Donor selection in the modern era

Iron Deficiency in Patients with Left Ventricular Assist Devices

Iron deficiency is a common and independent predictor of adverse outcomes in patients with heart failure. The implications of iron deficiency in patients implanted with a left ventricular assist device (LVAD) are less established. This review recaps data on the prevalence, characteristics and impact of Iron deficiency in the LVAD population. A systematic search yielded eight studies involving 517 LVAD patients, with iron deficiency prevalence ranging from 40% to 82%. IV iron repletion was not associated with adverse events and effectively resolved iron deficiency in most patients. However, the effects of iron deficiency and iron repletion on post-implant survival and exercise capacity remain unknown. Although iron deficiency is highly prevalent in LVAD patients, its true prevalence and adverse effects may be misestimated due to inexact diagnostic criteria. Future randomised controlled trials on IV iron treatment in LVAD patients are warranted to clarify the significance of this common comorbidity.

Impact of prolonged cardiopulmonary resuscitation on outcomes in heart transplantation with higher risk donor heart

OBJECTIVES

To evaluate the influence of prolonged cardiopulmonary resuscitation (CPR) on outcomes in heart transplantation with higher risk donor hearts (HRDHs).

METHODS

Patients transplanted in our hospital between May 2006 and December 2019 were divided into 2 groups, HRDH recipients and non HRDH recipients. HRDH was defined as meeting at least one of the following criteria: (1) donor left ventricular ejection fraction ≤ 50%, (2) donor-recipient predicted heart mass ratio < 0.8 or > 1.2, (3) donor age ≥ 55 years, (4) ischemic time > 4 h and (5) catecholamine index > 20. Recipients of HRDHs were divided into 3 groups according to the time of CPR (Group1: non-CPR, Group 2: less than 30 min-CPR, and Group 3: longer than 30 min CPR).

RESULTS

A total of 125 recipients were enrolled in this study, composing of HRDH recipients (n = 97, 78%) and non HRDH recipients (n = 28, 22%). Overall survival and the rate of freedom from cardiac events at 10 years after heart transplantation were comparable between two groups. Of 97 HRDH recipients, 54 (56%) without CPR, 22 (23%) with CPR < 30 min, and 21 (22%) with CPR ≥ 30 min were identified. One-year survival rates were not significantly different among three groups. The 1-year rate of freedom from cardiac events was not also statistically different, excluding the patients with coronary artery disease found in early postoperative period, which was thought to be donor-transmitted disease. Multivariate logistics regression for cardiac events identified that the CPR duration was not a risk factor even in HRDH-recipients.

CONCLUSION

The CPR duration did not affect the outcomes after heart transplantation in HRDH recipients.

Non-inferior outcomes in lower urgency patients transplanted with extended criteria donor hearts

BACKGROUND

Recent work has suggested that outcomes among heart transplant patients listed at the lower-urgency (United Network for Organ Sharing Status 4 or 6) status may not be significantly impacted by donor comorbidities. The purpose of this study was to investigate outcomes of extended criteria donors (ECD) in lower versus higher urgency patients undergoing heart transplantation.

METHODS

The United Network for Organ Sharing (UNOS) database was queried for all adult patients undergoing heart transplantation from October 18, 2018 through December 31, 2021. Patients were stratified by degree of urgency (higher urgency: UNOS 1 or 2 vs lower urgency: UNOS 4 or 6) and receipt of ECD hearts, as defined by donor hearts failing to meet established acceptable use criteria. Outcomes were compared using propensity score matched cohorts.

RESULTS

Among 9,160 patients included, 2,320 (25.4%) were low urgency. ECD hearts were used in 35.5% of higher urgency (HU) patients and 39.2% of lower urgency (LU) patients. While ECD hearts had an impact on survival among high-urgency patients (p < 0.01), there was no difference in 1- and 2-year survival (p > 0.05) found among low urgency patients receiving ECD versus standard hearts. Neither ECDs nor individual ECD criteria were independently associated with mortality in low urgency patients (p > 0.05).

CONCLUSIONS

Post-transplant outcomes among low urgency patients are not adversely affected by receipt of ECD vs. standard hearts. Expanding the available donor pool by optimizing use of ECDs in this population may increase transplant frequency, decrease waitlist morbidity, and improve postoperative outcomes for the transplant community at large.

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.

The ABC of Heart Transplantation-Part 1: Indication, Eligibility, Donor Selection, and Surgical Technique

Cardiac transplantation represents the gold standard of treatment for selected patients with advanced heart failure who have poor functional capacity and prognosis despite guideline-directed medical therapy and device-based therapy. Proper patient selection and appropriate referral of patients to centers for the treatment of advanced heart failure are the first but decisive steps for screening patients eligible for cardiac transplantation. The eligibility and the decision to list for cardiac transplantation, even for patients with relative contraindications, are based on a multidisciplinary evaluation of a transplant team. This review will discuss the practical indications, the process of patient eligibility for cardiac transplantation, the principle of donor selection, as well as the surgical technique.

Heart Transplantation in High-Risk Recipients Employing Donor Marginal Grafts Preserved With Ex-Vivo Perfusion

Extending selection criteria to face donor organ shortage in heart transplantation (HTx) may increase the risk of mortality. Ex-vivo normothermic perfusion (EVP) limits ischemic time allowing assessment of graft function. We investigated the outcome of HTx in 80 high-risk recipients transplanted with marginal donor and EVP-preserved grafts, from 2016 to 2021. The recipients median age was 57 years (range, 13-75), with chronic renal failure in 61%, impaired liver function in 11% and previous cardiac surgery in 90%; 80% were mechanically supported. Median RADIAL score was 3. Mean graft ischemic time was 118 ± 25 min, "out-of-body" time 420 ± 66 min and median cardiopulmonary bypass (CPB) time 228 min (126-416). In-hospital mortality was 11% and ≥moderate primary graft dysfunction 16%. At univariable analysis, CPB time and high central venous pressure were risk factors for mortality. Actuarial survival at 1 and 3 years was 83% ± 4%, and 72% ± 7%, with a median follow-up of 16 months (range 2-43). Recipient and donor ages, pre-HTx extracorporeal life support and intra-aortic balloon pump were risk factors for late mortality. In conclusion, the use of EVP allows extension of the graft pool by recruitment of marginal donors to successfully perform HTx even in high-risk recipients.

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.

A Holistic View of Advanced Heart Failure

Advanced heart failure (HF) may occur at any level of left ventricular (LV) ejection fraction (LVEF). The latter, which is widely utilized for the evaluation of LV systolic performance and treatment guidance of HF patients, is heavily influenced by LV size and geometry. As the accurate evaluation of ventricular systolic function and size is crucial in patients with advanced HF, the LVEF should be supplemented or even replaced by more specific indices of LV function such as the systolic strain and cardiac power output and size such as the LV diastolic diameters and volumes. Conventional treatment (cause eradication, medications, devices) is often poorly tolerated and fails and advanced treatment (mechanical circulatory support [MCS], heart transplantation [HTx]) is required. The effectiveness of MCS is heavily dependent on heart size, whereas HTx which is effective in the vast majority of the cases is limited by the small donor pool. Expanding the MCS indications to include patients with small ventricles as well as the HTx donor pool are major challenges in the management of advanced HF.

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.

The outcomes of marginal donor hearts compared with ideal donors: a single-center experience in Iran

Background

Heart transplantation has been considered the gold-standard treatment for patients with end-stage heart failure. This study assessed the survival outcomes of marginal donor hearts compared with ideal donor hearts in Iran.

Methods

This retrospective study is based on the follow-up data of heart donors and recipients in the Sina Hospital Organ Procurement Unit. Among the 93 participants, 75 were categorized as ideal donors (group A) and 18 as marginal donors (group B). Group C included heart recipients who received a standard organ, and group D included heart recipients who received a marginal one. To analyze differences in patient characteristics among the groups, posttransplant heart survival was assessed in all groups. All data were obtained from the hospital records.

Results

The mean age of the donors was 26.27±11.44 years (median age, 28 years). The marginal age showed a significant association with donor age. The age of recipients had a significant effect on survival days in the ideal group. Most patients survived for at least 1 year, with a median of 645 days in recipients from marginal donors and 689 days in recipients from ideal donors.

Conclusions

Considering the lack of organ availability in Iran, it may be possible to use marginal donors for marginal recipients, therefore reducing the number of people on the waitlist. We also recommend establishing a national marginal donor system specifically for Iranian patients to extend the donor pool.

Validation of existing risk scores for mortality prediction after a heart transplant in a Chinese population

OBJECTIVES

The objectives of this study were to validate 3 existing heart transplant risk scores with a single-centre cohort in China and evaluate the efficacy of the 3 systems in predicting mortality.

METHODS

We retrospectively studied 428 patients from a single centre who underwent heart transplants from January 2015 to December 2019. All patients were scored using the Index for Mortality Prediction After Cardiac Transplantation (IMPACT) and the United Network for Organ Sharing (UNOS) and risk stratification scores (RSSs). We assessed the efficacy of the risk scores by comparing the observed and the predicted 1-year mortality. Binary logistic regression was used to evaluate the predictive accuracy of the 3 risk scores. Model discrimination was assessed by measuring the area under the receiver operating curves. Kaplan-Meier survival analyses were performed after the patients were divided into different risk groups.

RESULTS

Based on our cohort, the observed mortality was 6.54%, whereas the predicted mortality of the IMPACT and UNOS scores and the RSSs was 10.59%, 10.74% and 12.89%, respectively. Logistic regression analysis showed that the IMPACT [odds ratio (OR), 1.25; 95% confidence interval (CI), 1.15-1.36; P < 0.001], UNOS (OR, 1.68; 95% CI, 1.37-2.07; P < 0.001) and risk stratification (OR, 1.61; 95% CI, 1.30-2.00; P < 0.001) scores were predictive of 1-year mortality. The discriminative power was numerically higher for the IMPACT score [area under the curve (AUC) of 0.691)] than for the UNOS score (AUC 0.685) and the RSS (AUC 0.648).

CONCLUSIONS

We validated the IMPACT and UNOS scores and the RSSs as predictors of 1-year mortality after a heart transplant, but all 3 risk scores had unsatisfactory discriminative powers that overestimated the observed mortality for the Chinese cohort.

Donor Cardiac Troponin for Prognosis of Adverse Outcomes in Cardiac Transplantation Recipients: a Systematic Review and Meta-analysis

BACKGROUND

Cardiac troponin is a highly specific and widely available marker of myocardial injury, and elevations in cardiac transplant donors may influence donor selection. We aimed to investigate whether elevated donor troponin has a role as a prognostic biomarker in cardiac transplantation.

METHODS

In a systematic review and meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library, without language restriction, from inception to December 2020. We included studies reporting the association of elevated donor troponin with recipient outcome after cardiac transplant. We generated summary odds ratios and hazard ratios for the association of elevated donor troponin with short- and long-term adverse outcomes. Methodological quality was monitored using the Quality In Prognosis Studies tool, and interstudy heterogeneity was assessed using a series of sensitivity and subgroup analyses.

RESULTS

We included 17 studies involving 15 443 patients undergoing cardiac transplantation. Elevated donor troponin was associated with increased odds of graft rejection at 1 y (odds ratio, 2.54; 95% confidence interval, 1.22-5.28). No significant prognostic relationship was found between donor troponin and primary graft failure, short- to long-term mortality, cardiac allograft vasculopathy, and pediatric graft loss.

CONCLUSIONS

Elevated donor troponin is not associated with an increased short- or long-term mortality postcardiac transplant despite increasing the risk of graft rejection at 1 y. Accordingly, an elevated donor troponin in isolation should not exclude donation.

Myocardial injury biomarkers at point of care for early identification of primary graft dysfunction after heart transplantation

INTRODUCTION

Primary graft dysfunction (PGD) is a leading cause of 30-day mortality following heart transplantation, and early intervention in PGD may correlate to improved survival. Our analysis aimed to determine the feasibility of measuring cardiac biomarkers from the donor heart in the early phase for use as a predictor of PGD.

METHODS

Blood samples from the coronary sinus were obtained at the time of transplantation in hearts preserved by cold static storage. The samples were analyzed for CK-MB and cTnI with a point-of-care method. The primary outcome was severe PGD or the need for veno-arterial extracorporeal membrane oxygenation within 7 days, referred to as severe graft dysfunction.

RESULTS

Of the total cohort (n = 63), eight patients (13%) were diagnosed with severe graft dysfunction within 7 days. Patients with high CK-MB had an increased risk for severe graft dysfunction with unadjusted Odds Ratio (OR) of 4.5 (95%CI .96-21.11 P = .057) and adjusted OR of 7.4 (95%CI 1.13-48.46, P = .037. Similar but non significant trends were observed for cTnI.

CONCLUSION

By measuring CK-MB from the coronary effluent in the donor heart, it may be possible to identify patients at increased risk for severe PGD after heart transplantation.

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 perfusion of the donor heart: Preliminary experience in high-risk transplantations

BACKGROUND

The number of heart transplantations (HTs) has decreased in France since 2017 (-5%/year) despite a stable rate of patients referred on the waiting list. Ex vivo heart perfusion (EVHP) is an innovative approach for organ preservation, reducing graft ischaemic time and facilitating continuous organ monitoring before transplantation.

AIM

To report our preliminary experience of seven donor hearts preserved with EVHP, including the first heart resuscitated after circulatory-determined death in France.

METHODS

Seven hearts were procured from donation after brain death (DBD) for HT or donation after circulatory-determined death (DCD) for research purposes (Protocol PFS20-004, Agence de la Biomédecine, La Plaine Saint-Denis, France). All grafts were preserved using the Organ Care System® (TransMedics Inc., Andover, MA, USA) for normothermic EVHP. Perfusion parameters were adjusted to achieve stable or decreasing arterial lactate trend consistent with suitability for organ transplantation.

RESULTS

Indications for EVHP were assessment of a marginal graft in four cases, prolonged preservation in two cases (anticipated duration for retrieval of recipient's heart>3hours) and resuscitation after circulatory-determined death in one case. Median duration of EVHP was 270 (interquartile range 216-343) minutes. five were transplanted, with a median ex situ preservation time (ischaemic time+EVHP time) of 334 (interquartile range 326-444) minutes. The two other grafts were discarded for HT. Three recipients had extracorporeal life support after HT, and presented complete cardiac recovery within a week after HT. One patient died at day 11 because of septic shock. The 3-month survival rate was 75% among recipients. Three months after HT, the left ventricular ejection fraction was>60% in all cases.

CONCLUSIONS

EVHP enabled safe prolonged preservation and assessment of marginal grafts. This approach provides an opportunity to expand the donor pool by resuscitating grafts from donors with extended criteria, including controlled DCD.

Heart transplant outcomes in patients with mechanical circulatory support: cold storage versus normothermic perfusion organ preservation

OBJECTIVES

Patients with mechanical circulatory support bridged to a heart transplant (HTx) are at higher risk of postoperative graft dysfunction. In this subset, a mode of graft preservation that shortens graft ischaemia should be beneficial.

METHODS

The outcomes of 38 patients on mechanical circulatory support (extracorporeal life support, left ventricular assist device and biventricular assist device) who received a HTx between 2015 and 2020 were analysed according to the method of graft preservation: cold storage (CS) group, 24 (63%) or ex vivo perfusion (EVP) group, 14 (37%).

RESULTS

The median age was 57 (range 30-73) vs 64 (35-75) years (P = 0.10); 88% were men (P = 0.28); extracorporeal life support was more frequent in the CS group (54% vs 36%; P = 0.27) versus left ventricular and biventricular assist devices in the EVP group (46% vs 64%; P = 0.27). Clamping time was shorter in the EVP group (P < 0.001) and ischaemic time >4 h was higher in the CS group (P = 0.01). Thirty-day mortality was 13% (0-27%) in the CS group and 0% (P = 0.28) in the EVP group. A significantly lower primary graft failure [7% (0-23%) vs 42% (20-63%); P = 0.03] was observed in the EVP group. Survival at 1 year was 79 ± 8% (63-95%) in the CS group and 84 ± 10% (64-104%) in the EVP group (P = 0.95).

CONCLUSIONS

Our results support the use of ex vivo graft perfusion in patients on mechanical circulatory support as a bridge to a HTx. This technique, by shortening graft ischaemic time, seems to improve post-HTx outcomes.

Donor Characteristics and Recipient Outcomes After Heart Transplantation in Adult Congenital Heart Disease

Background

Patients with adult congenital heart disease (ACHD) experience long waitlist times for heart transplantation (HTx) while a large proportion of donor hearts are refused. The goal of this study was to inform optimal donor selection for patients with ACHD listed for HTx by examining the impact of donor characteristics on post‐HTx outcomes.

Methods and Results

Using the Scientific Registry of Transplant Recipients, we conducted a retrospective analysis of patients aged ≥18 years listed for HTx in the United States between 2000 and 2016. We compared waitlist times between patients with ACHD and patients with noncongenital heart disease and constructed multivariate hazard models to identify donor characteristics associated with increased waitlist time. We then compared post‐HTx survival between patients with ACHD and patients with noncongenital heart disease and constructed multivariate hazard models to identify donor characteristics associated with mortality. There were very few differences in donor characteristics between HTx recipients with ACHD and those with noncongenital heart disease. Status 1A–listed patients with ACHD experienced longer waitlist times compared with patients with noncongenital heart disease. Increased wait times were associated with some donor characteristics. Post‐HTx outcomes varied over time, with patients with ACHD having inferior early mortality (0 to 30 days), similar intermediate mortality (31 days to 4 years), and superior late mortality (>4 years). We identified no donor characteristics associated with mortality to justify the observed differences in donor selection or waitlist time.

Conclusions

HTx candidates with ACHD wait longer for transplant but do not require unique donor selection criteria. HTx teams should consider liberalizing donor criteria and focusing only on evidence‐based selection to improve waitlist outcomes and reduce the recipient–donor disparity.

The current state of artificial intelligence in cardiac transplantation

PURPOSE OF REVIEW

The field of heart transplantation is a complex practice that combines both science and art to optimize the quality and quantity of an organ transplant recipient's life span. In the current age of Transplant Medicine there are many limiting factors that prevent potentially usable organs to be transplanted in addition to the many unknown factors in assessing the risk of posttransplant complications in a proactive manner. This review focuses on the current state, and potential use, and implementation of artificial intelligence technologies in the field of heart transplantation. Furthermore, the utilization of predictive algorithms to assess donor quality, graft function, posttransplant complications and prediction of high-risk complications will be discussed. Artificial intelligence technologies in the pretransplant population is also explored.

RECENT FINDINGS

Artificial intelligence process use has been increasing over the past decade. Early adoption in radiology and laboratory medicine have shown promise for future applications. Implementation of nascent technologies within the field of transplant medicine remains in its infancy. Cardiac and renal medicine have been recent focuses of large-scale artificial intelligence projects because of the wealth of data, the main limiting factor for producing accurate models. Understanding the true role of artificial intelligence in medicine is key - and has been divided into three areas of focus: data quality, interpretation, and clinical application. These areas allow the clinician to translate problems facing patients into algorithms utilized by data scientists to create solutions, which may provide in-depth analysis and detection of relationships not immediately clear. Although some published data has led to commercial products for cardiac, diabetic, and dermatologic applications -- widespread adoption remains limited to specialized centers.

SUMMARY

Artificial intelligence applications with clinically relevant models in transplant medicine have the potential to optimize organ utilization, prediction of complications, and potential pretransplant management, which may mitigate the need for transplant. Further translational projects are under development at major centers, with proof of concepts demonstrating validity and safety in the clinical setting. Limiting factors of infrastructure, expertise, and data availability continue to be addressed. Ongoing efforts for commercialization and large-scale trials will provide a foundation for the development of artificial intelligence applications in transplant medicine.

Impact of Reported Donor Ejection Fraction on Outcome after Heart Transplantation

OBJECTIVES

 The global shortage of donor organs has urged transplanting units to extend donor selection criteria, for example, impaired left ventricular function (LVF), leading to the use of marginal donor hearts. We retrospectively analyzed our patients after orthotopic heart transplantation (oHTX) with a focus on the clinical outcome depending on donor LVF.

METHODS

 Donor reports, intraoperative, echocardiographic, and clinical follow-up data of patients undergoing oHTX at a single-center between September 2010 and June 2020 were retrospectively analyzed. Recipients were divided into two groups based on donor left ventricular ejection fraction (dLVEF): impaired dLVEF (group I; dLVEF ≤ 50%; n = 23) and normal dLVEF group (group N; dLVEF > 50%; n = 137).

RESULTS

 There was no difference in 30-day, 90-day, and 1-year survival. However, the duration of in-hospital stay was statistically longer in group I than in group N (N: 40.9 ± 28.3 days vs. I: 55.9 ± 39.4 days, p < 0.05). Furthermore, postoperative infection events were significantly more frequent in group I (p = 0.03), which was also supported by multivariate analysis (p = 0.03; odds ratio: 2.96; confidence interval: 1.12-7.83). Upon correlation analysis, dLVEF and recipient LVEF prove as statistically independent (r = 0.12, p = 0.17).

CONCLUSIONS

 Impaired dLVEF is associated with prolonged posttransplant recovery and slightly increased morbidity but has no significant impact on survival up to 1 year posttransplant.

Continuous-flow left ventricular assist device versus orthotopic heart transplantation in adults with heart failure: a systematic review and meta-analysis

Background

Due to the lack of donor hearts, many studies have assessed the prognosis of heart failure (HF) patients treated with a continuous-flow left ventricular assist device (CF-LVAD). However, previous results have not been consistent and minimal data is available regarding long-term outcomes. There is no consensus on whether CF-LVAD as a bridge or destination therapy (DT) can equal orthotopic heart transplantation (HTx). The purpose of our study is to compare clinical outcomes between CF-LVAD and HTx in adults.

Methods

We searched controlled trials from PubMed, Cochrane Library, and Embase databases until July 1, 2020. The mortality at different time points and adverse events were analyzed among 12 included studies.

Results

No significant differences were found in mortality at one-year [odds ratio (OR) =1.08; 95% CI: 0.97-1.21], two-year (OR =1.01; 95% CI: 0.91-1.12), three-year (OR =1.02; 95% CI: 0.69-1.51), and five-year (OR =1.02; 95% CI: 0.93-1.11), as well as the comparison of stroke, bleeding, and infection between CF-LVAD as a bridge versus HTx. The pooled analysis of one-year mortality (OR =2.76; 95% CI: 0.38-20.18) and two-year mortality (OR =1.64; 95% CI: 0.22-12.23) revealed no significant difference between CF-LVAD DT and HTx. Comparisons of adverse events showed no differences in bleeding or infection, but a higher risk of stroke (OR =5.09; 95% CI: 1.74-14.84) for patients treated with CF-LVAD DT than with HTx.

Conclusions

CF-LVAD as a bridge results in similar outcomes as HTx within five years. CF-LVAD as a DT is associated with similar one-year and two-year mortality, but carries a higher risk of stroke, as compared with HTx.

The adapted Heart Donor Score

The Heart Donor Score (HDS) predicts donor organ discard for medical reasons and survival after heart transplantation (HTX) in the Eurotransplant allocation system. Our aim was to adapt the HDS for application in the United Network for Organ Sharing (UNOS) registry. To adjust for differences between the Eurotransplant and UNOS registries, the "adapted HDS" was created (aHDS) by exclusion of the covariates "valve function," "left-ventricular hypertrophy," and exclusion of "drug abuse" from the variable "compromised history." Two datasets were analyzed to evaluate associations of the aHDS with donor organ discard (n = 70 948) and survival (n = 19 279). The aHDS was significantly associated with donor organ discard [odds ratio 2.72, 95% confidence interval (CI) 2.68-2.76, P < 0.001; c-statistic: 0.937). The score performed comparably in donors <60 and ≥60 years of age. The aHDS was a significant predictor of survival as evaluated by univariate Cox proportional hazards analysis (hazard ratio 1.04, 95% CI 1.01-1.07, P = 0.023), although the association lost significance in a multivariable model. The aHDS predicts donor organ discard. Negative effects of most aHDS components on survival are likely eliminated by highly accurate donor selection processes.

Donor and Recipient Size Matching in Heart Transplantation With Predicted Heart and Lean Body Mass

Donor and recipient size matching during heart transplant can be assessed using weight or predicted heart mass (PHM) ratios. We developed sex-specific allomteric equations for PHM and predicted lean body mass (PLBM) using the United Kingdom Biobank (UKB) and evaluated their predictive value in the United Network of Organ Sharing database. Donor and recipient size matching was based on weight, PHM and PLBM ratios. PHM was calculated using the Multiethnic Study of Atherosclerosis and UKB equations. PLBM was calculated using the UKB and National Health and Nutrition Examination Survey equations. Relative prognostic utility was compared using multivariable Cox analysis, adjusted for predictors of 1-year survival in the Scientific Registry of Transplant Recipients model. Of 53,648 adult patients in the United Network of Organ Sharing database between 1996 and 2016, 6528 (12.2%) died within the first year. In multivariable analysis, undersized matches by any metric were associated with increased 1-year mortality (all P < 0.01). Oversized matches were at increased risk using PHM or PLBM (all P < 0.01), but not weight ratio. There were significant differences in classification of size matching by weight or PHM in sex-mismatched donor-recipient pairs. A significant interaction was observed between pulmonary hypertension and donor undersizing (hazard ratio 1.15, P = 0.026) suggesting increased risk of undersizing in pulmonary hypertension. Donor and recipient size matching with simplified PHM and PLBM offered an advantage over total body weight and may be more important for sex-mismatched donor-recipient pairs. Donor undersizing is associated with worse outcomes in patients with pulmonary hypertension.

Trends in Renal Function Among Heart Transplant Recipients of Donor-Derived Hepatitis C Virus

Donor-derived hepatitis C (dd-HCV) infection may increase the risk of renal impairment (RI) among heart transplantation (HT) recipients. Sofosbuvir, an integral component of HCV direct-acting antivirals (DAAs) has also been linked to RI. To date, no study has examined the trends in renal function for HT recipients of dd-HCV infection and assessed safety and efficacy of Sofosbuvir-based DAAs. Between September 2016 and June 2018, 46 HCV-naive patients and one patient with a history of HCV treated pretransplant, underwent HT from HCV-positive donors (follow-up available through October 10, 2018). Patients were treated with Ledipasvir-Sofosbuvir (genotype 1) or Sofosbuvir-Velpatasvir (genotype 3) for 12 or 24 weeks; no dose adjustments were made for renal function. Data on renal function were available for 23 patients who achieved a sustained virologic response at 12 weeks after the treatment (SVR12; cohort A) and 18 patients who completed 1 year of follow-up (cohort B). Treatment of dd-HCV infection was initiated at a median of 6 weeks post-HT. In both cohorts, a nonsignificant reduction in median estimated glomerular filtration rate (eGFR; ml/min/1.73 m) was noted (cohort A: pretransplant eGFR: 62 [interquartile range {IQR}: 1-84] to SVR12 eGFR: 49 [IQR: 37-82]; p = 0.43; cohort B: pretransplant eGFR: 65 [IQR: 54-84] to 1 year post-HT eGFR: 56 [IQR: 39-75]; p = 0.29). Pretreatment renal function had no significant impact on changes in renal function during treatment. All patients tolerated DAAs well with 100% completion rate to the assigned therapy and duration and 100% success at achieving SVR12. In this first and largest reported case series to date of HT recipients with dd-HCV infection, we observed that neither the dd-HCV infection nor its treatment with Sofosbuvir-based DAAs increased the risk of RI. Sofosbuvir-based DAAs appear safe, tolerable, and effective for HCV treatment even in presence of severe RI.

Cocaine use in organ donors and long-term outcome after heart transplantation: An International Society for Heart and Lung Transplantation registry analysis

BACKGROUND

Cardiac allografts from donors with a history of cocaine use (DHCU) are often discarded owing to concerns regarding organ quality. We investigated long-term outcomes of de novo adult heart transplantation (HTx) using DHCU.

METHODS

Using the International Society for Heart and Lung Transplantation Thoracic Organ Transplant Registry, we identified 24,430 adult recipients of primary, deceased donor, heart-alone transplants between January 1, 2000, and June 30, 2013. Transplants were categorized on the basis of DHCU. Survival rates were compared using Kaplan-Meier curves and log-rank tests.

RESULTS

A total of 3,246 (13.3%) HTx were performed using DHCU during the study period. Of these, 1,477 (45.5%) were classified as current users. Organs from DHCU were transplanted at a later sequence number (data from a sub-group of patients transplanted in the United States) than those from the non-cocaine use group (mean sequence number 16.1 ± 55.6 vs 11.5 ± 38.2; p < 0.001), suggesting higher decline rates by centers. Kaplan-Meier estimates of survival were not different between groups (p = 0.16), with post-transplant survival rates at 1, 5, and 10 years of 88.1%, 75.8%, and 58.5%, respectively, in the non-cocaine use group and 90.0%, 76.7%, and 59.7%, respectively, in the DHCU group. On multivariate analysis, DHCU were not associated with mortality (hazard ratio [HR]: 0.94; 95% CI: 0.88-1.00; p = 0.050), cardiac allograft vasculopathy (HR: 1.02; 95% CI: 0.94-1.11; p = 0.56), or allograft rejection (HR: 0.98; 95% CI: 0.92-1.05; p = 0.61).

CONCLUSIONS

Our findings demonstrate that adult HTx performed using DHCU is not associated with an adverse impact on long-term clinical outcomes. These findings should spur efforts to reduce discard rates of organs from DHCU.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Increasing Heart Transplant Volume by Expansion of Donor Heart Selection Criteria: A Single-Center Analysis

BACKGROUND

Our transplant center recently expanded the acceptance criteria for cardiac donors to increase heart transplant volume. Our purpose was to assess the success of this strategy while maintaining acceptable 1-year survival.

METHODS

We retrospectively reviewed patients who underwent heart transplantation at our institution from January 2011 through December 2017. This time period was divided into 2 periods: 2011 to 2014 (Period A) and 2015 to 2017 (Period B) because we implemented our new donor acceptance policy at the onset of 2015. We compared recipient and donor characteristics from the 2 time periods. The primary outcomes were 1-year graft and patient survival.

RESULTS

Transplant volume increased in Period B with the expanded donor acceptance policy: 128 heart transplants over 36 months compared to 52 transplants in 48 months in Period A. Mean (± SD) recipient age was significantly higher in Period B (54 ± 12 vs 50 ± 15 years; P = .04) whereas other recipient variables were similar. Donors in Period B were significantly older, more likely to be female, had larger body mass index, were located a greater distance from the transplant center, and had a higher sequence number. Female donor to male recipient occurred more often in Period B than in Period A (27% vs 10%; P = .01). Both 1-year patient survival and graft survival were unchanged between Period B (95% for both) and Period A (96% for both).

CONCLUSIONS

Using a more aggressive donor acceptance policy allowed for an increase in heart transplant volume while maintaining acceptable 1-year graft and patient survival.

Validating patient prioritization in the 2018 Revised United Network for Organ Sharing Heart Allocation System: A single-center experience

The 2018 Revised United Network for Organ Sharing Heart Allocation System (HAS) was proposed to reclassify status 1A candidates into groups of decreasing acuity; however, it does not take into account factors such as body mass index (BMI) and blood group which influence waitlist (WL) outcomes. We sought to validate patient prioritization in the new HAS at our center. We retrospectively evaluated patients listed for heart transplantation (n = 214) at Emory University Hospital from 2011 to 2017. Patients were reclassified into the 6-tier HAS. Multistate modeling and competing risk analysis were used to compare outcomes of transplantation and WL death/deterioration between new tiers. Additionally, a stratified sensitivity analysis by BMI and blood group was performed. Compared with tier 4 patients, there was progressively increasing hazard of WL death/deterioration in tier 3 (HR: 2.52, 95% CI: 1.37-4.63, P = .003) and tier 2 (HR: 5.03, 95% CI: 1.99-12.70, P < .001), without a difference in transplantation outcome. When stratified by BMI and blood group, this hierarchical association was not valid in patients with BMI ≥30 kg/m2 and non-O blood groups in our cohort. Therefore, the 2018 HAS accurately prioritizes the sickest patients in our cohort. Factors such as BMI and blood group influence this relationship and iterate that the system can be further refined.

Potential for donation after circulatory death heart transplantation in the United States: Retrospective analysis of a limited UNOS dataset

Donation after Circulatory Death (DCD) is an alternative to Donation after Brain death (DBD), and is a growing strategy for organ procurement in the United States(US). The purpose of this analysis was to review the number and quality of hearts in one United Network for Organ Sharing (UNOS) Region that were not utilized as a potential consequence of nonheart DCD donation. We retrospectively identified all successful US DCD solid organ donors from 1/2011 to 3/1/2017, defined an ideal heart donor by age and left ventricular ejection fraction (LVEF), and then reviewed the donor charts of unused hearts in New York and Vermont (UNOS Region 9). Of 8302 successful DCD donors across the United States, 5033 (61%) were between 18 and 49 years of age, and 872 had a screening echocardiogram, with 573 (66%) measuring an EF >50%. Of these 573 potential donors, 44 (7.7%) were from Region 9. Detailed donor chart review identified 36 ideal heart donors, 24 (66.7%) with anoxic brain injury. Trends in Region 9 DCD donation increased from 4 unused hearts in 2011, to 13 in 2016. In the context of severe organ scarcity, these data indicate that implementation of DCD heart transplantation in the United States would improve overall donation rates and provide a pathway to utilize these ideal donor hearts.