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Körperliche Leistungsfähigkeit und hämodynamische Veränderungen bei Patienten mit einem linksventrikulären Herzunterstützungssystem
Abstract
Spitzenforschung Herz-Kreislauf-Medizin - Innovationen und Auszeichnungen 2020.
Ausgabe zur 86. Jahrestagung und zu den Herztagen 2020 der DGK vom 14. bis 17. Oktober 2020 in Berlin.
ResearchGate has not been able to resolve any citations for this publication.
Aims
Left ventricular assist device (LVAD) therapy is a promising option for patients with advanced heart failure (HF), refractory to guideline‐mandated medical treatment either as a bridge to heart transplantation or as lifelong therapy. Functional capacity improves after LVAD implantation but remains reduced in patients with long‐term LVAD therapy. Exercise training (ET) improves functional capacity and quality of life (QoL) in HF and may provide incremental benefits in patients supported with LVAD therapy.
Methods
The primary objective of Ex‐VAD is to investigate whether a 12‐week supervised ET can improve peak oxygen uptake (peakVO2) measured by cardiopulmonary exercise testing (CPET) on an ergometer. The study is powered to demonstrate a group difference of 3 mL/min/kg in peakVO2 at week 12, with a power of 0.9 and a standard deviation of 5 mL/min/kg. After baseline assessments to determine whether ET is safe, 66 patients at six trial sites with advanced HF and LVAD therapy will be randomized 2:1 to supervised ET or to the control arm of usual care alone. Patients randomized to ET will perform supervised aerobic endurance and resistance ET (three times/week) for 12 weeks. At baseline and during follow‐up, anthropometry, CPET, echocardiography (at rest and exercise), and QoL evaluation will be performed. Blood samples will be collected to examine cardiac‐specific relevant biomarkers. Overall physical activity, training sessions, and adherence will be monitored and documented throughout the study using accelerometers and patient diaries.
Conclusions
The Ex‐VAD trial will assess the effects of a supervised ET programme on peakVO2 and QoL in patients with LVAD. As LVAD therapy moves from crisis support to ambulatory functional enhancement, this trial will provide a rationale to improve functional capacity and, in perspective, cardiovascular outcomes in LVAD‐supported patients with advanced HF.
The implantation of left ventricular assist devices (LVAD) has been established as a successful treatment for terminal heart failure (HF) for many years. Patient benefits include significantly improved survival, as well as improved quality of life. However, peak exercise capacity following LVAD implantation remains considerably restricted. This could be due to the predominate use of continuous-flow pumps, which operate at a fixed rotational speed and do not adapt to exercise conditions. Therefore, current research is focused on whether, and to what extent, adaptations in pump speed can influence and improve patient exercise capacity. We performed a systematic PubMed literature search on this topic, and found 11 relevant studies with 161 patients. Exercise time, peak work load, total cardiac output (TCO), peak oxygen consumption (peak VO2) and, if available, values at the anaerobic threshold (AT) were all taken into consideration. Possible complications were documented. This paper aims to compare the results from these studies in order to discuss the effects of pump speed adaptations on exercise capacity.
In patients with left ventricular assist devices (LVAD), exercise capacity is a decisive factor regarding the quality of life. When evaluating exercise capacity, precise information about the total cardiac output generated is crucial.
To date, complex measurements using a right-heart catheter were necessary in order to determine total cardiac output. The inert gas rebreathing method facilitates non-invasive, direct and valid measurement of total cardiac output as well as associated parameters, like the difference in arteriovenous oxygen saturation, both at rest and during exercise.
It is the aim of this paper to focus on this conclusive method which is, despite its simplicity and low-risk reproducibility, rarely used within the framework of LVAD patient treatment at the present time. The test protocol used at our hospital is presented to facilitate the implementation of this helpful tool in other interested institutions.
The increasing use of ventricular assist devices (VADs) in terminal heart failure patients provides new challenges to cardiac rehabilitation physicians. Structured cardiac rehabilitation strategies are still poorly implemented for this special patient group. Clear guidance and more evidence for optimal modalities are needed. Thereby, attention has to be paid to specific aspects, such as psychological and social support and education (e.g., device management, INR self-management, drive-line care, and medication).
In Germany, the post-implant treatment and rehabilitation of VAD Patients working group was founded in 2012. This working group has developed clear recommendations for the rehabilitation of VAD patients according to the available literature. All facets of VAD patients’ rehabilitation are covered. The present paper is unique in Europe and represents a milestone to overcome the heterogeneity of VAD patient rehabilitation.
Cardiac rehabilitation physicians are faced to an increasing number of heart failure patients supported by left ventricular assist devices (LVAD). Many of these patients have complex medical issues and prolonged hospitalizations and therefore need special cardiac rehabilitation strategies including psychological, social, and educational support which are actually poorly implemented.
Cardiac rehabilitation with clear guidance and more evidence should be considered as an essential component of the patient care plan especially regarding the increasing number of destination patients and their long-term follow-up.
In this article the working group for postimplant treatment and rehabilitation of LVAD patients of the German Society for Prevention and Rehabilitation of Cardiovascular Diseases has summarized and updated the recommendations for the cardiac rehabilitation of LVAD patients considering the latest literature.
Following implantation of a left ventricular assist device, the build-up and long-term maintenance of adequate exercise capacity and functional performance become crucial. The aim of this study was to observe the development of exercise-related values at different times, as well as to detect possible influencing factors. We performed a prospective single-centre study: 10 patients (63 years, 100% male, body mass index = 27.5, 100% HeartWare) underwent the following diagnostic tests during cardiac rehabilitation and during two subsequent ambulatory visits: 6-min walking test, handgrip strength test, cardiopulmonary exercise test and Minnesota Living with Heart Failure questionnaire. Mean follow-up was 482 days after left ventricular assist device implantation. Significant improvements could be observed between the end of cardiac rehabilitation and ambulatory visit 1; 6-min walking distance increased from 367 to 449 m (p < 0.01), peak VO2 from 10.0 to 11.9 mL/kg/min (p < 0.05) and peak load from 62.4 to 83.0 W (p < 0.01). However, there were no further improvements between ambulatory visit 1 and ambulatory visit 2. In the long term, a significant mean weight gain of more than 10 kg could be observed (p < 0.01). A negative linear correlation between weight gain and absolute improvement in peak load (r = −0.77, p < 0.01) and peak VO2 (r = −0.75, p < 0.05) could be demonstrated. In conclusion, exercise-related values following left ventricular assist device implantation initially improve significantly. Later, however, no further improvements can be observed. In the long term, pronounced weight gain is conspicuous, concomitant with a significantly lower increase in exercise values of the patients. In the future, both dietary and structured physical activity follow-up interventions should be integrated in patient routines.
Background:
With an increasing number of left ventricular assist devices (LVADs) being implanted, the need for adequate cardiac rehabilitation (CR) regimens meeting the special needs of these patients arises. Only a few studies have reported experience gained on this topic. Structured CR strategies are poorly implemented. The aim was to evaluate the characteristics, therapeutic needs, and scope of LVAD patients at admission to CR within a greater cohort in order to identify their special CR needs.
Methods:
Retrospective single-center study; 69 LVAD patients (50.7 ± 13.6 y; 59 male; 48 HVAD; 21 HeartMate II) who completed first inpatient CR were included. Patient records were used to document relevant medical information (including the results of a 6-min walk test and a maximal isometric strength test for quadriceps femoral muscles in both legs) and the International Classification of Functioning, Disability and Health for classification of health and health-related domains.
Results:
Patient characteristics demonstrated a heterogeneous group: CR was started 44 ± 38.6 d after implantation; CR duration was 28 ± 9.7 d. Despite similar etiology, physical and psychological condition was diverse, although, overall a high degree of impairment was present, especially in the body function (79.7%) and activity and participation (95.7%) domains. The results demonstrated the need for a highly individualized approach in the somatic and also in the education, psychosocial, and social therapeutic regimes.
Conclusion:
The results demonstrate a heterogeneous group with a high level of impairment and special needs in many CR domains. The development and evaluation of a special highly individualized approach of CR, which meets the special needs of these patients, is needed.
Following implantation of a left ventricular assist device (LVAD), acceptable functional performance is now being achieved; however, peak VO2 and peak work load (watts) remain considerably limited. Maximum physical capacity is essentially dependent on generated cardiac output (CO) and arteriovenous oxygen difference (avDO2). We investigated the changes in CO and avDO2 during exercise in LVAD patients with an HVAD pump (HeartWare Inc., Framingham, MA, USA). Approximately 6 weeks after implantation, 20 patients (100% male, 60.8 ± 7.3 years old, BMI 25.7 ± 3.3) underwent a six-minute walk test (6MWT), a cardiopulmonary exercise test (CPET), and noninvasive hemodynamic measurement. The mean six-minute walking distance (6MWD) was 403 m (68% of predicted), and mean peak VO2 was 10.9 mL/kg/min (39% of predicted). Mean total CO improved from 3.8 L at rest to 7.0 L at maximum exercise. The mean avDO2 increased from 7.4 mL/dL (44% of oxygen content) at rest to 13.2 mL/dL (75% of oxygen content) at maximum exercise. There was a significant increase in both total CO (P < 0.01) and avDO2 (P < 0.05) between rest and sub-maximum exercise. As exercise levels increased, however, no further significant changes were achieved. Long-term studies, especially in combination with exercise programs, would be desirable in order to observe the development of these parameters.
Adequate physical and functional performance is an important prerequisite for renewed participation and integration in self-determined private and (where appropriate) professional lives following left ventricular assist device (LVAD) implantation. During cardiac rehabilitation (CR), individually adapted exercise programs aim to increase exercise capacity and functional performance. A retrospective analysis of cardiopulmonary exercise capacity and functional performance in LVAD patients at discharge from a cardiac rehabilitation program was conducted. The results from 68 LVAD patients (59 males, 9 females; 55.9 ± 11.7 years; 47 HVAD, 2 MVAD, 15 HeartMate II, 4 HeartMate 3, and 4 different implanting centers) were included in the analysis. Exercise capacity was assessed using a cardiopulmonary exercise test on a bicycle ergometer (ramp protocol; 10 W/min). The 6-min walk test was used to determine functional performance. At discharge from CR (53 ± 17 days after implantation), the mean peak work load achieved was 62.2 ± 19.3 W (38% of predicted values) or 0.79 ± 0.25 W/kg body weight. The mean cardiopulmonary exercise capacity (relative peak oxygen uptake) was 10.6 ± 5.3 mL/kg/min (37% of predicted values). The 6-min walk distance improved significantly during CR (325 ± 106 to 405 ± 77 m; P < 0.01). No adverse events were documented during CR. The results show that, even following LVAD implantation, cardiopulmonary exercise capacity remains considerably restricted. In contrast, functional performance, measured by the 6-min walk distance, reaches an acceptable level. Light everyday tasks seem to be realistically surmountable for patients, making discharge from inpatient rehabilitation possible. Long-term monitoring is required in order to evaluate the situation and how it develops further.
Continuous-flow left ventricular assist devices (LVADs) have revolutionized advanced heart failure care. These compact, fully implantable heart pumps are capable of providing meaningful increases in survival, functional capacity, and quality of life. Implantation volumes continue to grow, but several challenges remain to be overcome before LVADs will be considered as the therapy of choice for all patients with advanced heart failure. They must be able to consistently extend survival for the long term (7 to 10 years), rather than the midterm (3 to 5 years) more typical of contemporary devices; they must incorporate design elements that reduce shear stress and avoid stasis to reduce the frequent adverse events of bleeding, stroke, and pump thrombosis; and they must become more cost-effective. The advancements in engineering, implantation technique, and medical management detailed in this review will highlight the progress made toward achieving lifelong LVAD support and the challenges that remain.
Over time left ventricular assist devices (LVAD) have become an alternative to heart transplantation because of enormous technical development and miniaturization. Most patients present a significant improvement in clinical conditions and exercise capacity. Nevertheless, exercise tolerance remains markedly limited even after LVAD implantation compared to a control group. The complex physiological and hemodynamic changes in LVAD patients, both at rest and during exercise, are not yet understood, or at least not completely.
It is the aim of the present paper to describe the current state of scientific knowledge. Furthermore, the spectrum of diagnostic tools, including the noninvasive inert gas rebreathing method for measurement of cardiac output and associate parameters, are discussed. Options for training control in this special patient group are presented.
OBJECTIVES
Patients with ventricular assist device (VAD) show a limited exercise capacity. The aim of this work is to investigate whether VAD speed increase has an effect on exercise performance in the upright position.
METHODS
Fourteen patients implanted with a HeartMate II underwent two cardiopulmonary maximal exercise tests on an upright bicycle ergometer the same day. During one test, VAD speed was set as constant (CONST) and during the other test, VAD speed was increased by 200 rpm each minute (INCR).
RESULTS
No statistical differences were found between the two tests in terms of maximum heart rate, peak oxygen uptake, peak minute ventilation, ventilation efficiency slope and arterial blood pressure. Patients' fatigue perception, measured with a Borg scale, was similar between the two tests over the entire group (15 ± 1 for both CONST and INCR). VAD flow increased from 4.5 ± 0.7 to 6.0 ± 1.0 l/min during CONST and to 7.6 ± 1.4 l/min during INCR. Four patients experienced an easier cycling during INCR, and the other patients noticed no difference. One patient had a suction event during INCR and another had non-sustained ventricular tachycardia at peak exercise. A negative correlation was found between the rate of increase in VAD power during exercise and peak oxygen uptake.
CONCLUSIONS
Although VAD speed increase provided an additional pump flow of 1.6 l/min at peak exercise, no significant objective and subjective benefits on patients' exercise performance were observed. Finally, VAD power could be a useful parameter to monitor patients during exercise.
In the course of time implantation of left ventricular assist devices (LVAD) has become an alternative to heart transplantation due to the enormous technical developments and miniaturization of these systems. Following implantation most patients show a significant improvement in their clinical condition and exercise capacity as measured by the New York Heart Association (NYHA) classification; nevertheless, exercise tolerance remains clearly limited even after LVAD implantation. The complex physiological and hemodynamic changes in LVAD patients both at rest and during exercise are ultimately not completely understood. The aim of this article is to describe the current state of scientific knowledge with respect to the physical capacity of patients with terminal heart failure after LVAD implantation at rest and during exercise. The influence of increasing the pump speed and continuous physical exercise training on the physical capacity in the long-term course is reviewed. The significance of new diagnostic tools, such as the non-invasive inert gas rebreathing method for measurement of cardiac output and arteriovenous oxygen difference (AVDO2) in assessment of the performance of LVAD patients is discussed.
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