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.

Human factors issues in ventricular assist device recipients and their family caregivers.

Ultimately, for ventricular assist devices (VADs) to be acceptable as permanent alternatives to heart transplantation, patients' and their families' satisfaction with specific features and risks of VADs must be addressed. Of 42 eligible patients who received VADs between February of 1996 and December of 1998, we interviewed 37 patients (17 Novacor, 18 Thoratec, 2 with both devices) and 20 of their primary family caregivers about device related concerns and reactions. Demographic and health related correlates of respondents' concerns were examined. Eleven patients discharged from the hospital with the VAD in place were then reinterviewed 1 month after discharge. At baseline, patients' general perceptions of the VAD were positive, although 22-52% reported specific concerns, including most often worry about infection (52%), difficulty sleeping due to the position of the driveline (52%), pain at the driveline exit site (46%), worry about device malfunction (40%), and being bothered during the day by device noise (32%). The prevalence of most concerns rose with duration of VAD support. Caregivers' perceptions did not differ significantly from patients' perceptions. Outpatients were somewhat more concerned than inpatients about device noise and risk of stroke, but were markedly less concerned about infection. Across all patients, higher levels of device related concerns were correlated with more physical functional limitations and more psychological distress, and reduced quality of life. Demographic characteristics and device type were not uniformly related to device concerns.

Blood biocompatibility analysis in the setting of ventricular assist devices.

Ventricular assist devices (VADs) are increasingly applied to support patients with advanced cardiac failure. While the benefit of VADs in supporting this patient group is clear, substantial morbidity and mortality occur during the VAD implant period due to thromboembolic and infective complications. Efforts at the University of Pittsburgh aimed at evaluating the blood biocompatibility of VADs in the clinical, animal, and in vitro setting over the past decade are summarized. Emphasis is placed on understanding the mechanisms of thrombosis and thromboembolism associated with these devices.

Quality of life outcomes in left ventricular assist system inpatients and outpatients.

This study empirically evaluates the quality of life (QOL) effects associated with hospital discharge among heart transplant candidates whose lives are maintained by left ventricular support systems (LVAS). Thirty-five LVAS inpatients (18 Novacor, 17 Thoratec) received structured QOL assessments approximately 1 month after device implant. Ten of the patients (8 Novacor, 2 Thoratec) were subsequently discharged to either home or a home-like outpatient facility where their QOL was reassessed. The QOL of LVAS patients, before and after discharge, was compared with that of demographically similar nonhospitalized heart transplant candidates (n = 55) and recipients (n = 97). Their caregivers' QOL was also assessed. The QOL of LVAS outpatients showed statistically significant (p<0.05) advantages over remaining LVAS inpatients and nonhospitalized heart candidates. Advantages appeared in physical, emotional, and social functioning domains. The QOL of LVAS outpatients also improved (p<0.05) over their own QOL before discharge, with the greatest change in physical functional and emotional status. The QOL of LVAS outpatients most closely resembled QOL in the transplant recipients. Family caregivers to LVAS outpatients reported some increases in caregiving burden after patient discharge, but their overall well being was not adversely affected. These data provide an empiric basis for the provision of outpatient programs as appropriate care for eligible LVAS patients.

Assessment of timing right ventricular assist device withdrawal using left ventricular assist device filling characteristics.

Right ventricular assist devices (RVAD) are often needed on a short term basis in patients who develop RV failure after left ventricular assist device (LVAD) implantation. The purpose of this study was to use LVAD filling characteristics to help determine the timing for weaning a patient from RVAD support. Eleven patients (age 50 years +/- 15) supported with an LVAD (Novacor) and an RVAD (Biomedicus or ABIOMED) were studied. Eight patients (RV recovery group) were studied before RVAD removal and all were successfully weaned from RVAD support. Five patients (RV failure group) were studied at the time of RVAD placement to determine baseline characteristics of RV failure. Simultaneous measures of LVAD volume and routine hemodynamics were recorded during periods of high and low RVAD flow. The LVAD filling was assessed as the first derivative of LVAD volume and the mean filling rate for each cardiac cycle was calculated and averaged over 10 sec periods at both RVAD flows. The mean pump rate corrected filling rates did not change in the RV recovery group (89 +/- 13 vs. 87 +/- 8 ml/beat) and significantly decreased in the RV failure group (84 +/- 19 vs. 62 +/- 22 ml/ beat) (p < 0.001) with decreasing RVAD flow. These data suggest that LVAD filling rates may be used to assess RV systolic function and the proper timing of RVAD removal in selected patients.

Right ventricular performance and left ventricular assist device filling.

BACKGROUND: Right ventricular (RV) function is believed to be an important determinant of left ventricular assist device (LVAD) filling. This study was designed to demonstrate this relation in patients. METHODS: To demonstrate the interaction between RV ejection and LVAD filling, 10 patients (mean age, 49 +/- 13 years) supported with an LVAD were studied. Right ventricular pressure-area loops from cross-sectional area using transesophageal echocardiographic automated border detection and high-fidelity RV pressure were recorded simultaneously with LVAD volume during intraoperative inferior vena cava occlusion. Beat-by-beat RV ejection phase indices were calculated: stroke area, peak ejection rate, and stroke work. The LVAD filling rate was calculated as the first derivative of the volume, and the peak filling rate and the mean filling rate during RV systole were determined for each cardiac cycle. RESULTS: Right ventricular stroke area, peak ejection rate, and stroke work were closely correlated with LVAD peak filling rate (r = 0.87 +/- 0.09, r = 0.83 +/- 0.09, and r = 0.85 +/- 0.10, respectively). Also, baseline LVAD mean filling rate correlated with RV stroke work (r = 0.77) and LVAD peak filling rate with RV peak ejection rate for the group (r = 0.75). CONCLUSIONS: These correlations demonstrate predictable associations of RV ejection with LVAD filling.

Results of extended bridge to transplantation: window into the future of permanent ventricular assist devices.

BACKGROUND: There is interest in expanding ventricular assist device use from short-term bridging to transplantation to long-term and permanent support. METHODS: We have reviewed the outcome of 162 patients who had as mechanical bridge to transplantation that lasted at least 60 days. Eighty-five patients received the HeartMate, 40 the Novacor, and 37 the Thoratec device. RESULTS: Of the 162 patients, 125 received transplants, and 115 survived after transplantation (93%). Within the group there were 174 complications including 54 infections of the driveline, 73 other infections, and thromboembolic strokes in 47. Infections of the driveline were considered major in 24 of 54 cases, and other infections were major in 36 of 73 cases. Twenty-seven of those who sustained thromboembolic events had residual effects. Of 11 patients with a major stroke and infection, only 1 survived transplantation. Eighty-two patients were supported between 60 and 100 days, 63 patients between 101 and 200 days, 12 patients between 201 and 300 days, and only 5 patients in excess of 300 days. A greater percentage of candidates died waiting between 101 and 200 days than between 60 and 100 days (25% versus 10%). The incidence of complications also rose in those patients bridged more than 100 days. CONCLUSIONS: The data reinforce the excellent results obtained in the bridge to transplantation trials that reported a shorter duration of support. For those interested in extended bridge to transplantation or permanent use of the currently available devices, the results suggest reasonable success can be anticipated, but the serious infections and strokes tend to be more common with longer duration of support.

Discharging patients who are undergoing mechanical circulatory support.

Six patients supported by the Baxter Novacor left ventricular assist system have been discharged during the period of mechanical circulatory support at the University of Pittsburgh Medical Center. Benefits of discharge couple quality of life improvements and economic advantages for mechanical circulatory support patients. Limitations caused by regulations within current protocols have been shown to detract from patient and caregiver quality of life. Eliminating the unnecessary regulations will improve discharge capabilities without increasing the risk for clinical complications.

Protocol for releasing Novacor left ventricular assist system patients out-of-hospital.

Between September 1984 and April 1995, the Novacor left ventricular assist system (LVAS) has provided more than 13,000 days of mechanical circulatory support to cardiac transplant candidates in the United States and Europe. The duration of support of these 312 patients has ranged between 1 and 370 days, with an average support of 40 days, including use of the console based system and the wearable system. Of this group, 21% have been supported for more than 60 days, with an average support of 118 days. We have seen that patients who have been supported for more than 30 days have recovered from the effects of LVAS implant surgery and have shown a potential for rehabilitation from morbid congestive heart failure. Few changes to the pump settings or the medical orders have been needed after the third postoperative week. The reliability of the LVAS and the degree to which patients can be rehabilitated suggest that restricting patients to a hospital environment is unnecessary. In addition, the increasing wait for a donor heart, the quality of life that can be achieved, and the high cost of inpatient care make it desirable to discharge patients from the hospital and allow them to await a donor heart in a more home-like setting.

Nursing management and rehabilitation of chronic ventricular assist device (VAD) patients.

With the increasing number of heart transplants performed annually and the number of available organs decreasing, more patients are being bridged to transplant by mechanical circulatory support (MCS) systems during their wait for a donor organ. The duration of assistance with MCS has also increased due to this shortage of donor organs. The Artificial Heart Program at the University of Pittsburgh, recognizing this changing population, has shifted the focus of care from acute support to chronic support of VAD patients. Providing care directed at long-term support has promoted rehabilitation and helped to improve the overall bridge experience. At the University of Pittsburgh, 34 patients were implanted with MCS devices as a bridge to transplant between June 1987 and September 1992 (Figure 1). Thirteen of these patients were supported for over 60 days. Of these, three were eventually discharged to an out-of-hospital facility six blocks from the medical center. Eleven of the 13 patients supported over 60 days were discharged following successful orthotopic cardiac transplantation. In response to this increasing duration of support in the bridge to transplant patient, the role of the nurse has changed significantly. Nursing care initially focused on acute physiologic monitoring procedures that are restricted to an intensive care setting. Today the role of the MCS nurse encompasses a much broader area including medical care, education, and patient rehabilitation. It is important to realize that these aspects of care begin when a patient is identified as a MCS candidate and continue throughout the acute postoperative phase into the chronic phase of recovery.