Staged discharge out of hospital of the Novacor left ventricular assist system (LVAS) recipients

Initial Results of Clinical Trial with a New Left Ventricular Assist Device (LVAD) Providing Synchronous Pulsatile Flow

Objectives

A multicentric European Clinical Study is ongoing to evaluate safety and efficacy of a new pulsatile implantable LVAD (BestBeat), smaller and lighter than similar devices, capable of providing synchronous and counterpulsating flow with respect to the LV of end-stage heart failure patients. Preliminary clinical results are reported.

Methods

The new BestBeat LVAD was used, consisting of an implantable pulsatile blood pump, electromechanically driven by a ball screw mechanism, and a wearable electronic controller and power sources. The clinical trial was conducted at 5 European centers. Adult patients affected by CHF in NYHA Class IV despite optimized medical treatment were enrolled. The primary study endpoint was survival at 90 days. Further study endpoints were maintenance of adequate LVAD pump flow and a minimum rate of adverse events during support.

Results

As of June 2008, 6 patients received the implant. Cumulative support time was 3.7 years, median support time 176 days. All patients who completed the study survived except for one, who died after 48 days, due to combined infection and cerebrovascular accident. Another two patients died: one from intracranial bleeding 113 days after implant, and one from septic shock after 123 days. Hemodynamic improvement with Cl>2.0 l/min/m2 and recovery of end-organ function expressed by consistent improvement of BUN, creatinine and bilirubin were reached in all patients. No device failure was observed. There was no bleeding requiring re-exploration, no hemolysis and only two device-related infections (both in one patient). Neurologic events were reported, the most serious ones occurring in patients with pre-implant respiratory and kidney failure. Three patients were discharged home. Two patients were successfully transplanted, one after 6 months and one after 13 months on device.

Conclusions

Good performance and efficacy of the device were observed; the endpoints of the study were achieved, and its safety was consistent with expectations. The ongoing study will allow further conclusions to be drawn.

The Experience of Family Caregivers of Patients With a Left Ventricular Assist Device

Objective:

The purpose of this review is to understand the experience of caregivers of patients with left ventricular assist device (LVAD) and to evaluate how health professionals can support them properly.

Background:

Left ventricular assist device can improve quality of life, enhance functional status, and prolong survival in patients with advanced heart failure. Nonetheless, LVAD can adversely influence quality of life for their family caregivers.

Methods:

An integrative literature review was conducted using scientific databases between January to March 2015.

Results:

A total of 15 studies are included in the final review. Three major themes emerged “emotional distress,” “responsibility,” and “coping strategies” that characterize family caregivers’ experiences with care of patients with LVAD.

Conclusion:

Health care providers should understand the pivotal role of caregivers in promoting and maintaining patients’ well-being and be able to help the caregiver to moderate the impact being overloaded. Research should be addressed to create interventions that motivate the caregivers to engage in activities that promote their health.

Quality of life outcomes after heart transplantation in individuals bridged to transplant with ventricular assist devices

BACKGROUND

Increasing numbers of individuals receive ventricular assist devices (VADs) as bridges to heart transplantation. Physical morbidity risks and benefits, and quality of life (QOL) during VAD support have been documented. Effects of pre-transplant VAD support on functional and QOL outcomes after transplantation have received no empirical attention.

METHODS

Sixty-three VAD patients who received heart transplants underwent QOL evaluations of physical functioning, emotional and cognitive well-being, and social functioning at 2, 7, and 12 months after transplant (response rate = 95%). Ninety patients who had not received VADs--matched to the VAD group on cardiac-related and sociodemographic characteristics--served as longitudinal controls.

RESULTS

Both VAD and non-VAD groups showed similar levels and similar, statistically significant (p < 0.05) improvement in physical functioning (sleep, body care, mobility, ambulation, overall functional status, number of somatic complaints) across the study period. Emotional well-being (elevated depressive, anxiety, and anger symptoms; post-traumatic stress disorder rate) was stable or improved in both groups, and VAD patients showed significantly lower anxiety rates. The VAD patients' post-transplant cognitive status was significantly poorer. The VAD patients were significantly less likely to return to employment; other social functioning measurers (daily concerns, interpersonal activities/involvement, role function) showed mixed effects. Cognitive impairment explained much of the association between VAD support and post-transplant employment.

CONCLUSIONS

Although post-transplant physical and emotional recovery is similar in VAD and non-VAD patients, VAD patients retain more cognitive impairment and show mixed changes in social functioning. Increased attention to strategies to maximize VAD patients' cognitive capacity is required to facilitate social reintegration.

Flight Experience with the Novacor LVAS

As Novacor LVAS recipients continue to be discharged from the hospital to await cardiac transplantation, an increasing number of patients either need or desire to use air transportation. To date, two test experiences have been reported with the Novacor LVAS operating in a mock circulatory loop during air travel. One involved the transport of a mock loop on a medical helicopter, and another preceded an international flight of an LVAS recipient from Japan to the United States. In each situation, the LVAS, connected to a water-filled mock circulatory loop, was placed on the aircraft and instrumentation was checked to verify that there was no adverse effect on the Novacor equipment, or on aircraft systems, during flight. Novacor LVAS recipients have also been reported to have flown more than 37 commercial air transports throughout Europe, in both rotary and fixed wing aircraft, without incident. Laboratory testing of electromagnetic emissions were also conducted to include specific frequencies utilized by aircraft instrumentation. These tests show that the Novacor LVAS is well below the International Special Committee on Radio Interference (CISPR 11) emissions limits; these data can be provided to an air carrier anticipating transport of a Novacor recipient. Details of the results from the mock loop field testing, as well as the laboratory testing of electromagnetic emissions pertinent to air travel, are presented. This experience suggests that that there has been no impact on aircraft electronics from the LVAS, nor has the aircraft instrumentation generated any interference with the components of the Novacor LVAS.

Mechanical circulatory support for advanced heart failure: effect of patient selection on outcome

BACKGROUND

Use of wearable left ventricular assist systems (LVAS) in the treatment of advanced heart failure has steadily increased since 1993, when these devices became generally available in Europe. The aim of this study was to identify in an unselected cohort of LVAS recipients those aspects of patient selection that have an impact on postimplant survival.

METHODS AND RESULTS

Data were obtained from the Novacor European Registry. Between 1993 and 1999, 464 patients were implanted with the Novacor LVAS. The majority had idiopathic (60%) or ischemic (27%) cardiomyopathy; the median age at implant was 49 (16 to 75) years. The median support time was 100 days (4.1 years maximum). Forty-nine percent of the recipients were discharged from the hospital on LVAS; they spent 75% of their time out of the hospital. For a subset of 366 recipients, for whom a complete set of data was available, multivariate analysis revealed that the following preimplant conditions were independent risk factors for survival after LVAS implantation: respiratory failure associated with septicemia (odds ratio 11.2), right heart failure (odds ratio 3.2), age >65 years (odds ratio 3.01), acute postcardiotomy (odds ratio 1.8), and acute infarction (odds ratio 1.7). For patients without any of these factors, the 1-year survival after LVAS implantation including the posttransplantation period was 60%; for the combined group with at least 1 risk factor, it was 24%.

CONCLUSIONS

Careful selection, specifically implantation before patients become moribund, and improvement of management may result in improved outcomes of LVAS treatment for advanced heart failure.

Improved outcomes with an implantable left ventricular assist system: a multicenter study

BACKGROUND

Cumulative experience with the Novacor wearable electric left ventricular assist system (LVAS) now exceeds 850 recipients. The pump inflow conduit (IFC) has been implicated in embolic complications.

METHODS

Clinical outcomes were compared for two IFC designs in a retrospective, nonrandomized, multicenter study. The original IFC (woven, unsupported, crimped polyester: control group) and an alternative IFC (knitted, gelatin-sealed, integrally supported, uncrimped polyester: test group) were utilized upon availability in North American and European centers. Differences in cerebral embolism to 180 days postimplant were analyzed.

RESULTS

Four hundred ninety patients implanted between August 1996 and August 1999, were studied. Two hundred eighty-eight received the control IFC and 202 received the test IFC. The groups (control, test) were well matched for age (48, 49 years), etiology (idiopathic 53%[152 of 288], 55% [112 of 202]; ischemic 34% [97 of 288], 33% [66 of 202]) and mean observation time (97, 91 days). The incidence of embolic cerebrovascular accidents (CVA) was 21% (60 of 288) in the control and 12% (24 of 202) in the test group (p = 0.010). Independent risk factors for embolic CVA were found to be preimplant acute myocardial infarction (odds ratio 4.3), age above 50 years (odds ratio 2.1), and ischemic etiology (odds ratio 1.7). There was no difference in survival between the groups (71% [205 of 288], 68% [137 of 202]).

CONCLUSIONS

The alternative (test) IFC has significantly reduced the incidence of embolic CVA. This improvement is likely due to increased resistance to deformation at implant, improved neointimal adhesion, and more favorable blood flow characteristics within the conduit.

Mechanical circulatory devices for the treatment of heart failure

BACKGROUND

During the last four decades substantial efforts have been made in the development of effective mechanical circulatory devices. Since the first clinical utilization in the 1960s, the field has gone from the stage of clinical experimentation to that of a valid and effective heart failure treatment alternative. Experience gained during the short-term use of these devices, typically as a bridge to cardiac transplantation, has led to increased expectations of devices capable of long-term or permanent support to be used as a permanent treatment for end-stage heart failure patients. This article reviews the history, current state of the art, and future of the field of mechanical circulatory devices.

METHODS

Mechanical circulatory devices can be classified into three major categories: (1) total artificial hearts, (2) pulsatile ventricular assist devices, and (3) nonpulsatile ventricular assist devices. The most widely used devices have been the pulsatile ventricular assist devices with more than 5,800 reported cases, whereas the use of total artificial hearts has been limited to less than 350 reported cases. Nonpulsatile devices have been used clinically, but only in short-term cases (i.e., hours and days), whereas the pulsatile devices have been used in the long-term application, with patients supported for weeks, months, and in a small number of cases, years. The technological evolution of these devices has gone from large, extracorporeal systems designed to keep the patient alive in the intensive care unit (ICU) until a donor organ could be found, to portable devices that allow the patient to be mobilized outside of the hospital setting.

RESULTS

The clinical experience with mechanical circulatory devices as a bridge to cardiac transplantation has saved the lives of thousands of patients. Exciting new research discoveries related to recovery of native heart function during extended circulatory support have provided new hope for many more patients. Additional research efforts currently underway are being tested at various laboratories around the world and will soon provide the next generation of systems. These new systems will offer the recipients an unparalleled quality of life with minimal limitations on daily activities. The progress in this field has reached the point where circulatory support will soon be considered a valid long-term or permanent therapy and an elective to transplantation.