Mechanical circulatory support as a bridge to transplant or for destination therapy

Implications of Transitional Care Interventions on Hospital Readmissions in Patients With Destination Therapy Left Ventricular Assist Devices

BACKGROUND

The rising number of patients with a left ventricular assist device (LVAD) require care management to successfully transition home after implantation. These patients and their families need to manage their heart failure, and the complexities of an LVAD and the associated lifestyle modifications. Translating knowledge of transitional care interventions in patients with chronic diseases to those with an LVAD may provide valuable insight. To help inform the furthering of care transitions in the LVAD patient population, an integrative review was conducted.

AIM

The aim of this review was to explore the transitions of care interventions of care in patients and its potential for application in the destination therapy LVAD.

METHODS

This integrative review was guided by the Whittemore and Knafl's methodology.

RESULTS

A total of 12 articles from 264 retrieved articles met inclusion criteria and were included in the literature review.

DISCUSSION

This review identified that evidence-based transitional care interventions have been shown to decrease avoidable rehospitalization, the associated costs, and improve quality of life when compared to usual care.

IMPLICATIONS FOR PRACTICE

A common feature of transitional care interventions is the inclusion of nurse leadership. Nurses should be prepared to participate in transitional care interventions to optimally improve outcomes for patients with heart failure and potentially those with an LVAD. Additionally, to make transitional care interventions more effective they should be implemented with moderate intensity or greater.

CONCLUSION

This review provided information supporting the trialing of transitional care interventions in patients with an LVAD and suggests pilot research to optimize interventions for this population.

Performance Improvement to Decrease Readmission Rates for Patients With a Left Ventricular Assist Device

BACKGROUND

The 30-day readmission rate for patients with a left ventricular assist device implantation at a large, urban, Midwest hospital system (from October 2013 to September 2014) was estimated at 32.1%.

PROBLEM STATEMENT

Readmission rates were a concern at this facility. Review of the readmissions, change in practice, and home expectations of patients and families have identified an opportunity to improve the transitions of care for this left ventricular assist device (LVAD) program. Therefore, the purpose of this project was to evaluate the effectiveness and feasibility of a transitional care model (TCM) for care of patients with left ventricular devices.

METHODS

Ten patients were enrolled in the pilot that was implemented in June 2015. A transitional care nurse trained to support patients with ventricular assist devices was used to facilitate patient flow. The goal was to create an individualized plan for the development or improvement of self-management skills to decrease readmission rates. The transitional care nurse collaborated with the ventricular device team.

OUTCOMES

The 30-day readmission rate during the pilot was 14.3% compared to the previous annual overall rate of 42.6%.

IMPLICATIONS FOR PRACTICE

Based on these results, further research is recommended into interventions consistent with the TCM to advance care coordination and to facilitate care transition in the this fragile patient population.

Nursing care protocol for patients with a ventricular assist device

ABSTRACT Objective: to develop and validate a nursing care protocol for patients with a ventricular assist device (VAD). Method: descriptive study, with a quantitative approach, for an instrument's methodological validation. Three stages were conducted: development of the instrument; protocol content validation according to the Delphi technique, and agreement among experts and the scientific literature. Results: based on the content validation, a care protocol for patients with a VAD was created and assessed by Spanish experts. Of the 15 items evaluated by means of the content validity index (CVI), 10 presented solid evidence of validation, with Kappa ranging between 0.87 and 1. Conclusion: the method enabled the validation of interventions that will contribute to qualified and standardized care for patients with a VAD.

DURABLE MECHANICAL CIRCULATION SUPPORT AS AN ALTERNATIVE TO HEART TRANSPLANTATION

In the review a comparative analysis of the treatment of end-stage chronic heart failure using heart transplantation and durable mechanical circulatory is conducted. It shows the main advantages and limitations of heart transplantation and the prospects of application of durable mechanical circulatory support technology. The main directions of this technology, including two-stage heart transplant (bridge to transplant – BTT), assisted circulation for myocardial recovery (bridge to recovery – BTR) and implantation of an auxiliary pump on a regular basis (destination therapy, DT). 

Developing a Kit and Video to Standardize Changes of Left Ventricular Assist Device Dressings

Context—

Driveline infection is a major cause of morbidity and mortality in the patients with a left ventricular assist device (LVAD). Our center developed 2 LVAD dressing change kits and instructional videos for the purpose of standardizing a protocol for the dressing changes.

Objective—

To develop 2 different types of driveline dressing kits and videos to help in standardizing the education of our patients, caregivers, and staff.

Design—

A survey to evaluate patient, caregiver, and staff satisfaction and ease of use relating to the newly implemented dressing kits and videos. A comparison of driveline infection rates before and after the quality improvement project also was conducted.

Patients/Participants, Settings—

LVAD patients, their caregivers, and staff from Spectrum Health in Grand Rapids, Michigan.

Results—

Surveys were sent to 80 patient/caregiver pairs and 330 staff members. A total of 5 patients, 10 caregivers, and 48 staff members completed the surveys. All participants agreed that patients' driveline sites looked about the same, if not better than, they did before the kits were made available. They also overwhelmingly agreed that the kits were convenient (98%) and easy to use (99%). Patients and their caregivers gave favorable responses to the videos. The project experienced a slight increase in driveline infection rates, but the difference was not statistically significant.

Conclusion—

Standardizing and producing a driveline kit facilitates the delivery of care in an LVAD program.

The Use of Fluid Mechanics to Predict Regions of Microscopic Thrombus Formation in Pulsatile VADs

We compare the velocity and shear obtained from particle image velocimetry (PIV) and computational fluid dynamics (CFD) in a pulsatile ventricular assist device (VAD) to further test our thrombus predictive methodology using microscopy data from an explanted VAD. To mimic physiological conditions in vitro, a mock circulatory loop is used with a blood analog that matched blood's viscoelastic behavior at 40% hematocrit. Under normal physiologic pressures and for a heart rate of 75 bpm, PIV data is acquired and wall shear maps are produced. The resolution of the PIV shear rate calculations are tested using the CFD and found to be in the same range. A bovine study, using a model of the 50 cc Penn State V-2 VAD, for 30 days at a constant beat rate of 75 beats per minute (bpm) provides the microscopic data whereby after the 30 days, the device is explanted and the sac surface analyzed using scanning electron microscopy (SEM) and, after immunofluorescent labeling for platelets and fibrin, confocal microscopy. Areas are examined based on PIV measurements and CFD, with special attention to low shear regions where platelet and fibrin deposition are most likely to occur. Data collected within the outlet port in a direction normal to the front wall of the VAD shows that some regions experience wall shear rates less than 500 s^-1, which increases the likelihood of platelet and fibrin deposition. Despite only one animal study, correlations between PIV, CFD, and in vivo data show promise. Deposition probability is quantified by the thrombus susceptibility potential, a calculation to correlate low shear and time of shear with deposition.

Caring for a spouse with end-stage heart failure through implantation of a left ventricular assist device as destination therapy

OBJECTIVES

This qualitative study describes the experiences of spousal caregivers of a patient with end-stage heart failure (HF) from pre-LVAD to post-LVAD-DT implantation.

BACKGROUND

LVAD-DTs are implanted as permanent devices for end-stage HF patients with the goal of improving the length and quality of life. LVADs create new demands for both patients and caregivers.

METHODS

In-depth, semi-structured interviews of 10 spousal caregivers were thematically analyzed.

RESULTS

Throughout the process of caregiving, pre-implant through post-implant, all caregivers discussed their ability to adapt within the role as a caregiver. Adaptation as a caregiver occurred through three distinct time frames following the progression of the patient's HF and subsequent LVAD implantation: caring for a spouse with HF, decision for LVAD implantation made, and caring for a spouse with the LVAD-DT.

CONCLUSIONS

Caregivers were able to adapt and develop effective strategies to incorporate the demands of caring for a spouse with an LVAD-DT, but the role remained challenging. The findings underscore the need for continued research that may be translated into effective interventions to support patient and caregivers as they live through this end-of-life trajectory.

A fluid dynamics study in a 50 cc pulsatile ventricular assist device: influence of heart rate variability

Although left ventricular assist devices (LVADs) have had success in supporting severe heart failure patients, thrombus formation within these devices still limits their long term use. Research has shown that thrombosis in the Penn State pulsatile LVAD, on a polyurethane blood sac, is largely a function of the underlying fluid mechanics and may be correlated to wall shear rates below 500 s(-1). Given the large range of heart rate and systolic durations employed, in vivo it is useful to study the fluid mechanics of pulsatile LVADs under these conditions. Particle image velocimetry (PIV) was used to capture planar flow in the pump body of a Penn State 50 cubic centimeters (cc) LVAD for heart rates of 75-150 bpm and respective systolic durations of 38-50%. Shear rates were calculated along the lower device wall with attention given to the uncertainty of the shear rate measurement as a function of pixel magnification. Spatial and temporal shear rate changes associated with data collection frequency were also investigated. The accuracy of the shear rate calculation improved by approximately 40% as the resolution increased from 35 to 12 μm/pixel. In addition, data collection in 10 ms, rather than 50 ms, intervals was found to be preferable. Increasing heart rate and systolic duration showed little change in wall shear rate patterns, with wall shear rate magnitude scaling by approximately the kinematic viscosity divided by the square of the average inlet velocity, which is essentially half the friction coefficient. Changes in in vivo operating conditions strongly influence wall shear rates within our device, and likely play a significant role in thrombus deposition. Refinement of PIV techniques at higher magnifications can be useful in moving towards better prediction of thrombosis in LVADs.