Device Therapy and Cardiac Transplantation for End-Stage Heart Failure

Advancing cardiac regeneration through 3D bioprinting: methods, applications, and future directions

Cardiovascular diseases (CVDs) represent a paramount global mortality concern, and their prevalence is on a relentless ascent. Despite the effectiveness of contemporary medical interventions in mitigating CVD-related fatality rates and complications, their efficacy remains curtailed by an array of limitations. These include the suboptimal efficiency of direct cell injection and an inherent disequilibrium between the demand and availability of heart transplantations. Consequently, the imperative to formulate innovative strategies for cardiac regeneration therapy becomes unmistakable. Within this context, 3D bioprinting technology emerges as a vanguard contender, occupying a pivotal niche in the realm of tissue engineering and regenerative medicine. This state-of-the-art methodology holds the potential to fabricate intricate heart tissues endowed with multifaceted structures and functionalities, thereby engendering substantial promise. By harnessing the prowess of 3D bioprinting, it becomes plausible to synthesize functional cardiac architectures seamlessly enmeshed with the host tissue, affording a viable avenue for the restitution of infarcted domains and, by extension, mitigating the onerous yoke of CVDs. In this review, we encapsulate the myriad applications of 3D bioprinting technology in the domain of heart tissue regeneration. Furthermore, we usher in the latest advancements in printing methodologies and bioinks, culminating in an exploration of the extant challenges and the vista of possibilities inherent to a diverse array of approaches.

Recapitulating porcine cardiac development in vitro: from expanded potential stem cell to embryo culture models

Domestic pigs (Sus scrofa) share many genetic, anatomical, and physiological traits with humans and therefore constitute an excellent preclinical animal model. Fundamental understanding of the cellular and molecular processes governing early porcine cardiogenesis is critical for developing advanced porcine models used for the study of heart diseases and new regenerative therapies. Here, we provide a detailed characterization of porcine cardiogenesis based on fetal porcine hearts at various developmental stages and cardiac cells derived from porcine expanded pluripotent stem cells (pEPSCs), i.e., stem cells having the potential to give rise to both embryonic and extraembryonic tissue. We notably demonstrate for the first time that pEPSCs can differentiate into cardiovascular progenitor cells (CPCs), functional cardiomyocytes (CMs), epicardial cells and epicardial-derived cells (EPDCs) in vitro. Furthermore, we present an enhanced system for whole-embryo culture which allows continuous ex utero development of porcine post-implantation embryos from the cardiac crescent stage (ED14) up to the cardiac looping (ED17) stage. These new techniques provide a versatile platform for studying porcine cardiac development and disease modeling.

Anatomical human fitting of the BiVACOR total artificial heart

BACKGROUND

BiVACOR is a novel total artificial heart (TAH) utilizing a single centrifugal magnetically levitated rotor with the ability to modulate pulsatile flow. The device has been successfully tested in a bovine model. We undertook a multicenter anatomical and virtual fitting study of the BiVACOR in patients undergoing heart transplantation.

METHODS

10 patients were recruited across two heart transplant centers. A sterilized 1:1 titanium model of the device was inserted into the patient's chest post heart explant, prior to implantation of the donor heart. Measurements were recorded in situ. The device was then removed. Following this, retrospective 3D reconstructions were created from computed tomography chest scans to simulate a virtual fitting.

RESULTS

Mean age was 53 years (range 38-67). Mean BMI was 28 (range 20-37). Heart failure etiology was varied-with ischemic cardiomyopathy being the most common. Mean spine-to-sternum distance at the tenth thoracic vertebrae (T10) was 14 cm (range 11-18). Mean aorta to aortic Port distance was 0.2 cm (range 0-0.5). Mean pulmonary artery to pulmonary artery port distance was 4.2 cm (range 1-7). The device fitted suitably in all patients without gross distortion to the geometry between native vessel/chamber and port.

CONCLUSIONS

This study described the anatomical and virtual fitting of the BiVACOR TAH. The device fit well within the chest cavities of all 10 patients, who represented a variety of body morphologies and heart failure etiology.

Omentum support for cardiac regeneration in ischaemic cardiomyopathy models: a systematic scoping review

OBJECTIVES

Preclinical in vivo studies using omental tissue as a biomaterial for myocardial regeneration are promising and have not previously been collated. We aimed to evaluate the effects of the omentum as a support for bioengineered tissue therapy for cardiac regeneration in vivo. 

METHODS

A systematic scoping review was performed. Only English-language studies that used bioengineered cardio-regenerative tissue, omentum and ischaemic cardiomyopathy in vivo models were included.

RESULTS

We initially screened 1926 studies of which 17 were included in the final qualitative analysis. Among these, 11 were methodologically comparable and 6 were non-comparable. The use of the omentum improved the engraftment of bioengineered tissue by improving cell retention and reducing infarct size. Vascularization was also improved by the induction of angiogenesis in the transplanted tissue. Omentum-supported bioengineered grafts were associated with enhanced host reverse remodelling and improved haemodynamic measurements.

CONCLUSIONS

The omentum is a promising support for myocardial regenerative bioengineering in vivo. Future studies would benefit from more homogenous methodologies and reporting of outcomes to allow for direct comparison.

How well do we understand pulsatility in the context of modern ventricular assist devices?

BACKGROUND

Modern ventricular assist devices (VADs) use a continuous flow design. It has been suggested that a lack of pulsatility contributes to a range of adverse outcomes including pump thrombus, gastrointestinal bleeding and stroke. To better assess the role of pulsatility in these adverse events, we first require a clear definition of 'pulsatility' in the setting of a severely impaired ventricle and a modern continuous flow VAD.

METHODS

A literature review was conducted to elucidate the understanding of pulsatility in modern VAD literature. Search engines used included PUBMED, EMBASE and the Cochrane library. Articles were appraised on three aspects: Whether they mentioned pulsatility; whether they mentioned which pulsatility measure was used and finally which methodology was used to obtain the value.

RESULTS

Of 354 articles reviewed, only 13 met our broad inclusion criteria. Of these articles, the most cited measure was pulsatility index (PI) - used by 11 of the publications. The methodology used to obtain the value was not uniform and five articles did not clearly state it. Other measures included pulse pressure and surplus haemodynamic energy. The majority of articles did not directly discuss pulsatility in the setting of patient-pump interaction.

CONCLUSION

Most publications did not provide a definition for pulsatility. In those that did, the most common measure was PI. Measuring PI was not standardised. Few papers addressed the impact of intrinsic ventricular function and arterial compliance on pulsatility. We suggest that future publications adopt a uniform definition which encompasses both patient and pump characteristics.

Recent advancements in cardiovascular bioprinting and bioprinted cardiac constructs

Three-dimensionally bioprinted cardiac constructs with biomimetic bioink helps to create native-equivalent cardiac tissues to treat patients with myocardial infarction.

Ventricular Assist Device Technology and Black-White Disparities on the Heart Transplant Wait List

Introduction:

Heart transplantation is the definitive treatment for end-stage heart failure. Left ventricular assist devices (LVADs) are a continually improving technology that extends life for some candidates on the heart transplant waiting list. Research Questions: Our objective is to compare Black-White differences in LVAD implantation and heart transplant outcomes during a period of technological innovation when the pulsatile flow LVAD was largely replaced by the continuous flow LVAD between 1999-2014.

Design:

We used transplant registry data from the United Network for Organ Sharing (N = 5,550) to identify Black and White patients with heart failure who used an LVAD as a bridge-to-transplant (BTT). Using logistic regression, we compared Black-White differences in access to newer LVAD technology and timing of implantation relative to wait listing for heart transplantation. We used competing-risks event history models to predict transplant outcomes across race, LVAD type, and timing of LVAD implantation.

Results:

Black and White candidates were equally likely to receive newer continuous flow LVADs, but Black candidates received LVADs later in the disease course (i.e. after transplant listing). This later timing of technological intervention contributed to poorer wait list outcomes among black transplant candidates, including lower likelihood of receiving a heart transplant and greater likelihood of being removed from the wait list due to worsening health.

Discussion:

Delayed LVAD implantation is more common among Black patients and is associated with poorer transplant outcomes.

Mesenchymal stem cells from human amniotic membrane differentiate into cardiomyocytes and endothelial-like cells without improving cardiac function after surgical administration in rat model of chronic heart failure

Introduction: Human amnion-derived mesenchymal stem cells (hAMSCs) have been used in the treatment of acute myocardial infarction. In the current study, we investigated the efficacy of hAMSCs for the treatment of chronic model of myocardial ischemia and heart failure (HF) in rats. Methods: Male Wistar rats weighing between 250 to 350 g were randomized into three groups: sham, HF control and HF+hAMSCs. For HF induction, animals were anesthetized and underwent left anterior descending artery ligation. In HF+hAMSCs group, 2×106 cells were injected into the left ventricular muscle four weeks post ischemia in the border zone of the ischemic area. Cardiac function was studied using echocardiography. Masson's trichrome staining was used for studying tissue fibrosis. Cells were transduced with green fluorescent protein (GFP) coding lentiviral vector. Immunohistochemistry was used for detecting GFP, vascular-endothelial growth factor (VEGF) and troponin T markers in the tissue sections. Results: Assessment of the cardiac function revealed no improvement in the myocardial function compared to the control HF group. Moreover, tissue fibrosis was similar in two groups. Immunohistochemical study revealed the homing of the injected hAMSCs to the myocardium. Cells were stained positive for VEGF and troponin T markers. Conclusion: injection of hAMSCs 4 weeks after ischemia does not improve cardiac function and cardiac muscle fibrosis, although the cells show markers of differentiation into vascular endothelial cells and cardiomyocytes. In sum, it appears that hAMSCs are effective in the early phases of myocardial ischemia and does not offer a significant advantage in patients with chronic HF.

Long-Term Mechanical Durability of Left Ventricular Assist Devices: An Urgent Call for Periodic Assessment of Technical Integrity

Long-term durability and incidence of potential mechanical device failure (MDF) are largely unknown. In this study, we investigated the incidence and potential predictors of MDF in continuous flow left ventricular assist device (CF-LVAD) patients. We conducted a retrospective study of all CF-LVADs (type HeartMate II) implanted in our center. MDF was defined as a failure of driveline, inflow-outflow graft, electrical power, drive unit, or motor failure, excluding device failure because of a biologic complication (e.g., device thrombosis, hemolysis, or infections). A total of 69 CF-LVADs were implanted in 59 patients (median support time 344 days [interquartile range {IQR}, 149-712 days], mean age 50.1 ± 10.7 years, 75% male). MDF occurred in 9 (13%) CF-LVAD patients at a median follow-up time of 846 (IQR, 708-1337) days after implantation. Freedom of MDF through the first, second, and third year after LVAD implantation was 100%, 85%, and 64%, respectively. Patients who experienced MDF were significantly longer supported by their LVAD (median 846 [IQR, 708-1337] vs 268 [IQR, 103-481] days; p = 0.001) and were more frequently readmitted because of LVAD-related technical problems (p = 0.002), including a higher rate of LVAD controllers exchange (44% vs 12%, respectively; p = 0.03). The main reason for MDF was a damaged or fractured driveline (n=8, 89%). In 2 patients, sudden death was related to MDF. Patients needing extended CF-LVAD support are at increasing risk for MDF. Various technical problems precede the onset of MDF. Periodical extensive assessment of the technical integrity of the device is urgently needed during long-term LVAD support.

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.

Selection of Patients for Initial Clinical Trials of Solid Organ Xenotransplantation

Several groups have reported extended survival of genetically engineered pig organs in nonhuman primates, varying from almost 10 months for life-supporting kidney grafts and more than 2 years for non-life-supporting heart grafts to less than 1 month for life-supporting liver and lung grafts. We have attempted to define groups of patients who may not have an option to wait for an allograft. These include kidney, heart, and lung candidates who are highly-allosensitized. In addition, some kidney candidates (who have previously lost at least 2 allografts from rapid recurrence of native kidney disease) have a high risk of further recurrence and will not be offered a repeat allotransplant. Patients with complex congenital heart disease, who may have undergone previous palliative surgical procedures, may be unsuitable for ventricular assist device implantation. Patients dying of fulminant hepatic failure, for whom no alternative therapy is available, may be candidates for a pig liver, even if only as a bridge until an allograft becomes available. When the results of pig organ xenotransplantation in nonhuman primates suggest a realistic potential for success of a pilot clinical trial, highly selected patients should be offered participation.

Renal function in heart transplant patients after switch to combined mammalian target of rapamycin inhibitor and calcineurin inhibitor therapy

BACKGROUND

A calcineurin inhibitor (CNI)-based immunosuppression combined with mammalian target of rapamycin inhibitors (mTORs) seems to be attractive in patients after heart transplantation (HTX) in special clinical situations, for example, in patients with adverse drug effects of prior immunosuppression. Previous studies in patients after HTX detected advantageous effects regarding renal function of a tacrolimus (TAC)-based vs cyclosporine-A (CSA)-based immunosuppression (in combination with mycophenolate mofetil). However, data regarding renal function after HTX in mTOR/CNI patients remain limited.

AIM

Primary end point of the present study was to analyze renal function in HTX patients 1 year after switch to an mTOR/CNI-based immunosuppression.

METHODS

Data of 80 HTX patients after change to mTOR/CNI-based immunosuppression were retrospectively analyzed. Renal function was assessed by measured serum creatinine and by estimated glomerular filtration rate (eGFR) calculated from Modification of Diet in Renal Disease equation.

RESULTS

Twenty-nine patients received mTOR/CSA-based treatment and 51 patients received mTOR/TAC-based therapy. At time of switch and at 1-year follow-up, serum creatinine and eGFR did not differ significantly between both study groups (all P=not statistically significant). Analysis of variances with repeated measurements detected a similar change of renal function in both study groups.

CONCLUSION

The present study detected no significant differences between both mTOR/CNI study groups, indicating a steady state of renal function in HTX patients after switch of immunosuppressive regimen.

Nanoimaging in cardiovascular diseases: Current state of the art

Nanotechnology has been integrated into healthcare system in terms of diagnosis as well as therapy. The massive impact of imaging nanotechnology has a deeper intervention in cardiology i.e. as contrast agents, to target vulnerable plaques with site specificity and in a theranostic approach to treat these plaques, stem cell delivery in necrotic myocardium, etc. Thus cardiovascular nanoimaging is not limited to simple diagnosis but also can help real time tracking during therapy as well as surgery. The present review provides a comprehensive description of the molecular imaging techniques for cardiovascular diseases with the help of nanotechnology and the potential clinical implications of nanotechnology for future applications.

Building a bridge to save a failing ventricle: radiologic evaluation of short- and long-term cardiac assist devices

Heart failure is recognized with increasing frequency worldwide and often progresses to an advanced refractory state. Although the reference standard for treatment of advanced heart failure remains cardiac transplantation, the increasing shortage of donor organs and the unsuitability of many patients for transplantation surgery has led to a search for alternative therapies. One such therapy is mechanical circulatory support, which helps relieve the load on the ventricle and thereby allows it to recover function. In addition, there is increasing evidence supporting the use of mechanical devices as a bridge to recovery in patients with acute refractory heart failure. In this article, the imaging evaluation of various commonly used short- and long-term cardiac assist devices is discussed, and their relevant mechanisms of action and physiology are described. Imaging, particularly computed tomography (CT), plays a crucial role in preoperative evaluation for assessment of candidacy for implantation of a left ventricular assist device (LVAD) or total artificial heart (TAH). Also, echocardiography and CT are indispensable in assessment of complications associated with cardiac devices. Complications commonly associated with short-term assist devices include bleeding and malpositioning, whereas long-term devices such as LVADs may be associated with infection, pump thrombosis, and cannula malfunction, as well as bleeding. CT is also commonly performed for preoperative planning before LVAD or TAH explantation, replacement of a device or one of its components, and cardiac transplantation. Online supplemental material is available for this article.

Clinical psychological and neuropsychological issues with left ventricular assist devices (LVADs)

BACKGROUND

Left ventricular assist devices (LVADs) are increasingly being used to treat patients in end-stage heart failure (HF) as bridge-to-transplantation, lifetime support or destination therapy. However, the importance of this newer technique for chronic cardiac support compared to heart transplantation is still open to discussion. To date, there are few studies that extensively explore the psychological and cognitive profiles of patient with ventricular assist devices (VADs).

METHODS

We studied the psychological aspects, quality of life (QOL) and cognitive profiles of 19 patients with HF before VAD implantation and then at two, five and 16 months post-implantation.

RESULTS

Our results showed that after VAD implantation, patients did not show any psychopathological problems such as anxiety and/or depression. More interestingly, despite the constant risk of neurological events determined by the continuous-blood-flow pump (CBFP), patients' cognitive functioning did not worsen. In fact, significant enhancements were observed over time.

CONCLUSIONS

Psychological and cognitive deficits are common in advanced HF and often worsen over time. Appropriately designed and randomized studies are needed to demonstrate whether earlier VAD implantation is warranted to arrest cognitive decline and encourage better post-implantation adaptation.

Everolimus initiation and early calcineurin inhibitor withdrawal in heart transplant recipients: a randomized trial

In a randomized, open-label trial, everolimus was compared to cyclosporine in 115 de novo heart transplant recipients. Patients were assigned within 5 days posttransplant to low-exposure everolimus (3–6 ng/mL) with reduced-exposure cyclosporine (n = 56), or standard-exposure cyclosporine (n = 59), with both mycophenolate mofetil and corticosteroids. In the everolimus group, cyclosporine was withdrawn after 7–11 weeks and everolimus exposure increased (6–10 ng/mL). The primary efficacy end point, measured GFR at 12 months posttransplant, was significantly higher with everolimus versus cyclosporine (mean ± SD: 79.8 ± 17.7 mL/min/1.73 m2 vs. 61.5 ± 19.6 mL/min/1.73 m2; p < 0.001). Coronary intravascular ultrasound showed that the mean increase in maximal intimal thickness was smaller (0.03 mm [95% CI 0.01, 0.05 mm] vs. 0.08 mm [95% CI 0.05, 0.12 mm], p = 0.03), and the incidence of cardiac allograft vasculopathy (CAV) was lower (50.0% vs. 64.6%, p = 0.003), with everolimus versus cyclosporine at month 12. Biopsy-proven acute rejection after weeks 7–11 was more frequent with everolimus (p = 0.03). Left ventricular function was not inferior with everolimus versus cyclosporine. Cytomegalovirus infection was less common with everolimus (5.4% vs. 30.5%, p < 0.001); the incidence of bacterial infection was similar. In conclusion, everolimus-based immunosuppression with early elimination of cyclosporine markedly improved renal function after heart transplantation. Since postoperative safety was not jeopardized and development of CAV was attenuated, this strategy may benefit long-term outcome.

Relationship between early inflammatory response and clinical evolution of the severe multiorgan failure in mechanical circulatory support-treated patients

Background. The mechanical circulatory support (MCS) is an effective treatment in critically ill patients with end-stage heart failure (ESHF) that, however, may cause a severe multiorgan failure syndrome (MOFS) in these subjects. The impact of altered inflammatory response, associated to MOFS, on clinical evolution of MCS postimplantation patients has not been yet clarified. Methods. Circulating cytokines, adhesion molecules, and a marker of monocyte activation (neopterin) were determined in 53 MCS-treated patients, at preimplant and until 2 weeks. MOFS was evaluated by total sequential organ failure assessment score (tSOFA). Results. During MCS treatment, 32 patients experienced moderate MOFS (tSOFA < 11; A group), while 21 patients experienced severe MOFS (tSOFA ≥ 11) with favorable (B group) or adverse (n = 13, C group) outcomes. At preimplant, higher values of left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate (eGFR) were the only parameter independently associated with A group. In C group, during the first postoperative week, high levels of interleukin-8 (IL-8) and tumor necrosis factor (TNF)-α, and an increase of neopterin and adhesion molecules, precede tSOFA worsening and exitus. Conclusions. The MCS patients of C group show an excessive release to IL-8 and TNF-α, and monocyte-endothelial activation after surgery, that might contribute to the unfavourable evolution of severe MOFS.

Survival in elderly patients supported with continuous flow left ventricular assist device as bridge to transplantation or destination therapy

BACKGROUND

Published data on mechanical circulatory support for elderly patients in continuous flow devices are sparse and suggest relatively poor survival. This study investigated whether LVADs can be implanted in selected patients over the age of 65 years with acceptable survival compared with published outcomes.

METHODS AND RESULTS

A single-center retrospective analysis was conducted in 64 consecutive patients ≥65 years of age implanted with a continuous-flow left ventricular assist device (CF-LVAD) as either bridge to transplantation or destination therapy from August 2005 to January 2012. Baseline laboratory and hemodynamic characteristics and follow-up data were obtained. Median survival was 1,090 days. Survival was 85%, 74%, 55%, and 45% at 6 months and 1, 2, and 3 years, respectively. Our cohort had a baseline mean Seattle Heart Failure Model (SHFM) score of 2.6 ± 0.9. Observed survival was significantly better than SHFM-predicted medical survival. Stratification by age subsets, renal function, SHFM, implantation intention, or etiology did not reveal significant differences in survival. The most common cause of death was sepsis and nonlethalcomplication was bleeding.

CONCLUSIONS

Our experience with patients over the age of 65 receiving CF-LVADs suggests that this group demonstrates excellent survival. Further research is needed to discern the specific criteria for risk stratification for LVAD support in the elderly.

A review of cardiac transplantation

Perioperative anesthetic management for cardiac transplantation is reviewed. Recent developments in adult cardiac transplantation are noted. This review includes demographics and historical results, recipient and donor selection and evaluation, mechanical circulatory support and heart transplantation techniques, and patient management immediately postimplantation.

The spectrum of complications following left ventricular assist device placement

INTRODUCTION

Left ventricular assist device (LVAD) support is associated with many complications, but relatively few studies have examined the full spectrum of complications beyond infectious and bleeding events.

METHODS

We conducted a retrospective review of patients receiving either a pulsatile-flow Heartmate XVE (HM1; Thoratec Corp., Pleasanton, CA, USA) or continuous-flow Heartmate II (HM2; Thoratec Corp.) LVAD at our institution (June 2000 to March 2012). Frequency and date of onset of nonbleeding, noninfectious complications were examined.

RESULTS

One hundred eighty-two LVADs were implanted, 49 HM1, and 133 HM2. Support duration was longer for HM2s (median 358 vs. 112 days; p = 0.0003). Overall, the most frequent complications were respiratory failure, ventricular arrhythmia, atrial arrhythmia, right heart failure, and renal failure. Respiratory failure, arrhythmias, severe psychiatric events, and renal failure all occurred with median date of onset ≤ seven days postprocedure. Right heart failure, hepatic failure, thromboembolism, and transient ischemic attacks had a median date of onset 8 to 30 days postprocedure. Stroke, hemolysis, and device failure occurred mostly more than a month postoperatively. Right heart failure, hepatic failure, and device failure were more frequent in HM1 patients than in HM2 patients. Several events, including stroke, had much later onset in HM2 patients.

CONCLUSION

In this 10-year review of complications following LVAD implantation, the most common adverse events tended to occur early after implantation. As pulsatile-flow HM1s showed greater frequency and earlier onset of some adverse events, our data suggest better overall outcomes with the continuous-flow HM2s.

Gazing through the Crystal Ball of Science—Cardiovascular Disease in 2100

Recently, we had the opportunity to review the progress that has been made in the field of cardiovascular disease over the past century in The FASEB Journal and, based on those thoughts, in this article we predict what may transpire in this ‘century of biology’. Although it is true that ‘the best way to predict the future is to invent it’, we gaze through the prism of modern biomolecular science for a vision of a possible future and see cardiology practice that is transformed. In the second half of the 20th century, we developed a more fundamental understanding of atherosclerotic vascular disorders and invented life-saving therapeutics. We saw a similar development of mechanism-based pharmacotherapy to address heart failure, primarily through agents that antagonize the excessive concentration of circulating neurohumoral agents. Now we are in the midst of the device era, from stents to cardiac resynchronization therapy to transcatheter valves. The next wave of treatments will build on an increasingly sophisticated understanding of the molecular determinants of cardiovascular disorders and engineering feats that are barely perceptible now. Genomic profiling, molecular prescriptions for prevention and personalized therapeutics, regenerative medicine and the new field of cardiovascular tissue bioengineering will transform cardiovascular medicine. If the human species can survive threats of our own doing, such as the related epidemics of obesity and diabetes, by the turn of the next century, treatment of cardiovascular disease will not resemble the present in almost any way.

The pharmacotherapy implications of ventricular assist device in the patient with end-stage heart failure

Advances in mechanical circulatory support, such as the use of ventricular assist devices (VADs), have become a means for prolonging survival in end-stage heart failure (HF). VADs decrease the symptoms of HF and improve quality of life by replacing some of the work of a failing heart. They unload the ventricle to provide improved cardiac output and end-organ perfusion, resulting in improvement in cardiorenal syndromes and New York Heart Association functional class rating. VADs are currently used asa bridge to heart transplantation, a bridge to recovery of cardiac function, or as destination therapy. Complications of VAD include bleeding, infections, arrhythmias, multiple organ failure, right ventricular failure, and neurological dysfunction. Patients with VAD have unique pharmacotherapeutic requirements in terms of anticoagulation, appropriate antibiotic selection, and continuation of HF medications. Pharmacists in acute care and community settings are well prepared to care for the patient with VAD. These patients require thorough counseling and follow-up with regard to prevention and treatment of infections, appropriate levels of anticoagulation, and maintenance of fluid balance. A basic understanding of this unique therapy can assist pharmacists in attending to the needs of patients with VAD.

Myocardial restoration: is it the cell or the architecture or both?

Myocardial infarction is the leading cause of death in developed countries. Cardiac cell therapy has been introduced to clinical trials for more than ten years but its results are still controversial. Tissue engineering has addressed some limitations of cell therapy and appears to be a promising solution for cardiac regeneration. In this review, we would like to summarize the current understanding about the therapeutic effect of cell therapy and tissue engineering under purview of functional and structural aspects, highlighting actual roles of each therapy towards clinical application.

Sirolimus as primary immunosuppression attenuates allograft vasculopathy with improved late survival and decreased cardiac events after cardiac transplantation

BACKGROUND

We retrospectively analyzed the potential of sirolimus as a primary immunosuppressant in the long-term attenuation of cardiac allograft vasculopathy progression and the effects on cardiac-related morbidity and mortality.

METHODS AND RESULTS

Forty-five cardiac transplant recipients were converted to sirolimus 1.2 years (0.2, 4.0) after transplantation with complete calcineurin inhibitor withdrawal. Fifty-eight control subjects 2.0 years (0.2, 6.5 years) from transplantation were maintained on calcineurin inhibitors. Age, sex, ejection fraction, and time from transplantation to baseline intravascular ultrasound study were not different (P>0.2 for all) between the groups; neither were secondary immunosuppressants and use of steroids. Three-dimensional intravascular ultrasound studies were performed at baseline and 3.1 years (1.3, 4.6 years) later. Plaque index progression (plaque volume/vessel volume) was attenuated in the sirolimus group (0.7±10.5% versus 9.3±10.8%; P=0.0003) owing to reduced plaque volume in patients converted to sirolimus early (<2 years) after transplantation (P=0.05) and improved positive vascular remodeling (P=0.01) in patients analyzed late (>2 years) after transplantation. Outcome analysis in 160 consecutive patients maintained on 1 therapy was performed regardless of performance of intravascular ultrasound examinations. Five-year survival was improved with sirolimus (97.4±1.8% versus 81.8±4.9%; P=0.006), as was freedom from cardiac-related events (93.6±3.2% versus 76.9±5.5%; P=0.002).

CONCLUSIONS

Substituting calcineurin inhibitor with sirolimus as primary immunosuppressant attenuates long-term cardiac allograft vasculopathy progression and may improve long-term allograft survival owing to favorable coronary remodeling. Because of the lack of randomization and retrospective nature of our analysis, the differences in outcome should be interpreted cautiously, and prospective clinical trials are required.

Stem cell-based cardiac tissue engineering

Cardiovascular diseases are the leading cause of death worldwide, and cell-based therapies represent a potential cure for patients with cardiac diseases such as myocardial infarction, heart failure, and congenital heart diseases. Towards this goal, cardiac tissue engineering is now being investigated as an approach to support cell-based therapies and enhance their efficacy. This review focuses on the latest research in cardiac tissue engineering based on the use of embryonic, induced pluripotent, or adult stem cells. We describe different strategies such as direct injection of cells and/or biomaterials as well as direct replacement therapies with tissue mimics. In this regard, the latest research has shown promising results demonstrating the improvement of cardiac function with different strategies. It is clear from recent studies that the most important consideration to be addressed by new therapeutic strategies is long-term functional improvement. For this goal to be realized, novel and efficient methods of cell delivery are required that enable high cell retention, followed by electrical integration and mechanical coupling of the injected cells or the engineered tissue to the host myocardium.

The power of Pasteur's quadrant: cardiovascular disease at the turn of the century

During the life span of The FASEB Journal, the decline in cardiovascular mortality was astonishing as the fundamental bases of the complex syndromes of cardiovascular disease were illuminated. In this Silver Anniversary Review, we highlight a few pivotal advances in the field and relate them to research in Pasteur's quadrant, the region of investigation driven by both a desire for fundamental understanding and the consideration of its use. In the second half of the 20th century, we advanced from little pathophysiologic understanding to a near-complete understanding and effective, evidence-based therapeutics for vascular disorders and a similar development of pharmacotherapy to address heart failure, primarily through agents that antagonize the excessive concentration of circulating neurohumoral agents. In the current era, we have witnessed "the rise of the machines," from stents to cardiac resynchronization therapy. The next wave of treatments will build on an increasingly sophisticated understanding of the molecular determinants of cardiovascular disorders. We briefly consider the promise of regenerative medicine and are intrigued by the possibility for the direct reprogramming of resident cardiac fibroblasts into cardiomyocytes. As for the future, genomic profiling should help physicians recommend individualized risk factor modification targeted to prevent specific manifestations of cardiovascular disease. Transcriptional and biomarker analyses will almost surely be used individually to tailor therapy for those at risk of or experiencing cardiovascular disease. Given the ongoing exponential expansion of scientific knowledge, all of human ingenuity will be needed to fully utilize the power of Pasteur's quadrant and to unleash another quarter century in cardiology as scientifically fruitful and effective on human health as the last.

HeartMate® II continuous-flow left ventricular assist system

Left ventricular assist devices (LVADs) have emerged as a beneficial therapeutic strategy proven to improve the morbidity and mortality of patients with advanced heart failure. Continuous-flow rotary LVADs have been developed in the hopes of delivering circulatory support in a more durable manner with fewer device-related complications. The HeartMate(®) II continuous-flow left ventricular assist system (LVAS; Thoratec Corporation, Pleasanton, CA, USA) has become the standard of care for heart failure patients who require long-term mechanical circulatory support. The efficacy of the HeartMate II has been demonstrated in patients where temporary support with an LVAD is needed until a suitable donor organ can be found for transplant (termed 'bridge to transplantation'), as well as for terminally-ill heart failure patients who are not candidates for transplant ('destination therapy'). When directly compared with a pulsatile LVAD, the implantation of a HeartMate II LVAS resulted in an overall improvement in survival with a reduction in the number of device-related complications and adverse events. The purpose of this article is threefold: to describe the history of the development of continuous-flow LVADs; to describe the technology of the HeartMate II; and, finally, to review the clinical outcomes in patients who have been implanted with the device.