Donor heart selection and outcomes: An analysis of over 2,000 cases

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.

The Clinical Outcomes of Marginal Donor Hearts: A Single Center Experience

BACKGROUND AND OBJECTIVES

Although the shortage of donor is a common problem worldwide, a significant portion of unutilized hearts are classified as marginal donor (MD) hearts. However, research on the correlation between the MD and the prognosis of heart transplantation (HTx) is lacking. This study was conducted to investigate the clinical impact of MD in HTx.

METHODS

Consecutive 73 HTxs during 2014 and 2021 in a tertiary hospital were analyzed. MD was defined as follows; a donor age >55 years, left ventricular ejection fraction <50%, cold ischemic time >240 minutes, or significant cardiac structural problems. Preoperative characteristics and postoperative hemodynamic data, primary graft dysfunction (PGD), and the survival rate were analyzed. Risk stratification by Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score was performed to examine the outcomes according to the recipient state. Each group was sub-divided into 2 risk groups according to the IMPACT score (low <10 vs. high ≥10).

RESULTS

A total of 32 (43.8%) patients received an organ from MDs. Extracorporeal membrane oxygenation was more frequent in the non-MD group (34.4% vs. 70.7, p=0.007) There was no significant difference in PGD, 30-day mortality and long-term survival between groups. In the subgroup analysis, early outcomes did not differ between low- and high-risk groups. However, the long-term survival was better in the low-risk group (p=0.01).

CONCLUSIONS

The outcomes of MD group were not significantly different from non-MD group. Particularly, in low-risk recipient, the MD group showed excellent early and long-term outcomes. These results suggest the usability of selected MD hearts without increasing adverse events.

Donor heart selection: Evidence-based guidelines for providers

The proposed donor heart selection guidelines provide evidence-based and expert-consensus recommendations for the selection of donor hearts following brain death. These recommendations were compiled by an international panel of experts based on an extensive literature review.

Donor Utilization in the Recent Era: Effect of Sex, Drugs, and Increased Risk

Background:

Heart transplantation volumes have increased in recent years, yet less than a third of donors are typically accepted for transplantation. Whether donor sex, donor drug use, or perception of increased risk affects utilization for transplantation is unclear.

Methods:

The United Network for Organ Sharing database was queried for donors from January 1, 2007, to December 31, 2017. Donor toxicology was collected when available. Multivariate analysis was conducted to examine correlations with donor utilization.

Results:

Between January 1, 2007, and December 31, 2017, there were 87 816 heart donors aged ≥15 years. The mean age was 42.7±15.8 years, and 24 831 donors (28.3%) were utilized for heart transplantation. Subsequent analyses focused on donors between 15 and 39 years old.

The strongest associations with donor acceptance were for male donor sex, blood type, hepatitis C antibody, donor age, left ventricular hypertrophy, and history of donor drug use. After removing hepatitis C, Public Health Service Increased Risk was identified as a strong negative predictor. Most positive drug toxicology results were associated with donor nonuse except for donors between 15 and 19 years of age. Exceptions included alcohol, marijuana, and cocaine. Opiates were associated with less utilization at all donor ages. The Public Health Service Increased Risk status was associated with significantly less utilization in all age groups except 15- to 19-year-old donors.

Conclusions:

While male donors were preferentially utilized, donors with drug use or those deemed Public Health Service Increased Risk were significantly less utilized for heart transplantation. Further consideration of such donors would be appropriate particularly as the demand for transplantation continues to increase.

Post-Transplant Extracorporeal Membrane Oxygenation for Severe Primary Graft Dysfunction to Support the Use of Marginal Donor Hearts

Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18 years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7 days following OHT (range: 1-12 days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.

Donor risk analysis and validation in heart transplants: a single-centre experience

OBJECTIVES

A heart transplant (Htx) remains the gold standard treatment for patients with advanced heart failure. Considering the limited availability of organs, donor risk scores might improve organ selection and allocation. The objective of the study was to compare United Network for Organ Sharing, RADIAL and Eurotransplant scoring models in calculating post-Htx outcomes in an Italian Htx population.

METHODS

Between January 2000 and December 2017, a total of 461 adult patients underwent Htxs. United Network for Organ Sharing, RADIAL and Eurotransplant scores were calculated. Clinical features and donor risk scores were tested to identify preoperative, intraoperative and postoperative risk variables and eventually validate the scores on our population.

RESULTS

Early graft failure was detected in 16.1% (74/461). Post-Htx extracorporeal life support was used in 11.1% (51/461). Of the donor-related factors, the use of noradrenaline (P = 0.015) negatively influenced early outcomes, whereas an ischaemic time >240 min (P = 0.037) influenced early graft failure occurrence. The Eurotransplant donor score did not impact outcomes; the RADIAL score significantly influenced both early and late mortality; and the United Network for Organ Sharing score influenced only late mortality. On the multivariable analysis, after adjustment of scores per cohort, noradrenaline infusion was the main independent predictor of in-hospital mortality for the donors, whereas age of the recipient [odds ratio (OR) 1.003, 1.003-1.081; P = 0.032] and use of preoperative extracorporeal membrane oxygenation (OR 3.320, 1.124-9.805; P = 0.030) were the main independent predictors for the recipients.

CONCLUSIONS

None of the validated donor scoring systems fully behave as reliable predictors of transplant outcomes. According to our 'local only' graft selection, specific donor and recipient risk variables should be monitored in order to predict early and late outcomes satisfactorily.

Great variability in donor heart acceptance practices across the United States

Disparities in organ acceptance practices exacerbate donor heart nonuse and lead to increased waiting times and mortality for heart transplant candidates. We studied disparities in donor heart acceptance among US transplant centers and their relations to posttransplant outcomes. Candidate, potential transplant recipient match run, and deceased donor data were obtained from the United Network for Organ Sharing. We analyzed donor, candidate, and transplant center characteristics with respect to organ acceptance, offer acceptance, number of offers before acceptance (organ sequence number), and association with posttransplant mortality. A total of 693 420 donor heart offers made between April 2007 and December 2015 were included. We identified great variability in donor heart acceptance practices among US heart transplant centers. We identified donor and recipient characteristics that were strongly associated with heart organ and offer acceptance, and organ sequence number, and identified inconsistencies among centers with respect to how these characteristics influenced acceptance decisions. Finally, we identified characteristics that were highly predictive of donor heart nonuse and were not associated with increased recipient mortality, which may guide future efforts aimed at increasing use of available hearts for transplantation.

Use of Organs for Heart Transplantation after Rescue Allocation: Comparison of Outcome with Regular Allocated High Urgent Recipients

BACKGROUND

 The number of patients waiting for heart transplantation (HTx) is exceeding the number of actual transplants. Subsequently, waiting times are increasing. One possible solution may be an increased acceptance of organs after rescue allocation. These organs had been rejected by at least three consecutive transplant centers due to medical reasons.

METHODS

 Between October 2010 and July 2019, a total of 139 patients underwent HTx in our department. Seventy (50.4%) of the 139 patients were transplanted with high urgency (HU) status and regular allocation (HU group); the remaining received organs without HU listing after rescue allocation (elective group, n = 69).

RESULTS

 Donor parameters were comparable between the groups. Thirty-day mortality was comparable between HU patients (11.4%) and rescue allocation (12.1%). Primary graft dysfunction with extracorporeal life support occurred in 26.9% of the elective group with rescue allocated organs, which was not inferior to the regular allocated organs (HU group: 35.7%). No significant differences were observed regarding the incidence of common perioperative complications as well as morbidity and mortality during 1-year follow-up.

CONCLUSIONS

 Our data support the use of hearts after rescue allocation for elective transplantation of patients without HU status. We could show that patients with rescue allocated organs showed no significant disadvantages in the early perioperative morbidity and mortality as well at 1-year follow-up.

Review of the discard and/or refusal rate of offered donor hearts to pediatric waitlisted candidates

We aimed to review current literature on the discard rate of donor hearts offered to pediatric recipients and assess geographical differences. Consequences and ways to reduce the discard rate are discussed. A systemic review on published literature on pediatric transplantation published in English since 2010 was undertaken. Additionally, a survey was sent to international OPOs with the goal of incorporating responses from around the world providing a more global picture. Based on the literature review and survey, there is a remarkably wide range of discard and/or refusal for pediatric hearts offered for transplant, ranging between 18% and 57% with great geographic variation. The data suggest that that the overall refusal rate may have decreased over the last decade. Reasons for organ discard were difficult to identify from the available data. Although the refusal rate of pediatric donor hearts seems to be lower compared to that reported in adults, it is still as high as 57% with geographic variation.

Current Status of Discarded Grafts in Korean Organ Transplantation

OBJECTIVES

Despite the severe shortage of available organs, many are discarded after procurement. This study aims to analyze the current status of discarded organs (retrieved, but not transplanted organs) from deceased donors in Korea.

METHODS

Deceased donor organ and procurement data were collected from the Korean Network for Organ Sharing and Korea Organ Donation Agency database from 2013 to 2016.

RESULTS

Between 2013 and 2016, a total of 6315 deceased donor organ transplants were performed nationwide. A total of 63 organs were discarded. The most commonly discarded organs were kidney (n = 24), followed by islet cell (n = 23), lung (n = 9), liver (n = 6), and pancreas (n = 1). The most common cause for discarding solid organs was poor organ condition (n = 24). Other reasons included aggravation of donor condition, incidental cancer detection of the donor, and the abscence of matching recipient. Islet cells (n = 23) were not used because of inadequate separation and purification.

CONCLUSIONS

To reduce unnecessary graft discard in Korea, systems-based improvements in preprocurement organ evaluation and postprocurement preservation are imperative.