Marginal donor grafts in heart transplantation: lessons learned from 25 years of experience

Donor evaluation and management system (medical consultant system) in Japan: experience from 200 consecutive brain-dead organ donation

PURPOSE

As the donor shortage is extremely severe in Japan because of a strict Organ Transplantation Act, special strategies must be established to maximize organ transplant opportunities. The purpose of this study was to evaluate our strategies to identify and manage 200 consecutive brain-dead organ donors.

METHODS AND MATERIALS

We retrospectively reviewed the 200 donors procured since the Organ Transplantation Act was issued in 1997, including 118 males, a mean overall age of 45.1 years and cause of death being cerebrovascular disease (n = 119), head trauma (n = 37), and asphyxia (n = 44). DONOR EVALUATION AND MANAGEMENT SYSTEM: Since November in 2002, special transplant management doctors ("medical consultants") were sent to donor hospitals to assess organ function and identify transplantable organs. They also provided intensive care to stabilize hemodynamics and improve cardiac and lung functions by administering antidiuretic hormone intravenously and providing bronchofiberscopic pulmonary toilet.

RESULTS

We obtained 146 heart, 1 heart-lung, and 154 lung (87 single and 67 bilateral), 175 liver (28 splitted liver), 142 pancreas (114 pancreas-kidney), 253 kidney and 12 small bowel grafts. Organs procured from 1 donor increased from 4.5 to 6.8 after applying these strategies.

CONCLUSIONS

Although the number of cases was still small, the availability of organs and outcomes of transplantation have been acceptable.

Donor predictors of allograft use and recipient outcomes after heart transplantation

BACKGROUND

Despite a national organ-donor shortage and a growing population of patients with end-stage heart disease, the acceptance rate of donor hearts for transplantation is low. We sought to identify donor predictors of allograft nonuse, and to determine whether these predictors are in fact associated with adverse recipient post-transplant outcomes.

METHODS AND RESULTS

We studied a cohort of 1872 potential organ donors managed by the California Transplant Donor Network from 2001 to 2008. Forty-five percent of available allografts were accepted for heart transplantation. Donor predictors of allograft nonuse included age >50 years, female sex, death attributable to cerebrovascular accident, hypertension, diabetes mellitus, a positive troponin assay, left-ventricular dysfunction and regional wall motion abnormalities, and left-ventricular hypertrophy. For hearts that were transplanted, only donor cause of death was associated with prolonged recipient hospitalization post-transplant, and only donor diabetes mellitus was predictive of increased recipient mortality.

CONCLUSIONS

Whereas there are many donor predictors of allograft discard in the current era, these characteristics seem to have little effect on recipient outcomes when the hearts are transplanted. Our results suggest that more liberal use of cardiac allografts with relative contraindications may be warranted.

Coronary artery bypass graft surgery during heart transplantation

We report the case of a patient who was submitted to coronary artery bypass graft surgery (CABG) during heart transplant as, during bench exploration, the donor heart presented a palpable atherosclerotic lesion in the anterior descending artery, not detected before harvesting. The patent internal thoracic artery from a previous CABG was used.

Influence of HBcAb positivity in the organ donor in heart transplantation

OBJECTIVE

There is a significant risk of hepatitis B transmission from HBsAg (-), HBcAb (+) donors in liver transplantation, but there is little information about hepatitis B transmission from HBcAb heart donors. The present study examines the influence of HBcAb presence in relation to heart donor acceptance and offers an update of the published studies.

DESIGN

Survey and medical database update from 1994 to October 2011.

SETTING

Spanish heart transplantation teams.

PATIENTS

Not applicable.

STUDY VARIABLES

Acceptance of heart transplant from an HBcAb (+) organ donor.

RESULTS

Twelve out of 15 surveyed teams were seen to vaccinate against HBV, and two quantify HBsAb titers. Seven teams specifically request donor HBcAb status. If the latter proves positive, two do not accept transplantation, two accept if the donor is also HBsAb (+), one selects the receptor under emergency conditions, and three use drug prophylaxis isolatedly or complementary to the above. Only one case of hepatitis B has been reported in a HBcAb (-) and HBsAb (-) receptor that did not receive prophylactic measures. There have been reports of seroconversion of the HBcAb and HBsAb markers, though with an uncertain etiology.

CONCLUSIONS

HBcAb seropositivity influences acceptance of a heart donor, but agreement is lacking. There is limited information on receptor evolution. To date there has been one reported case of hepatitis B after heart transplant. Although rare, an HBcAb (+) donor can harbor occult HBV infection. The risk of infection can be prevented with appropriate HBsAb titers following vaccination or by pharmacological measures.

Donor scoring system for heart transplantation and the impact on patient survival

BACKGROUND

The aim of this study was to design and validate a heart donor score that reflects experts' perceived risk of allograft failure.

METHODS

All heart donors reported to Eurotransplant between January 1, 2005 and December 31, 2008 (N = 4,110) were used to create a donor score. Based on observed discard rates and using multivariate regression, points were assigned for the following donor factors: age; cause of death; body mass index (BMI); diabetes mellitus (DM); duration of ICU stay; compromised history (drug, abuse, sepsis, meningitis, malignancy, HBsAg(+) or anti-HCV(+)); hypertension; cardiac arrest; echocardiography; coronary angiogram; serum sodium; and noradrenaline and dopamine/dobutamine doses. The donor score was obtained by adding all points. All heart donors reported to Eurotransplant in 2009 were included to validate the score (N = 885).

RESULTS

All donor factors, except BMI, DM and duration of ICU stay, significantly predicted discard. Based on the median value of the score, donors were classified into low-risk donors (LRDs: ≤16 points) and high-risk donors (HRDs: ≥17 points). In the validation set, discard rates were significantly different when comparing HRDs (35%) and LRDs (7%) (p < 0.0001). In addition, the heart donor score was significantly associated with 3-year survival: LRD 81.5% vs HRD 70.0% (p = 0.004).

CONCLUSIONS

The heart donor score accurately reflects the likelihood of organ acceptance and predicts long-term patient mortality. Application of this score at time of donor reporting may facilitate donor risk assessment and allow for more appropriate matching of extended criteria donor hearts.

The beneficial effects of deferred delivery on the efficiency of hydrogel therapy post myocardial infarction

Biomaterials are increasingly being investigated as a means of reducing stress within the ventricular wall of infarcted hearts and thus attenuating pathological remodelling and loss of function. In this context, we have examined the influence of timing of delivery on the efficacy of a polyethylene glycol hydrogel polymerised with an enzymatically degradable peptide sequence. Delivery of the hydrogel immediately after infarct induction resulted in no observable improvements, but a delay of one week in delivery resulted in significant increases in scar thickness and fractional shortening, as well as reduction in end-systolic diameter against saline controls and immediately injected hydrogel at both 2 and 4 weeks post-infarction (p < 0.05). Hydrogels injected at one week were degraded significantly slower than those injected immediately and this may have played a role in the differing outcomes. The hydrogel assumed markedly different morphologies at the two time points having either a fibrillar or bulky appearance after injection immediately or one week post-infarction respectively. We argue that the different morphologies result from infarction induced changes in the cardiac structure and influence the degradability of the injectates. The results indicate that timing of delivery is important and that very early time points may not be beneficial.

Transcatheter aortic valve implantation in a heart transplant recipient: a case report

Transcatheter aortic valve implantation (TAVI) has evolved into a feasible therapeutic option for the management of selected patients with severe aortic stenosis and high or prohibitive risk for standard surgery. Symptomatic severe aortic stenosis occasionally occurs in the allograft long after heart transplantation. Because of specific characteristics and comorbidities of heart transplant recipients, these patients may be considered candidates for this less invasive approach. We report a first case of successful transapical TAVI in a heart transplant recipient with symptomatic severe calcific aortic valvular disease and relevant comorbidities long after heart transplantation.

Solid organ procurement from donors with carbon monoxide poisoning and/or burn--a systematic review

INTRODUCTION

Traditionally, carbon monoxide poisoning and/or burn are considered contraindications to organ procurement. Previously reported cases have shown mixed results and many have been redundantly reported in the literature.

METHODS

We performed a systematic review of all reported cases of organ transplantation procured from donors with carbon monoxide poisoning and/or burn to investigate whether these patients are suitable donors for solid organ transplantations.

RESULTS

Organ survival rates of reported organs were high (86%). All organs procured from donors with carbon monoxide poisoning and burn survived during follow-up. Mean donors' peak carbon monoxide levels were comparable for organs surviving or failing during follow-up (31 ± 2.7 vs. 29 ± 26.8; p=0.95). Eighty-seven per cent of organs procured from donors supported with inotropes or vasopressors prior to organ procurement and 91% of organs procured from donors who were cardiopulmonary resuscitated prior to organ procurement survived during follow-up.

CONCLUSIONS

Burn, carbon monoxide poisoning, high peak carbon monoxide-levels, use of inotropes or vasopressors or cardiopulmonary resuscitation prior to procurement are not contraindications for organ procurement and transplantation. New guidelines for burn units defining the special requirements for organ procurement from donors with carbon monoxide poisoning and/or burn are needed to raise the awareness for potential organ donors and to ultimately increase the donor pool and save patients' lives.

The European experience

This mini-review on European experiences with tackling the problem of organ shortage for transplantation was based on a literature review of predominantly European publications dealing with the issue of organ donation from deceased donors. The authors tried to identify the most significant factors that have demonstrated to impact on donation rates from deceased donors and subsequent transplant successes. These factors include legislative measures (national laws and European Directives), optimization of the donation process, use of expanded criteria donors, innovative preservation and surgical techniques, organizational efforts, and improved allocation algorithms.

[Evaluation of the potential organ donor with special regards to heart donation]

Angesichts der auch in Österreich vorherrschenden Knappheit an verfügbaren Organspendern für Herztransplantationen erscheint es dringlich notwendig, eine Optimierung von Spenderevaluierung und Management zu diskutieren. In der vorliegenden Arbeit werden allgemeine Spenderkriterien und herzspezifische Parameter detailliert diskutiert und im Zusammenhang mit der internationalen Literatur dargestellt. Es wird der "marginale" und im Gegensatz dazu der "optimale" Organspender definiert. Das Spendermanagement wird besprochen, wobei neben der hämodynamischen Optimierung auch auf zusätzliche intensivmedizinische Aspekte eingegangen wird. Erst die exakte Evaluierung erlaubt die individuelle Zuteilung des Organs zum passenden Empfänger und stellt somit insbesondere bei marginalen Spendern die Grundlage eines Therapieerfolgs dar.

Long-term outcomes after 1000 heart transplantations in six different eras of innovation in a single center

The objective of this study was to evaluate long-term outcomes of cardiac transplantation (HTx) in different eras of innovation at a single center during a period of 27 years. We performed a retrospective analysis of 960 cardiac allograft recipients (40 re-HTx) between 1981 and 2008. The results of six different eras based on milestones in HTx were analysed: Era 1: the early years (n = 222,1981-1992); era 2: introduction of inhalative nitric oxide, prostanoids, University of Wisconsin solution (UW) replacing Bretschneider's solution (HTK,n = 118, 1992-1994); era 3: statins (n = 102, 1994-1995); era 4: tacrolimus(n = 115, 1995-1996); era 5: mycophenolate mofetil (MMF, n = 143, 1997-2000) and era 6: sirolimus (n = 300, 2000-2008). Outcome variables weresurvival, freedom from cardiac allograft vasculopathy (CAV) and from acute rejection episodes (AREs). Differences in survival was found comparing era 1 and era 2 with era 4 and era 6 (P < 0.001). Organ preservation through UW demonstrated a significantly better survival as compared with HTK(P < 0.001). Less AREs occurred in patients receiving tacrolimus-sirolimus ortacrolimus-MMF (P < 0.001). Patients receiving tacrolimus-MMF showed less CAV than when treated with cyclosporine-MMF (P < 0.005). There were more ventricular assist device implantations and more re-HTx in era 6 (P < 0.0001)than when compared with other eras. Although the causes for improvement in survival over time are multifactorial, we believe that changes in immunosuppressive therapy have had a major impact on survival.

Interactions among donor characteristics influence post-transplant survival: a multi-institutional analysis

BACKGROUND

Quantification of donor-associated risk in a specific heart transplant recipient is often difficult. Our aim was to identify donor characteristics that affect survival in the contemporary era.

METHODS

Between 1990 and 2006, 7,322 patients from 32 centers in the Cardiac Transplant Research Database underwent heart transplantation. Multivariable logistic regression analysis was used to identify donor-associated risk predictors and important interactions between these donor characteristics. Recipient survival was examined using parametric regression analysis in the hazard function domain.

RESULTS

Donor characteristics associated with post-transplant death included donor age, donor requirement for vasoactive therapy, positive donor cytomegalovirus serology, longer graft ischemic time, and lower donor body weight. Several interactions between individual donor characteristics affected survival. In male donors, history of hypertension and diabetes mellitus were risk factors for death (p = 0.006, p = 0.04, respectively), but not in female donors (p = 0.5, p = 0.8, respectively). There was a significant interaction between donor age and recipient-donor weight difference. If the donor was of younger age, increasing recipient-donor weight difference did not result in increased death. With increasing donor age, weight difference did result in compromised survival (p < 0.0003). Donor and recipient gender further modified the degree of risk: risk was higher in female donors and when recipients were male (p < 0.0003).

CONCLUSIONS

This multi-institutional analysis identified important interactions between donor characteristics that affect post-transplant survival that explain some of the discrepancies in the results of previous studies. The results are likely to aid in efficient organ allocation.

Change in donor profile influenced the percentage of organs transplanted from multiple organ donors

We hypothesized that the change in donor profile over the years influenced the percentage of transplantations. We reviewed medical records for all multiple-organ donors (MODs) within our network. The percentage of transplanted organs was compared between 1991-1992 (A) and 2006-2007 (B). In period A, 156 potential MODs were identified compared with 278 in period B. Fifteen potential donors (10%) in period A and 114 (41%) in period B were rejected because they were medically not suitable (40% vs 75%) or there was no family consent (60% vs 25%). Of the remaining effective MODs (141 in period A and 164 in period B), mean (standard deviation = SD) age was 34 (5) years vs 49 (17) years (P < .001). Brain death resulted from craniocerebral trauma in 69% vs 39%, cerebrovascular disease in 24% vs 46%, hypoxia in 4% vs 15%, and brain tumor in 2% vs 0.6% (P < .001). Chest trauma was present in 19% vs 9% (P < .01). The percentage of MODs who received mechanical ventilation for more than 5 days was 8% vs 24% (P < .001). The percentage of organs transplanted in periods A vs B was kidneys, 97% vs 79%; livers, 64% vs 85%; hearts, 60% vs 26%; lungs, 7% vs 35%; and pancreas, 6% vs 13% (P < .001). The number of referred potential MODs increased by 80%, resulting in a small increase in effective MOD organs (17%), mainly because of medical contraindications. The MOD profile changed to older age, fewer traumatic brain deaths, and longer ventilation time. We transplanted more livers, lungs, and pancreases but fewer kidneys and hearts.