Secondary Logo

Journal Logo

Patients’ Perspectives on Transplantation While Undergoing Left Ventricular Assist Device Support

Wilhelms, Lidija A.*; Blumenthal-Barby, Jennifer S.*; Kostick, Kristin M.*; Estep, Jerry D.; Bruce, Courtenay R.*

doi: 10.1097/MAT.0000000000000567
Adult Circulatory Support
Free
SDC

Left-ventricular assist device (LVAD) therapy is a growing mechanical circulatory support therapy used to treat patients with advanced heart failure. There is a general assumption among clinicians that patients would prefer to accept a heart to any other treatment were they eligible. However, little research has been done to clarify the nuances of patient treatment preferences for LVAD therapy versus transplantation. The objective of this study was to investigate this treatment preference assumption from patients’ perspectives. In a single-site study, 15 LVAD patients, 15 LVAD candidates, 15 LVAD decliners, and 15 LVAD caregivers (n = 60) participated in structured, in-depth interviews to assess decisional processes and treatment preferences for advanced heart failure. The interview guides were consistent with the Ottawa framework on decision-making processes. All participants were identified by the LVAD coordination team and recruited consecutively between February and November 2014. The patient and candidate groups included both LVAD designations: destination therapy (n = 22), bridge-to-transplant (n = 4), as well as four participants who deferred designation pending worsening clinical status. The interviews were analyzed using qualitative description with constant comparisons, aided by ATLAS.ti. Although LVAD eligible patients generally show a preference for heart transplantation as the ideal treatment for heart failure, some patients begin to show ambivalence as they experience LVAD therapy and begin to prefer LVAD as a long-term, destination treatment. Some themes that emerged from the interviews concerning transplantation centered on the consequences of multiple major surgeries (i.e., LVAD placement followed by heart transplantation, n = 18), fears surrounding lifestyle changes of accepting a heart transplant (n = 14) and life satisfaction with an LVAD as a “new normal” (n = 18). Findings suggest that experience with an LVAD can sometimes cause ambivalence about transplant with some patients preferring LVAD as destination even when transplant is an option. We provide clinical and programmatic implications of this, concluding with practical recommendations for how to fully address patients’ goals of treatment as their health and situation changes over time.

From the *Center for Medical Ethics & Health Policy, Baylor College of Medicine, Houston, Texas; and Houston Methodist DeBakey Heart & Vascular Center and J.C. Walter Jr. Transplant Center, Houston Methodist Hospital, Houston, Texas.

Submitted for consideration April 2016; accepted for publication in revised form March 2017.

Disclosure: Dr. Estep is currently receiving consultant and research support from Thoratec Corporation. The corporation had no role in the funding or writing of this paper. For the remaining authors, none was declared. This research was supported by CDR-1306–01769 from the Patient Centered Outcomes Research Institute (PCORI). ClinicalTrials.gov Identifier: NCT02248974. All statements in this report, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of PCORI, its Board of Governors or Methodology Committee.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text, and links to the digital files are provided in the HTML and PDF versions of this article on the journal’s Web site (www.asaiojournal.com).

Correspondence: Lidija A. Wilhelms, Center for Medical Ethics & Health Policy, Baylor College of Medicine, One Baylor Plaza, MS: BCM 420, Houston, TX 77030. Email: wilhelms@bcm.edu.

There is a prevailing assumption among clinicians that the goal of many left ventricular assist device (LVAD) patients is to ultimately receive a heart transplant, commonly believed to be “the gold standard” of treatment for advanced heart failure.1 However, patients who receive an LVAD on their way to receiving a transplant (i.e., bridge-to-transplant [BTT]) constitute a shrinking minority, with a majority of patients receiving LVAD as “destination therapy” (DT). Whereas clinicians have assumed that the DT designation is involuntary, because of changing health status or other contraindications that effect transplant eligibility, little is understood about circumstances in which DT is elected by choice.

DT patients refer to patients who are not eligible for a heart transplant and for whom an LVAD is the only treatment option beyond comfort-only therapies for end-stage heart failure.2 A BTT LVAD recipient indicates that the patient has undergone LVAD placement but has also been approved and listed to receive heart transplantation.3,4 The assumption that most LVAD patients prefer a heart transplant over DT has significant implications for patient selection committee meetings and medical review boards that assess patient eligibility. For example, a common practice of LVAD health care teams is to try to ameliorate barriers—medical, surgical, and psychosocial—to transplantation with the belief that the patient would want to proceed with a heart transplant were one to become available. These efforts may be undertaken in the absence of understanding the full range of patient preferences with respect to DT versus transplant.

This brief report presents the results of a qualitative exploration of patient attitudes toward LVAD as DT versus BTT, based on interviews designed to assess informational and decisional needs regarding LVAD placement among LVAD patients and their caregivers, eligible LVAD candidates, and decliners of LVAD treatment. Exploration of this topic is important to ensure clinical resources and time are allocated appropriately while also aiding patients and their families make medical decision that are most in line with their values and goals.

Back to Top | Article Outline

METHODS

Participants.

Interviews were conducted with 15 LVAD patients (device already implanted with an average of 539 days post-implant), 15 LVAD candidates (approved for LVAD therapy, received education about the LVAD and in the process of making a decision about LVAD placement), 15 LVAD decliners (candidates who initially or persistently declined LVAD placement) and 15 LVAD caregivers (the primary caregiver of an LVAD patient). All patient, candidate, and decliner participants met the following criteria: 1) classified as NYHA Class III and IV; 2) aged between 30 and 85 years old with decision-making capacity; 3) had an acceptable surgical risk/benefit ratio for LVAD implantation with good psychosocial support, coping mechanisms, and financial resources determined by “clearance” from the transplant social worker. LVAD decliners met two additional criteria: 1) they described themselves as declining an LVAD and 2) they met with consultants (e.g., bioethicists, social workers, and psychologists) to address any concerns that may impact their declination. Some decliners only initially declined LVAD therapy and eventually accepted an LVAD (n = 7) and received designations (BTT, n = 4 and DT, n = 3). Every participant belonged to only one group and interviewed caregivers were not recruited as dyads with interviewed LVAD patients.

Back to Top | Article Outline

Recruitment and Consent Process.

Between February 2014 and November 2014, members of the LVAD clinical team identified participants through patient rosters distributed weekly. All patients, candidates, and decliners who met eligibility requirements were approached by the research team consecutively and asked to participate in in-depth interviews. Caregivers were identified by an LVAD coordinator or social worker and approached consecutively through the same process but requiring they are the primary caregiver of an LVAD patient. For the consent process, a written form was read and signed by all participants and explained verbally by the interviewer. The study was approved by both Institutional Review Boards of the coordinating site (Baylor College of Medicine) and the participating site (Houston Methodist Hospital).

Back to Top | Article Outline

Communication of Risks and Benefits of LVAD Placement

Interview Guide Development and Interviews. Interviewers conducted structured, in-depth interviews using a team developed semistructured interview guide. The research team reviewed the initial guide based on expert opinion, an extensive literature review, and familiarity with the LVAD decision-making process. During the participant enrollment, the interview guide was modified iteratively to evaluate decisional processes and perspectives of participants regarding LVAD therapy. The final interview guide consisted of open-ended questions exploring five prespecified domains consistent with the Ottawa framework on decision-making processes. These interview guides can be found in our previous publications.5,6 Interviews were conducted (by five research staff J.B.B., C.B., E.D., K.K., and L.W.) and used to assess decisional processes and perspectives of LVAD patients, candidates, decliners, and caregivers. Interview transcripts were uploaded and analyzed using ATLAS.ti.

Analysis. We used grounded theory method to recognize and assess decisional needs of our 60 person sample.7 Grounded theory centers on initially determining themes that are based on repeating or reoccurring statements in data from participants. All participant interview transcripts were digitally recorded, professionally transcribed verbatim, cleaned, and double checked for accuracy. The transcriptions were then uploaded and analyzed using ATLAS.ti (Scientific Software Development Gmbh).8 ATLAS.ti is a software that allows qualitative, content thematic analysis of interview transcripts through a systematic process of documentation, coding, and interpretation. Quotations from the transcribed interviews were then grouped based on theme and presented in this article.

Back to Top | Article Outline

RESULTS

Theme 1: Of the 15 LVAD candidates interviewed, 9 were designated as DT, 2 were designated as BTT, and 4 were deferred designation pending worsening clinical status. Most candidates (n = 9) including those designated as DT, and most decliners (n = 11) stated a desire for “going straight to a heart transplant” as treatment for their heart failure to reduce surgical risk. Six candidates and six decliners expressly stated their fear of having more than one surgery. A decliner described his feelings about the risk of two surgeries: “When I get ready for a heart transplant, they’re going to have to cut me open and do the same thing all over again, so I was waiting on them to say, ‘You were approved for a heart transplant.’”

Several LVAD patients (n = 6) shared this same fear of surgical risk but in the context of accepting a heart transplant after already having undergone LVAD implantation surgery. When discussing the possibility of a future heart transplant, one patient stated, “These doctors don’t like cracking a chest more than twice. So to crack it a third time, I would have to really be 100 percent in top shape.” Some patients who had a longer recovery time because of complications after their LVAD implantation reflected that they did not want to go through another surgery because of the burden it could place on their loved ones. As one patient stated, “I just couldn’t put his wife through another major surgery recovery” if he were to be reevaluated for a heart transplant.

Theme 2: Several LVAD patients (n = 4) explained their reluctance for transplant with respect to their concerns about rejection of the donor heart during transplant recovery. One patient said, “I worry about everything matching. With the LVAD, it’s your same heart and everything’s going to match.” Another patient said, “I think I would be a little bit more sensitive than other people to anti-rejection drugs to keep a new heart that really bothers me so I didn’t like the idea of a heart transplant at all.”

Lifestyle limitations are another salient issue for patients following an immunosuppressant regimen after transplant, with some candidates expressing concerns about the limitations on their lifestyle with immunosuppressants following transplant, such as: “You’ve got to worry about everything you can contract. Going to the mall, to a restaurant, there are germs everywhere. Worrying about who sneezes on you, places you can and can’t go. If you have a sick relative, you can’t go. You can’t see them because of the potential chance [of getting sick].” Having to take immunosuppressants to combat rejection is also a concern because many of the candidates (n = 6) mentioned their grandchildren as motivators to seek heart failure treatment. Despite having undergone basic transplant education, many participants still held the misconception that a regimen of immunosuppressants requires limited contact with young children. This sentiment proved to be an important source of reluctance for many participants when considering a heart transplant. Others had concerns about how an immunosuppressant regimen would interfere with their hobbies, such as, “I’d much rather would have gone with the LVAD than a heart transplant because of the anti-rejection drugs you’d have to take—because now I can still dig in the dirt. I love gardening.”

Theme 3: Another aspect that contributed to LVAD patients’ hesitation of accepting a heart transplant is that they felt satisfied with their life on the LVAD (n = 5 of 15), echoing a “if it’s not broke, don’t fix it” sentiment. Three of these patients reported that even if a heart were available to them, they would prefer to continue management of their heart failure symptoms with the LVAD. For instance, one patient explained, “I don’t want to do [a heart transplant]. Not as long as this here [LVAD] works.”

Of the seven decliners who eventually accepted an LVAD, five acknowledged that they were satisfied with their life on the LVAD. A decliner explained, “Life [with the LVAD] is pretty good now. The LVAD is a good thing, a real good thing.” Other decliners expressed their adjustment to life with an LVAD: “I learned to get most of my life back, there are just certain things I got to live without, but it’s brought me back on my degree of quality of life.”

Caregiver perspectives: Many LVAD caregivers (n = 8) reported similar satisfaction as patients and initial decliners about adjustment and satisfaction to life with an LVAD. Most of the caregivers (n = 7) interviewed agreed that their loved ones were able to return to “normal” after, although very few of them provided details about what “normal” meant to them. Caregivers suggested that there is an adjustment period right after LVAD placement, particularly with regard to helping their loved one clean and maintain the device. After this period of time, caregivers and patients report adjusting to a new baseline of what life like on a device. One caregiver, whose loved one was designated as BTT, exemplified this sentiment by saying, “We’re happy the way we are. We’re used to it; we know how to take care of him. Do we have to start all over?”

Back to Top | Article Outline

DISCUSSION

Our work extends and deepens our understanding of patients’ decision-making processes by challenging the commonly held presupposition that candidates, like clinicians, view the LVAD as an ideal a BTT with a hope of getting to a transplant. Our analysis focused on grouping the overall themes of LVAD patient, candidate, decliner attitudes toward this ideation as well as the LVAD caregivers’ perspectives. For most LVAD candidates and many decliners, the surgical risk of a major surgery is only “worth it” if it is to receive a heart transplant (i.e., “bridging” would not be a sufficient basis to undergo surgery).6 On the other hand, some patients who already have an LVAD believe that getting a heart is not worth the surgical risk and consequences of an additional major surgery—or at least have ambivalence about this.

One possible reason why some LVAD patients do not want to undergo transplantation can be explained by adaption theory.9 In the context of LVAD implantation, this theory would suggest that LVAD patients have adapted their life—from daily routine and activity to body image—to accommodate an LVAD as their “new normal.”10 In addition to physical adaptation, most LVAD patients are also capable of cognitively adapting to LVAD therapy resulting in little to no psychologic problems such as anxiety or depression.11 The idea of having to create an even “newer” normal after another significant change, like accepting a heart transplant, is intimidating, even unwanted, by some patients and many caregivers.12–14 This new normal idea may cause some patients who initially hoped for a heart transplant to come to view a heart transplant as yet another challenge accompanied by a new battery of adjustments that would again change their “normal” as well as affect their lifestyle and hobbies. Many of the caregivers interviewed supported this same idea because, serving as a patient’s main support, they hesitate at the idea of having to make another major adjustment after already changing their life and routine to accommodate caring for someone with an LVAD.

In addition to avoiding an even newer normal that accompanies a heart transplant, some patients expressed caution when considering a transplant because they had heard stories of other patients receiving hearts but “not lasting a long time,” especially when they feel an LVAD gives them certainty of “waking up in the morning.” This observation resonates with empirical evidence that a growing percentage of the DT population experiences a 2 year survival rate that competes with a 2 year transplant survival rate, a rate that will likely continue to grow as technology continues to progress to smaller, more reliable mechanical assist devices.15,16 As DT-LVAD clinical outcomes continue to improve, potentially overcoming those of heart transplant, patients choosing to stay with LVAD therapy over a transplant may become more a commonplace decision with comparable clinical outcomes.

Although there are no clinical outcomes specific to this self-selecting DT-LVAD patient population, this brief qualitative report suggests that clinical studies could be conducted on this group to investigate whether choosing continued LVAD therapy over heart transplantation improves outcomes.

Back to Top | Article Outline

Clinical Implications and Recommendations

These findings should not be interpreted to suggest that most patients would prefer to stay with an LVAD rather than move to transplant. In fact, most patients are overly optimistic and hopeful regarding transplant, often considering themselves candidates for transplant, even when, objectively, they are not candidates.1 These findings should, however, be read to indicate that some patients may prefer to stay with an LVAD even if they are potentially transplant eligible, and that their preferences may evolve and change over time as they adapt to life with an LVAD.

These findings indicate ambivalence among some patients toward LVAD as a BTT. This observed variation in attitudes could have implications for education and informed consent processes, which assume a preference for transplant over LVAD when available. Our first recommendation based on these findings is that, rather than assuming that every LVAD patient would aim for the “ideal treatment” and be listed for transplant, clinicians should consider that for some patients, LVAD is—or becomes—the ideal treatment. Moreover, even if transplant eligible patients do wish to move to transplant if possible, they may still have significant concerns and ambivalence that need to be addressed through additional, targeted education. Since we found that patients and candidates had concerns about what transplant would mean for time with grandchildren, engaging in hobbies, and how life impacting or life limiting the immunosuppressant medications would be, we suggest that clinical teams consider creating “myths and truths” fact sheets to address some of these perceptions, while keeping mind patients who are or are not eligible for transplant to avoid confusion or false hope. If patients are or become transplant candidates, we suggest using decision and informational tools, such as decision aids, to help with quality decision making. Decision aids are tools developed to aid patients to consider difference aspects of a difficult health decision in which there is more than one reasonable option. These tools describe the options available, the risks and benefits of each option and encourage patients to consider their options based on their unique set of values and goals with their health care team.17,18 Decision aids are web-based or paper-based decision tools to help patients make these preference-based health care decisions.18 Our research team has recently developed one such tool to help patients and their loved ones with this decision.19

Second, the LVAD team should monitor and address the evolutions and changes in patients’ treatment preferences through iterative discussion and clarifications between clinicians and patients at different time intervals. One specific time for clarification and clinician–patient discussion would be before LVAD placement, focusing on the different LVAD trajectories and how LVAD therapy may affect patients’ and caregivers’ lifestyles. The second time for clarification and discussion could also be after an LVAD recipient has had more experience with the LVAD and perhaps has reached a “new normal” and can discuss changes in treatment preferences and patient ambivalence, if any. At this time, clinicians should explicitly ask about patient preferences and whether patients’ goals toward transplant might have changed. The final opportunity for clarification would be when a BTT patient accepts a heart transplant, to ensure he or she fully understands the consequences of transplantation (i.e., immunosuppressants, adjusting to another “new normal,” any impact on hobbies). By determining the nuances of treatment preferences before a patient proceeds to the medical review board for a heart transplant, both time and resources can be spared making the clinical flow of heart failure patients more efficient.

Third, it is important to remember that adjusting to the “new normal” takes time, and the adjustment process can be enhanced by having rich discussions between clinicians and patients prior to LVAD surgery, whereby clinicians describe the types of challenges patients might experience post-LVAD placement. LVAD placement is a highly preference-sensitive decision; it involves a number of risk–benefit tradeoffs among mortality, adverse events, and functionality that require robust clinician–patient dialogue early in the course of patients’ illnesses to allow for preference-congruent decisions. We recommend introducing the LVAD option to patients with Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profiles 4–7 (as opposed to just INTERMACS profiles 1–3) so that these rich conversations can occur which should, in turn, enhance the adjustment period post-LVAD placement.20

Back to Top | Article Outline

LIMITATIONS

Limitations to this study with respect to generalizability are inherent to qualitative methodologies. Although this is a small study based on one site, the number of participants (n = 60) is larger than most qualitative studies, and we feel that our analysis reached an adequate level of “saturation,” with new interviews yielding diminishing returns in findings. However, this methodology did not allow for definitive causal assertions and empirical comparisons between BTT and DT patients. Nevertheless, it was important for this study to include both BTT and DT designations for multiple reasons. First, those in the sample size who received a designation reflects larger national allocation between DT versus BTT according to INTERMACS data.21 Additionally, because of stricter requirements required by the Centers for Medicare and Medicaid Services, the designations have become more rigid, resulting in a larger population of DT-LVAD patients.4 This accounts for the large DT-LVAD population in this study’s sample size. Second, because implant strategies can change over time, DT patient perspectives on cardiac transplantation are valuable as the patient’s designation may change to BTT further deepening our understanding of BTT perspective on transplant versus LVAD therapy. A final limitation is that participant recruitment took place over a 10 month period that could be considered too short time for this population’s perspectives to significantly change. The patient population was recruited over 10 months, but the average length of LVAD treatment for the 15 patients was 539 days, an adequate amount of time for their treatment preferences to evolve as they experience LVAD treatment.5 INTERMACS data confirm that the majority of LVAD patients have experienced an adverse event while undergoing LVAD therapy within 1 year of implantation allowing the average patient to understand the risks associated with LVAD treatment.20 During the interviews, patients were asked whether they had undergone an adverse event and how it affected their perspective on LVAD treatment (see Appendix, Supplemental Digital Content, http://links.lww.com/ASAIO/A151).5 Self-reporting of adverse events is sufficient in elucidating their impact on patients’ perspectives as they only reported relevant or serious events that affected their experience while undergoing treatment.

Back to Top | Article Outline

CONCLUSIONS

Providers must be cognizant of their patients’ values and goals when determining the best treatment option for advanced heart failure. Rather than assume all eligible patients want to pursue a heart transplant, providers should revisit treatment preferences with BTT-LVAD patients at multiple points during their LVAD therapy. It is important for the clinical team to recognize that some patients may decide to continue LVAD therapy, effectively self-designating themselves from BTT to DT-LVAD. Clinicians should discuss these points with patients to better understand the sources and implications of any changes in their treatment preferences as they gain experience with their LVAD and may choose to remain with an LVAD despite being eligible for a heart.

Back to Top | Article Outline

REFERENCES

1. Lund LH, Edwards LB, Kucheryavaya AY, et al; International Society for Heart and Lung Transplantation: The Registry of the International Society for Heart and Lung Transplantation: Thirtieth Official Adult Heart Transplant Report–2013; focus theme: age. J Heart Lung Transplant 2013.32: 951–964.
2. Puehler T, Ensminger S, Schoenbrodt M, et al. Mechanical circulatory support devices as destination therapy—current evidence. Ann Cardiothorac Surg 2014.3: 513–524.
3. Centers for Medicare and Medicaid Services. Decisions memo for ventricular assist devices as destination therapy (CAG-00119R). 2007.Appendix B: Joint Commission Disease-Specific Certification Program: Ventricular Assist Device Destination Therapy Certification Final Recommendations.
4. CMS, 2013. Decision Memo for Ventricular Assist Devices for Bridge-to-Transplant and Destination Therapy. [Online] Available at: https://www.cms.gov/medicare-coverage-database/details/nca-decision-memo.aspx?NCAId=268#Top [Accessed April 6, 2016].
5. Blumenthal-Barby JS, Kostick KM, Delgado ED, et al. Assessment of patients’ and caregivers’ informational and decisional needs for left ventricular assist device placement: Implications for informed consent and shared decision-making. J Heart Lung Transplant 2015.34: 1182–1189.
6. Bruce CR, Kostick KM, Delgado ED, Wilhelms LA, Volk RJ, Smith ML, McCurdy SA, Loebe M, Estep JD, Blumenthal-Barby JS. Reasons Why Eligible Candidates Decline Left Ventricular Assist Device Placement. Journal of Cardiac Failure. 2015.835–839.
7. Strauss A, Corbin J. Basics of qualitative research: Grounded theory procedures and techniques. 1990.41, Sage Publications, Inc.
8. Muhr T, Friese S. User’s manual for ATLAS.ti 5.0.Berlin: ATLAS.ti Scientific Software Development GmbH. 2004.
9. Radley A, Green R. Illness as adjustment: A methodology and conceptual framework. Sociol Health Illn. 1987.179–207.
10. Casida JM, Marcuccilli L, Peters RM, Wright S. Lifestyle adjustments of adults with long-term implantable left ventricular assist devices: a phenomenologic inquiry. Heart Lung 2011.40: 511–520.
11. Mapelli D, Cavazzana A, Cavalli C, et al. Clinical psychological and neuropsychological issues with left ventricular assist devices (LVADs). Ann Cardiothorac Surg 2014.3: 480–489.
12. DeLong MR. The way we look: A framework for visual analysis of dress. 1987.Iowa State University Press.
13. DeLong MR. The way we look: Dress and aesthetics. 1998.Fairchild Publications.
14. Marcuccilli L, Casida JJ. Overcoming alterations in body image imposed by the left ventricular assist device: a case report. Prog Transplant 2012.22: 212–216.
15. Kirklin JK, Naftel DC, Pagani FD, et al. Long-term mechanical circulatory support (destination therapy): on track to compete with heart transplantation? J Thorac Cardiovasc Surg 2012.144: 584–603; discussion 597.
16. Porepa LF, Starling RC. Destination therapy with left ventricular assist devices: for whom and when? Can J Cardiol 2014.30: 296–303.
17. Stacey D, Légaré F, Col NF, et al. Decision aids for people facing health treatment or screening decisions (Review). The Cochrane Collaboration. 2014.3.
18. Elwyn G, O’Connor A, Stacey D, et al; International Patient Decision Aids Standards (IPDAS) Collaboration: Developing a quality criteria framework for patient decision aids: online international Delphi consensus process. BMJ 2006.333: 417.
19. Kostick K, Delgado E, Wilhelms LA, et al. “Development and Pilot-Testing of a Patient Decision Aid for Left Ventricular Assist Device Placement”. The VAD Journal, 2016.
20. Bruce CR, Blumenthal-Barby JS, Meyers D. Benefits and Challenges of Early Introduction of Left Ventricular Assist Device Placement: A Patient-Centered Perspective. J Am Coll Cardiol 2015.66: 1762–1765.
21. Kirklin JK, Naftel DC, Myers SL, Clark ML, Collum SC, Hollifield K, Cantor RS. INTERMACS Interagency registry for mechanically assisted circulatory support: Quarterly Statistical Report 2014 2nd Quarter. 2014.31.
Keywords:

heart failure; left ventricular assist device; heart transplantation

Supplemental Digital Content

Back to Top | Article Outline
Copyright © 2017 by the American Society for Artificial Internal Organs