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

Heart transplantation using a donor heart with repaired tetralogy of Fallot: a case report

Background

Heart transplantation is the gold standard therapy for end-stage heart failure; however, it is limited by a shortage of available donors. In recent years, heart transplantations have been performed using marginal donor hearts with valvular and/or congenital cardiac abnormalities.

Case summary

A 60-year-old woman with acromegalic cardiomyopathy underwent left ventricular assist device implantation and aortic valve (AV) closure 4 years prior. After 2 months, repeat AV closure and omental flap transposition were performed. During the outpatient follow-up, the patient developed recurrent severe AV regurgitation and bacteraemia-induced subarachnoid haemorrhage. She underwent urgent heart transplantation using a marginal donor heart with preserved cardiac function, mild pulmonary valve stenosis, and regurgitation after pulmonary valve-sparing tetralogy of Fallot (TOF) repair. An anatomical anastomosis was possible. She had no signs of infection, heart failure, arrhythmia, or immune rejection 15 months after the heart transplantation.

Discussion

In this case, the donor heart with repaired TOF did not require pulmonary valve replacement and was anatomically intact. Donor hearts with repaired TOF that are expected to have long-term durability in terms of cardiac function may be used for successful heart transplantations. The repair of marginal donor hearts creates an opportunity to increase the number of viable donors.

Short-term outcomes after heart transplantation using donor hearts preserved with ex vivo perfusion

The standard Conventional Cold Storage (CCS) during heart transplantation procurement is associated with time-dependent ischemic injury to the graft, which is a significant independent risk factor for post-transplant early morbidity and mortality - especially when cold ischemic time exceeds four hours. Since 2018, Rigshospitalet (Copenhagen, Denmark) has been utilising ex vivo perfusion (Organ Care System, OCS) in selected cases. The objective of this study was to compare the short-term clinical outcomes of patients transplanted with OCS compared to CCS. Methods: This retrospective single-centre study was based on consecutive patients undergoing a heart transplant between January 2018 and April 2021. Patients were selected for the OCS group when the cold ischemic time was expected to exceed four hours. The primary outcome measure was six-month event-free survival. Results: In total, 48 patients were included in the study; nine were transplanted with an OCS heart. The two groups had no significant differences in baseline characteristics. Six-month event-free survival was 77.8% [95% CI: 54.9-100%] in the OCS group and 79.5% [95% CI: 67.8-93.2%] in the CCS group (p = 0.91). While the OCS group had a median out-of-body time that was 183 min longer (p < 0.0001), the cold ischemic time was reduced by 51 min (p = 0.007). Conclusion: In a Scandinavian setting, our data confirms that utilising OCS in heart procurement allows for a longer out-of-body time and a reduced cold ischemic time without negatively affecting safety or early post-transplant outcomes.

Donor Heart Preservation: Current Knowledge and the New Era of Machine Perfusion

Heart transplantation remains the conventional treatment in end-stage heart failure, with static cold storage (SCS) being the standard technique used for donor preservation. Nevertheless, prolonged cold ischemic storage is associated with the increased risk of early graft dysfunction attributed to residual ischemia, reperfusion, and rewarming damage. In addition, the demand for the use of marginal grafts requires the development of new methods for organ preservation and repair. In this review, we focus on current knowledge and novel methods of donor preservation in heart transplantation. Hypothermic or normothermic machine perfusion may be a promising novel method of donor preservation based on the administration of cardioprotective agents. Machine perfusion seems to be comparable to cold cardioplegia regarding donor preservation and allows potential repair treatments to be employed and the assessment of graft function before implantation. It is also a promising platform for using marginal organs and increasing donor pool. New pharmacological cardiac repair treatments, as well as cardioprotective interventions have emerged and could allow for the optimization of this modality, making it more practical and cost-effective for the real world of transplantation. Recently, the use of triiodothyronine during normothermic perfusion has shown a favorable profile on cardiac function and microvascular dysfunction, likely by suppressing pro-apoptotic signaling and increasing the expression of cardioprotective molecules.

TAVI in a Heart Transplant Recipient-Rare Case Report and Review of the Literature

The global demand for cardiac transplants continues to rise, even with advancements in assistive devices. Currently, the estimated annual mortality rate stands at 3-5%, and patients often face a waiting time of approximately four years on transplant waiting lists. Consequently, many transplant centers have started to consider heart transplants from donors who may be deemed "less than ideal" or marginal. However, the decision to accept such donors must be highly individualized, taking into consideration the risks associated with remaining on the waiting list versus those posed by the transplantation procedure itself. A potential solution lies in the creation of two distinct recipient lists, matched with donor criteria, allowing marginal donors to provide the lifeline that selected patients require. This paper follows a two-step approach. Firstly, it offers an overview of the current state of affairs regarding the topic of transcatheter aortic valve implantation (TAVI) in orthotopic heart transplant (OHT) patients. Secondly, it presents firsthand experience from our clinical center with a comprehensive case presentation of a patient in this unique medical context. The clinical case refers to a 62-year-old male patient, a smoker with a history of hypertension, dyslipidemia, and a prior OHT a decade earlier, who presented with fatigue during minimal physical exertion. The Heart Team carefully reviewed the case, considering the patient's immunosuppressed status and the heightened risk associated with a repeat intervention. In this instance, transcatheter aortic valve implantation (TAVI) was deemed the appropriate treatment. The TAVI procedure yielded successful results, leading to improved clinical status and enhanced cardiac function. The inclusion of marginal donors has introduced novel challenges related to the utilization of previously diseased marginal organs. TAVI has already demonstrated its efficacy and versatility in treating high-risk patients, including heart transplant recipients. Consequently, it emerges as a vital tool in addressing the unique challenges posed by the inclusion of marginal donors.

Prevalence, Characteristics, and Prognostic Relevance of Donor-Transmitted Coronary Artery Disease in Heart Transplant Recipients

BACKGROUND

The reported prevalence of donor-transmitted coronary artery disease (TCAD) in heart transplantation (HT) is variable, and its prognostic impact remains unclear.

OBJECTIVES

The goal of this study was to characterize TCAD in a contemporary multicentric cohort and to study its prognostic relevance.

METHODS

This was a retrospective study of consecutive patients >18 years old who underwent HT in 11 Spanish centers from 2008 to 2018. Only patients with a coronary angiography (c-angio) within the first 3 months after HT were studied. Significant TCAD (s-TCAD) was defined as any stenosis ≥50% in epicardial coronary arteries, and nonsignificant TCAD (ns-TCAD) as stenosis <50%. Clinical outcomes were assessed by means of Cox regression and competing risks regression. Patients were followed-up for a median period of 6.3 years after c-angio.

RESULTS

From a cohort of 1,918 patients, 937 underwent c-angio. TCAD was found in 172 patients (18.3%): s-TCAD in 65 (6.9%) and ns-TCAD in 107 (11.4%). Multivariable Cox regression analysis did not show a statistically significant association between s-TCAD and all-cause mortality (adjusted HR: 1.44; 95% CI: 0.89-2.35; P = 0.141); however, it was an independent predictor of cardiovascular mortality (adjusted HR: 2.25; 95% CI: 1.20-4.19; P = 0.011) and the combined event cardiovascular death or nonfatal MACE (adjusted HR: 2.42; 95% CI: 1.52-3.85; P < 0.001). No statistically significant impact of ns-TCAD on clinical outcomes was detected. The results were similar when reassessed by means of competing risks regression.

CONCLUSIONS

TCAD was not associated with reduced survival in patients alive and well enough to undergo post-HT angiography within the first 3 months; however, s-TCAD patients showed increased risk of cardiovascular death and MACE.

ADONHERS (Aged DONor HEart Rescue by Stress Echo) National Protocol: Recipient's Survival after 10-Year Follow-Up

Background: The gold-standard treatment for end-stage heart failure is heart transplantation, but the lack of organ donors remains an important limitation in this field. An accurate selection of marginal hearts is fundamental to increase organ availability. Purpose: In our study we analyzed if recipients receiving marginal donor (MD) hearts, selected by dipyridamole stress echocardiography according to the ADOHERS national protocol, had different outcomes compared to recipients with acceptable donor (AD) hearts. Methods: Data were collected and retrospectively analyzed from patients who received an orthotopic heart transplant at our institution between 2006 and 2014. Dipyridamole stress echo was performed on identified marginal donors and selected hearts were eventually transplanted. Clinical, laboratory and instrumental features of the recipients were evaluated and patients with homogenous baseline characteristics were selected. Results: Eleven recipients transplanted with a selected marginal heart and eleven recipients transplanted with an acceptable heart were included. Mean donor age was 41 ± 23. The median follow-up was 113 months (IQR 86-146 months). Age, cardiovascular risk and morpho-functional characteristics of the left ventricle were comparable between the two populations (p > 0.05). Left atrial size was significantly higher in patients with marginal hearts (acceptable atrial volume: 23 ± 5 mL; marginal atrial volume: 38 ± 5 mL; p = 0.003). Acceptable donor recipients showed a higher impact of Cardiac Allograph Vasculopathy (p = 0.019). No rejection differences were found between the two groups. Four patients deceased, three were standard donor recipients and one was from the marginal donor group. Conclusions: Our study shows how cardiac transplant (Htx) from selected marginal donor hearts through a non-invasive bedside technique can alleviate the shortage of organs without a difference in survival compared to acceptable donor hearts.

First Successful Human Coronary Artery Bypass Surgery Postoperative Heart Transplant: A Case Report

Heart transplant is now the treatment of choice for patients with advanced heart failure who are refractory to medical treatment. With a small number of candidates who meet the traditional criteria of a heart donor, we aimed to alleviate this shortage. In this article, we report a 43-year-old woman with a highly urgent heart requirement, according to acute decompensated heart failure, who received a heart with coronary artery grafts from a 50-year-old woman with the diagnosis of 3-vessel disease. Our review of her 1-year follow-up demonstrated the absence of any cardiac or other problems and survival of the patient. There have been no reports in the relevant literature of transplanting marginal hearts from donors who have previously undergone coronary artery bypass graft before transplant. According to our findings, transplant of a marginal heart with coronary artery grafts can be successful; additional studies with larger samples are warranted to further investigate the results of transplanting marginal hearts from donors who have previously undergone coronary artery bypass graft procedures.

Orthotopic Heart Transplant with Concurrent Supracoronary Ascending Aortic Replacement

BACKGROUND

We report a case of successful orthotopic heart transplant with concurrent supracoronary ascending aortic replacement (SCAAR) using a vascular conduit.

CASE PRESENTATION

An orthotopic heart transplant was performed on a 29-year-old White man with idiopathic dilated cardiomyopathy and reduced ejection fraction (20%). During the revision of the donor heart, a wall defect was detected in the ascending part of the donor aorta that could not be corrected. It was decided to perform a SCAAR using a 22-mm polytetrafluoroethylene vascular conduit and double-patch sandwich technique with Teflon patches. Two months later postoperative computed topography scan demonstrated sufficient patency of the vascular conduit and aorta with an improvement in the general somatic and functional state of the patient, and normal systolic and diastolic function of the transplanted heart.

CONCLUSIONS

Our clinical case is unique in the complexity of the procedure with potential high intraoperative and early postoperative risks as well as the fact that SCAAR was performed immediately after heart transplant. In this clinical case, reconstruction of the ascending aorta with a vascular conduit is a strategically correct solution in the event of aortic defects that cannot be corrected with a suture technique.

Is a Bioengineered Heart From Recipient Tissues the Answer to the Shortage of Donors in Heart Transplantation?

With the increase in life expectancy worldwide, end-organ failure is becoming more prevalent. In addition, improving post-transplant outcomes has contributed to soaring demand for organs. Unfortunately, thousands have died waiting on the transplant list due to the critical shortage of organs. The success of bioengineered hearts may eventually lead to the production of limitless organs using the patient’s own cells that can be transplanted into them without the need for immunosuppressive medications. Despite being in its infancy, scientists are making tremendous strides in “growing” an artificial heart in the lab. We discuss these processes involved in bioengineering a human-compatible heart in this review. The components of a functional heart must be replicated in a bioengineered heart to make it viable. This review aims to discuss the advances that have already been made and the future challenges of bioengineering a human heart suitable for transplantation.

Marginal versus Standard Donors in Heart Transplantation: Proper Selection Means Heart Transplant Benefit

BACKGROUND

In this study, we assessed the mid-term outcomes of patients who received a heart donation from a marginal donor (MD), and compared them with those who received an organ from a standard donor (SD).

METHODS

All patients who underwent HTx between January 2012 and December 2020 were enrolled at a single institution. The primary endpoints were early and long-term survival of MD recipients. Risk factors for primary graft failure (PGF) and mortality in MD recipients were also analyzed. The secondary endpoint was the comparison of survival of MD versus SD recipients.

RESULTS

In total, 238 patients underwent HTx, 64 (26.9%) of whom received an organ from an MD. Hospital mortality in the MD recipient cohort was 23%, with an estimated 1 and 5-year survival of 70% (59.2-82.7) and 68.1% (57.1-81), respectively. A multivariate analysis in MD recipients showed that decreased renal function and increased inotropic support of recipients were associated with higher mortality (p = 0.04 and p = 0.03). Cold ischemic time (p = 0.03) and increased donor inotropic support (p = 0.04) were independent risk factors for PGF. Overall survival was higher in SD than MD (85% vs. 68% at 5 years, log-rank = 0.008). However, risk-adjusted mortality (p = 0.2) and 5-year conditional survival (log-rank = 0.6) were comparable.

CONCLUSIONS

Selected MDs are a valuable resource for expanding the cardiac donor pool, showing promising results. The use of MDs after prolonged ischemic times, increased inotropic support of the MD or the recipient and decreased renal function are associated with worse outcomes.

Outcomes following use of pediatric and young adult donor hearts with bicuspid aortic valves: A single-center case series

BACKGROUND

Valvular disease in pediatric and young adult donor hearts may be a relative contraindication to graft use. Outcomes following the use of donor hearts with bicuspid aortic valve (BAV) have not been previously reported in children. We describe 4 cases of pediatric heart transplantation (HTx) utilizing a donor heart with a BAV.

CASE SERIES

Of the 469 HTx included in this study, 4 utilized a donor heart with a BAV. All recipients were female; median age was 11 years (range 0.3 to 19 years). In all cases, the BAV was not discovered until after HTx. All donors were less than 30 years old. The patients were followed for a median of 6 years (range 2 to 9 years) with all patients alive at last follow-up. Two patients have transitioned to adult care, and 2 patients continue to follow in our clinic. In follow-up, no patient has required an aortic valve intervention or had infective endocarditis. At last review, no patient had greater than mild aortic insufficiency or more than mild aortic stenosis. Three patients developed mild-to-moderate left ventricular hypertrophy in the first year post-transplant that improved over time. One patient experienced a peri-operative embolic stroke at time of transplant unrelated to the BAV.

CONCLUSION

On short- and intermediate-term follow-up, pediatric and young adult donor hearts with BAV demonstrated acceptable graft longevity and valvular function. A functionally normal BAV in a pediatric heart transplant donor should not be a contraindication to organ acceptance.

Successful Liver Transplantation from a Deceased Donor After Ethylene Glycol Ingestion: A Case Report and Review of the Literature of Organ Donation from Poisoned Donors

Despite the increase in deceased organ donation over the past ten years, the gap between patients awaiting transplant and available organs continues to widen. Deceased donors secondary to acute fatal poisonings represent less than 1% of all organ donors. Organs from poisoned donors have largely been discarded due to concerns of toxin transmission and poor organ function as well as the paucity of data that exists regarding this donor population. Here, we report a case of a 40-year-old male who underwent successful liver re-transplantation from a donor who died following ethylene glycol ingestion. To our knowledge this case report is the first to describe successful re-transplantation from an ethylene glycol-poisoned donor. We also provide a comprehensive review of the literature describing organ donation from poisoned donors.

Impact of using higher-risk donor hearts for candidates with pre-transplant mechanical circulatory support

BACKGROUND

We evaluated post-heart transplant (HTx) outcomes after use of higher-risk donor hearts for candidates supported with pre-HTx mechanical circulatory support (MCS).

METHODS

In this retrospective analysis of the national United Network for Organ Sharing registry, a total of 9,915 adult candidates on MCS underwent HTx from January 1, 2010 to March 31, 2019. Multi-organ, re-transplant, and congenital heart disease patients were excluded. Higher-risk donor organs met at least one of the following criteria: left ventricular ejection fraction <50%, donor to recipient predicted heart mass ratio <0.86, donor age >55 years, or ischemic time >4 hours. Primary outcome was 1 year post-transplant survival.

RESULTS

Among HTx recipients, 3688 (37.2%) received higher-risk donor hearts. Candidates supported with pre-HTx extracorporeal membrane oxygenation or biventricular assist device (n = 374, 3.8%) who received higher-risk donor hearts had comparable 1 year survival (HR: 1.14, 95% CI: [0.67-1.93], p = 0.64) to recipients of standard-risk donor hearts, when adjusted for recipient age and sex. In candidates supported with intra-aortic balloon pump (n = 1391, 14.6%), transplantation of higher-risk donor hearts did not adversely affect 1 year survival (HR: 0.80, 95% CI: [0.52-1.22], p = 0.30). Patients on durable left ventricular assist devices (LVAD) who received higher-risk donor hearts had comparable 1 year survival to continued LVAD support on the waitlist, but mortality was increased compared to those who received standard-risk donor hearts (HR: 1.37, 95% CI: [1.11-1.70], p = 0.004).

CONCLUSIONS

Patients requiring pre-HTx temporary MCS who received higher-risk donor hearts had comparable 1 year post-transplant survival to those who received standard-risk donor hearts. Stable patients on durable LVADs may benefit from waiting for standard-risk donor hearts.

Ex vivo normothermic perfusion in heart transplantation: a review of the TransMedics® Organ Care System

Cardiac transplantation is the gold standard for treatment for select patients with end-stage heart failure, yet donor supply is limited. Ex vivo machine perfusion is an emerging technology capable of safely preserving organs and expanding the viable donor pool. The TransMedics^® Organ Care System™ is an investigational device which mimics physiologic conditions while maintaining the heart in a warm, beating state rather than cold storage. The use of Organ Care System allows increased opportunities for using organs from marginal donors, distant procurement sites, donation after cardiac death, and in recipients with complex anatomy. In the future, bioengineering technologies including use of mesenchymal stem cells, viral vector delivery of gene therapy, and alternate devices may further broaden the field of ex vivo machine perfusion.

Allograft discard risk index for heart transplantation

BACKGROUND

The numberof patients awaiting heart transplantation (HTx) substantially exceeds the number of donor hearts transplanted each year, yet nearly 65% of eligible donor hearts are discarded rather than transplanted.

METHODS

Deceased organ donors listed within the UNOS Deceased Donor Database between 2010 and 2020 were reviewed. Those greater than 10 years old and consented for heart donation were included and randomly separated into training (n = 48 435) and validation (n = 24 217) cohorts. A discard risk index (DSRI) was created using the results of univariable and multivariable analyses. Discard data were assessed at DSRI value deciles, and stratum-specific likelihood ratio (SSLR) analysis and Kaplan-Meier survival function were used for mortality data.

RESULTS

Factors associated with higher DSRI values included donor age > 45, LVEF, HBV-core antibodies, hypertension, and diabetes. The DSRI C-statistic was .906 in the training cohort and .904 in the validation cohort. The DSRI did not reliably predict 30-day or 1-year mortality after transplantation (C-statistic .539 and .532, respectively).

CONCLUSIONS

The factors leading to heart allograft discard are not correlated to the same degree with post-transplant outcomes. This suggests that optimizing utilization of certain allografts with slightly higher risk of discard could increase the heart donor pool with limited impact on posttransplant mortality.

The Human Explanted Heart Program: A translational bridge for cardiovascular medicine

The progression of cardiovascular research is often impeded by the lack of reliable disease models that fully recapitulate the pathogenesis in humans. These limitations apply to both in vitro models such as cell-based cultures and in vivo animal models which invariably are limited to simulate the complexity of cardiovascular disease in humans. Implementing human heart tissue in cardiovascular research complements our research strategy using preclinical models. We established the Human Explanted Heart Program (HELP) which integrates clinical, tissue and molecular phenotyping thereby providing a comprehensive evaluation into human heart disease. Our collection and storage of biospecimens allow them to retain key pathogenic findings while providing novel insights into human heart failure. The use of human non-failing control explanted hearts provides a valuable comparison group for the diseased explanted hearts. Using HELP we have been able to create a tissue repository which have been used for genetic, molecular, cellular, and histological studies. This review describes the process of collection and use of explanted human heart specimens encompassing a spectrum of pediatric and adult heart diseases, while highlighting the role of these invaluable specimens in translational research. Furthermore, we highlight the efficient procurement and bio-preservation approaches ensuring analytical quality of heart specimens acquired in the context of heart donation and transplantation.

Cardiac rehabilitation program improves exercise capacity in heart transplantation recipients regardless of marginal donor factors

Cardiac rehabilitation (CR) is recommended to improve exercise capacity after heart transplantation (HTx); however, the effects of marginal donor factors are unclear. Forty-one recipients participated in a 3-month CR program early after HTx (mean age 39 ± 14 years; 88% male). Patients were divided into marginal (≥ 2 marginal donor factors; n = 24) and control groups (< 2 marginal donor factors; n = 17). We examined donor and recipient factors related to change in peak oxygen uptake (peak VO₂) during the CR program using multiple linear regression analysis. Baseline characteristics were similar between groups, although the mean age was higher in the marginal group (43 ± 13 vs. 34 ± 14 years, p = 0.043). Peak VO₂ and knee extensor muscular strength (KEMS) improved significantly in both groups (p < 0.05), but there were no observed inter-group differences. Multiple analysis revealed change in KEMS (β = 0.52, 95% CI = 0.023-1.01) as an independent predictor of change in peak VO₂ after adjustment for recipients' age, sex, and CR attendance frequency (adjusted R² = 0.25, p = 0.0084), whereas marginal donor factors were not a predictor (p = 0.76). The CR program improved exercise capacity in HTx recipients regardless of marginal donor factors, suggesting that recipients of marginal donor hearts should be referred to CR programs.

Valvular surgery in donor hearts before orthotopic heart transplantation

BACKGROUND

Donor heart shortage has extended the waiting time and increased the mortality of patients on the transplant waiting list. Widening old standard donor criteria has successfully increased the number of heart transplantations, but for many years, a valve disease in a donor heart has been considered a primary contraindication for organ donation.

AIMS

To analyse the results of aortic and mitral valvular surgery in marginal donor hearts with valvulopathy before orthotopic heart transplantation.

METHODS

Between January 2012 and November 2015, we performed 53 heart transplantations in our department. In four donors, echocardiography performed at the time of organ procurement showed a valvular disease: three had moderate-to-severe mitral regurgitation; and one had moderately severe aortic valve stenosis.

RESULTS

The mean bench mitral repair and aortic replacement time, aortic cross-clamp time and total ischaemic time were: 18 (range 7-25) minutes, 78.7 (range 57-98) minutes and 184 (range 89-255) minutes, respectively. Intraoperative transoesophageal echocardiography showed good mitral repair or aortic prosthetic valve function, and good right and left ventricular function. One patient died of infectious pneumonia after 1 month. The mean duration of follow-up for the patients discharged home was 75±13 months, and all have returned to an active unrestricted lifestyle.

CONCLUSIONS

Our limited series demonstrates that conventional valvular procedures performed on otherwise healthy donor hearts with mitral and aortic valve pathology can efficaciously expand the donor pool for orthotopic cardiac transplantation and decrease the mortality rate on the waiting list.

Successful Heart Transplantation after Cardiopulmonary Resuscitation of Donors

BACKGROUND

 Heart transplantation (HTx) is the best therapy for end-stage heart failure. Unfortunately, death on the waiting list remains a problem. Decreasing the number of rejected organs could increase the donor pool.

METHODS

 A total of 144 patients underwent HTx at our department between 2010 and 2019. Of them, 27 patients received organs of donors with cardiopulmonary resuscitation (CPR) prior to organ donation (donor CPR) and were compared with patients who received organs without CPR (control; n = 117).

RESULTS

 We did not observe any disadvantage in the outcome of the donor CPR group compared with the control group. Postoperative morbidity and 1-year survival (control: 72%; donor CPR: 82%; p = 0.35) did not show any differences. We found no impact of the CPR time as well as the duration between CPR and organ donation, but we found an improved survival rate for donors suffering from anoxic brain injury compared with cerebral injury (p = 0.04).

CONCLUSIONS

 Donor organs should not be rejected for HTx due to resuscitation prior to donation. The need for CPR does not affect the graft function after HTx in both short- and mid-term outcomes. We encourage the use of these organs to increase the donor pool and preserve good results.

New Strategies to Expand and Optimize Heart Donor Pool: Ex Vivo Heart Perfusion and Donation After Circulatory Death: A Review of Current Research and Future Trends

Heart transplantation remains the definitive management for end-stage heart failure refractory to medical therapy. While heart transplantation cases are increasing annually worldwide, there remains a deficiency in organ availability with significant patient mortality while on the waiting list. Attempts have therefore been made to expand the donor pool and improve access to available organs by recruiting donors who may not satisfy the standard criteria for organ donation because of donor pathology, anticipated organ ischemic time, or donation after circulatory death. "Ex vivo" heart perfusion (EVHP) is an emerging technique for the procurement of heart allografts. This technique provides mechanically supported warm circulation to a beating heart once removed from the donor and before implantation into the recipient. EVHP can be sustained for several hours, facilitate extended travel time, and enable administration of pharmacological agents to optimize cardiac recovery and function, as well as allow assessment of allograft function before implantation. In this article, we review recent advances in expanding the donor pool for cardiac transplantation. Current limitations of conventional donor criteria are outlined, including the determinants of organ suitability and assessment, involving transplantation of donation after circulatory death hearts, extended criteria donors, and EVHP-associated assessment, optimization, and transportation. Finally, ongoing research relating to organ optimization and functional ex vivo allograft assessment are reviewed.

Impact of Coronary Artery Calcification in the Donor Heart on Transmitted Coronary Artery Disease in Heart Transplant Recipients

BACKGROUND

Coronary artery disease (CAD) after heart transplantation (HTx) develops as a combination of donor-transmitted coronary atherosclerosis (DTCA) and cardiac allograft vasculopathy. Assessing donor CAD before procurement is important. Because coronary artery calcification (CAC) is a predictor for CAD, donor-heart CAC is usually evaluated to estimate the risk of donor CAD. The usefulness of CAC for predicting DTCA, however, is not known. Methods and Results: Sixty-four HTx recipients whose donor underwent chest computed tomography before procurement or ≤2 weeks after HTx and who underwent coronary angiography and intravascular ultrasound (IVUS) ≤3 months after HTx were enrolled. Eight patients had CAC (CAC group) and 56 patients did not have CAC (no-CAC group). Patients in the CAC group were significantly older and had a higher prevalence of maximum intimal thickness (MIT) of the coronary artery ≥0.5 mm at initial IVUS than patients in the no-CAC group (100% vs. 55%, P=0.02). Adverse cardiac events and death were not significantly different. Everolimus tended to be used more often in the CAC group.

CONCLUSIONS

Donor-heart CAC is a significant predictor for MIT of the coronary artery ≥0.5 mm after HTx. The presence of CAC, however, is not associated with future cardiac events. The higher prevalence of everolimus use in the CAC group may have affected the results.

Impact of Melatonin in Solid Organ Transplantation-Is It Time for Clinical Trials? A Comprehensive Review

Solid organ transplantation is the "gold standard" for patients with end-stage organ disease. However, the supply of donor organs is critical, with an increased organ shortage over the last few years resulting in a significant mortality of patients on waiting lists. New strategies to overcome the shortage of organs are urgently needed. Some experimental studies focus on melatonin to improve the donor pool and to protect the graft; however, current research has not reached the clinical level. Therefore, this review provides a comprehensive overview of the data available, indicating that clinical evaluation is warranted.

Extended donor criteria in heart transplantation: a retrospective study from a single Chinese institution

Background

Heart donor selection criteria have been progressively widened due to increasing donor recipient mismatch. This study evaluates the outcomes of the use marginal donor hearts for orthotopic heart transplantation (OHT) based on a single center experience in China.

Methods

We retrospectively analyzed outcomes of patients undergoing OHT in our hospital between September 2008 and December 2015. All the donor hearts were from voluntary donation of brain-dead patients. The primary outcome was overall survival; secondary outcomes included cardiopulmonary bypass (CPB) time, ventilation time, post-operative mechanical support and medium-term complications.

Results

Overall, 278 patients with OHT were analyzed. Whereas 180 patients (64.7%) underwent OHT utilizing marginal donors (MD group), only 98 patients (35.3%) underwent OHT with standard donors (SD group). Compared to the SD group, the MD group had longer CPB time (P=0.001), ventilation time (P=0.010) and increased mechanical support rate (P=0.011). Survival rates were comparable between the two groups at 30 days, 1 year, 3 years and 5 years (92.2%, 83.3%, 70.6%, 70.6% vs. 95.9%, 91.4%, 80.2%, 80.2% respectively). Multivariate Cox regression analysis revealed that female recipient gender [hazard ratio (HR) =2.632 (1.325-5.227), P=0.006], diagnosis (P=0.014) and abnormal donor heart structure [HR =3.638 (1.005-13.167), P=0.049] were three predictors for 1-year all-cause mortality. The occurrence of complications in the recipients with more than 3-year follow-up did not differ between the two cohorts.

Conclusions

Marginal donor can be reasonably applied to expand the benefits of transplantation. Changing previous MD criteria to include donors with an age greater than 50 years, cold ischemic time less than 6 hours, donor/recipient weight ratio less than 0.8, compatible blood type, hepatitis virus seropositivity and MD used for male recipient will likely offer a good prognosis.

Utilization and Outcomes of Temporary Mechanical Circulatory Support for Graft Dysfunction After Heart Transplantation

Graft dysfunction is the main cause of early mortality after heart transplantation. In cases of severe graft dysfunction, temporary mechanical circulatory support (TMCS) may be necessary. The aim of this systematic review was to examine the utilization and outcomes of TMCS in patients with graft dysfunction after heart transplantation. Electronic search was performed to identify all studies in the English literature assessing the use of TMCS for graft dysfunction. All identified articles were systematically assessed for inclusion and exclusion criteria. Of the 5,462 studies identified, 41 studies were included. Among the 11,555 patients undergoing heart transplantation, 695 (6.0%) required TMCS with patients most often supported using venoarterial extracorporeal membrane oxygenation (79.4%) followed by right ventricular assist devices (11.1%), biventricular assist devices (BiVADs) (7.5%), and left ventricular assist devices (LVADs) (2.0%). Patients supported by LVADs were more likely to be supported longer (p = 0.003), have a higher death by cardiac event (p = 0.013) and retransplantation rate (p = 0.015). In contrast, patients supported with BiVAD and LVAD were more likely to be weaned off support (p = 0.020). Overall, no significant difference was found in pooled 30 day survival (p = 0.31), survival to discharge (p = 0.19), and overall survival (p = 0.51) between the subgroups. Temporary mechanical circulatory support is an effective modality to support patients with graft dysfunction after heart transplantation. Further studies are needed to establish the optimal threshold and strategy for TMCS and to augment cardiac recovery and long-term survival.

High-dose catecholamine donor support and outcomes after heart transplantation

BACKGROUND

Higher dose norepinephrine donor support is a frequent reason for donor heart decline, but its associations with outcomes after heart transplantation are unclear.

METHODS

We retrospectively analyzed 965 patients transplanted between 1992 and 2015 in the Heart Transplant Program Vienna. Stratification was performed according to donor norepinephrine dose administered before organ procurement (Group 0: 0 µg/kg/min; Group 1: 0.01 to 0.1 µg/kg/min; Group 2: >0.1 µg/kg/min). Sub-stratification of Group 2 was performed for comparison of high-dose subgroups (Group HD 1: 0.11 to 0.4 µg/kg/min; Group HD 2: >0.4 µg/kg/min). Associations between groups and outcome variables were investigated using a multivariable Cox proportional hazards model and logistic regression analyses.

RESULTS

Donor norepinephrine dose groups were not associated with overall mortality (Group 1 vs 0: hazard ratio [HR] 1.12, 95% confidence interval [CI] 0.87 to 1.43; Group 2 vs 0: HR 1.07, 95% CI 0.82 to 1.39; p = 0.669). No significant group differences were found for rates of 30-day mortality (p = 0.35), 1-year mortality (p = 0.897), primary graft dysfunction (p = 0.898), prolonged ventilation (p = 0.133) and renal replacement therapy (p = 0.324). Groups 1 and 2 showed higher rates of prolonged intensive care unit stay (18.9% vs 28.5% vs 27.5%, p = 0.005). High-dose subgroups did not differ significantly in 1-year mortality (Group HD 1: 14.3%; Group HD 2: 17.8%; p = 0.549).

CONCLUSIONS

Acceptance of selected donor hearts supported by higher doses of norepinephrine may be a safe option to increase the donor organ pool.

Maximizing donor allocation: A review of UNOS region 9 donor heart turn-downs

This study was performed to determine if organ selection practices for heart utilization by Region 9 transplant programs were optimal, and to identify opportunities to increase local organ recovery. A retrospective review of de-identified region-wide donor data January 1, 2010 through December 31, 2013 was performed. Over the study period 537 heart donors were identified, of which 321 (60%) were transplanted. Two hundred-sixteen consented hearts were not used; 190 of these were not recovered, and 26 were recovered but not transplanted. Of these, 245/321 (76%) hearts were transplanted at one of 5 regional programs, 15 (5%) were transplanted out of region as primary offers, and 61 (19%) were turned down in region and exported. Of the 61 exported hearts, 43 were turned down in region for donor-related "quality" codes (UNOS 830, 833-837) by at least one program, the remaining 18 hearts were turned down for non-"quality" reasons, primarily histocompatibility and size. Only 5/43 exported were turned down for "quality" reasons by all regional programs offered the organ. A review of consented, not recovered donor offers suggested an additional 28 organs were possibly appropriate for transplant. Our review of regional turn-downs suggests transplant centers could potentially identify additional usable organs without compromising short-term outcomes.

Cardiac Surgery After Heart Transplantation: Elective Operation or Last Exit Strategy?

Background

Because of improved long-term survival after heart transplantation (HTx), late graft pathologies such as valvular disease or cardiac allograft vasculopathy (CAV) might need surgical intervention to enhance longer survival and ensure quality of life. To this date, there exist no guidelines for indication of cardiac surgery other than retransplantation after HTx.

Methods

In this retrospective, single-center study, we evaluated patients who underwent cardiac surgery after HTx at our institution.

Results

Between March 1984 and October 2016, 17 (1.16%) of 1466 HTx patients underwent cardiac surgery other than retransplantation after HTx. Indication were valvular disease (n = 7), CAV (n = 6), and other (n = 4). Of these, 29.4% (n = 5) were emergency procedures and 70.6% were elective cases. Median age at time of surgery was 61 years (interquartile range, 52-66 years); 82.4% (n = 14) were male. Median time to surgery after HTx was 9.3 years (2.7-11.1 years). In-hospital, mortality was 11.8% (n = 2); later need of retransplantation was 11.8% (n = 2) due to progressing CAV 3 to 9 months after surgery. One-year survival was 82.35%; overall survival was 47.1% (n = 8) with a median follow-up of 1477 days (416-2135 days). Overall survival after emergency procedures was 209 days (36-1119.5 days) whereas, for elective procedures, it was 1583.5 days (901.5-4319 days).

Conclusions

Incidence of cardiac surgery after HTx in our cohort was low (1.16%) compared with that of other studies. In elective cases, long-term survival was good.

Complement-mediated inflammation and injury in brain dead organ donors

The importance of the complement system in renal ischemia-reperfusion injury and acute rejection is widely recognized, however its contribution to the pathogenesis of tissue damage in the donor remains underexposed. Brain-dead (BD) organ donors are still the primary source of organs for transplantation. Brain death is characterized by hemodynamic changes, hormonal dysregulation, and immunological activation. Recently, the complement system has been shown to be involved. In BD organ donors, complement is activated systemically and locally and is an important mediator of inflammation and graft injury. Furthermore, complement activation can be used as a clinical marker for the prediction of graft function after transplantation. Experimental models of BD have shown that inhibition of the complement cascade is a successful method to reduce inflammation and injury of donor grafts, thereby improving graft function and survival after transplantation. Consequently, complement-targeted therapeutics in BD organ donors form a new opportunity to improve organ quality for transplantation. Future studies should further elucidate the mechanism responsible for complement activation in BD organ donors.

Transcatheter aortic valve implantation in a young heart transplant recipient crossing the traditional boundaries

Transcatheter aortic valve implantation (TAVI) is an established therapeutic alternative to surgical aortic valve replacement (SAVR) in high-risk or inoperable patients with symptomatic aortic valve stenosis. Hitherto, TAVI is not recommended in young and low-intermediate risk patients. However, TAVI may also serve as an alternative to SAVR in selected young patients, e.g., patients who have previously undergone multiple cardiac surgery procedures. We report a case of trans-femoral TAVI in a 25-year-old heart transplant (HTx) recipient with prior surgery for congenital heart disease.

Targeting the Innate Immune Response to Improve Cardiac Graft Recovery after Heart Transplantation: Implications for the Donation after Cardiac Death

Heart transplantation (HTx) is the ultimate treatment for end-stage heart failure. The number of patients on waiting lists for heart transplants, however, is much higher than the number of available organs. The shortage of donor hearts is a serious concern since the population affected by heart failure is constantly increasing. Furthermore, the long-term success of HTx poses some challenges despite the improvement in the management of the short-term complications and in the methods to limit graft rejection. Myocardial injury occurs during transplantation. Injury initiated in the donor as result of brain or cardiac death is exacerbated by organ procurement and storage, and is ultimately amplified by reperfusion injury at the time of transplantation. The innate immune system is a mechanism of first-line defense against pathogens and cell injury. Innate immunity is activated during myocardial injury and produces deleterious effects on the heart structure and function. Here, we briefly discuss the role of the innate immunity in the initiation of myocardial injury, with particular focus on the Toll-like receptors and inflammasome, and how to potentially expand the donor population by targeting the innate immune response.

Left ventricular assist devices: current controversies and future directions

Advanced heart failure is a growing epidemic that leads to significant suffering and economic losses. The development of left ventricular assist devices (LVADs) has led to improved quality of life and long-term survival for patients diagnosed with this devastating condition. This review briefly summarizes the short history and clinical outcomes of LVADs and focuses on the current controversies and issues facing LVAD therapy. Finally, the future directions for the role of LVADs in the treatment of end-stage heart failure are discussed.

Management of the Potential Organ Donor in the ICU: Society of Critical Care Medicine/American College of Chest Physicians/Association of Organ Procurement Organizations Consensus Statement

This document was developed through the collaborative efforts of the Society of Critical Care Medicine, the American College of Chest Physicians, and the Association of Organ Procurement Organizations. Under the auspices of these societies, a multidisciplinary, multi-institutional task force was convened, incorporating expertise in critical care medicine, organ donor management, and transplantation. Members of the task force were divided into 13 subcommittees, each focused on one of the following general or organ-specific areas: death determination using neurologic criteria, donation after circulatory death determination, authorization process, general contraindications to donation, hemodynamic management, endocrine dysfunction and hormone replacement therapy, pediatric donor management, cardiac donation, lung donation, liver donation, kidney donation, small bowel donation, and pancreas donation. Subcommittees were charged with generating a series of management-related questions related to their topic. For each question, subcommittees provided a summary of relevant literature and specific recommendations. The specific recommendations were approved by all members of the task force and then assembled into a complete document. Because the available literature was overwhelmingly comprised of observational studies and case series, representing low-quality evidence, a decision was made that the document would assume the form of a consensus statement rather than a formally graded guideline. The goal of this document is to provide critical care practitioners with essential information and practical recommendations related to management of the potential organ donor, based on the available literature and expert consensus.

CD11c+ Dendritic Cells Accelerate the Rejection of Older Cardiac Transplants via Interleukin-17A

BACKGROUND

Organ transplantation has seen an increased use of organs from older donors over the past decades in an attempt to meet the globally growing shortage of donor organs. However, inferior transplantation outcomes when older donor organs are used represent a growing challenge.

METHODS AND RESULTS

Here, we characterize the impact of donor age on solid-organ transplantation using a murine cardiac transplantation model. We found a compromised graft survival when older hearts were used. Shorter graft survival of older hearts was independent of organ age per se, because chimeric young or old organs repopulated with young passenger leukocytes showed comparable survival times. Transplantation of older organs triggered more potent alloimmune responses via intragraft CD11c+ dendritic cells augmenting CD4+ and CD8+ T-cell proliferation and proinflammatory cytokine production, particularly that of interleukin-17A. Of note, depletion of donor CD11c+ dendritic cells before engraftment, neutralization of interleukin-17A, or transplantation of older hearts into IL-17A(-/-) mice delayed rejection and reduced alloimmune responses to levels observed when young hearts were transplanted.

CONCLUSIONS

These results demonstrate a critical role of old donor CD11c+ dendritic cells in mounting age-dependent alloimmune responses with an augmented interleukin-17A response in recipient animals. Targeting interleukin-17A may serve as a novel therapeutic approach when older organs are transplanted.

National decline in donor heart utilization with regional variability: 1995-2010

The severe shortage of donor hearts limits the availability of transplantation for the growing population of patients with end-stage heart disease. We examined national trends in donor heart acceptance for transplant. OPTN data were analyzed for all potential adult cardiac organ donors between 1995 and 2010. Donor heart disposition was categorized as transplanted, declined for transplant or other. We studied changes in the probability of donor heart acceptance according to demographic and clinical characteristics, nationwide and by UNOS region. Of 82 053 potential donor hearts, 34% were accepted and 48% were declined (18% used for other purposes). There was a significant decrease in donor heart acceptance from 44% in 1995 to 29% in 2006, and subsequent increase to 32% in 2010. Older donor age, female sex and medical co-morbidities predicted non-acceptance. Donor age and co-morbidities increased during the study period, with a concomitant decrease in acceptance of hearts from donors with undesirable characteristics. Overall, predictors of heart non-use were similar across UNOS regions, although utilization varied between regions. Regional variation suggests a potential to improve heart acceptance rates in under-performing regions, and supports research and policy efforts aimed at establishing evidence-based criteria for donor heart evaluation and acceptance for transplantation.

Can carbon monoxide-poisoned victims be organ donors?

The increasing demand for organ allografts to treat end-stage organ failure has driven changes in traditional donor criteria. Patients who have succumbed to carbon monoxide (CO) poisoning, a common cause of toxicological mortality, are usually rejected as organ donors. To fulfill the increasing demand, selection criteria must be expanded to include CO-poisoned donors. However, the use of allografts exposed to high CO concentrations is still under debate. Basic research and literature review data suggest that patients with brain death caused by CO poisoning should be considered appropriate organ donors. Accepting organs from CO-poisoned victims could increase the number of potential donors and lower the death rate of patients on the waiting lists. This review and reported cases may increase awareness among emergency department physicians, as well as transplant teams, that patients dying of CO exposure may be acceptable organ donors.

Mimicking isovolumic contraction with combined electromechanical stimulation improves the development of engineered cardiac constructs

Electrical and mechanical stimulation have both been used extensively to improve the function of cardiac engineered tissue as each of these stimuli is present in the physical environment during normal development in vivo. However, to date, there has been no direct comparison between electrical and mechanical stimulation and current published data are difficult to compare due to the different systems used to create the engineered cardiac tissue and the different measures of functionality studied as outcomes. The goals of this study were twofold. First, we sought to directly compare the effects of mechanical and electrical stimulation on engineered cardiac tissue. Second, we aimed to determine the importance of the timing of the two stimuli in relation to each other in combined electromechanical stimulation. We hypothesized that delaying electrical stimulation after the beginning of mechanical stimulation to mimic the biophysical environment present during isovolumic contraction would improve construct function by improving proteins responsible for cell-cell communication and contractility. To test this hypothesis, we created a bioreactor system that would allow us to electromechanically stimulate engineered tissue created from neonatal rat cardiac cells entrapped in fibrin gel during 2 weeks in culture. Contraction force was higher for all stimulation groups as compared with the static controls, with the delayed combined stimulation constructs having the highest forces. Mechanical stimulation alone displayed increased final cell numbers but there were no other differences between electrical and mechanical stimulation alone. Delayed combined stimulation resulted in an increase in SERCA2a and troponin T expression levels, which did not happen with synchronous combined stimulation, indicating that the timing of combined stimulation is important to maximize the beneficial effect. Increases in Akt protein expression levels suggest that the improvements are at least in part induced by hypertrophic growth. In summary, combined electromechanical stimulation can create engineered cardiac tissue with improved functional properties over electrical or mechanical stimulation alone, and the timing of the combined stimulation greatly influences its effects on engineered cardiac tissue.

Japanese strategies to maximize heart and lung availabilities: experience from 100 consecutive brain-dead donors

OBJECTIVE

Because the donor shortage is extremely severe in Japan because of a strict organ transplantation law, special strategies have been established to maximize heart and lung transplantations (HTs and LTs, respectively). We reviewed 100 consecutive brain-dead donors to evaluate our strategies to identify and manage heart and lung donors.

METHODS

We retrospectively reviewed all 100 consecutive brain-dead donors procured since the law was issued in 1997. There were 56 mens and the overall mean donor age was 43.5 years. The causes of death were cerebrovascular disease (n = 62), head trauma (n = 20), and asphyxia (n = 16): Since November 2002, special transplant management doctors were sent to donor hospitals to assess cardiac and lung functions, seeking to identify transplant opportunities. They stabilized donor hemodynamics and lung function by administering antidiuretic hormone intravenously and performing bronchofibroscopy for pulmonary toilet.

RESULTS

Seventy-nine HTs, 1 heart-lung transplantations, and 78 LTs (46 single and 32 bilateral) were performed. By applying these strategies organs per donor were increased from 4.5 to 6.8. Among heart donors, 61/80 were marginal: high inotrope requirement (n = 29), cardiopulmonary resuscitation (n = 28), and/or >55 years old (n = 20). None of the 80 HT recipients died of primary graft failure (PGF). Patient survival rate at 10 years after HT was 95.4%. Among lung donors, 48/65 were marginal: pneumonia (n = 41), chest trauma (n = 4), and >55 years old (n = 9). Only 2/78 LT recipients died of PGF. Patient survival rate at 3 years after LT was 72.2%. After inducing frequent pulmonary toilet, lung procurement and patient survival rates increased significantly after LT.

CONCLUSIONS

Although the number of cases was still small, the availability of organs has been greater and the outcomes of HT/LT acceptable.

Cardiac transplantation and concomitant coronary artery bypass grafting: our experiences in 11 cases

INTRODUCTION

The shortage of donor hearts for transplantation could be alleviated by including the hearts of older donors. Previous literature revealed similar early and medium-term survival outcomes compared with those of younger donors. This study presents our experience with patients who underwent orthotopic heart transplantation and concomitant coronary artery bypass grafting at our institution.

METHODS

We present our experience with 11 patients with end-stage cardiomyopathy (8 men and 3 women) undergoing orthotopic heart transplantation and concomitant coronary artery bypass grafting from September 2002 to November 2011 at our institute.

RESULTS

All 11 donor organs would otherwise have been rejected, depriving potential recipients of organ transplantation. Two patients received concurrent 2-coronary-artery bypass, and the other 9 patients received concurrent single-coronary-artery bypass during orthotopic heart transplantation. All patients had an uneventful postoperative course, with follow-up completed 3 to 128 months after cardiac transplantation and concomitant coronary artery bypass grafting surgery.

CONCLUSIONS

Our experiences suggest that donor hearts requiring coronary artery bypass grafting, which form a small but significant donor subgroup, can be used effectively and safely when matched to the recipients' age and medical condition.

An echocardiographic measurement of superior vena cava to inferior vena cava distance in patients<20 years of age with idiopathic dilated cardiomyopathy

In normal pediatric echocardiograms, the distance from the junction of superior vena cava (SVC) and right atrium to inferior vena cava (IVC) and right atrium is linearly related to height. We examine this relation in children listed for heart transplant with idiopathic dilated cardiomyopathy (IDC) compared with the previously defined normal distribution of SVC-IVC to improve matching of heart sizes. Measurements of SVC-IVC and left ventricular end-diastolic diameter in 55 pediatric patients with IDC were correlated with height, weight, and body surface area. Regression analyses were performed to find the best-fit equation and correlation coefficient. Generalized linear modeling compared SVC-IVC in patients with IDC with normal SVC-IVC values from 254 patients. There was a strong linear relation in patients with IDC between SVC-IVC and height (R2=0.84) and a logarithmic relation to weight (R2=0.80). Left ventricular end-diastolic diameter did not correlate with SVC-IVC or any other parameter. In 87% of patients with IDC, SVC-IVC was over 2 SDs above predicted normal values (mean z-score=4.3±2.1). In conclusion, predicted SVC-IVC in patients with IDC was different from published norms (p<0.001). SVC-IVC in pediatric patients with IDC, although linearly related to height, is consistently above normal values.

Bilirubin rinse of the graft ameliorates ischemia reperfusion injury in heart transplantation

Ischemia and reperfusion contribute to substantial organ damage in transplantation. Clinically feasible measures for the prevention thereof are scarce. We tested whether rinsing rodent hearts with the antioxidant bilirubin ameliorates ischemia reperfusion injury (IRI). Left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDevP), rate per pressure product (RPP), coronary flow, maximum (+dP/dt) and minimum (-dP/dt) rate of contraction were analyzed in Lewis rat hearts rinsed with bilirubin prior to reperfusion on a Langendorff apparatus after 12 h of cold ischemia. In vivo, isogenic C57Bl/6 mouse hearts rinsed with bilirubin were transplanted after 12 h of cold ischemia. Cardiac function and apoptosis were assessed 24 h after reperfusion. Heart lysates recovered 15 min after reperfusion were probed for the total and the phosphorylated forms of extracellular signal-related protein kinases (ERK), JNK, p38-MAPK, and Akt. In isolated perfused hearts, bilirubin rinse resulted in significantly lower LVEDP and improved LVDevP, RPP, coronary flow, +dP/dt and -dP/dt. In vivo, after reperfusion, all mitogen-activated protein kinases (MAPKs) were suppressed significantly by bilirubin pretreatment. Bilirubin rinse improved cardiac scores (3.4 ± 0.5 vs. 2.0 ± 1.0 in controls, P < 0.05) and significantly suppressed apoptosis. Ex vivo administration of bilirubin to heart grafts prior reperfusion ameliorates IRI and provides a simple and effective tool to ameliorate outcome in heart transplantation.