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Characteristics, Therapeutic Needs, and Scope of Patients With a Continuous-Flow Left Ventricular Device Entering Cardiac Rehabilitation


Hildebrandt, Anke, PhD; Willemsen, Detlev, MD; Reiss, Nils, MD, PhD; Bartsch, Petra, MD; Schmidt, Thomas, MA; Bjarnason-Wehrens, Birna, PhD

Journal of Cardiopulmonary Rehabilitation and Prevention: March 2019 - Volume 39 - Issue 2 - p 91–96
doi: 10.1097/HCR.0000000000000342
Cardiac Rehabilitation

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.

Retrospective single-center study including 69 left ventricular assist device (LVAD) patients aimed to evaluate characteristics, therapeutic needs, and scope of LVAD patients at admission to cardiac rehabilitation (CR). The results demonstrated a heterogeneous group with a high level of impairment and special demands in many CR domains, resulting in a need for a highly individualized CR approach.

Department for Cardiac Rehabilitation, Schüchtermann-Klinik Bad Rothenfelde, Bad Rothenfelde, Germany (Drs Hildebrandt, Willemsen, Reiss, Bartsch, and Schmidt); and Institute of Cardiology and Sports Medicine, Department for Preventive and Rehabilitative Sport and Exercise Medicine, German Sports University Cologne, Cologne, Germany (Drs Hildebrandt, Schmidt, and Bjarnason-Wehrens).

Correspondence: Anke Hildebrandt, PhD, Institute of Cardiology and Sports Medicine, Department for Preventive and Rehabilitative Sport and Exercise Medicine, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933 Cologne, Germany (

The authors declare no conflicts of interest.

The incidence and prevalence of heart failure are increasing. Demographic change, advanced drug, and interventional therapy are resulting in an increasing number of end-stage heart failure patients surviving longer.1 End-stage heart failure is associated with major disability and poor prognosis.1 Heart transplantation is the gold standard therapy and associated with improved survival and quality of life in patients with end-stage heart failure. Because of the lack of donor hearts, however, the use of continuous-flow left ventricular assist devices (LVADs) in end-stage heart failure patients has increased, whether as a bridge to transplant or as destination therapy.2 This therapy is associated with improved survival and functional capacity.2 The continued development of LVADs has made their application for therapists, as well as for the patients themselves, easier and has led to less limitations in patient mobility, activity, and participation. Thus, an increasing number of LVAD patients are now eligible and accepted for specialized cardiac rehabilitation (CR) programs.3 , 4 Structured CR strategies for this group are poorly implemented.3–7 Ben Gal et al7 published a snapshot from exercise-based CR currently offered in the European Society of Cardiology–affiliated countries. The results demonstrate a great variance in availability and programs provided. Of the 77 implanting centers from 26 European countries, only 58% reported to provide any kind of exercise-based CR to eligible patients. Only a few small studies have reported experience gained in this field.8–14 However, these studies showed promising results. The aim of this study was to evaluate the patient characteristics at admission to CR and their therapeutic needs and scope within a greater cohort. This knowledge will help identify their special CR requirements, develop adapted CR programs, and improve CR efficacy in this patient group.

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In this retrospective single-center study, we included the records of 84 consecutive patients with a continuous-flow LVAD (HeartWare System with HVAD pump [HVAD], HeartMate II [HM II], Thoratec Corporation), who were admitted for their first CR in an inpatient rehabilitation center. According to German law, every eligible patient has the right to go to CR, which is paid by the health care system. Thus, most of the patients were transferred directly from the implanting to the rehabilitation center as soon as their clinical condition allowed.

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All relevant medical information was documented from the patient records and the therapy documentation system (TIMEBASE, v2.0, Magrathea) of the clinic. Personal data were anonymized with a code according to the German Data Protection Act. The study protocol was approved by the local ethics commission. We used the International Classification of Functioning, Disability and Health (ICF)15 for the classification of health and health-related domains, with a special focus on relevant everyday impairment.

The medical records included the results of a 6-min walk test performed according to the American Thoracic Society guidelines16 at the admission to CR. Moreover, it included the results of 2-legged isometric maximal strength test of the quadriceps femoris. The test was performed using a computerized force sensor. The patient was asked to press as hard as possible against the fixed arm for 3 sec, avoiding the Valsalva maneuver and upper body movement. The measurement was repeated 3 times with the best result recorded as the maximal isometric force.

We used PASW Statistics 20.0 (SPSS, IBM) for recording and analyzing the data. Results of a frequency analysis are reported as prevalence and percent values. Results of descriptive statistics are reported as means and standard deviations.

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From 84 consecutive patients, 69 completed CR and were included in the analyses (50.7 ± 13.6 y; 10 female, 59 male; 48 HVAD; 21 HM II; etiology: 38 ischemic, 29 dilated cardiomyopathy, 1 myocarditis, 1 endocarditis and heart valve disorder). Patients who dropped out of CR because of health problems or for personal reasons were excluded. The Figure describes the reasons for the exclusion from the analyses (n = 15). We compared baseline characteristics of the excluded patients with those who completed CR and found no significant differences between the groups. The characteristics of the 69 patients at admission to CR are summarized in Table 1.



Table 1

Table 1

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In the initial medical anamnesis, patients were asked about their perceived everyday relevant impairments. Impairment in body function (79.7%), cardiovascular function (73.9%), and neuromuscular-skeletal and movement-related function (73.9%) was seen in more than 70% of the patients. Impairments in activity and participation were relevant in 95.7% of the patients (limitation in mobility [89.9%], domestic living [68.1%], and community, social, and civic life [71.0%]). Table 2 summarizes the results classified according to the first level of the ICF.

Table 2

Table 2

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Cardiac rehabilitation was started 44 ± 38.6 d (15-222 d) after implantation. The mean CR duration was 28 ± 9.7 d (11-60 d). During CR, medical complications requiring transfer back to the implanting hospital occurred in 7 patients. The reasons were ventricular fibrillation with syncope, pericardial effusion, cardiac decompensation, incorrect cannula location of the LVAD, decubitus, angiectasis in the colon with hemorrhage, and infection. The mean ± standard deviation duration of the interim hospital stay was 7 ± 6.6 d (1-21 d). All patients subsequently resumed their CR.

Table 3 summarizes the therapeutic treatment in certain domains completed during CR in the LVAD patients, compared with the treatment in overall CR population in Germany.17 The main components of exercise intervention were individually adapted monitored aerobic endurance training on a cycle ergometer (n = 51; 9.1 ± 4.4 treatments; 272.9 ± 133.4 min) and/or resistance exercises (n = 69; 8.1 ± 3.2 treatments; 242.6 ± 95 min).

Table 3

Table 3

Since the LVAD patients admitted to CR were a heterogeneous group regarding age, comorbidities, post-implantation time, and degree of deconditioning, the decision as to which exercise intervention the patients would be able to perform and benefit from was developed individually in every case by the CR team. Every patient, who was physically able, took part in both aerobic cycle training and resistance training.

Individually coached aerobic exercise training was performed with monitoring 5 times per wk, 30 min per session on a cycle ergometer. The training was started at low level and was gradually increased and adapted, using the Borg scale18 (<13-15 rating of perceived exertion in patients in good physical condition) and breathing frequency (should allow for a conversation) to control intensity. The resistance training was performed with individual coaching 3 times per wk for 30 min per session at moderate intensity. The intensity was determined by gradually increasing weight. The aim was to find intensity that allowed the patient to perform 3 sets of 20 repetitions at an individualized speed. Between exercises, rest time was 1 to 2 min. Resistance training was performed using weighted balls as well as elastic bands and weight machines (leg press, leg extension, leg curl, and lateral pull/arm extension, and in a few patients, shoulder pull and back extension). No exercise-related complications were documented. The exercise training resulted in significant (P < .001) improvements in 6MWD (+98.7 m or 33%) and both legs peak torque of the quadriceps femoris by 25.6% (+99.6 Newton).

All patients received individually adapted education (20.1 ± 7.2 treatments). The main topics beside heart failure topics were LVAD-related issues especially about daily reliable handling with the assist device, oral anticoagulation, or care of the driveline exit side.

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In the early phase after LVAD implantation, patients still experience a variety of impairments and major disabilities. Results of a recent review demonstrated that our understanding of factors influencing functional status and disability in this patient population is incomplete and needs to be enhanced.19 To our knowledge, this is the first study with a large cohort to present a retrospective comprehensive impression of LVAD patients admitted to CR.

The expectations of CR in patients with recent LVAD implantation are not clearly defined or formulated and may vary widely depending on the patient's clinical condition. In Germany, phase 2 CR in LVAD patients is performed only in an inpatient setting in specialized CR centers. The main objective of CR in LVAD patients is the achievement of independent home care. To achieve this goal, the patient's physical condition and mobility must be improved during CR. Furthermore, daily reliable handling of the LVAD and the oral anticoagulation regimen must be learned. The driveline must be free from inflammation or irritation and self-care or care at home must be ensured. In patients with unrestricted CR capability, who are able to follow the complex CR program (physical and cognitive) and who do not have limited activities of daily living (ADL), the goals of independent home care can be achieved. In Germany, a 3-wk CR program is a standard of care. If needed, an extension of CR is possible at the request of the treating CR cardiologist. The reasons for extension can vary widely on the basis of the clinical condition: limiting comorbidities; need for further nursing and medical care; situations in the patient's home requiring nursing or medical care; ADL limitations; and limited CR capability at baseline.

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Similar to previous publications,9–13 , 19–24 our results demonstrate that, despite similar etiologies, patients with a new LVAD are a heterogeneous group, especially regarding age distribution,25 New York Heart Association classification, left ventricular ejection fraction, functional capacity,9 , 10 , 14 , 18 , 26 and level of muscular deconditioning.11 , 13 , 25 This is reflected by the length of hospital stay post-implantation, with a range of 15 to 222 d, emphasizing the different clinical conditions of LVAD patients when admitted to CR. Different etiologies, overall duration of the disease, post-operative complications, and recovery time might contribute to this. Medical complications required transfers to the hospital where the LVAD implant was done necessary in 7 patients (10%), but all patients subsequently resumed their CR. Other studies9 , 26 reported shorter or similar13 , 14 lengths of hospital stay after LVAD implantation prior to CR admittance. In the study by Chu et al,26 patients (n = 58) were admitted to CR 27.0 ± 15.3 d post-implantation. In contrast to our results, 36% of the cohort in this study needed at least 1 transport to acute care and <50% of those returned and completed CR.

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At admittance to CR, functional status was heterogeneous, with a 6-min walk distance ranging from 100 to 560 m and muscular strength of the quadriceps femoris ranging from 22 to 900 Newton. The mean 6-min walk distance of 291.7 ± 116.7 m, corresponding to <50% of predicted values,27 is considerably lower than reported in other studies with LVAD patients.12 , 24 , 28 Decreased muscular strength, especially in the lower limbs, has been previously reported.13 Rehabilitation programs including exercise training can enhance 6-min walk distance12 , 23 , 28 and muscular strength13 in LVAD patients.

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Earlier studies9 , 10 , 14 , 26 have assessed the severity of patient disability at the time patients were admitted to CR using the Functional Independent Measure score. The results show markedly reduced Functional Independent Measure scores, as well as significant improvements after CR.9 , 10 , 14 , 26 In our study, impairments and restrictions were classified using the ICF.15 The classification of impairments and restrictions using the ICF enables not only the identification of domains of deficits but also its specific appearance in tasks of daily living.3 This can help identify special needs of patients and match them to the therapy approach best suited to their need.

Despite variable physical and psychological condition, the overall degree of impairment was high, especially in the body function (79.7%) and activity and participation (95.7%) domains. In the body function domain, reduced cardiopulmonary exercise capacity (73.9%) and peripheral muscle weakness (73.9%) were most prominent. In the activity and participation domain, limitation in mobility (89.9%), especially limitation in walking capacity (72.5%) and limitation in climbing stairs (73.9%), impairments managing the ADL (65%), and risk of loss of social contacts (37.7%) were most frequently mentioned.

The use of ICF is a new approach in CR so that values for other CR populations are rare29 and comparison is difficult. However, the results show that these patients need a highly individualized and comprehensive approach in CR that enables them to live a self-determined, independent life with good quality supported by the LVAD. Thus, based on clinical stabilization, the focus of CR efforts should be to restore physical and psychosocial function as a precondition to improving participation and reducing activity and mobility limitations associated with the disease. This can be achieved only through individually tailored CR in the somatic and also in the education, psychosocial, and social therapeutic domains.

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Cardiac rehabilitation in LVAD patients requires a highly qualified multidisciplinary rehabilitation team.3 Since the mean CR duration was 28 d compared with a mean duration of 21.2 d for the total CR population in Germany,30 many patients might also need a prolonged duration of CR. The longer treatment duration and high demand for individual therapeutic measures are, furthermore, associated with a need for greater employee resources and increased costs of rehabilitation measures compared with other indications for CR.

Compared with therapeutic treatment in overall CR population in Germany, LVAD patients received significant more physical therapy, physiotherapy occupational therapy, and specialized education but not the same amount of exercise therapy (Table 3). This reflects the limitations in the activity and participation domains, (ie, mobility walking capacity, climbing stairs, managing the ADL), causing an increased demand for an individualized approach to therapy. All patients received approximately 50 treatments of exercise therapy, physical therapy, and individual physiotherapy during 28 ± 9.7 d of CR. The need for physical therapy was high. Many patients suffered from back and neck complaints caused by the extra weight of the LVAD system. All patients received massages (7 ± 2.5 treatments) and 94.2% were treated with heat packs, while breathing therapy (eg, equipment-assisted respiratory training) was frequently provided (71% of LVAD patients 9.4 ± 4.8 times) to improve respiratory muscle strength. In addition, 29% of patients received individualized occupational therapy to treat impairments in mobility and especially executing ADL.

The results of the retrospective analysis of the therapeutic measures delivered in the education domain show high demand for educational content.31 This applies especially to LVAD-specific education of patients and family members, such as a thorough training in dealing with the LVAD system, the international normalized ratio and blood pressure management, enabling them to live a self-determined, independent life with the LVAD. The learning aptitude of patients might be influenced by age, cognitive performance, or affinity for technology, resulting in more or less time needed for education. All patients received educational lessons that were time-consuming, with an average teaching time of 14 hr. Finally, the need for individualized nursing care was high.

An LVAD implantation is associated with a high psychological burden for patients and their family members.3 , 32 This may be caused by permanent dependence on the device and/or the uncertainty of prognosis and fear of life-threatening complications (eg, stroke, cerebral bleeding, and infections), resulting in various psychological disorders (eg, depression, anxiety),4 , 22 , 32 , 33 which must be treated during CR. The results show a high demand for individualized therapeutic measures in clinical psychology/neuropsychology. Psychological counseling was delivered to 71% of the patients in this study, with great variance in the demand (1-16 treatments; 30-690 min). Surprisingly, if compared with the general CR population, the volume of therapeutic treatment seems to be lower in the LVAD patients. In fact, the psychological counseling was much more intensive in the LVAD group since it was almost individual treatment only, while the counseling in a CR cohort was mainly administrated in groups (group discussions, relaxation training).

In addition, LVAD patients usually have a close relationship with the LVAD coordinator at the implanting clinic. The LVAD coordinator is the first contact person for all LVAD patients concerning most of the relevant issues. This kind of psychological and social treatment/support is not covered in the treatment statistic and must be taken into account. The close contact to the LVAD coordinator is continued during CR. This also explains the lower need of social treatments during CR.

Before LVAD patients are discharged from CR, the necessary requirements in their specific situations and circumstances have to be addressed and resolved (eg, availability of a continuous power supply for the LVAD device at home or the procurement of domestic or nursing support). Therefore, LVAD patients have an increased need for social services (98.6%). Most of the patients received support for participation (71%) and/or domestic assistance (46%).

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This is a single-center study with a retrospective analysis without a control group. In the future, prospective randomized controlled studies with larger sample sizes would be valuable.

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Left ventricular assist device patients admitted to CR are a heterogeneous group with a high level of impairments and special needs across many CR domains. This refers not only to exercise therapy, physiotherapy, and physical therapy but also to individually adapted education, psychological therapy, and social support. Further research, especially randomized controlled studies with sufficiently large samples, is needed to evaluate the efficacy of CR in this group of patients.

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The authors ensure that the ethical publication standards of the American Psychological Association and guidelines of the Journal of Cardiopulmonary Rehabilitation and Prevention were followed in this study.

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1. Ponikowski P, Voors AA, Anker SD, et al 2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: The Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure of the European Society of Cardiology (ESC). Developed with the special contribution of the Heart Failure Association (HFA) of the ESC. Eur J Heart Fail. 2016;18(8):891–975.
2. Kirklin JK, Naftel DC, Pagani FD, et al Seventh INTERMACS annual report: 15,000 patients and counting. J Heart Lung Transplant. 2015;34(12):1495–1504.
3. Willemsen D, Cordes C, Bjarnason-Wehrens B, et al Rehabilitation standards for follow-up treatment and rehabilitation of patients with ventricular assist device (VAD). Clin Res Cardiol Suppl. 2016;11(suppl 1):2–49.
4. Feldman D, Pamboukian SV, Teuteberg JJ, et al The 2013 International Society for Heart and Lung Transplantation Guidelines for mechanical circulatory support: executive summary. J Heart Lung Transplant. 2013;32(2):157–187.
5. Wells CL. Physical therapist management of patients with ventricular assist devices: key considerations for the acute care physical therapist. Phys Ther. 2013;93(2):266–278.
6. Compostella L, Russo N, Setzu T, et al A practical review for cardiac rehabilitation professionals of continuous-flow left ventricular assist devices: historical and current perspectives. J Cardiopulm Rehabil Prev. 2015;35(5):301–311.
7. Ben Gal T, Piepoli MF, Corra U, et al Exercise programs for LVAD supported patients: a snapshot from the ESC affiliated countries. Int J Cardiol. 2015;201:215–219.
8. Kugler C, Malehsa D, Schrader E, et al A multi-modal intervention in management of left ventricular assist device outpatients: dietary counselling, controlled exercise and psychosocial support. Eur J Cardiothorac Surg. 2012;42(6):1026–1032.
9. English ML, Speed J. Effectiveness of acute inpatient rehabilitation after left ventricular assist device placement. Am J Phys Med Rehabil. 2013;92(7):621–626.
10. Alsara O, Reeves RK, Pyfferoen MD, et al Inpatient rehabilitation outcomes for patients receiving left ventricular assist device. Am J Phys Med Rehabil. 2014;93(10):860–868.
11. Kerrigan DJ, Williams CT, Ehrman JK, et al Muscular strength and cardiorespiratory fitness are associated with health status in patients with recently implanted continuous-flow LVADs. J Cardiopulm Rehabil Prev. 2013;33(6):396–400.
12. Kerrigan DJ, Williams CT, Ehrman JK, et al Cardiac rehabilitation improves functional capacity and patient-reported health status in patients with continuous-flow left ventricular assist devices: the Rehab-VAD randomized controlled trial. JACC Heart Fail. 2014;2(6):653–659.
13. Marko C, Danzinger G, Kaferback M, et al Safety and efficacy of cardiac rehabilitation for patients with continuous flow left ventricular assist devices. Eur J Prev Cardiol. 2015;22(11):1378–1384.
14. Yost G, Coyle L, Milkevitch K, Adair R, Tatooles A, Bhat G. Efficacy of inpatient rehabilitation after left ventricular assist device implantation. PM R. 2017;9(1):40–45.
15. World Health Organization. International Classification of Functioning, Disability and Health: ICF. Genève, Switzerland: World Health Organization; 2001.
16. American Thoracic Society. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002;166(1):111–117.
17. Deutsche Rentenversicherung Bund. Reha-Bericht 2015—Die medizinische und berufliche Rehabilitation der Rentenversicherung im Licht der Statistik. Accessed February 9, 2017. In German.
18. Borg G. Perceived exertion as an indicator of somatic stress. Scand J Rehabil Med. 1970;2(2):92–98.
19. Abshire M, Dennison Himmelfarb CR, Russell SD. Functional status in left ventricular assist device-supported patients: a literature review. J Card Fail. 2014;20(12):973–983.
20. Jung MH, Gustafsson F. Exercise in heart failure patients supported with a left ventricular assist device. J Heart Lung Transplant. 2015;34(4):489–496.
21. Loyaga-Rendon RY, Plaisance EP, Arena R, Shah K. Exercise physiology, testing, and training in patients supported by a left ventricular assist device. J Heart Lung Transplant. 2015;34(8):1005–1016.
22. Bruce CR, Delgado E, Kostick K, et al Ventricular assist devices: a review of psychosocial risk factors and their impact on outcomes. J Card Fail. 2014;20(12):996–1003.
23. Karapolat H, Engin C, Eroglu M, et al Efficacy of the cardiac rehabilitation program in patients with end-stage heart failure, heart transplant patients, and left ventricular assist device recipients. Transplant Proc. 2013;45(9):3381–3385.
24. Hayes K, Leet AS, Bradley SJ, Holland AE. Effects of exercise training on exercise capacity and quality of life in patients with a left ventricular assist device: a preliminary randomized controlled trial. J Heart Lung Transplant. 2012;31(7):729–734.
25. Chung CJ, Wu C, Jones M, et al Reduced handgrip strength as a marker of frailty predicts clinical outcomes in patients with heart failure undergoing ventricular assist device placement. J Card Fail. 2014;20(5):310–315.
26. Chu SK, McCormick Z, Hwang S, Sliwa JA, Rydberg L. Outcomes of acute inpatient rehabilitation of patients with left ventricular assist devices. PM R. 2014;6(11):1008–1012.
27. Chetta A, Zanini A, Pisi G, et al Reference values for the 6-min walk test in healthy subjects 20-50 years old. Respir Med. 2006;100(9):1573–1578.
28. Laoutaris ID, Dritsas A, Adamopoulos S, et al Benefits of physical training on exercise capacity, inspiratory muscle function, and quality of life in patients with ventricular assist devices long-term postimplantation. Eur J Cardiovasc Prev Rehabil. 2011;18(1):33–40.
29. Racca V, Di Rienzo M, Mazzini P, et al ICF-based approach to evaluating functionality in cardiac rehabilitation patients after heart surgery. Eur J Phys Rehabil Med. 2015;51(4):457–468.
31. Kato N, Jaarsma T, Ben Gal T. Learning self-care after left ventricular assist device implantation. Curr Heart Fail Rep. 2014;11(3):290–298.
32. Brouwers C, Denollet J, Caliskan K, et al Psychological distress in patients with a left ventricular assist device and their partners: an exploratory study. Eur J Cardiovasc Nurs. 2015;14(1):53–62.
33. Reynard AK, Butler RS, McKee MG, Starling RC, Gorodeski EZ. Frequency of depression and anxiety before and after insertion of a continuous flow left ventricular assist device. Am J Cardiol. 2014;114(3):433–440.

cardiac rehabilitation; functional capacity; left ventricular assist device; rehabilitation needs

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