those with DIOS and their characterizations, then we evaluated the association between plasma catecholamines status and hypertension in DIOS.

METHODS

We compared 101 hypertensive patients with 50 healthy participants (control group). Iron (iron, transferrin, and ferritin), insulin, and plasma catecholamine (adrenaline, noradrenaline, and dopamine), profiles were measured for both groups. Homeostasis model assessment of insulin resistance index and transferrin saturation were also calculated.

RESULTS

Out of 101 hypertensive patients, 64 were diagnosed with MS, and 6 of the latter met the DIOS diagnostic criteria. Significantly, DIOS patients were older and had lower body mass index (BMI) compared with hypertensive non-DIOS patients with p-values of (0.026), and (0.033), respectively. Adrenaline, noradrenaline, and dopamine levels did not differ significantly between DIOS and non-DIOS patients.

CONCLUSIONS

Of the MS patients, 9.3% were diagnosed with DIOS. Accordingly, complete iron profiling should be performed routinely in the cases of MS for early diagnosis of DIOS, to prevent future complications. Further studies are required to test the hypothesis linking older age and lower BMI with the pathogenesis of DIOS.

Biomechanical properties of erythrocytes circulating in artificial hearts measured by dielectrophoretic method

Blood damage is recognized as one of the major problems caused by non-physiological shear force induced by artificial hearts. At present, the generally accepted manifestation of mechanical blood damage is the amount of free hemoglobin released into the blood. However, there is little research on the changes of blood cell state after circulating in artificial hearts at the single-cell level. It is well known that the mechanical properties of cells are of enormous relevance in the regulation of cellular physiological and pathological processes. In this regard, it is highly needed to study the mechanical properties of blood cells affected by non-physiological shear force. In this paper, a dielectrophoresis-based method of measuring the mechanical properties of erythrocytes circulating in artificial hearts was proposed, which was quantified with some crucial parameters such as strain, elongation index (EI), and Young's modulus. Experimental results indicated that with the increase of the working time of artificial hearts, the deformability of erythrocytes decreased, the stiffness substantially increased, and the mechanical stability decreased, particularly at long exposure times. The proposed method provides a deep insight into the mechanism of subhemolytic damage at the single-cell level and has a great potential to serve as a new tool for in vitro evaluation of potential blood damage in artificial hearts.

Perioperative Care of the Patient With the Total Artificial Heart

Advanced heart failure continues to be a leading cause of morbidity and mortality despite improvements in pharmacologic therapy. High demand for cardiac transplantation and shortage of donor organs have led to an increase in the utilization of mechanical circulatory support devices. The total artificial heart is an effective biventricular assist device that may be used as a bridge to transplant and that is being studied for destination therapy. This review discusses the history, indications, and perioperative management of the total artificial heart with emphasis on the postoperative concerns.

The total artificial heart

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

Mechanical circulatory support devices in the ICU

The medical community has used implantable mechanical circulatory support devices at increasing rates for patients dying from heart failure and cardiogenic shock. Newer-generation devices offer a more durable and compact option when compared with bulky early-generation devices. This article is a succinct introduction and overview of the hemodynamic principles and complications after device implantation for ICU clinicians. We review the concepts of device physiology, clinical pearls for perioperative management, and common medical complications after device implantation.

Building new hearts: a review of trends in cardiac tissue engineering

Cardiovascular disease (CVD) is the number one cause of death in the United States. However, few treatments for CVD provide a means to regain full cardiac function with no long-term side effects. Novel tissue-engineered products may provide a way to overcome the limitations of current CVD therapies by replacing injured myocardium with functioning tissue or by inducing more constructive forms of endogenous repair. In this review, we discuss some of the factors that should be considered in the development of tissue-engineered products, and we review the methods currently being investigated to generate more effective heart valves, cardiac patches and whole hearts.

Durable mechanical circulatory support in advanced heart failure: a critical care cardiology perspective

Though cardiac transplantation for advanced heart disease patients remains definitive therapy for patients with advanced heart failure, it is challenged by inadequate donor supply, causing durable mechanical circulatory support (MCS) to slowly become a new primary standard. Selecting appropriate patients for MCS involves meeting a number of prespecifications as is required in evaluation for cardiac transplant candidacy. As technology evolves to bring forth more durable smaller devices, selection criteria for appropriate MCS recipients will likely expand to encompass a broader, less sick population. The "Holy Grail" for MCS will be a focus on clinical recovery and explantation of devices rather than the currently more narrowly defined indications of bridge to transplantation or lifetime device therapy.

Identification of differentially expressed transcripts and pathways in blood one week and six months following implant of left ventricular assist devices

Introduction

Continuous-flow left ventricular assist devices (LVADs) are an established therapy for patients with end-stage heart failure. The short- and long-term impact of these devices on peripheral blood gene expression has not been characterized, and may provide insight into the molecular pathways mediated in response to left ventricular remodeling and an improvement in overall systemic circulation. We performed RNA sequencing to identify genes and pathways influenced by these devices.

Methods

RNA was extracted from blood of 9 heart failure patients (8 male) prior to LVAD implantation, and at 7 and 180 days postoperatively. Libraries were sequenced on an Illumina HiSeq2000 and sequences mapped to the human Ensembl GRCh37.67 genome assembly.

Results

A specific set of genes involved in regulating cellular immune response, antigen presentation, and T cell activation and survival were down-regulated 7 days after LVAD placement. 6 months following LVAD placement, the expression levels of these genes were significantly increased; yet importantly, remained significantly lower than age and sex-matched samples from healthy controls.

Conclusions

In summary, this genomic analysis identified a significant decrease in the expression of genes that promote a healthy immune response in patients with heart failure that was partially restored 6 months following LVAD implant.