Survival on the Heart Transplant Waiting List: Impact of Continuous Flow Left Ventricular Assist Device as Bridge to Transplant

doi:10.1016/j.athoracsur.2014.05.019

The Annals of Thoracic Surgery

Volume 98, Issue 3, September 2014, Pages 830-834

Presented at the Sixtieth Annual Meeting of the Southern Thoracic Surgical Association, Scottsdale, AZ, Oct 30–Nov 2, 2013.

https://doi.org/10.1016/j.athoracsur.2014.05.019 Get rights and content

Background

Continued donor organ shortage and improved outcomes with current left ventricular assist device (LVAD) technology have increased the number of patients supported with bridge-to-transplantation (BTT) therapy. Using the United Network of Organ Sharing (UNOS) database, we assessed the impact on survival in patients supported with BTT while on the heart transplant waiting list.

Methods

The UNOS database was queried from January 2005 to June 2012 to identify patients listed for heart transplantation as UNOS status 1A or 1B. Patients implanted with a pulsatile-flow device or an LVAD other than the HeartMate II (HM II; Thoratec Inc, Pleasanton, CA) were excluded. Patients were divided into LVAD and non-LVAD groups based on status at the time of listing. Patients were propensity matched (LVAD –non-LVAD = 1:2) for age, sex, weight, presence of diabetes, creatinine levels, mean pulmonary artery pressure, and UNOS status. Kaplan-Meier curves were analyzed for survival.

Results

A total of 8,688 patients were analyzed, with 1,504 (17%) in the LVAD group. Average age (52.6 ± 11.8 versus 51.3 ± 12.9 years; p = 0.0002) and weight (86.6 ± 18.6 versus 80.8 ± 18.2 kg; p < 0.0001) at time of listing were higher in the LVAD group. There were more men (79% versus 74%; p < 0.0001) and more patients with diabetes (30% versus 27%; p = 0.03) in the LVAD group. Of all patients, 6,943 patients (80%) underwent transplantation, 862 (10%) died, and 883 (10%) remained on the waiting list. After propensity matching, survival to transplantation was significantly better in the LVAD group than in the non-LVAD group at both 1 year (91% versus 77%) and 2 years (85% versus 68%).

Conclusions

Patients supported with an HM II LVAD as BTT therapy were older with increased comorbidities; they demonstrated an improved survival while listed for heart transplantation. The use of LVADs as a BTT strategy can potentially improve patient survival while waiting for transplantation and allow better allocation of donor hearts.

Section snippets

Data and Study Population

The study was conducted after approval by the University of Louisville Institutional Review Board. Thoracic organ transplantation data were requested from UNOS (1994–June 2012). The UNOS database was then queried for patients aged 18 years or older who were on the waiting list for heart transplantation between 2005 and 2012. At the time of listing with UNOS, patients who were implanted with an LVAD other than the HeartMate II (HM II) (Thoratec Inc, Pleasanton, CA) for BTT therapy were excluded

Results

From 2005 to 2012, there were a total of 8,688 patients who met the criteria, with 1,504 (17%) supported with an HM II LVAD as BTT treatment. The average age (52.6 ± 11.8 versus 51.3 ± 12.9 years; p = 0.0002) and weight (86.6 ± 18.6 versus 80.8 ± 18.2 kg (p < 0.0001) at time of listing were higher in the HM II group than in the non-LVAD group. In addition, there were more men (79% versus 74%; p < 0.0001) and more patients with diabetes (30% versus 27%; p = 0.03) in the HM II group than in those

Comment

Heart failure remains 1 of the most significant health problems in the United States, with high morbidity, mortality, and resource use. Progression of heart failure leads to advanced disease that is refractory to medical management and was noted as a direct cause of death in 56,000 patients and an associated cause of death in about 280,000 patients in 2009 [2]. According to a national hospital discharge survey, heart failure was the first-listed diagnosis on 30% of all hospital admissions and

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Cited by (97)

Effect of the 2018 heart allocation system on patients with durable left ventricular assist devices
2024, Journal of Thoracic and Cardiovascular Surgery
In this study we report trends and survival of durable left ventricular assist device (LVAD) patients who underwent heart transplantation under the 2018 allocation system.
The United Network for Organ Sharing database was queried for adult recipients of heart transplants after durable LVAD implantation from January 1, 2016, to December 31, 2020. We excluded patients with additional mechanical support, multiorgan transplants, previous heart transplants, or loss to follow-up.
One thousand seven hundred eighty-three patients with durable LVADs received heart transplants under the new allocation system (new), and 3445 under the old (old). New recipients were more likely hospitalized at transplant (n = 376 [22.4%] vs n = 446 [13.6%]; P < .001) and inotrope-dependent (n = 134 [7.5%] vs n = 206 [6.0%]; P = .038). Donors of the new cohort were more likely to have history of smoking (n = 234 [13.4%] vs n = 373 [11.0%]; P = .013), cocaine use (n = 506 [29.0%] vs n = 829 [24.4%]; P < .001), Centers for Disease Control and Prevention high risk status (n = 656 [36.8%] vs n = 1046 [30.4%]; P < .001), with ejection fraction <45% (n = 15 [0.8%] vs n = 10 [0.3%]; P = .012), and higher donor sequence numbers (mean 22.3 vs 12.0; P < .001)—trends that are not observed in non-LVAD transplants. Distances were further (mean 240 vs 144 miles; P < .001) and ischemic times longer (3.41 vs 3.04 hours; P < .001). Kaplan–Meier curves show worse survival in new recipients in unadjusted analysis (P = .005), and trends toward worse survival on propensity matching (P = .058). Similarly, increased mortality risk in the new era was shown in univariable Cox regression (hazard ratio, 1.27; 95% CI, 1.07-1.49; P = .005), but not multivariable analysis (P = .090).
Durable LVAD patients are more likely to accept marginal donor organs under the new system because of difficulty in receiving offers. Worse survival trends might be attributed to recipient conditions and donor organ differences.
Expanding the heart donor pool: Can left ventricular assist devices substitute for marginal donor heart allografts?
2023, Surgery (United States)
Generally, heart transplantation with marginal donor allografts is reserved for a subset of high-risk patients. However, given the improved survival rates for patients on left ventricular assist devices, it is worth analyzing if they could potentially substitute for marginal donor allografts. This study aimed to compare survival outcomes of waitlisted patients with left ventricular assist devices who did not undergo heart transplantation to those who underwent heart transplantation with marginal allografts.
This was a retrospective cohort study of adults (≥18 years) listed for heart transplantation between 2010 and 2022 in the Organ Procurement and Transplantation Network database. A previously validated risk score was used to define marginal donor organs. The primary outcome was death after transplantation or on the waitlist, as appropriate.
Of 5,713 patients with left ventricular assist devices, 4,683 (82%) comprised the left ventricular assist devices group and 1,030 (18%) the marginal group. The marginal cohort was older (57 [49–64] vs 55 [45–62] years, P < .001), similarly female (26 vs 24%, P = .16), and less often White (51 vs 60%, P < .001). Relative to the left ventricular assist devices group, the marginal group demonstrated higher 5-year survival from 2010 to 2014 (81 vs 43%, P < .001) and from 2015 to 2019 (77 vs 66%, P < .001). After adjustment, marginal patients demonstrated a significantly reduced hazard of 5-year mortality for those listed from 2010 to 2014 (hazard ratio 0.25, confidence interval 0.20–0.31; P < .001) and from 2015 to 2019 (hazard ratio 0.46, confidence interval 0.37–0.57; P < .001).
Our study validates the superiority of transplantation relative to left ventricular assist devices but also underscores the survival benefit of heart transplantation with marginal donor allografts, even in high-risk patients.
Risk Prediction Model for Survival of Wait-List Patients on Axial CF-LVAD: A UNOS Database Analysis
2022, Transplantation Proceedings
Continuous flow left ventricular assist devices (CF-LVADs) have become a viable option for patients with end-stage heart failure as a bridge to transplantation or the destination therapy.
Adult patients listed for heart transplantation (2010-2015) with an axial CF-LVAD on the wait list were obtained from the UNOS database. The multivariate Cox regression model was used to predict the probability of survival after listing. Patients were divided into derivation (80%) and validation (20%) groups. Receiver operating characteristics curves and area under curves were used to define the strength of the model.
Risk factors on multivariate analyses were diabetes type I (hazard ratio [HR], 2.5; P = .018), presence of inotropes (HR, 1.6; P = .005), creatinine at listing (HR, 1.2; P < .001). No significant differences were observed between the derivation and validation groups for any of the variables. The area under the curve at 3, 6, and 12 months on the wait list was 0.69, 0.65, 0.63, respectively in the training set and 0.71, 0.65, 0.60, respectively in the validation set. Survival analyses showed that patients implanted with Heartmate II before listing had a better survival than those who were implanted after being on the wait list (HR, 0.78; P = .048).
To our knowledge, this was the first time a risk prediction model was generated for wait-list survival of Heartmate II patients. A significant difference in survival was noted between patients who received their Heartmate II before being put on a wait list vs those who were implanted while on the list.
Progression to Transplant Under the New Heart Allocation System: The Society of Thoracic Surgeons Intermacs Database
2022, Annals of Thoracic Surgery
Citation Excerpt :
The failure to progress to heart transplant under the previous allocation policy likely reflects system- and patient-related factors.1,3 Importantly a relative lack of available organs for patients requiring a heart transplant results in increased wait times on the transplant list.10 Interestingly this study demonstrates that a patient’s odds of receiving a transplant are not constant over time.
Under the new heart allocation policy patients needing durable left ventricular assist devices receive lower priority on the transplant list. We sought to identify predictors of successful heart transplant after durable device implant as a means to inform patient care in the current era.
All patients (N = 25,164) undergoing primary durable left ventricular device implant in The Society of Thoracic Surgeons Intermacs database (2010-2019) were evaluated. Patients identified as bridge to transplant (BTT; n = 5242) or bridge to candidacy (n = 6248) were analyzed with the endpoint of transplant before (n = 10,588) and after (n = 902) the change in the heart allocation system on October 18, 2018. Multivariable hazard modeling was used to assess risk-adjusted time to event associations.
Of 11,490 patients, 45.5% progressed to transplant (BTT, 53.0%; bridge to candidacy, 36.6%), most by 14 months after left ventricular assist device implant. Under the new allocation system progression to transplant was significantly lower at 14 months (18.6% vs 34.8%, P < .001). Factors associated with successful BTT before the allocation change included BTT status, white race, and married. Under the new allocation system BTT status (hazard ratio, 1.79; 95% confidence interval, 1.19-2.69; P < .0054) remained a positive predictor, whereas blood type O (hazard ratio, 0.43; 95% confidence interval, 0.28-0.65; P < .0001) remained a negative predictor.
Despite having priority in the previous allocation system, less than half of BTT and bridge to candidacy patients progressed to transplant. Under the current system these numbers are further reduced. Heart teams should consider the implications of longer wait times for a durable left ventricular assist device when determining the optimal bridging strategy.
2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines
2022, Journal of the American College of Cardiology
The “2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure” replaces the “2013 ACCF/AHA Guideline for the Management of Heart Failure” and the “2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure.” The 2022 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with heart failure.
A comprehensive literature search was conducted from May 2020 to December 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (PubMed), EMBASE, the Cochrane Collaboration, the Agency for Healthcare Research and Quality, and other relevant databases. Additional relevant clinical trials and research studies, published through September 2021, were also considered. This guideline was harmonized with other American Heart Association/American College of Cardiology guidelines published through December 2021.
Heart failure remains a leading cause of morbidity and mortality globally. The 2022 heart failure guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with heart failure, with the intent to improve quality of care and align with patients’ interests. Many recommendations from the earlier heart failure guidelines have been updated with new evidence, and new recommendations have been created when supported by published data. Value statements are provided for certain treatments with high-quality published economic analyses.
Thirty-Year Trends in Graft Survival After Heart Transplant: Modeled Analyses of a Transplant Registry
2022, Annals of Thoracic Surgery
Citation Excerpt :
Waitlist times shortened to reach a global minimum in 2008, the year the US Food and Drug Administration approved the continuous-flow HeartMate II (Thoratec Inc, Pleasanton, CA) for bridge-to-transplant, with a steep decline in 2006 on implementation of a heart allocation policy targeting broader regional sharing. After 2008, waitlist times lengthened, in harmony with the previously documented association of the HeartMate II with longer waitlist times.17 Decreasing pretransplant intensive care is likely due to the hemodynamic stability afforded by MCSDs.
Heart failure is an epidemic in the United States, and transplantation remains the most definitive therapy. We describe multidecade trends in posttransplant graft survival, adjusted for concurrent changes in the population, over the 30 years antecedent to the most recent heart allocation policy change.
Scientific Registry of Transplant Recipients data were used to identify all primary adult heart recipients from 1989 to 2017. We described temporal changes in population characteristics (recipient and donor demographics and comorbidities, pretransplant interventions, clinical transplant measures, and providers). The primary outcome was graft survival, defined as freedom from all-cause death and graft failure, within 6 months posttransplant. Modified Poisson logistic regression estimated relative changes in risk of outcomes compared with 1989, with and without adjustment for changing population characteristics. We identified risk factors, quantified by associated risk ratios.
Among 56,488 primary adult heart recipients, we observed 5529 (9.8%) all-cause deaths and 1933 (3.4%) graft failure events within 6 months posttransplant. Prevalence of known recipient risk factors increased over time. Unadjusted modeling demonstrated a significant 30-year improvement in graft survival, averaging 2.6% per year (95% confidence interval, 2.4-2.9; P for trend < .001). After adjusting for population changes the 30-year trend remained significant and graft survival improved on average 3.0% per year (95% confidence interval, 2.6-3.3). Regression modeling identified multiple predictors of graft survival. Modeling 2 additional outcomes of 6-month mortality and 6-month graft failure produced similar results.
Short-term graft survival after heart transplantation has improved significantly leading up to the 2018 heart allocation policy change, despite concurrent increase in prevalence of higher risk population characteristics.

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Original articleAdult cardiacSurvival on the Heart Transplant Waiting List: Impact of Continuous Flow Left Ventricular Assist Device as Bridge to Transplant

Background

Methods

Results

Conclusions

Section snippets

Data and Study Population

Results

Comment

J Heart Lung Transplant

J Heart Lung Transplant

J Am Coll Cardiol

J Card Fail

J Thorac Cardiovasc Surg

J Heart Lung Transplant

Original article
Adult cardiac
Survival on the Heart Transplant Waiting List: Impact of Continuous Flow Left Ventricular Assist Device as Bridge to Transplant