Cardiac Donor Risk Factors Predictive of Short-Term Heart Transplant Recipient Mortality: An Analysis of the United Network for Organ Sharing Database

Post-transplant survival after normothermic regional perfusion versus direct procurement and perfusion in donation after circulatory determination of death in heart transplantation

BACKGROUND

Since 2019, the annual transplantation rate of hearts donated following circulatory death (DCD) has increased significantly in the United States. The 2 major heart procurement techniques following circulatory death are direct procurement and perfusion (DPP) and normothermic regional perfusion (NRP). Post-transplant survival for heart recipients has not been compared between these 2 techniques.

METHODS

This observational study uses data on adult heart transplants from donors after circulatory death from January 1, 2019 to December 31, 2021 in the Scientific Registry of Transplant Recipients. We identified comparable transplant cases across procurement types using propensity-score matching and measured the association between procurement technique and 1-year post-transplant survival using Kaplan-Meier and Cox proportional hazards model stratefied by matching pairs.

RESULTS

Among 318 DCD heart transplants, 216 (68%) were procured via DPP, and 102 (32%) via NRP. Among 22 transplant centers that accepted circulatory-death donors, 3 used NRP exclusively, and 5 used both procurement techniques. After propensity-score matching on recipient and donor factors, there was no significant difference in 1-year post-transplant survival (93.1% for NRP vs 91.1% for DPP, p = 0.79) between procurement techniques.

CONCLUSIONS

NRP and DPP procurements are associated with similar 1-year post-transplant survival. If NRP is ethically permissible and improves outcomes for abdominal organs, it should be the preferred procurement technique for DCD hearts.

Disparities in donor heart acceptance between the USA and Europe: clinical implications

BACKGROUND AND AIMS

Given limited evidence and lack of consensus on donor acceptance for heart transplant (HT), selection practices vary widely across HT centres in the USA. Similar variation likely exists on a broader scale-across countries and HT systems-but remains largely unexplored. This study characterized differences in heart donor populations and selection practices between the USA and Eurotransplant-a consortium of eight European countries-and their implications for system-wide outcomes.

METHODS

Characteristics of adult reported heart donors and their utilization (the percentage of reported donors accepted for HT) were compared between Eurotransplant (n = 8714) and the USA (n = 60 882) from 2010 to 2020. Predictors of donor acceptance were identified using multivariable logistic regression. Additional analyses estimated the impact of achieving Eurotransplant-level utilization in the USA amongst donors of matched quality, using probability of acceptance as a marker of quality.

RESULTS

Eurotransplant reported donors were older with more cardiovascular risk factors but with higher utilization than in the USA (70% vs. 44%). Donor age, smoking history, and diabetes mellitus predicted non-acceptance in the USA and, by a lesser magnitude, in Eurotransplant; donor obesity and hypertension predicted non-acceptance in the USA only. Achieving Eurotransplant-level utilization amongst the top 30%-50% of donors (by quality) would produce an additional 506-930 US HTs annually.

CONCLUSIONS

Eurotransplant countries exhibit more liberal donor heart acceptance practices than the USA. Adopting similar acceptance practices could help alleviate the scarcity of donor hearts and reduce waitlist morbidity in the USA.

Does donor treatment with inotropes and/or vasopressors impact post-transplant outcomes?

PURPOSE

The purpose was to evaluate the effects of the most commonly used cardiac donor inotropes/vasopressors on subsequent post-heart transplant survival.

METHODS

Adult heart transplant recipients from January 2000 to June 2022 were identified in the United Network for Organ Sharing (UNOS) database. Exclusion criteria included: multiorgan transplants, donor age < 15, and recipient age < 18. Donors receiving vasoactive medications at the time of procurement were compared to donors not receiving these medications. Those on vasoactive medications were stratified by medication: phenylephrine, dopamine, dobutamine, norepinephrine and epinephrine, the combination of these agents, and the concomitant administration of vasopressin with any single agent alone or in combination. The primary area of interest was short-and-long-term survival. Survival at 30 days, 1 year, and long-term (Median = 13.6 years) was compared using logistic and Cox models to quantify survival endpoints.

RESULTS

A total of 45,198 donors met inclusion criteria and had data on the use of vasoactive agents available. Mean donor age was 32.3 years with 71% male. Vasoactive medications and potential combinations included phenylephrine in 8156 donors (18.0%), dopamine in 9550 (21.1%), dobutamine in 718 (1.6%), epinephrine in 332 (.73%), and norepinephrine in 4854 (10.7%). A total of 25,856 donors (57.2%) were receiving vasopressin at the time of procurement. There was no impact of donor inotropes on 30-day survival. Donors receiving one inotrope and no vasopressin were associated with increased 1 year mortality (OR 1.14; p = .021), as were donors receiving 2+ inotropes and no vasopressin (OR 1.26; p = .006). For individual agents, 1 year mortality was increased for dopamine (OR 1.11; p = .042) and epinephrine (OR 1.59; p = .004).

CONCLUSIONS

There is no difference in heart transplant recipient survival at 30 days when the donor is receiving inotropes without vasopressin at the time of procurement. Inotropic support without vasopressin is associated with greater 1 year mortality. The impact of donor inotropic support on long term heart transplant survival, and the interaction with vasopressin warrants further study.

Donor substance abuse and heart transplantation outcomes

Heart failure continues to account for millions of cases and deaths worldwide. Heart transplant is the gold standard for treatment of advanced heart failure. Unfortunately, the supply of donor hearts continues to be limited with the increase in demand for heart transplantation. In this review, we aim to explore the safety and efficacy of using hearts from donors with history of substance use. Despite the theoretical effect of cocaine and alcohol on the cardiovascular system, several studies demonstrate no difference in outcomes (overall survival, graft rejection, graft vasculopathy) when using hearts from patients with history of cocaine and alcohol use. The opioid epidemic has expanded the potential donor pool where the current studies have not shown any adverse outcomes when considering donors with history of opioid use. The currently available evidence would support the use of donor hearts from patients with history of alcohol, cocaine, opioids, and marijuana use. Further studies are needed to evaluate the safety of using donor hearts from patients with history of nicotine use.

Donor Noradrenaline Support Is Not Associated with Decreased Survival in Heart Transplant Recipients

Objective: Although the application of higher doses of norepinephrine (NE) in potential organ donors is a frequent reason for heart decline, its associations with outcomes after heart transplantation (HTx) are discussed controversially. Therefore, we aimed to explore donor NE support’s potential impact on outcomes in our single-center heart transplant cohort. Methods: All patients who had undergone HTx in our center between September 2010 and April 2022 (n = 241) were screened for eligibility. From those, all patients with complete data on donor NE support (n = 238) were included. Recipients were divided into three groups according to their donor NE support: without support (n = 26), with low support of 0.01−0.2 µg/kg/min (n = 132), and with high support of > 0.2 µg/kg/min (n = 80). Receiver operating characteristics (ROC) and Kaplan Meier analysis was used to investigate the association of donor NE support and mortality after heart transplantation. Recipient and donor variables, including peri- and postoperative characteristics, were reviewed and compared. Results: NE support in donors ranged between 0 and 2.94 µg/kg/min (median 0.13 µg/kg/min, IQR 0.05−0.26 µg/kg/min). No association between donor NE support and mortality after HTx was observed (AUC for overall survival 0.494). Neither Kaplan-Meier analysis in survival up to 5 years after transplantation (Log Rank p = 0.284) nor group comparisons showed significant differences between the groups. With few exceptions, baseline characteristics in recipients and donors were comparable between the groups. Regarding peri- and postoperative parameters, increasing donor NE support was associated with a longer duration of mechanical ventilation (68 h and 95 h vs. 47 h), longer postoperative IMC/ICU stay (14 vs. 15 vs. 19 days), and a higher need for mechanical life support post-HTx (26% and 39% vs. 12%). Conclusion: In this retrospective analysis, NE support in donors prior to heart transplantation was unrelated to differing survival after heart transplantation. However, higher doses of donor NE were associated with prolonged ventilation, longer duration on IMC/ICU, and a higher need for extracorporeal life support in recipients post-HTx.

Heart Transplantation With Older Donors: Should There Be an Age Cutoff?

PURPOSE

Heart transplantation remains limited by donor availability. Currently, only some programs accept older donors, and their use remains contentious. We compared outcomes of heart transplant recipients who received donor hearts ≥55 years with those who received donor hearts <55 years.

METHODS

Records of first-time adult heart transplant recipients between 2010 and 2019 were reviewed. Endpoints included 30-day and 1-, 3-, and 5-year survival; freedom from cardiac allograft vasculopathy; freedom from nonfatal major adverse cardiac events; and freedom from any rejections. The effect of donor age ≥55 years was analyzed with Cox proportional hazards modeling, 1:2 propensity score matching, and Kaplan-Meier survival analysis.

RESULTS

Sixty-six patients received donor hearts ≥55 years and 766 received donor hearts <55 years. In the unmatched cohort, there was no significant difference in survival between the 2 groups at 30 days (93.9% vs 97.3%, P = .127), 1 year (87.9% vs 91.6%, P = .325), 3 years (86.4% vs 86.5%, P = .888), or 5 years (78.8% vs 83.8%, P = .497). The ≥55 years group had a significantly lower freedom from cardiac allograft vasculopathy and fatal major adverse cardiac events. In propensity-matched patients, recipients of donors ≥55 years had similar survival and freedom from cardiac allograft vasculopathy but significantly lower 1-year (76.7% vs 88.3%, P = .026), 3-year (68.3% vs 84.2%, P = .010), and 5-year (63.3% vs 83.3%, P = .002) freedom from nonfatal major adverse cardiac events when compared to recipients of younger donors.

CONCLUSIONS

Carefully selected older donors can be considered for a carefully selected group of recipients with acceptable outcomes.

Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit

Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 (n = 241). Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days (≤50th percentile, n = 92), 4 to 7 days (50th–75th percentile, n = 80), and ≥8 days (≥75th percentile, n = 69). Donor LOS in the ICU ranged between 0 and 155 days (median 4, IQR 3–8 days). No association between the LOS in the ICU and survival after HTx was observed (AUC for overall survival 0.514). Neither the Kaplan–Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients’ peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.

Intracerebral bleeding in donors is associated with reduced short-term to midterm survival of heart transplant recipients

Aim

The quality of the donor heart is known to have a crucial effect on outcome after heart transplantation (HTx). Although leading to brain death in the end, the initial cause of death of the donor and its potential influences on organ quality are heterogeneous. However, it is still controversial to which extent the donor cause of death is associated with outcome or survival post‐HTx.

Methods and results

We included all patients undergoing HTx in our centre between September 2010 and June 2021 (n = 218). Recipients were divided in five groups related to their donor cause of death: intracerebral bleeding (‘ICB’, n = 95, 44%), traumatic brain injury (‘trauma’, n = 54, 25%), hypoxic brain damage (‘hypoxic’, n = 34, 16%), cerebrovascular (‘vascular’, n = 15, 7%), or other cause (n = 20, 9%). Baseline characteristics, perioperative parameters, and survival after 30 and 90 days as well as 5 years after transplantation were collected.

Results

Intracerebral bleeding in donors compared with traumatic brain injury is associated with higher probability of need for ECLS post‐HTx (35% vs. 19%, P = 0.04) and significantly reduced survival up to 5 years post‐HTx (i.e. 1 year survival: 61% vs. 95%, P < 0.0001). Although other conditions also show significant changes in outcome and survival, the effect is strongest for ICB, where survival is also reduced compared with all other causes (1 year: 61% vs. 89%, P < 0.0001).

Conclusions

In this retrospective analysis, donor cause of death is associated with differing outcome and survival after HTx. Intracerebral bleeding hereby shows strongest decline in outcome and survival in comparison with all other causes.

Effect of UNOS policy change and exception status request on outcomes in patients bridged to heart transplant with an intra-aortic balloon pump

BACKGROUND

Intra-aortic balloon pumps (IABP) are used to bridge select end-stage heart disease patients to heart transplant (HT). IABP use and exception requests both increased dramatically after the UNOS policy change (PC). The purpose of this study was to evaluate the effect of PC and exception status requests on waitlist and post-transplant outcomes in patients bridged to HT with IABP support.

METHODS

We analyzed adult, first-time, single-organ HT recipients from the UNOS Registry either on IABP at the time of registration for HT or at the time of HT. We compared waitlist and post-HT outcomes between patients from the PRE (October 18, 2016 to May 30, 2018) and POST (October 18, 2018 to May 30, 2020) eras using Kaplan-Meier curves and time-to-event analyses.

RESULTS

A total of 1267 patients underwent HT from IABP (261 pre-policy/1006 post-policy). On multivariate analysis, PC was associated with an increase in HT (sub-distribution hazard ratio (sdHR): 2.15, p < .001) and decrease in death/deterioration (sdHR: 0.55, p = .011) on the waitlist with no effect on 1-year post-HT survival (p = .8). The exception status of patients undergoing HT was predominantly seen in the POST era (29%, 293/1006); only four patients in the PRE era. Exception requests in the POST era did not alter patient outcomes.

CONCLUSIONS

In patients bridged to heart transplant with an IABP, policy change is associated with decreased rates of death/deterioration and increased rates of heart transplantation on the waitlist without affecting 1-year post-transplant survival. While exception status use has markedly increased post-PC, it is not associated with patient outcomes.

Association of Donor Brain Death Due to Stroke With Prognosis After Heart Transplantation

BACKGROUND

The proximate cause of donor brain death is not considered a conventional risk factor in modern heart transplantation.

OBJECTIVES

This study aimed to investigate the effect of the cause of donor brain death on recipients.

METHODS

Using the United Network for Organ Sharing registry, long-term mortality and allograft failure were compared in recipients who underwent heart transplantation in the United States from 2005 through 2018 between allograft recipients from donors with stroke as the cause of brain death (n = 3,761) vs nonstroke causes (n = 14,677). Inverse probability weighting was used for risk adjustment. Interactions were investigated between the cause of brain death and other conventional donor risk factors for recipient mortality.

RESULTS

There was an interaction between the cause of brain death and donor age (P_interaction = 0.008). When allografts were procured from donors aged 40 years or younger, stroke as the cause of brain death was associated with an increased risk of mortality (23% vs 19% at 5 years; HR: 1.17; 95% CI: 1.02-1.35) and allograft failure (HR: 1.30; 95% CI: 1.04-1.63). When donors were older than 40 years, the cause of brain death was not associated with outcomes.

CONCLUSIONS

As the cause of donor brain death, stroke had a substantially different effect on recipient and allograft survival depending on donor age. In the case of younger donor ages, stroke was associated with higher recipient mortality and allograft failure than other causes of brain death. The strength of this association decreased with increasing donor age such that the increased hazard was no longer present in donors older than approximately 40 years.

Evaluation of donor heart for transplantation

Cardiac transplantation is considered the gold-standard treatment option for patients suffering from end-stage heart failure refractory to maximum medical therapy. A major determinant of graft function and recipient survival is a comprehensive evaluation of the donor allograft. Challenges arise when designing and implementing an evidence-based donor evaluation protocol due to the number of influential donor-specific characteristics and the complex interactions that occur between them. Here, we present our systematic approach to donor evaluation by examining the impact that relevant donor variables have on graft function and recipient outcomes.

Endocrine Management and Hormone Replacement Therapy in Cardiac Donor Management: A Retrospective Observational Study

BACKGROUND

Pituitary dysfunction after brainstem death can cause various hormone deficiencies in potential heart donors. The aim of this study was to evaluate the relationship between hormone replacement therapy (HRT; including antidiuretic hormone analog, thyroid hormone, and methylprednisolone) in heart donors and the recipients' outcomes after heart transplantation (HTx).

METHODS

We retrospectively analyzed HTxs performed between January 2012 and October 2018. Donor and recipient characteristics were retrieved with a focus on endocrine parameters and HRT. The primary outcome was primary graft dysfunction (PGD). Secondary outcomes were the 30-day and 2-year mortality of the recipients. Univariate and multivariate Cox regression analyses were applied.

RESULTS

The study included 297 HTxs. PGD occurred in 56 recipients (18.9%). In the multivariable Cox analysis, methylprednisolone and thyroxine treatment in donors were associated with a lower odds for PGD (odds ratio [OR], 0.43; 95% CI, 0.19-1.01; P = .052; and OR,: 0.34; 95% CI, 0.15-0.76; P = .009, respectively). In multivariate analysis, thyroxine treatment in donors was associated with a lower odds of PGD (OR, 0.38; 95% CI, 0.17-0.86; P = .020). Donor thyroxine supplementation also had a beneficial effect on recipients' 2-year survival (OR, 0.53; 95% CI, 0.29-0.96; P = .036).

CONCLUSIONS

Combined thyroxine and methylprednisolone treatment could be a protective factor against PGD. Thyroxine administration was associated with better 2-year survival in recipients.

Commentary: Planes, trains, and automobiles-Effective use of prolonged ex vivo heart preservation

Throughout the world, a shortage of donor organs has prompted development of unique strategies to expand the donor pool. Here, we review a report by Medressova and colleagues to the Journal of Cardiac Surgery detailing the 3-year follow-up of a patient who successfully underwent a heart transplant after 17 hours of ex-vivo preservation.

A mortality risk score for septuagenarians undergoing orthotopic heart transplantation

BACKGROUND

With septuagenarians undergoing orthotopic heart transplantation (OHT) more frequently, we aimed to develop a risk score for 1-year mortality in this population.

METHODS

Septuagenarian OHT recipients were identified from the UNOS registry between 1987 and 2018. The primary outcome was 1-year post-OHT mortality. Patients were randomly divided into derivation and validation cohorts. Associated covariates were entered into a multivariable logistic regression model. A risk score was created using the magnitudes of the odds ratios from the derivation cohort, and its 1-year post-OHT mortality prediction capacity was tested in the validation cohort.

RESULTS

A total of 1156 septuagenarians were included, and they were randomly divided into derivation (66.7%, n = 771) and validation (33.3%, n = 385) cohorts. An 11-point risk score incorporating 4 variables was created, which included mechanical ventilation, serum bilirubin, serum creatinine, and donor age. The predicted 1-year mortality ranged from 4.2% (0 points) to 48.1% (11-points) (p < .001). After cross-validation, the c-index was 0.67 with a Brier score of 0.10. Risk scores above 3 points portended a survival disadvantage at 1-year follow-up (p < .001).

CONCLUSIONS

This 11-point risk score for septuagenarians is predictive of mortality within 1-year of OHT and has potential utilization in improving recipient evaluation and selection of elderly patients.

Impact of donor smoking history on post heart transplant outcomes: A propensity-matched analysis of ISHLT registry

PURPOSE

Smoking is a major public health issue, and its effect on cardiovascular outcomes is well established. This study evaluates the impact of donor smoking on heart transplant (HT) outcomes.

METHODS

HT recipients between January 1, 2005, and December 31, 2016, with known donor smoking status were queried from the International Society of Heart and Lung Transplantation (ISHLT) registry. The primary outcome was all-cause mortality, and secondary endpoints were graft failure, acute rejection, and cardiac allograft vasculopathy. We utilized propensity-score matching to identify cohorts of recipients with and without a history of donor smoking. Hazard ratios for post-transplant outcomes for the matched sample were estimated from separate Cox proportional hazard models.

RESULTS

Of 26 390 patients in the cohort, 18.9% had history of donor smoking. Donors with history of smoking were older, predominantly male and had higher incidence of diabetes, hypertension, cocaine use, and "high-risk" status. In propensity-matched analysis, recipients with a history of donor smoking had increased risk of death (HR 1.11, 95% CI 1.03-1.20) and higher risk of graft failure (HR 1.11, 95% CI 1.03-1.20).

CONCLUSION

Donor smoking was associated with increased mortality and higher incidence of graft failure following HT. Consideration of donor smoking history is warranted while evaluating donor hearts.

The Effect of Supplemental Cardioplegia Infusion before Anastomosis in Patients Undergoing Heart Transplantation with Long Ischemic Times

Background

Prolonged ischemic time is a risk factor for primary graft dysfunction in patients who undergo heart transplantation. We investigated the effect of a supplemental cardioplegia infusion before anastomosis in patients with long ischemic times.

Methods

We identified 236 consecutive patients who underwent orthotopic heart transplantation between February 2010 and December 2014. Among them, the patients with total ischemic times of longer than 3 hours (n=59) were categorized based on whether they were administered a complementary cardioplegia solution (CPS) immediately before implantation (CPS+, n=30; CPS−, n=29).

Results

The mean total ischemic times in the CPS+ and CPS− groups were 238.1±30.1 minutes and 230.1±28.2 minutes, respectively (p=0.3). The incidence of left ventricular primary graft dysfunction (CPS+, n=6 [20.0%]; CPS−, n=5 [17.2%]; p=0.79) was comparable between the groups. In the Kaplan-Meier survival analysis, no significant difference in overall survival at 5 years was observed between the CPS+ and CPS− groups (83.1%±6.9% vs. 89.7%±5.7%, respectively; log-rank p=0.7). No inter-group differences in early mortality (CPS+, n=0; CPS−, n=1 [3.4%]; p=0.98) or complications were observed.

Conclusion

The additional infusion of a cardioplegia solution immediately before implantation in patients with longer ischemic times is a simple, reproducible, and safe procedure. However, we did not observe benefits of this strategy in the present study.

How Big Is Too Big?: Donor Severe Obesity and Heart Transplant Outcomes

BACKGROUND

As the population becomes increasingly obese, so does the pool of potential organ donors. We sought to investigate the impact of donors with body mass index ≥40 (severe obesity) on heart transplant outcomes.

METHODS

Single-organ first-time adult heart transplants from 2003 to 2017 were evaluated from the United Network for Organ Sharing database and stratified by donor severe obesity status (body mass index ≥40). Demographics were compared, and univariate and risk-adjusted analyses evaluated the relationship between severe obesity and short-term outcomes and long-term mortality. Further analysis evaluated the prevalence of severe obesity within the pool of organ donation candidates.

RESULTS

A total of 26 532 transplants were evaluated, of which 939 (3.5%) had donors with body mass index ≥40, with prevalence increasing over time (2.2% in 2003, 5.3% in 2017). Severely obese donors more likely had diabetes mellitus (10.4% versus 3.1%, P<0.01) and hypertension (33.3% versus 14.8%, P<0.01), and 67.4% were size mismatched (donor weight >130% of recipient). Short-term outcomes were similar, including 1-year survival (10.6% versus 10.7%), with no significant difference in unadjusted and risk-adjusted long-term survival (log-rank P=0.67, hazard ratio, 0.928, P=0.30). Organ donation candidates also exhibited an increase in severe obesity over time, from 3.5% to 6.8%, with a lower proportion of hearts from severely obese donors being transplanted (19.5% versus 31.6%, P<0.01).

CONCLUSIONS

Donor severe obesity was not associated with adverse post-transplant outcomes. Increased evaluation of hearts from obese donors, even those with body mass index ≥40, has the potential to expand the critically low donor pool.

Relation of Length of Survival After Orthotopic Heart Transplantation to Age of the Donor

We aim to evaluate the impact of donor age on the outcomes in orthotropic heart transplantation recipients. The United Network for Organ Sharing database was queried for adult patients (age; ≥60) underwent first-time orthotropic heart transplantation between 1987 and 2019 (n = 18,447). We stratified the cohort by donor age; 1,702 patients (9.2%) received a heart from a donor age of <17 years; 11,307 patients (61.3%) from a donor age of 17 ≥, < 40; 3,525 patients (19.1%) from a donor age of 40 ≥, < 50); and 1,913 patients (10.4%) from a donor age of ≥50. There was a significant difference in the survival likelihood (p < 0.0001) based on donor's age-based categorized cohort, however, the median survival was 10.5 years in the cohort in whom the donor was <17, 10.3 years in whom the donor was 17 ≥, < 40, 9.4 years in whom the donor was 40 ≥, < 50, and 9.0 years in whom the donor was ≥ 50. Additionally, there was no significant difference in the episode of acute rejection (p = 0.19) nor primary graft failure (p = 0.24). In conclusion, this study demonstrated that patients receiving hearts from the donor age of ≥50 years old showed slight inferior survival likelihood, but appeared to be equivalent median survival.

Review of interactions between high-risk pediatric heart transplant recipients and marginal donors including utilization of risk score models

BACKGROUND

Donor organ acceptance practices vary among pediatric heart transplant professionals. We sought to understand what is known about the interactions between the "high-risk" recipient and the "marginal donor," and how donor risk scores can impact this discussion.

METHODS

A systematic review of published literature on pediatric HTx was undertaken with the assistance of a medical librarian. Two authors independently assessed search results, and papers were reviewed for inclusion.

RESULTS

We found that there are a large number of individual factors, and clusters of factors, that have been used to label individual recipients "high-risk" and individual donors "marginal." The terms "high-risk recipient" and "marginal donor" have been used broadly in the literature making it virtually impossible to make comparisons between publications. In general, the data support that patients who could be easily agreed to be "sicker recipients" are at more risk compared to those who are clearly "healthier," albeit still "sick enough" to need transplantation. Given this variability in the literature, we were unable to define how being a "high-risk" recipient interplays with accepting a "marginal donor." Existing risk scores are described, but none were felt to adequately predict outcomes from factors available at the time of offer acceptance.

CONCLUSIONS

We could not determine what makes a donor "marginal," a recipient "high-risk," or how these factors interplay within the specific recipient-donor pair to determine outcomes. Until there are better risk scores predicting outcomes at the time of organ acceptance, programs should continue to evaluate each organ and recipient individually.

Clinical-based Cell Therapies for Heart Disease-Current and Future State

Patients have an ongoing unmet need for effective therapies that reverse the cellular and functional damage associated with heart damage and disease. The discovery that ~1%-2% of adult cardiomyocytes turn over per year provided the impetus for treatments that stimulate endogenous repair mechanisms that augment this rate. Preclinical and clinical studies provide evidence that cell-based therapy meets these therapeutic criteria. Recent and ongoing studies are focused on determining which cell type(s) works best for specific patient population(s) and the mechanism(s) by which these cells promote repair. Here we review clinical and preclinical stem cell studies and anticipate future directions of regenerative medicine for heart disease.

Donor history of malignancy: A limited risk for heart transplant recipients

Organ donor contraindications are frequently reassessed for impact on recipient outcomes in attempt to meet demand for transplantation. This study retrospectively analyzed the United Network for Organ Sharing (UNOS) registry for adult heart transplants from 1987 to September 2016 to characterize the impact of donor malignancy history in heart transplantation. Kaplan-Meier estimates illustrated 10-year survival. Propensity score matching was utilized for 1:1 matching of donors with and without history of malignancy, and Cox proportional hazards and logistic regressions were used to analyze the matched population. Of 38 781 heart transplants, 622 (1.6%) had a donor history of malignancy. Cox regressions demonstrated that donor malignancy predicted increased 10-year mortality (HR = 1.16 [1.01-1.33]), but this difference did not persist when conditioned upon 1 year post-transplant survival (log-rank = 0.643). Cox regressions of the propensity score-matched population (455 pairs) found no association between donor malignancy and 10-year mortality (HR = 1.02 [0.84-1.24]). Older age and higher rates of hypertension were observed in donors with a history of malignancy whose recipients died within the first year post-transplant. Therefore, increased recipient mortality is likely due to donor characteristics beyond malignancy, creating the potential for expanded donor selection.

Sex Differences in Advanced Heart Failure Therapies

This in-depth review of sex differences in advanced heart failure therapy summarizes the existing literature on implantable cardioverter defibrillators, biventricular pacemakers, mechanical circulatory support, and transplantation with a focus on utilization, efficacy/clinical effectiveness, adverse events, and controversies. One will learn about the controversies regarding efficacy/clinical effectiveness of implantable cardioverter defibrillators and understand why these devices should be implanted in women even if there are sex differences in appropriate shocks. Individuals will learn about the sex differences with biventricular pacemakers with respect to ventricular remodeling and reduction in heart failure hospitalizations/mortality, as well as, possible mechanisms. We will demonstrate sex differences in heart transplantation and waitlist survival. Despite similar survival for women and men with left ventricular assist devices, there are sex differences in adverse events. These devices do successfully bridge women and men to transplant, yet women are less likely than men to have a left ventricular assist at time of listing and time of transplantation. Finally, one will learn about the concerns regarding poor outcome for men who receive female donor hearts and discover this may not be due to sex, but rather size. More research is needed to better understand sex differences and further improve advanced heart failure therapy for both women and men.

Impact of Donor Obesity on Outcomes After Orthotopic Heart Transplantation

Background

The impact of donor obesity on the outcome of orthotopic heart transplantation has not been studied. The aim of this study was to investigate the impact of donor obesity on the outcomes of adult orthotopic heart transplantation recipients.

Methods and Results

Data were obtained from the United Network for Organ Sharing database. All adult (age ≥18 years) patients undergoing orthotopic heart transplantation from 2000 through 2016 were included (n=31 920). We stratified the cohort by donor body mass index (BMI); 13 015 patients (40.8%) received a heart from a normal‐weight donor (BMI 18.5–24.9), 11 271 patients (35.3%) received a heart from an overweight donor (BMI 25.0–29.9), 4910 patients (15.4%) received a heart from an obese donor (BMI 30.0–34.9), and 2724 patients (8.5%) received a heart from an extremely obese donor (BMI ≥35). The cohort of obese donors was older, included a higher incidence of diabetes mellitus, and had a higher creatinine. Our data also showed that the recipients of obese donor grafts were older, had a higher BMI, creatinine, percentage of diabetes mellitus, and longer total waiting period. There was no significant difference detected in the survival likelihood (P=0.08) of patients based on a donor's BMI‐based categorized cohort. There were no significant differences found in the overall survival probability among 4 groups in the adjusted survival analyses (P=0.25).

Conclusions

This study demonstrated that patients receiving higher BMI donor hearts might not be subjected to an increased risk of death, at least during the short term after transplant, compared with those using the normal‐weight donors.

[Left ventricle myocardium hypertrophy of donor heart: the results and outlook]

Left ventricular hypertrophy - is one of the most frequent structural changes in the heart. This article is devoted to the assessment of modern views on the causes of myocardial hypertrophy of the donor heart, indications and contraindications for the heart trans‑ plantation, the outlook of expanding the pool of effective donors through the use of these hearts. Here are considered the issues of post-transplantation remodeling of the donor heart myocardium, The pathogenesis features, the nascence risk and possibilities of drug regulation of the transplanted heart's myocardial hypertrophy of the left ventricle.

Alternative methods for virtual heart transplant-Size matching for pediatric heart transplantation with and without donor medical images available

BACKGROUND

Listed pediatric heart transplant patients have the highest solid-organ waitlist mortality rate. The donor-recipient body weight (DRBW) ratio is the clinical standard for allograft size matching but may unnecessarily limit a patient's donor pool. To overcome DRBW ratio limitations, two methods of performing virtual heart transplant fit assessments were developed that account for patient-specific nuances. Method 1 uses an allograft total cardiac volume (TCV) prediction model informed by patient data wherein a matched allograft 3-D reconstruction is selected from a virtual library for assessment. Method 2 uses donor images for a direct virtual transplant assessment.

METHODS

Assessments were performed in medical image reconstruction software. The allograft model was developed using allometric/isometric scaling assumptions and cross-validation.

RESULTS

The final predictive model included gender, height, and weight. The 25th-, 50th-, and 75th-percentiles for TCV percentage errors were -13% (over-prediction), -1%, and 8% (under-prediction), respectively. Two examples illustrating the potential of virtual assessments are presented.

CONCLUSION

Transplant centers can apply these methods to perform their virtual assessments using existing technology. These techniques have potential to improve organ allocation. With additional experience and refinement, virtual transplants may become standard of care for determining suitability of donor organ size for an identified recipient.

Temporal Changes on the Risks and Complications of Posttransplantion Diabetes Mellitus Following Cardiac Transplantation

Background

Recent changes in the demographic of cardiac donors and recipients have modulated the rate and risk, associated with posttransplant diabetes mellitus (PTDM). We investigated the secular trends of the risk of PTDM at 1 year and 3 years after transplantation over 30 years and explored its effect on major outcomes.

Methods

Three hundred and three nondiabetic patients were followed for a minimum of 36 months, after a first cardiac transplantation performed between 1983 and 2011. Based on the year of their transplantation, the patients were divided into 3 eras: (1983-1992 [era 1], 1993-2002 [era 2], and 2003-2011 [era 3]).

Results

In eras 1, 2, and 3, the proportions of patients with PTDM at 1 versus 3 years were 23% versus 39%, 21% versus 26%, and 33% versus 38%, respectively. Independent risk factors predicting PTDM at one year were recipient's age, duration of cold ischemic time, treatment with furosemide, and tacrolimus. There was a trend for overall survival being worse for patients with PTDM in comparison to patients without PTDM (p = 0.08). Patients with PTDM exhibited a significantly higher rate of renal failure over a median follow-up of 10 years (p = 0.03).

Conclusion

The development of PTDM following cardiac transplantation approaches 40% at 3 years and has not significantly changed over thirty years. The presence of PTDM is weakly associated with an increased mortality and is significantly associated with a worsening in renal function long-term following cardiac transplantation.

Donor and recipient risk factor analysis of inferior postheart transplantation outcome in the era of durable mechanical assist devices

The study objective is to quantify the impact of donor and recipient variables on heart transplant survival in recipients with a significant proportion of implanted continuous-flow left ventricular assist devices (LVADs). This is a prospective cohort study of International Society for Heart and Lung Transplantation (ISHLT) Registry that includes all primary heart-alone transplants in adult recipients (January 2005 and June 2013, N = 15 532, 27% LVADs). Donor and recipient characteristics were assessed for association with death or graft failure within 90 days and between 90 days and 5 years after transplantation. On Cox proportional hazard model donor cause of death other than head trauma (hazard ratio [HR] 1.985, P < 0.0001), recipient congenital (HR 2.7555, P < 0.0001) and ischemic (HR 1.165, P = 0.0383) vs dilated etiology and female donor heart transplanted into male recipient (HR 1.207, P = 0.0354) were predictors of death or graft failure within 90 days. Between 90 days and 5 years, donor cigarette use (HR 1.232, P = 0.0001), recipient cigarette use (HR 1.193, P = 0.0003), diabetes (HR 1.159, P = 0.0050), arterial hypertension (HR 1.129, P = 0.0115), and ischemic vs dilative cardiomyopathy had an increased probability of death or graft failure.

Report From the American Society of Transplantation Conference on Donor Heart Selection in Adult Cardiac Transplantation in the United States

Cardiac transplantation remains the only definitive treatment for end-stage heart failure. Transplantation rates are limited by a shortage of donor hearts. This shortage is magnified because many hearts are discarded because of strict selection criteria and concern for regulatory reprimand for less-than-optimal posttransplant outcomes. There is no standardized approach to donor selection despite proposals to liberalize acceptance criteria. A donor heart selection conference was organized to facilitate discussion and generate ideas for future research. The event was attended by 66 participants from 41 centers with considerable experience in cardiac donor selection. There were state-of-the-art presentations on donor selection, with subsequent breakout sessions on standardizing the process and increasing utilization of donor hearts. Participants debated misconceptions and established agreement on donor and recipient risk factors for donor selection and identified the components necessary for a future donor risk score. Ideas for future initiatives include modification of regulatory practices to consider extended criteria donors when evaluating outcomes and prospective studies aimed at identifying the factors leading to nonacceptance of available donor hearts. With agreement on the most important donor and recipient risk factors, it is anticipated that a consistent approach to donor selection will improve rates of heart transplantation.

91-Year-Old Allograft: Oldest Surviving Donor Heart Still Going: A Case Report

For patients with end-stage heart failure, heart transplantation remains one of the most successful therapies with excellent long-term survival rates. However, over the past few decades, there has been a worsening supply/demand mismatch given the rising epidemic of heart failure and the relatively fixed availability of donor hearts. In this case report, we describe the case of a 30-year-old woman who underwent transplantation with a 68-year-old donor heart and who has survived for 23 years without any major cardiac problems. To our knowledge, this patient has one of the oldest surviving donor hearts (91-year-old heart). Review of the latest guidelines and recent studies have demonstrated a gradual expansion of donor criteria to meet this critical shortage of donor organs.

Impact of donor age on cardiac transplantation outcomes and on cardiac function

OBJECTIVES

Although the impact of older donors on heart transplant outcomes has been previously published, the survival results are conflicting. We herein analyse the impact of older donors on transplant survival and myocardial function.

METHODS

The records of the patients who underwent heart transplant at Baylor University Medical Center at Dallas from November 2012 until March 2015 were reviewed and the data were extracted. The heart recipients were divided into two groups based on donors age; 50 years of age was the division point. The two groups were compared with regard to the following transplant outcomes: in-hospital and 1-year survival, severe (3R) rejection, primary graft dysfunction, myocardial performance as reflected by the inotropic score, left ventricular ejection fraction, intensive care unit and overall length of stay.

RESULTS

Anoxia was more common cause of death in younger donors (43.9%), whereas intracranial bleeding was more frequent in older donors (48.1%, P = 0.016). The in-hospital survival and 1-year survival were the same between the two groups. Additionally, cardiac transplantation from older donors was not associated with higher incidence of graft dysfunction, higher inotropic support score, longer intensive care unit and total hospital length of stay or more frequent severe rejection episodes. The left ventricular ejection fraction was similar between the two groups.

CONCLUSIONS

Heart transplant from older donors is not associated with lower in-hospital and mid-term survival if donors are carefully selected; furthermore, the graft function is comparable. The use of hearts from donors older than 50 years of age can be expanded beyond critically ill recipients in carefully selected recipients.