The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-eighth adult heart transplantation report - 2021; Focus on recipient characteristics

Donor pulmonary hemodynamics does not impact recipient outcomes in adult heart transplantation

PURPOSE

The impact of donor pulmonary hemodynamics as assessed by mean pulmonary artery pressure (mPAP) and transpulmonary gradients (TPG) on the clinical outcome of heart transplant (HT) recipients is unknown. We compared outcomes of adult HT recipients as stratified by donor pulmonary hemodynamics in the contemporary era in the United States.

METHODS

We reviewed adult donor hearts (age ≥ 18 years) which were offered for transplantation between January 2010 and March 2023 in the UNOS database with available right heart catheterization (RHC) data. Adjusted Cox regression was performed to evaluate the relationship between 30-day and 1-year mortality after HT and donor mPAP, TPG, and mean arterial pressure (MAP). Each hemodynamic parameter was modeled as a quadratic polynomial to not assume a linear relationship with mortality.

RESULTS

2038 HT recipients with complete donor RHC were included: 58 % were on inotrope support. Elevated mPAP (≥25 mmHg), TPG (≥15), and PVR (≥1.5) were present in 416 (20.4 %), 179 (8.8 %), and 2038 (100 %), respectively. No significant association was found between donor mean PAP (HR 1.47, 95 % CI 0.80-2.67), donor TPG (HR 0.47, 95 % CI 0.20-1.08), and donor PVR (HR 1.69, 95 % CI 0.77-3.72) and 30-day mortality. Similarly, no significant association was found between donor mPAP (HR 1.33, 95 % CI 0.90-1.95), donor TPG (HR 0.65, 95 % CI 0.37-1.12), and donor PVR (HR 1.38, 95 % CI 0.83-2.32) and 1-year mortality.

CONCLUSIONS

Donor pulmonary pressures did not impact post-heart transplant survival in adult recipients. Donors with abnormal pulmonary hemodynamics remain viable donor hearts for transplantation.

Cause of death for heart transplant patients, an autopsy study

INTRODUCTION

Heart transplantations are lifesaving for patients with end-stage heart failure. It is pertinent for the multidisciplinary care team to understand how heart transplant patients succumbed to death and the complications that occurred. In this study, we performed a comprehensive retrospective review of all the autopsies performed in our institute for heart transplant patients and report the trend of demographic data, cause of death, and autopsy findings.

MATERIALS AND METHODS

Reports, photos, and slides of autopsies performed at our institute from 1990 to 2023 for heart transplant patients were reviewed. Pertinent demographic data (age, gender, pretransplant diagnosis), clinical data (clinical history of rejection, complication, time interval from transplant to death, clinical cause of death) and pathological findings (allograft pathology, infectious etiology, other findings related to cause of death) were reviewed, documented, and analyzed.

RESULTS

We identified 88 cases, consisting of 53 male and 35 female patients. The median age at transplant was 26 years, while 28.5 years was the median age at death. The median interval from transplant to death was 10 months. The cases were classified in three categories based on length of survival post-transplant: Superacute (<1 month, 21%), Early (1 month-12 months, 30%), and Late (> 12 months, 49%). Slides were unavailable for review in 15 cases, which were excluded from cause of death (COD) evaluation. We categorized 41.1% of cases as allograft-related COD and 58.9% as non-allograft-related COD. Six of the CODs were not perceived premortem. These unexpected CODs included moderate/severe acute cellular rejection in a patient with a recently negative biopsy, dehiscent suture caused by a fungal abscess, an aorto-bronchial fistula, CMV myocarditis, acute abdominal bleeding, and ruptured atherosclerotic plaques with acute myocardial infarction.

CONCLUSION

We systematically reviewed 33 years of heart transplant autopsies. We found that 41.1% of deaths were allograft related, with infection being the most frequent COD. While the rate of unexpected findings was low, the findings demonstrate the continued utility of autopsy in patient evaluation.

Comparing 3-year survival and readmissions between HeartMate 3 and heart transplant as primary treatment for advanced heart failure

OBJECTIVE

To compare 3-year survival and readmissions of patients who received the HeartMate 3 (HM3) left ventricular assist device (LVAD) or underwent orthotopic heart transplantation (OHT) as primary treatment for advanced heart failure.

METHODS

We retrospectively analyzed 381 adult patients who received an HM3 LVAD or were listed for OHT between January 2014 and March 2021 at our center. To minimize crossover bias, OHT recipients with a prior LVAD were excluded, and HM3 patients were censored at the time of transplant. Cohorts were propensity score-matched to reduce confounding variables. The primary outcome was 3-year survival, and the secondary outcome was mean cumulative all-cause unplanned readmission.

RESULTS

The study population comprised 185 HM3 patients (49%) and 196 OHT patients (51%), with 104 propensity score-matched patients in each group. After propensity score matching, there was no statistical difference in 3-year survival (83.7% for HM3 vs 87.0% for OHT; P = .91; relative risk [RR], 1.00; 95% confidence interval [CI], 0.45-2.20). In the unmatched cohorts, patients age 18 to 49 years had comparable survival with HM3 and OHT (96.9% vs 95.9%; N = 91; P = 1.00; RR, 0.92; 95% CI, 0.09-9.78). Patients age 50+ years had slightly inferior survival with HM3 (75.0% vs 83.9%; N = 290; P = .60; RR, 1.51; 95% CI, 0.85-2.68). The mean number of readmissions at 3 years was higher in the HM3 group (3.89 vs 2.05; P < .001).

CONCLUSIONS

This exploratory analysis suggests that for similar patients, HM3 may provide comparable 3-year survival to OHT as a primary treatment for heart failure but may result in more readmissions.

Can Grading of Mild Cardiac Allograft Vasculopathy be Further Refined? An angiographic and physiologic assessment of heart transplant recipients with ISHLT CAV 1

BACKGROUND

Cardiac allograft vasculopathy (CAV) results in impaired blood flow in both epicardial vessels and the microvasculature and is a leading cause of poor outcomes in heart transplant (HT) recipients. Most patients have mild (ISHLT CAV 1) disease. This study examined outcomes amongst those with ISHLT CAV 1 and investigated the value of physiologic assessment via cardiac positron emission tomography/computed tomography (PET/CT) for added risk stratification.

METHODS

CAV was graded using ISHLT criteria. Those with CAV 1 were further sub-grouped into CAV 1a (maximal lesion < 30% stenosis) or CAV 1b (maximal lesion ≥ 30% stenosis).

RESULTS

299 heart transplant recipients underwent invasive coronary angiography for CAV assessment with median follow up 4.7 years. ISHLT CAV 1 was associated with a 2.9-fold risk of death/re-transplantation compared to ISHLT CAV 0 (95% CI 1.7 -5.3, p<0.001). Of those with ISHLT CAV 1, 12% had ISHLT CAV 1b which was associated with a 2.8 times greater risk of death/re-transplantation compared to CAV 1a (95% CI 1.4-5.9, p=0.003). In a subgroup of 158 patients with contemporary cardiac PET/CT, amongst those with CAV 1a a myocardial blood flow reserve (MBFR) ≤ 2 was associated with a 4.6-fold risk of death/re-transplantation compared to a normal MBFR (95% CI 1.7-12.6, p=0.001).

CONCLUSION

Patients with ISHLT CAV 1 fared worse than those with ISHLT CAV 0. Within ISHLT CAV 1, patients with CAV 1b had worse outcomes than those with CAV 1a. Amongst those with CAV 1a, the poorer outcomes than ISHLT CAV 0 observed were predominantly associated with reduced MBFR. These data suggest additional anatomic classification and physiologic assessment can further risk stratify those with ISHLT CAV 1.

Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support in New Era of Heart Transplant

Heart failure is a serious and challenging medical condition characterized by the inability of the heart to pump blood effectively, leading to reduced blood flow to organs and tissues. Several underlying causes may be linked to this, including coronary artery disease, hypertension, or previous heart attacks. Therefore, it is a chronic condition that requires ongoing management and medical attention. HF affects >64 million individuals worldwide. Heart transplantation remains the gold standard of treatment for patients with end-stage cardiomyopathy. The recruitment of marginal donors may be considered an asset at the age of cardiac donor organ shortage. Primary graft dysfunction (PGD) is becoming increasingly common in the new era of heart transplantations. PGD is the most common cause of death within 30 days of cardiac transplantation. Mechanical Circulatory Support (MCS), particularly venoarterial extracorporeal membrane oxygenation (V-A ECMO), is the only effective treatment for severe PGD. VA-ECMO support ensures organ perfusion and provides the transplanted heart with adequate rest and recovery. In the new era of heart transplantation, early use allows for increased patient survival and careful management reduces complications.

Novel Therapeutic Agents for Cardiometabolic Risk Mitigation in Heart Transplant Recipients

Heart transplant (HT) recipients experience high rates of cardiometabolic disease. Novel therapies targeting hyperlipidemia, diabetes, and obesity, including proprotein convertase subtilisin/kexin inhibitors (PCSK9i), sodium-glucose cotransporter-2 (SGLT2) inhibitors, and glucagon-like peptide-1 (GLP-1) agonists are increasingly used for cardiometabolic risk mitigation in the general population. However, limited data exist to support the use of these agents in patients who have undergone heart transplantation. Herein, we describe the mechanisms of action and emerging evidence supporting the use of novel pharmacologic agents in the post-HT setting for cardiometabolic risk mitigation and review evidence supporting their ability to modulate immune pathways associated with atherogenesis, epicardial adipose tissue (EAT), and coronary allograft vasculopathy (CAV).

Donor HLA-DQ reactive B cells clonally expand under chronic immunosuppression and include atypical CD21 low CD27 - B cells with high-avidity germline B-cell receptors

Long-term allograft survival is limited by humoral-associated chronic allograft rejection, suggesting inadequate constraint of humoral alloimmunity by contemporary immunosuppression. Heterogeneity in alloreactive B cells and the incomplete definition of which B cells participate in chronic rejection in immunosuppressed transplant recipients limits our ability to develop effective therapies. Using a double-fluorochrome single-HLA tetramer approach combined with single-cell in vitro culture, we investigated the B-cell receptor (BCR) repertoire characteristics, avidity, and phenotype of donor HLA-DQ reactive B cells in a transplant recipient with end-stage donor specific antibody (DSA)-associated cardiac allograft vasculopathy while receiving maintenance immunosuppression (tacrolimus, mycophenolate mofetil, prednisone). Donor DQB1*03:02/DQA1*03:01 (DQ8)-reactive IgG+ B cells were enriched for minimally mutated and germline encoded high avidity BCRs (median K D 4.26×10 -09 ) with an atypical, antigen-experienced and proliferative phenotype (CD27 - CD21 low CD71 + CD11c +/- ). These B cells coexisted with a smaller subset of more highly mutated, affinity matured IgG+CD27+ B cells. Circulating donor-reactive B cells and DSA remained detectable after rituximab, contrasting with the marked reduction in DSA after allograft explant and retransplant. Together, these findings define the persistence of germline high-avidity HLA-DQ alloreactive B cells and their co-existence with affinity matured clones that were both driven by the allograft despite conventional immunosuppression.

Collaborative care models in adult congenital heart disease transplant

PURPOSE OF REVIEW

While multidisciplinary collaboration is a tenant of quality heart failure care and critical to the success of transplant programs, this essay challenges the temptation to shoehorn adult congenital heart disease (ACHD) patients into preexisting processes and paradigms. We explore the development of more relevant models, purposefully designed to improve ACHD transplant volumes and outcomes.

RECENT FINDINGS

Globally, the rapid acceleration of ACHD patients living with and dying from HF stands in stark contrast to their access to transplant. Inferior early outcomes after ACHD transplant remain an undeniable barrier. And yet while all large registry datasets attest to this statistic, a few centers have achieved results comparable to those in acquired heart disease. This despite increases in both ACHD candidate complexity and referrals for Fontan Circulatory Failure. Perhaps something in their approach to care delivery is key?.

SUMMARY

Alone, neither ACHD nor transplant programs can provide optimal management of HF in ACHD. A siloed approach is similarly inadequate. Building new ACHD-HF-Transplant teams, centered on the patient and supplemented by ad hoc expert partnerships, is an exciting approach that can improve outcomes, create a high-quality training environment, and in our experience, is a truly rewarding way of working together.

HeartMate 3: Analysis of Outcomes and Future Directions

Heart failure (HF) remains a public health concern affecting millions of individuals worldwide. Despite recent advances in device-related therapies, the prognosis for patients with chronic HF remains poor with significant long-term risk of morbidity and mortality. Left ventricular assist devices (LVADs) have transformed the landscape of advanced HF management, offering circulatory support as destination therapy or as a bridge for heart transplantation. Among the latest generation of LVADs, the HeartMate 3 has gained popularity due to improved clinical outcomes and lower risk of serious adverse events when compared with previous similar devices. The ELEVATE (Evaluating the HeartMate 3 with Full MagLev Technology in a Post-Market Approval Setting) Registry and the MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3) trial represent landmark investigations into the performance and comparative effectiveness of the HeartMate 3 LVAD. This review provides a comprehensive synthesis of the safety and efficacy of the 2-year and 5-year HeartMate LVAD outcomes, highlighting key findings, methodological considerations, implications for clinical practice, and future directions.

Burden of atherogenic lipids and association with cardiac allograft vasculopathy in heart transplant recipients. J Clin Lipidol 2024:S1933-2874(24)00263-0. [PMID: 39542809 DOI: 10.1016/j.jacl.2024.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

BACKGROUND

Cardiac Allograft Vasculopathy (CAV) is a leading cause of morbidity and mortality after heart transplantation. There are limited contemporary studies examining post-transplant lipid management and cardiometabolic health.

OBJECTIVE

We study the burden of cardiometabolic derangements post transplantation and its impact on CAV in a modern cohort of heart transplant recipients.

METHODS

All heart transplant (HTx) recipients between January 2019 and December 2020, with two lipid assessments and angiographic surveillance were included. Logistic regression was used to assess association of lipid levels with cardiovascular outcomes and CAV.

RESULTS

Among 87 HTx recipients, atherogenic lipids were significantly elevated after Htx. Median LDL-C increased from a baseline level of 69.5 mg/dL to 86.5 mg/dL, p = 0.002, non-HDL-C 91.5 mg/dL to 118 mg/dL, p < 0.001, triglycerides 94.5 mg/dL to 133 mg/dL, p < 0.001, and remnant cholesterol 19 mg/dL to 27 mg/dL, p < 0.001. Increases in non-HDL-C, triglycerides, and remnant cholesterol were significantly associated with increased risk of CAV (Stanford Grade 4 and intimal thickness). Increases in triglycerides and remnant-C were associated with increased risk of composite major adverse cardiovascular events.

CONCLUSION

We demonstrate a significant increase in atherogenic lipids two years following transplantation with low use (20 %) of high-intensity statin. Increase in atherogenic lipids was associated with increased risk of CAV and increase in triglycerides and remnant cholesterol with increased MACE. Future studies examining cardiometabolic consequences of heart transplantation and optimal treatment strategies to reduce risk of CAV and MACE are needed.

Heart Transplantation Outcomes in Patients With Hypertrophic Cardiomyopathy in the Era of Mechanical Circulatory Support

Mechanical circulatory support has emerged as a vital therapeutic modality for patients awaiting heart transplantation (HT). However, it is unknown how it affected the characteristics and post-HT outcomes of patients with hypertrophic cardiomyopathy (HCM). This retrospective cohort study analyzed adult HT recipients from the International Society for Heart and Lung Transplantation registry (1998-2017). Two equal-duration eras were defined: era 1 1998-2007 and era 2 2008-2017. Patients with HCM were compared across the two eras (n1 = 742 and n2 = 1,211) and within each era, they were contrasted with individuals with nonischemic (NICM) (n1 = 15,964 and n2 = 20,394) and ischemic cardiomyopathy (ICM) (n1 = 14,140 and n2 = 12,986). Across eras, the number of HTs among patients with HCM increased by 63%. The rate of recipients with HCM in the intensive care unit (ICU) supported with intra-aortic balloon pump (IABP) increased, yet their pre-HT functional status improved, and 5 year post-HT survival remained unchanged and favorable. In era 2, at the time of HT, patients with HCM were more frequently than their NICM and ICM counterparts in the ICU and supported with inotropes. In the same era, 1 and 5 year survival were more favorable in HCM compared to ICM and comparable to NICM.

The Association Between Preoperative Pectoralis Muscle Quantity and Outcomes After Cardiac Transplantation

BACKGROUND

Sarcopenia is underappreciated in advanced heart failure and is not routinely assessed. In patients receiving a left ventricular assist device, preoperative sarcopenia, defined by using computed-tomography (CT)-derived pectoralis muscle-area index (muscle area indexed to body-surface area), is an independent predictor of postoperative mortality. The association between preoperative sarcopenia and outcomes after heart transplant (HT) is unknown.

OBJECTIVES

The primary aim of this study was to determine whether preoperative sarcopenia, diagnosed using the pectoralis muscle-area index, is an independent predictor of days alive and out of the hospital (DAOHs) post-transplant.

METHODS

Patients who underwent HT between January, 2018, and June, 2022, with available preoperative chest CT scans were included. Sarcopenia was diagnosed as pectoralis muscle-area index in the lowest sex-specific tertile. The primary endpoint was DAOHs at 1 year post-transplant.

RESULTS

The study included 169 patients. Patients with sarcopenia (n = 55) had fewer DAOHs compared to those without sarcopenia, with a median difference of 17 days (320 vs 337 days; P = 0.004). Patients with sarcopenia had longer index hospitalizations and were also more likely to be discharged to a facility other than home. In a Poisson regression model, sarcopenia was a significant univariable and the strongest multivariable predictor of DAOHs at 1 year (parameter estimate = -0.17, 95% CI -0.19 to -14; P = < 0.0001).

CONCLUSIONS

Preoperative sarcopenia, diagnosed using the pectoralis muscle-area index, is an independent predictor of poor outcomes after HT. This parameter is easily measurable from commonly obtained preoperative CT scans and may be considered in transplant evaluations.

A patient with out-of-hospital cardiac arrest saved from heart transplantation and amputation through a collaboration between modern and traditional Chinese medicine: A case report

INTRODUCTION

Patients with end-stage heart failure have limited options for medical treatment, and this ultimately necessitates heart transplantation. Patients undergoing heart transplant surgery are burdened with substantial costs related to finances, procedural risks, and postoperative quality of life. This report presents a case of heart failure in a patient whose limbs and heart were preserved through a collaboration between modern and traditional Chinese medicine (TCM).

PATIENT PRESENTATION

A 47-year-old man was admitted to the emergency department with out-of-hospital cardiac arrest (OHCA) and was diagnosed with 3-vessel disease and acute decompensated heart failure on October 27, 2020. After extracorporeal membrane oxygenation (ECMO), the patient presented with cyanosis and gangrene in all four limbs. Cardiologists and plastic surgeons recommended heart transplantation and amputation. The patient wanted to keep his limbs and heart intact and requested to receive TCM. A TCM physician was consulted by visiting staff to provide combined care. After TCM intervention, both the ejection fraction (EF) and gangrene improved. Until now, the patient continues to receive TCM treatment, lives with preserved limbs and heart, and went through SARS-CoV2 infection smoothly in 2023.

CONCLUSION

TCM met the expectations of the patient and reduced the high medical expenses. This approach may improve the outlook and be a more economical option for patients with end-stage heart failure.

The Effect of Everolimus Versus Calcineurin Inhibitors on Quality of Life 10-12 Years After Heart Transplantation: The Results of a Randomized Controlled Trial (SCHEDULE Trial)

BACKGROUND

Calcineurin inhibitors (CNIs) are associated with long-term complications after heart transplantation (HTx). Everolimus (EVR)-based immunosuppression allows for CNI withdrawal. We used data from The Scandinavian heart transplant everolimus de novo study with early CNI avoidance (SCHEDULE) trial to assess whether health-related quality of life (HRQoL) differed between patients on long-term treatment with EVR versus a CNI-based regimen.

METHODS

In SCHEDULE, we randomized 115 patients (mean age 51 ± 13 years, 27% women) to cyclosporine (CNI group; n = 59), or early introduction of EVR and cyclosporine withdrawal within 11 weeks of HTx (EVR group; n = 56). The primary endpoint was the glomerular filtration rate. We used the Short Form-36 (SF-36v2), the EuroQoL visual analogue scale (EQ VAS), and the Beck Depression Inventory (BDI) to assess HRQoL. We re-evaluated the participants after 10-12 years.

RESULTS

Seventy-eight patients attended follow-up at a median of 11 years after HTx. The SF-36 physical component summary score increased from 32 ± 10 pre-HTx to 44 ± 12 11 years after HTx (p < 0.01) in the EVR group and from 33 ± 9 to 44 ± 11 (p < 0.01) with CNI. The mental component summary score increased from 46 ± 12 to 53 ± 13 (EVR); p = 0.04 and from 38 ± 13 to 49 ± 13 (CNI); p < 0.01. Similar improvements were observed regarding EQ-VAS and the BDI. There were no significant between-group differences for either measure of HRQoL.

CONCLUSIONS

In heart transplant recipients, an EVR-based immunosuppressive strategy resulted in similar long-term improvements in HRQoL as treatment with a CNI-based regimen.

Limitations of the inotrope score use as a measure of primary graft dysfunction

Allograft dysfunction is the major cause of early morbidity and mortality following cardiac transplantation. Poor graft function can be secondary to transplant complications or, when no identifiable cause is present, primary graft dysfunction (PGD). To standardize the definition of PGD, a consensus conference was convened which produced a document that defines severity categories and criteria for assessing left and right ventricular dysfunction. A critical sub-criterion in the consensus definition of PGD is a score intended to reflect the need for inotropic support after transplant. However, during the Australian and New Zealand trial of Hypothermic Oxygenated Perfusion preservation of donor hearts, we realized that the consensus inotrope score was inflated by the disproportionate impact of norepinephrine (NE), upcoding PGD grades from mild to moderate. A review of 50 heart transplant patients at The Alfred Hospital showed that in 38% of the instances when the inotropic score exceeded the consensus cutoff value due to NE, there was no identifiable PGD or vasoplegia and in 16% of instances, the cutoff was exceeded due to vasoplegia without PGD. Given the importance of accurate PGD classification in an era when static cold storage preservation is being replaced by machine perfusion and temperature controlled static storage, we contend that NE should be removed from the inotrope score equation to prevent up coding of mild to moderate PGD. Furthermore, we think that PGD classification should incorporate sensitive load- independent cardiac performance measures in the context of given levels of pharmacological and mechanical cardiac support.

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Reduction of Cardiac Allograft Vasculopathy by PCI: Quantification and Correlation With Outcome After Heart Transplantation

BACKGROUND

Percutaneous coronary intervention (PCI) might improve outcome at severe stages of cardiac allograft vasculopathy (CAV) among patients after heart transplantation (HTx). Yet, risk stratification of HTx patients after PCI remains challenging.

AIMS

To assess whether the International Society for Heart and Lung Transplantation (ISHLT) CAV classification remains prognostic after PCI and whether risk-stratification models of non-transplanted patients extend to HTx patients with CAV.

METHODS

At 2 European academic centers, 203 patients were stratified in cohort 1 (ISHLT CAV1, without PCI, n = 126) or cohort 2 (ISHLT CAV2 and 3, with PCI). At first diagnosis of CAV or first PCI, respectively, ISHLT CAV grades, SYNTAX scores I and II (SXS-I, SXS-II) were used to quantify baseline and residual CAV (rISHLT, rSXS-I, rSXS-II). RSXS-I > 0 defined incomplete revascularization (IR).

RESULTS

SXS-II predicted mortality in cohort 1 (P = 0.004), whereas SXS-I (P = 0.009) and SXS-II (P = 0.002) predicted mortality in cohort 2. Post-PCI, IR (P = 0.004), high rISHLT (P = 0.02) and highest tertile of rSXS-II (P = 0.006) were associated with higher 5-year mortality. In bivariable Cox analysis, baseline SXS-II, IR and rSXS-II remained predictors of 5-year mortality post-PCI. There was a strong inverse relationship between baseline and rSXS-I (r = -0.55; P < 0.001 and r = -0.50; P = 0.003, respectively) regarding the interval to first reintervention.

CONCLUSION

People with ISHLT CAV classification could apply for risk stratification after PCI. SYNTAX scores could be complemental for risk stratification and individualization of invasive follow-up of HTx patients with CAV.

CAV Trajectories Among Patients With No or Mild CAV at 10 Years Posttransplant

Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality following heart transplantation (HT). Prior studies identified distinct CAV trajectories in the early post-HT period with unique predictors, but the evolution of CAV in later periods is not well-described. This study assessed the prevalence of late CAV progression and associated risk factors in HT recipients with ISHLT CAV 0/1 at 10 years post-HT. Consecutive adult patients who underwent HT from January 2000 to December 2008 were evaluated and grouped by CAV trajectories into progressors (developed ISHLT CAV 2/3) or nonprogressors (remained ISHLT CAV 0/1). A total of 130 patients were included with a median age at angiography of 61.7 years and a median follow-up time of 4.8 years. 8.5% progressed to CAV 2/3, while the remaining 91.5% were nonprogressors. Progression was not associated with death or retransplantation (27.3% [progressor] vs. 21.0% [nonprogressor], p = 0.70). These data may inform shared decision-making about late CAV screening.

Postoperative, but Not Preoperative, MELD-3.0 Prognosticates 3-Month Procedural Success in Patients Undergoing Orthotopic Heart Transplantation

Background/Objectives: Multi-organ failure (MOF) often complicates advanced heart failure (HF), contributing to a poor prognosis. The Model of End-Stage Liver Disease 3.0 (MELD-3.0) scale incorporates liver and kidney function parameters. This study aims to evaluate the prognostic significance of the MELD-3.0 score in patients with advanced HF who have undergone heart transplantation (HTx). Methods: The MELD-3.0 score was computed using the average values of the international normalized ratio and bilirubin, creatinine, sodium, and albumin levels during a hospital stay following HTx. The average MELD-3.0 scores from the period of 1 month preceding HTx and 1 week after HTx were analyzed. The primary endpoint of the study was the 6-month total mortality, and the secondary endpoint was ICU hospitalization time after HTx. Results: The analysis included 106 patients undergoing HTx, with a median age of 53 years (44-63), 81% of whom were male. Within 6 months post-HTx, 17 patients (16%) died; those patients had a higher 1-week post-HTx MELD-3.0 score of 18.3 (14.5-22.7) in comparison to survivors, whose average score was 13.9 (9.5-16.4), p < 0.01. There was no difference in MELD 3.0 score in the pre-HTx period: 16.6 (11.4-17.8) vs. 12.3 (8.6-17.1), p = 0.36. The post-HTx MELD-3.0 score independently predicted death: RR 1.17 (95% CI 1.05-1.30), p < 0.01. A Receiver Operating Characteristic (ROC) determined the cut-off value of the MELD-3.0 score as 17.3 (AUC = 0.83; sensitivity-67%; specificity-86%). Survivors with scores above this value had a longer ICU hospitalization time: 7 (5.0-11.0) vs. 12 (8-20) days (p = 0.01). Conclusions: The post-HTx MELD-3.0 score serves as an independent predictor of an unfavorable prognosis in patients with advanced HF undergoing HTx. The evaluation of MELD-3.0 scores provides additional prognostic information in this population.

The Potential for Heart Donation After Death Determination by Circulatory Criteria in the Province of Québec

Background

Heart donation (HD) by those with death determination by circulatory criteria (DDCC) has been proposed as a method to increase the heart donor pool in response to the growing need for heart transplantation (HT). However, the potential level of HD after DDCC in the province of Québec has not yet been reported. This study aims to assess the suitability for HD among donors with DDCC, and to estimate its impact on HT activity.

Methods

Donation records by those with DDCC in the province of Québec, from January 2016 to December 2020, were retrospectively reviewed for donor and predonation characteristics. Predetermined exclusion criteria were used to evaluate eligibility for HD.

Results

Of the 122 patients with DDCC who were included, 42 (34%) were identified as potentially-eligible heart donors. The median age of potentially-eligible donors was 52 years; 60% were female; and the most prevalent causes leading to organ donation in this group were medical aid in dying (26%), traumatic brain injury (26%), and anoxia (24%). A 19% increase (42 of 225) in potential HT activity was estimated using strict criteria. In only one case did functional warm ischemia time exceed the 30-minute limit.

Conclusions

Using those with DDCC as a new source of heart donors can significantly increase the volume of heart donation in the province of Québec. Implementing an HD program for those with DDCC in Québec may reduce waiting time and increase the number of heart recipients.

Pediatric Combined Heart-liver Transplantation: A Single-center Long-term Experience

Background

Combined heart liver transplant (CHLT) continues to gain attention as a surgical treatment for patients with end-stage heart and liver disease but remains rare. We present our institutional longitudinal experience with up to 14 y of follow-up, focused on long-term outcomes in CHLT recipients.

Methods

We conducted a single-institutional, retrospective review from January 1, 2010, to December 31, 2023, including 7 patients ages 7-17 y who underwent CHLT.

Results

Most patients were surgically palliated via Fontan procedure pretransplant (n = 6), and all had evidence of advanced fibrosis or cirrhosis before transplant. The 30-d mortality was 14.3% (n = 1, multiorgan failure). During the follow-up period, 1 patient developed acute heart rejection which required treatment and 2 developed acute liver rejection. In all cases, rejection was successfully treated. Two patients developed acute heart rejection which did not require treatment (grade 1R). No patients developed chronic or refractory rejection. No patients developed allograft coronary artery vasculopathy.

Conclusions

CHLT remains a rarely performed treatment for pediatric patients with end-stage heart and liver disease, but our long-term data suggest that this treatment strategy should be considered more frequently.

Hypothermic oxygenated perfusion of the donor heart in heart transplantation: the short-term outcome from a randomised, controlled, open-label, multicentre clinical trial

BACKGROUND

Static cold storage (SCS) remains the gold standard for preserving donor hearts before transplantation but is associated with ischaemia, anaerobic metabolism, and organ injuries, leading to patient morbidity and mortality. We aimed to evaluate whether continuous, hypothermic oxygenated machine perfusion (HOPE) of the donor heart is safe and superior compared with SCS.

METHODS

We performed a multinational, multicentre, randomised, controlled, open-label clinical trial with a superiority design at 15 transplant centres across eight European countries. Adult candidates for heart transplantation were eligible and randomly assigned in a 1:1 ratio. Donor inclusion criteria were age 18-70 years with no previous sternotomy and donation after brain death. In the treatment group, the preservation protocol involved the use of a portable machine perfusion system ensuring HOPE of the resting donor heart. The donor hearts in the control group underwent ischaemic SCS according to standard practices. The primary outcome was time to first event of a composite of either cardiac-related death, moderate or severe primary graft dysfunction (PGD) of the left ventricle, PGD of the right ventricle, acute cellular rejection at least grade 2R, or graft failure (with use of mechanical circulatory support or re-transplantation) within 30 days after transplantation. We included all patients who were randomly assigned, fulfilled inclusion and exclusion criteria, and received a transplant in the primary analysis and all patients who were randomly assigned and received a transplant in the safety analyses. This trial was registered with ClicalTrials.gov (NCT03991923) and is ongoing.

FINDINGS

A total of 229 patients were enrolled between Nov 25, 2020, and May 19, 2023. The primary analysis population included 204 patients who received a transplant. There were no patients who received a transplant lost to follow-up. All 100 donor hearts preserved with HOPE were transplantable after perfusion. The primary endpoint was registered in 19 (19%) of 101 patients in the HOPE group and 31 (30%) of 103 patients in the SCS group, corresponding to a risk reduction of 44% (hazard ratio 0·56; 95% CI 0·32-0·99; log-rank test p=0·059). PGD was the primary outcome event in 11 (11%) patients in the HOPE group and 29 (28%) in the SCS group (risk ratio 0·39; 95% CI 0·20-0·73). In the HOPE group, 63 (65%) patients had a reported serious adverse event (158 events) versus 87 (70%; 222 events) in the SCS group. Major adverse cardiac transplant events were reported in 18 (18%) and 33 (32%) patients in the HOPE and SCS group (risk ratio 0·56; 95% CI 0·34-0·92).

INTERPRETATION

Although there was not a significant difference in the primary endpoint, the 44% risk reduction associated with HOPE was suggested to be a clinically meaningful benefit. Post-transplant complications, measured as major adverse cardiac transplant events, were reduced. Analysis of secondary outcomes suggested that HOPE was beneficial in reducing primary graft dysfunction. HOPE in donor heart preservation addresses the existing challenges associated with graft preservation and the increasing complexity of donors and heart transplantation recipients. Future investigation will help to further elucidate the benefit of HOPE.

FUNDING

XVIVO Perfusion.

Unmet need for heart transplantation in Africa

Heart transplantation is a critical treatment option for end-stage heart failure patients, offering a lifeline for those with severe cardiac conditions. However, in Africa, the unmet need for heart transplantation is a significant issue that poses challenges to the healthcare system and patient outcomes. Africa faces multiple barriers to heart transplantation, including limited infrastructure, a shortage of skilled healthcare professionals, a lack of funding, and inadequate organ donation systems. These challenges result in a considerable gap between the demand for heart transplants and the available resources to meet this need. As a result, many patients in Africa do not have access to life-saving heart transplantation procedures, leading to high mortality rates among those awaiting transplants. Addressing the unmet need for heart transplantation in Africa requires a multifaceted approach. The authors recommend that Africa as a continent build up a heart transplantation workforce involving a multidisciplinary team that consists of transplant surgeons, transplant physicians, nurses, anesthetists, pharmacists, etc. Heart transplant education and training programs should be well-constructed to ensure the delivery of safe and effective transplantation services. International collaborations have proven to be effective and should be encouraged between African institutions and transplant centers worldwide to facilitate knowledge transfer. Foreign and local organizations should promote public awareness about organ donation to address the myths about heart transplantation and promote heart donation. With these, African countries can improve access to heart transplantation, enhance patient outcomes, save lives in the region, and ultimately reduce the mortality rate in Africa.

Impact of new allocation policy on waitlist and transplant outcomes of adult congenital heart patients supported with ECMO

BACKGROUND

The use of ECMO as a bridge to heart transplantation has been growing rapidly in all heart transplant recipients since the implementation of the new UNOS allocation policy; however, the impact on adult congenital heart disease (ACHD) patients is not known.

METHODS

We analyzed the UNOS data (2015-2021) for ACHD patients supported with extracorporeal membrane oxygenation (ECMO) during the waitlist, before and after October 2018, to assess the impact on the waitlist and posttransplant outcomes. We compared the characteristics and outcomes of ACHD patients with or without ECMO use during the waitlist and pre- and postpolicy changes.

RESULTS

A total of 23 821 patients underwent heart transplantation, and only 918 (4%) had ACHD. Out of all ACHD patients undergoing heart transplants, 6% of patients in the prepolicy era and 7.6% in the postpolicy era were on ECMO at the time of listing. Those on ECMO were younger and sicker compared to the rest of the ACHD cohort. Those on ECMO had similar profiles pre- and postpolicy change; however, there was a very significant decrease in the waitlist time [136 days (IQR 29-384) vs. 38 days (IQR 11-108), p = 0.01]. There was no difference in waitlist mortality; however, competing risk analyses showed a higher likelihood of transplantation (51% vs. 29%) and a lower likelihood of death or deterioration (31% vs. 42%) postpolicy change. Long-term outcomes posttransplant for those supported with ECMO compared to the non-ECMO cohort are similar for ACHD patients, although there was higher attrition in the first year for the ECMO cohort.

CONCLUSION

The new allocation policy has resulted in shorter waitlist times and a higher likelihood of transplantation for ACHD patients supported by ECMO. However, the appropriate use of ECMO and the underuse of durable circulatory support devices in this population need further exploration.

Adverse Pregnancy Outcomes in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis

Importance

Transplant recipients experience high rates of adverse pregnancy outcomes; however, contemporary estimates of the association between solid organ transplantation and adverse pregnancy outcomes are lacking.

Objective

To evaluate the association between solid organ transplantation and adverse pregnancy outcomes and to quantify the incidence of allograft rejection and allograft loss during pregnancy.

Data Sources

PubMed/MEDLINE, EMBASE and Scopus databases were searched from January 1, 2000, to June 20, 2024, and reference lists were manually reviewed.

Study Selection

Cohort and case-control studies that reported at least 1 adverse pregnancy outcome in pregnant women with solid organ transplantation vs without solid organ transplant or studies that reported allograft outcomes in pregnant women with solid organ transplantation were included following independent dual review of abstracts and full-text articles.

Data Extraction and Synthesis

Two investigators abstracted data and independently appraised risk of bias using the Newcastle Ottawa Scale. A random-effects model was used to calculate overall pooled estimates using the DerSimonian-Laird estimator. Reporting followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline.

Main Outcomes and Measures

Primary pregnancy outcomes were preeclampsia, preterm birth (<37 weeks), and low birth weight (<2500 g). Secondary pregnancy outcomes were live birth rate, gestation, very preterm birth (<32 weeks), very low birth weight (<1500 g), and cesarean delivery. Allograft outcomes were allograft loss and rejection during pregnancy.

Results

Data from 22 studies and 93 565 343 pregnancies (4786 pregnancies in solid organ transplant recipients) were included; 14 studies reported adverse pregnancy outcomes, and 13 studies provided data for allograft outcomes. Pregnancies in organ transplant recipients were associated with significantly increased risk of preeclampsia (adjusted odds ratio [aOR], 5.83 [95% CI, 3.45-9.87]; I2 = 77.4%), preterm birth (aOR, 6.65 [95% CI, 4.09-12.83]; I2 = 81.8%), and low birth weight (aOR, 6.51 [95% CI, 2.85-14.88]; I2 = 90.6%). The incidence of acute allograft rejection was 2.39% (95% CI, 1.20%-3.96%; I2 = 68.5%), and the incidence of allograft loss during pregnancy was 1.55% (95% CI, 0.05%-4.44%; I2 = 69.2%).

Conclusions and Relevance

In this systematic review and meta-analysis, pregnancies in recipients of a solid organ transplant were associated with a 4 to 6 times increased risk of preeclampsia, preterm birth, and low birth weight during pregnancy. There was a low overall risk of graft rejection or loss during pregnancy.

Preparing the Heart for a New Baby: Management of Pregnancy in Heart Transplant Recipients

Heart transplant (HT) recipients are more frequently reaching childbearing age given improvement in median survival and outcomes after HT. Although most pregnancies in HT recipients have favorable outcomes, poor fetal outcomes and maternal complications such as hypertensive disorders of pregnancy are more common in HT recipients than in the general population. In this review, we summarize the current evidence to guide the management of pregnancy in HT recipients. Preconception counseling, focused on risk stratification and optimal timing of conception, is the first important step to optimize pregnancy outcomes. During pregnancy and in the postpartum period, frequent monitoring of graft function and immunosuppressive levels is recommended. Calcineurin inhibitors and corticosteroids should be the mainstay of treatment for both prevention and treatment of graft rejection. Delivery planning should follow usual obstetric indications, preferably with vaginal delivery at term using regional anesthesia. A multidisciplinary care team should be involved in management through all stages of pregnancy to ensure success.

The Utility of the Vasoactive-Inotropic Score and Its Nomogram in Guiding Postoperative Management in Heart Transplant Recipients

Background

In the early postoperative stage after heart transplantation, there is a lack of predictive tools to guide postoperative management. Whether the vasoactive-inotropic score (VIS) can aid this prediction is not well illustrated.

Methods

In total, 325 adult patients who underwent heart transplantation at our center between January 2015 and December 2018 were included. The maximum VIS (VISmax) within 24 h postoperatively was calculated. The Kaplan-Meier method was used for survival analysis. A logistic regression model was established to determine independent risk factors and to develop a nomogram for a composite severe adverse outcome combining early mortality and morbidity.

Results

VISmax was significantly associated with extensive early outcomes such as early death, renal injury, cardiac reoperation and mechanical circulatory support in a grade-dependent manner, and also predicted 90-day and 1-year survival (p < 0.05). A VIS-based nomogram for the severe adverse outcome was developed that included VISmax, preoperative advanced heart failure treatment, hemoglobin and serum creatinine. The nomogram was well calibrated (Hosmer-Lemeshow p = 0.424) with moderate to strong discrimination (C-index = 0.745) and good clinical utility.

Conclusion

VISmax is a valuable prognostic index in heart transplantation. In the early post-transplant stage, this VIS-based nomogram can easily aid intensive care clinicians in inferring recipient status and guiding postoperative management.

Donation After Circulatory Death Heart Transplant: Current State and Future Directions

Orthotopic heart transplant is the gold standard therapeutic intervention for patients with end-stage heart failure. Conventionally, heart transplant has relied on donation after brain death for organ recovery. Donation after circulatory death (DCD) is the donation of the heart after confirming that circulatory function has irreversibly ceased. DCD-orthotopic heart transplant differs from donation after brain death-orthotopic heart transplant in ways that carry implications for widespread adoption, including differences in organ recovery, storage and ethical considerations surrounding normothermic regional perfusion with DCD. Despite these differences, DCD has shown promising early outcomes, augmenting the donor pool and allowing more individuals to benefit from orthotopic heart transplant. This review aims to present the current state and future trajectory of DCD-heart transplant, examine key differences between DCD and donation after brain death, including clinical experiences and innovations in methodologies, and address the ongoing ethical challenges surrounding the new frontier in heart transplant with DCD donors.

Association between pre-heart transplant kidney function and post-transplant outcomes in Black and White adults

BACKGROUND

It remains unknown whether estimated glomerular filtration rate (eGFR) using the refit Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation without a term for race is associated with mortality and the need for kidney replacement therapy (KRT) differentially between Black and White heart transplant recipients.

METHODS

We studied 25,900 adults included in the Scientific Registry of Transplant Recipients. We classified recipients into six categories of eGFR (< 30, 30 to < 45, 45 to < 60, 60 to < 90, 90 to < 120, ≥ 120 ml/min/1.73 m2) using the race-neutral CKD-EPI refit equation, and assessed survival with multivariable adjusted Cox proportional hazards regression.

RESULTS

The association between pre-transplant race-neutral eGFR and mortality varied by race (Pinteraction = 0.006). Compared to White patients with an eGFR of 90-120 ml/min/1.73 m2, the mortality rates were 57% (95% CI 1.25, 1.98), 29% (95% CI 1.11, 1.51), 34% (95% CI 1.19, 1.52), and 19% (95% CI 1.06, 1.33) higher in Black patients with an eGFR less than 30, 30-45, 45-60, and 60-90 ml/min/1.73m2, respectively; and 53% (95% CI 1.28, 1.82), 49% (95% CI 1.33, 1.66), and 23% (95% CI 1.11, 1.35) higher among White patients with an eGFR less than 30, 30-45, and 45-60 ml/min/1.73 m2, respectively. The association between pre-transplant eGFR and the need for KRT during follow-up was similar between Black and White patients (Pinteraction = 0.57).

CONCLUSIONS

Worsening pre-transplant eGFR using the new race-neutral CKD-EPI refit equation was associated with a higher rate of post-heart transplant mortality and KRT in Black and White recipients. The racial disparity in post-heart transplant mortality was narrower in the setting of severe kidney dysfunction.

Comparative Analysis of Ischemia-Reperfusion Injury in Heart Transplantation: A Single-Center Study Evaluating Conventional Ice-Cold Storage versus the Paragonix SherpaPak Cardiac Transport System

BACKGROUND

Since the 2018 allocation system change in heart transplantation (HT), ischemic times have increased, which may be associated with peri-operative and post-operative complications. This study aimed to compare ischemia reperfusion injury (IRI) in hearts preserved using ice-cold storage (ICS) and the Paragonix SherpaPak TM Cardiac Transport System (CTS).

METHODS

From January 2021 to June 2022, consecutive endomyocardial biopsies from 90 HT recipients were analyzed by a cardiac pathologist in a single-blinded manner: 33 ICS and 57 CTS. Endomyocardial biopsies were performed at three-time intervals post-HT, and the severity of IRI manifesting histologically as coagulative myocyte necrosis (CMN) was evaluated, along with graft rejection and graft function.

RESULTS

The incidence of IRI at weeks 1, 4, and 8 post-HT were similar between the ICS and CTS groups. There was a 59.3% statistically significant reduction in CMN from week 1 to 4 with CTS, but not with ICS. By week 8, there were significant reductions in CMN in both groups. Only 1 out of 33 (3%) patients in the ICS group had an ischemic time >240 mins, compared to 10 out of 52 (19%) patients in the CTS group. During the follow-up period of 8 weeks to 12 months, there were no significant differences in rejection rates, formation of de novo donor-specific antibodies and overall survival between the groups.

CONCLUSION

The CTS preservation system had similar rates of IRI and clinical outcomes compared to ICS despite longer overall ischemic times. There is significantly more recovery of IRI in the early post operative period with CTS. This study supports CTS as a viable option for preservation from remote locations, expanding the donor pool.

Cardio-Renal-Metabolic Outcomes Associated With the Use of GLP-1 Receptor Agonists After Heart Transplantation

BACKGROUND

The use of glucagon-like-peptide 1 receptor agonists (GLP1-RA) has dramatically increased over the past 5 years for diabetes mellitus type 2 (T2DM) and obesity. These comorbidities are prevalent in adult heart transplant (HT) recipients. However, there are limited data evaluating the efficacy of this drug class in this population. The aim of the current study was to describe cardiometabolic changes in HT recipients prescribed GLP1-RA at a large-volume transplant center.

METHODS

We retrospectively reviewed all adult HT recipients who received GLP1-RA after HT for a minimum of 1-month. Cardiometabolic parameters including body mass index (BMI), lipid panel, hemoglobin A1C, estimated glomerular filtration rate (eGFR), and NT-proBNP were compared prior to initiation of the drug and at most recent follow-up. We also evaluated for significant dose adjustments to immunosuppression after drug initiation and adverse effects leading to drug discontinuation.

RESULTS

Seventy-four patients were included (28% female, 53% White, 20% Hispanic) and followed for a median of 383 days [IQR 209, 613] on a GLP1-RA. The majority of patients (n = 56, 76%) were prescribed semaglutide. The most common indication for prescription was T2DM alone (n = 33, 45%), followed by combined T2DM and obesity (n = 26, 35%). At most recent follow-up, mean BMI decreased from 33.3 to 31.5 kg/m2 (p < 0.0001), HbA1C from 7.3% to 6.7% (p = 0.005), LDL from 78.6 to 70.3 mg/dL (p = 0.018) and basal insulin daily dose from 32.6 to 24.8 units (p = 0.0002).

CONCLUSION

HT recipients prescribed GLP1-RA therapy showed improved glycemic control, weight loss, and cholesterol levels during the study follow-up period. GLP1-RA were well tolerated and were rarely associated with changes in immunosuppression dosing.

Reference values of strain-derived myocardial work indices in heart transplant patients

Aims

Myocardial work (MW) is a relatively novel non-invasive echocardiographic method with increasing fields of application. Normal reference ranges of MW indices in patients who have undergone a heart transplant (HTx) have not been determined yet. The aim of this study was to obtain the reference ranges for 2D echocardiographic indices of MW for adult HTx patients and to compare them with the results of the European Association of Cardiovascular Imaging (EACVI) Normal Reference Ranges for Echocardiography (NORRE) study.

Methods and results

All consecutive HTx patients admitted at our institution (University Hospital of Siena, Italy) between September 2019 and May 2022 who underwent endomyocardial biopsy (EMB) were considered. Patients with a history of rejection, a history of coronary artery vasculopathy, either acute cellular rejection or acute antibody-mediated rejection at EMB, and donor-specific antibodies were excluded. MW retrospectively performed for the included patients was retrieved, and the results were compared with those from the EACVI NORRE study. Out of 176 HTx patients who underwent EMB, 94 patients were excluded. The study population consisted of 82 HTx patients [68.3% male, median age 53 (46-62) years]. The median duration from HTx was 5 (2-22) months. The main MW indices such as global work efficiency (GWE, 84 ± 8%), global work index (GWI, 1447 ± 409 mmHg%), global constructive work (GCW, 2067 ± 423 mmHg%), and global wasted work [GWW, 310 (217-499) mmHg%] did not differ according to gender. Each of these indices significantly differed from those reported in the EACVI NORRE study (P-value <0.001), with lower GWI, GCW, and GWE and higher GWW values in the HTx population.

Conclusion

This study provides reference ranges for MW indices in an adult HTx population free from transplant-related complications which proved to be different from those previously reported in healthy volunteers.

Advanced heart failure therapies in the Eastern Mediterranean Region: current status, challenges, and future directions

While there has been a global decrease in rates of heart failure (HF) prevalence between 1990 and 2019, the Eastern Mediterranean region (EMR) is experiencing an increase. In 2019, approximately 1,229,766 individuals lived with moderate to severe HF in the EMR. Despite the growth in the utilization of advanced heart failure (AHF) therapies in the EMR in the past two decades, current volumes are yet to meet the growing AHF burden in the region. Heart transplantation (HT) volumes in EMR have grown from 9 in the year 2000 to 179 HTs in 2019. However, only a few centers provide the full spectrum of AHF therapies, including durable mechanical circulatory support (MCS) and HT. Published data on the utilization of left ventricular assist devices (LVAD) in the EMR are scarce. Notably, patients undergoing LVAD implantation in the EMR are on average, 13 year younger, and more likely to present with critical cardiogenic shock, as compared to their counterparts in the Western world. Furthermore, AHF care in the region is hampered by the paucity of multidisciplinary HF programs, inherent costs of AHF therapies, limited access to short and long-term MCS, organ shortage, and lack of public awareness and acceptance of AHF therapeutics. All stakeholders in the EMR should work together to strategize tackling the challenging AHF burden in the region.

Clinical Utility of the Molecular Microscope Diagnostic System in a Real-World Transplant Cohort: Moving Towards a New Paradigm

Objectives

To evaluate the clinical implications of adjunctive molecular gene expression analysis (MMDx ) of biopsy specimens in heart transplant (HT ) recipients with suspected rejection.

Introduction

Histopathological evaluation remains the standard method for rejection diagnosis in HT. However, the wide interobserver variability combined with a relatively common incidence of "biopsy-negative" rejection has raised concerns about the likelihood of false-negative results. MMDx, which uses gene expression to detect early signs of rejection, is a promising test to further refine the assessment of HT rejection.

Methods

Single-center prospective study of 418 consecutive for-cause endomyocardial biopsies performed between November 2022 and May 2024. Each biopsy was graded based on histology and assessed for rejection patterns using MMDx. MMDx results were deemed positive if borderline or definitive rejection was present. The impact of MMDx results on clinical management was evaluated. Primary outcomes were 1-year survival and graft dysfunction following MMDx-guided clinical management. Secondary outcomes included changes in donor-specific antibodies, MMDx gene transcripts, and donor-derived cell-free DNA (dd-cfDNA) levels.

Results

We analyzed 418 molecular samples from 237 unique patients. Histology identified rejection in 32 cases (7.7%), while MMDx identified rejection in 95 cases (22.7%). Notably, in 79 of the 95 cases where MMDx identified rejection, histology results were negative, with the majority of these cases being antibody-mediated rejection (62.1%). Samples with rejection on MMDx were more likely to show a combined elevation of dd-cfDNA and peripheral blood gene expression profiling than those with borderline or negative MMDx results (36.7% vs 28.0% vs 10.3%; p<0.001). MMDx results led to the implementation of specific antirejection protocols or changes in immunosuppression in 20.4% of cases, and in 73.4% of cases where histology was negative and MMDx showed rejection. 1-year survival was better in the positive MMDx group where clinical management was guided by MMDx results (87.0% vs 78.6%; log rank p=0.0017).

Conclusions

In our cohort, MMDx results more frequently indicated rejection than histology, often leading to the initiation of antirejection treatment. Intervention guided by positive MMDx results was associated with improved outcomes.

Graphical abstract

Correlation Between Tacrolimus Levels in Blood Samples Obtained from Central Catheter and Peripheral Venipuncture in Lung Transplant Patients (Ven-Cat Study)

BACKGROUND

Following lung transplantation (LT), receiving immunosuppressive therapy is crucial. Tacrolimus is considered a drug with a narrow therapeutic range and its use requires constant monitoring. This study aimed to evaluate the correlation between tacrolimus levels obtained from central venous catheter and direct venipuncture in adult patients undergoing LT.

METHODS

This prospective study included LT patients hospitalized in conventional ward carrying a central catheter through which no intravenous tacrolimus was administered. Trough samples were obtained through direct puncture and from the central catheter. Pearson correlation coefficient was calculated to quantify the mean difference between the 2 measures.

RESULTS

A total of 54 sample pairs from 16 LT patients were obtained, mostly male (81.3%) and bilateral transplant recipients (93.8%); the transplant procedure was the primary reason for admission (81.3%). The difference in tacrolimus levels between both samples was 0.3 (0.1-0.6) mcg/L, with the measurement for the samples obtained through venipuncture being mostly higher than that for those obtained from the catheter. A strong correlation was observed between the tacrolimus levels in the samples obtained from the catheter and through venipuncture (Pearson correlation coefficient, 0.991; P < 0.001; R2 = 0.982).

CONCLUSIONS

There is an excellent correlation between tacrolimus levels obtained from venipuncture and those obtained from central venous catheter in LT patients undergoing oral tacrolimus therapy.

Impact of institutional variables on centre performance in long-term survival after heart transplant

OBJECTIVES

The gold standard metric for centre-level performance in orthotopic heart transplantation (OHT) is 1-year post-OHT survival. However, it is unclear whether centre performance at 1 year is predictive of longer-term outcomes. This study evaluated factors impacting longer-term centre-level performance in OHT.

METHODS

Patients who underwent OHT in the USA between 2010 and 2021 were identified using the United Network of Organ Sharing data registry. The primary outcome was 5-year survival conditional on 1-year survival following OHT. Multivariable Cox proportional hazard models assessed the impact of centre-level 1-year survival rates on 5-year survival rates. Mixed-effect models were used to evaluate between-centre variability in outcomes.

RESULTS

Centre-level risk-adjusted 5-year mortality conditional on 1-year survival was not associated with centre-level 1-year survival rates [hazard ratio: 0.99 (0.97-1.01, P = 0.198)]. Predictors of 5-year mortality conditional on 1-year survival included black recipient race, pre-OHT serum creatinine, diabetes and donor age. In mixed-effect modelling, there was substantial variability between centres in 5-year mortality rates conditional on 1-year survival, a finding that persisted after controlling for recipient, donor and institutional factors (P < 0.001). In a crude analysis using Kaplan-Meier, the 5-year survival conditional on 1-year survival was: low volume: 86.5%, intermediate volume: 87.5%, high volume: 86.7% (log-rank P = 0.52). These measured variables only accounted for 21.4% of the between-centre variability in 5-year mortality conditional on 1-year survival.

CONCLUSIONS

Centre-level risk-adjusted 1-year outcomes do not correlate with outcomes in the 1- to 5-year period following OHT. Further research is needed to determine what unmeasured centre-level factors contribute to longer-term outcomes in OHT.

Prognostic Value of APACHE IV Score in Patients Bridged to Heart Transplantation on ECMO

BACKGROUND

Methods for risk stratification of candidates for heart transplantation (HTx) supported by extracorporeal membrane oxygenation (ECMO) are limited. We evaluated the reliability of the APACHE IV score to identify the risk of mortality in this patient subset in a multicenter study.

METHODS

Between January 2010 and December 2022, 167 consecutive ECMO patients were bridged to HTx; they were divided into two groups, according to a cutoff value of APACHE IV score, obtained by receiver operating characteristic curve analysis for 90-day mortality. Kaplan-Meier survival curves were plotted, and compared through the log-Rank test. Cox regression model was used to estimate which factors were associated with survival.

RESULTS

The 90-day mortality prediction of the APACHE IV score showed an area under the curve of 0.87 (95% CI: 0.80-0.94), with a cutoff value of 49 (specificity 91.7%-sensibility 69.6%). 125 patients (74.8%) showed an APACHE IV score value < 49 (Group A), and 42 (25.2%) ≥ 49 (Group B). 90-day mortality was 11.2% in Group A and 76.2% in Group B (p < 0.01). Survival at 1 and 5 years was 85.5%, 77% versus 23.4%, 23.4% (p < 0.01) in Groups A and B. Mortality correlated at univariable analysis with recipient age, body mass index, mechanical ventilation, APACHE IV score, and platelets number. At multivariable analysis only APACHE IV score (HR: 1.07 [1.05-1.09, 95% CI]) independently affected survival.

CONCLUSIONS

The APACHE IV score represents a powerful predictor of survival in patients bridged to HTx on ECMO support, and could guide candidacy of patients on ECMO.

Pathology of explanted pediatric hearts: An 11-year study. Population characteristics and implications for outcomes

BACKGROUND

As more pediatric patients become candidates for heart transplantation (HT), understanding pathological predictors of outcome and the accuracy of the pretransplantation evaluation are important to optimize utilization of scarce donor organs and improve outcomes. The authors aimed to investigate explanted heart specimens to identify pathologic predictors that may affect cardiac allograft survival after HT.

METHODS

Explanted pediatric hearts obtained over an 11-year period were analyzed to understand the patient demographics, indications for transplant, and the clinical-pathological factors.

RESULTS

In this study, 149 explanted hearts, 46% congenital heart defects (CHD), were studied. CHD patients were younger and mean pulmonary artery pressure and resistance were significantly lower than in cardiomyopathy patients. Twenty-one died or underwent retransplantation (14.1%). Survival was significantly higher in the cardiomyopathy group at all follow-up intervals. There were more deaths and the 1-, 5- and 7-year survival was lower in patients ≤10 years of age at HT. Early rejection was significantly higher in CHD patients exposed to homograft tissue, but not late rejection. Mortality/retransplantation rate was significantly higher and allograft survival lower in CHD hearts with excessive fibrosis of one or both ventricles. Anatomic diagnosis at pathologic examination differed from the clinical diagnosis in eight cases.

CONCLUSIONS

Survival was better for the cardiomyopathy group and patients >10 years at HT. Prior homograft use was associated with a higher prevalence of early rejection. Ventricular fibrosis (of explant) was a strong predictor of outcome in the CHD group. We presented several pathologic findings in explanted pediatric hearts.

"Durable left ventricular assist devices as a bridge to transplantation in The Old and The New World"

Heart transplantation remains the gold standard treatment for end-stage heart failure patients without contraindications. However, limited donor availability and long wait times have created a need for left ventricular assist devices (LVAD) to be used as a bridge to transplantation in appropriately selected patients. Improvements in LVAD technology have resulted in improved short- and long-term outcomes, further supporting the use of these devices for a bridge-to-transplant (BTT) indication. LVAD utilization as BTT exhibits notable disparities worldwide, mainly due to variations in organ availability, allocation policies, and financial constraints. Although Europe has experienced a consistent increase in the use of LVAD for this purpose, the United Network for Organ Sharing 2018 policy amendment resulted in a significant reduction in the number of LVADs used for BTT in the US. To overcome this issue, modifications in the US allocation policy to consider factors such as days on device support, age, and type of complications may be necessary to potentially increase implantation rates.The authors provide an overview comparing the current state of heart transplantation in the US and Europe, with a particular focus on how distinct allocation policies and organ availability impact medical practices. Additionally, the review will examine critical aspects ranging from patient selection and pre-implantation optimization to post-transplant outcomes.

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy

BACKGROUND

Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant.

OBJECTIVES

The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification.

METHODS

Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination. Epicardial CAV was assessed by intravascular ultrasound percent intimal volume (PIV) and microvascular CAV by endomyocardial biopsy.

RESULTS

A total of 136 PET studies from 74 patients were analyzed. At 12 months, median PIV increased 5.6% (95% CI: 3.6%-7.1%) with no change in microvascular CAV incidence (baseline: 31% vs follow-up: 38%; P = 0.406) and persistent microvascular disease in 13% of patients. Median capillary density increased 30 capillaries/mm2 (95% CI: -6 to 79 capillaries/mm2). PET myocardial flow reserve (2.5 ± 0.7 vs 2.9 ± 0.8; P = 0.001) and stress MBF (2.7 ± 0.6 vs 2.9 ± 0.6; P = 0.008) increased, and coronary vascular resistance (CVR) (49 ± 13 vs 47 ± 11; P = 0.214) was unchanged. At 12 months, PET and PIV had modest correlation (stress MBF: r = -0.35; CVR: r = 0.33), with lower stress MBF and higher CVR across increasing PIV tertiles (all P < 0.05). Receiver-operating characteristic curves for CAV defined by upper-tertile PIV showed areas under the curve of 0.74 for stress MBF and 0.73 for CVR.

CONCLUSIONS

The 1-year post-transplant PET MBF is associated with epicardial CAV, supporting potential use for early noninvasive CAV assessment. (Early Post Transplant Cardiac Allograft Vasculopahty [ECAV]; NCT03217786).

CD47 blockade reduces ischemia/reperfusion injury in murine heart transplantation and improves donor heart preservation

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is an important cause of early dysfunction and exacerbation of immune rejection in transplanted hearts. The integrin-related protein CD47 exacerbates myocardial ischemia-reperfusion injury by inhibiting the nitric oxide signaling pathway through interaction with thrombospondin-1 (TSP-1). In addition, the preservation quality of the donor hearts is a key determinant of transplant success. Preservation duration beyond four hours is associated with primary graft dysfunction. We hypothesized that blocking the CD47-TSP-1 system would attenuate ischemia-reperfusion injury in the transplanted heart and, thus, improve the preservation of donor hearts.

METHODS

We utilized a syngeneic mouse heart transplant model to assess the effect of CD47 monoclonal antibody (CD47mAb) to treat MIRI. Donor hearts were perfused with CD47mAb or an isotype-matched control immunoglobulin (IgG2a) and were implanted into the abdominal cavity of the recipients after being stored in histidine-tryptophan-ketoglutarate (HTK) solution at 4 °C for 4 h or 8 h.

RESULTS

At both the 4-h and 8-h preservation time points, mice in the experimental group perfused with CD47mAb exhibited prolonged survival in the transplanted heart, reduced inflammatory response and oxidative stress, significantly decreased inflammatory cell infiltration, and fewer apoptosis-related biomarkers.

CONCLUSION

The application of CD47mAb for the blocking of CD47 attenuates MIRI as well as improves the preservation and prognosis of the transplanted heart in a murine heart transplant model.

Examining a 12-year experience within Kazakhstan's national heart transplantation program

Kazakhstan has one of the lowest heart transplantation (HTx) rates globally, but there are no studies evaluating the outcomes of HTx. This study aimed to provide a comprehensive analysis of the national HTx program over a 12-year period (2012-2023). Survival analysis of the national HTx cohort was conducted using life tables, Kaplan‒Meier curves, and Cox regression methods. Time series analysis was applied to analyze historical trends in HTx per million population (pmp) and to make future projections until 2030. The number of patients awaiting HTx in Kazakhstan was evaluated with a regional breakdown. The pmp rates of HTx ranged from 0.06 to 1.08, with no discernible increasing trend. Survival analysis revealed a rapid decrease in the first year after HTx, reaching 77.0% at 379 days, with an overall survival rate of 58.1% at the end of the follow-up period. Among the various factors analyzed, recipient blood levels of creatinine and total bilirubin before surgery, as well as the presence of infection or sepsis and the use of ECMO after surgery, were found to be significant contributors to the survival of HTx patients. There is a need for public health action to improve the HTx programme.

Informing preconception counseling: Outcomes among female heart transplant recipients in the ISHLT registry

BACKGROUND

The numbers of women of child-bearing age undergoing heart transplantation (HT) and female pediatric HT recipients surviving to child-bearing age have increased, along with improvements in post-transplant survival. Data regarding life expectancy and comorbidities in reproductive-aged female HT recipients are needed to inform shared decision-making at the time of preconception counseling.

METHODS

The International Society for Heart and Lung Transplantation (ISHLT) Thoracic Organ Transplant Registry was investigated for HT recipients between January 1, 2000 and June 30, 2017. Women of childbearing age were defined as those aged 15-45 years, either at transplant, or at the respective post-transplant follow-up. Characteristics and outcomes of female recipients of childbearing age at transplant, 5-, 10-, and 15-year follow-up were compared to females > 45 years of age, males 15-45 years and males > 45 years of age at the corresponding time intervals. Outcomes included survival, development of diabetes (DM), severe renal dysfunction (CKD), and cardiac allograft vasculopathy (CAV).

RESULTS

During the study period, 71,585 HT recipients were included: 24% (n = 17,194) were female and 9.2% (n = 6602) were of childbearing age at HT. A pre-transplant diagnosis of peripartum cardiomyopathy was associated with significantly worse post-transplant survival, a finding that remained independent of panel reactive antibody levels. The presence of pre-transplant DM and/or severe CKD was significantly associated with lower survival as were the presence of CAV, DM, and CKD post-HT.

CONCLUSION

Knowledge of the impact of pre-existing comorbidities and complications post-HT on survival are important for risk stratification for preconception counseling post-HT.

Incidence of Acute Rejection Compared With Endomyocardial Biopsy Complications for Heart Transplant Patients in the Contemporary Era

BACKGROUND

The reference standard of detecting acute rejection (AR) in adult heart transplant (HTx) patients is an endomyocardial biopsy (EMB). The majority of EMBs are performed in asymptomatic patients. However, the incidence of treated AR compared with EMB complications has not been compared in the contemporary era (2010-current).

METHODS

The authors retrospectively analyzed 2769 EMBs obtained in 326 consecutive HTx patients between August 2019 and August 2022. Variables included surveillance versus for-cause indication, recipient and donor characteristics, EMB procedural data and pathological grades, treatment for AR, and clinical outcomes.

RESULTS

The overall EMB complications rate was 1.6%. EMBs performed within 1 mo after HTx compared with after 1 mo from HTx showed significantly increased complications (OR, 12.74, P  < 0.001). The treated AR rate was 14.2% in the for-cause EMBs and 1.2% in the surveillance EMBs. We found the incidence of AR versus EMB complications was significantly lower in the surveillance compared with the for-cause EMB group (OR, 0.05, P  < 0.001). We also found the incidence of EMB complications was higher than treated AR in surveillance EMBs.

CONCLUSIONS

The yield of surveillance EMBs has declined in the contemporary era, with a higher incidence of EMB complications compared with detected AR. The risk of EMB complications was highest within 1 mo after HTx. Surveillance EMB protocols in the contemporary era may need to be reevaluated.

Early Assessment of Cardiac Allograft Vasculopathy Risk Among Recipients of Hepatitis C Virus-infected Donors in the Current Era

BACKGROUND

Transplantation of hearts from hepatitis C virus (HCV)-positive donors has increased substantially in recent years following development of highly effective direct-acting antiviral therapies for treatment and cure of HCV. Although historical data from the pre-direct-acting antiviral era demonstrated an association between HCV-positive donors and accelerated cardiac allograft vasculopathy (CAV) in recipients, the relationship between the use of HCV nucleic acid test-positive (NAT+) donors and the development of CAV in the direct-acting antiviral era remains unclear.

METHODS AND RESULTS

We performed a retrospective, single-center observational study comparing coronary angiographic CAV outcomes during the first year after transplant in 84 heart transplant recipients of HCV NAT+ donors and 231 recipients of HCV NAT- donors. Additionally, in a subsample of 149 patients (including 55 in the NAT+ cohort and 94 in the NAT- cohort) who had serial adjunctive intravascular ultrasound examination performed, we compared development of rapidly progressive CAV, defined as an increase in maximal intimal thickening of ≥0.5 mm in matched vessel segments during the first year post-transplant. In an unadjusted analysis, recipients of HCV NAT+ hearts had reduced survival free of CAV ≥1 over the first year after heart transplant compared with recipients of HCV NAT- hearts. After adjustment for known CAV risk factors, however, there was no significant difference between cohorts in the likelihood of the primary outcome, nor was there a difference in development of rapidly progressive CAV.

CONCLUSIONS

These findings support larger, longer-term follow-up studies to better elucidate CAV outcomes in recipients of HCV NAT+ hearts and to inform post-transplant management strategies.

Usage of older donors is associated with higher mortality after heart transplantation: A UNOS observational study

BACKGROUND

Utilization of heart from older donors is variable across centers with uncertain outcomes of recipients. We sought to utilize a national registry to examine the usage and outcomes of heart transplant (HT) recipients from older donors. We also explored the impact of current donor heart allocation scheme on the outcomes of hearts from older donors.

METHODS

This observational study utilized the United Network for Organ Sharing database between 2015 and 2023 with donors categorized into age <45 years or ≥45 years and evaluated organ disposition and geographical variation. Thirty-day, 1-, and 3-year mortality, and graft failure rates were compared among recipients as per donor age group. We also evaluated annual trends in HT for each group over the follow-up period.

RESULTS

A total of 24,966 adult donors were recovered: 3,742 (15.0%) were ≥45 years; 3,349 (15.6%) adults received heart from such donors with significant geographical variation, and a declining utilization in the transplantation rate in current donor allocation system. Donors with age ≥45 years had higher comorbidities and were allotted with a significantly shorter ischemic time to recipients who were significantly less likely to receive temporary mechanical circulatory support and more likely female. Unadjusted and adjusted, 30-day mortality were similar but 1- and 3-year mortality and graft failure rates were significantly higher in recipients of such donors. Spline analysis suggested a higher 1-year mortality risk at older donor age with risk increasing after age 40 years.

CONCLUSIONS

Older donor age was associated with worsened 1- and 3-year mortality and graft failure for heart transplant recipients.

Early Outcomes in Patients With LVAD Undergoing Heart Transplant via Use of the SherpaPak Cardiac Transport System

BACKGROUND

Heart transplant (HT) in recipients with left ventricular assist devices (LVADs) is associated with poor early post-HT outcomes, including primary graft dysfunction (PGD). As complicated heart explants in recipients with LVADs may produce longer ischemic times, innovations in donor heart preservation may yield improved post-HT outcomes. The SherpaPak Cardiac Transport System is an organ preservation technology that maintains donor heart temperatures between 4 °C and 8 °C, which may minimize ischemic and cold-induced graft injuries. This analysis sought to identify whether the use of SherpaPak versus traditional cold storage was associated with differential outcomes among patients with durable LVAD undergoing HT.

METHODS

Global Utilization and Registry Database for Improved Heart Preservation-Heart (NCT04141605) is a multicenter registry assessing post-HT outcomes comparing 2 methods of donor heart preservation: SherpaPak versus traditional cold storage. A retrospective review of all patients with durable LVAD who underwent HT was performed. Outcomes assessed included rates of PGD, post-HT mechanical circulatory support use, and 30-day and 1-year survival.

RESULTS

SherpaPak (n=149) and traditional cold storage (n=178) patients had similar baseline characteristics. SherpaPak use was associated with reduced PGD (adjusted odds ratio, 0.56 [95% CI, 0.32-0.99]; P=0.045) and severe PGD (adjusted odds ratio, 0.31 [95% CI, 0.13-0.75]; P=0.009), despite an increased total ischemic time in the SherpaPak group. Propensity matched analysis also noted a trend toward reduced intensive care unit (SherpaPak 7.5±6.4 days versus traditional cold storage 11.3±18.8 days; P=0.09) and hospital (SherpaPak 20.5±11.9 days versus traditional cold storage 28.7±37.0 days; P=0.06) lengths of stay. The 30-day and 1-year survival was similar between groups.

CONCLUSIONS

SherpaPak use was associated with improved early post-HT outcomes among patients with LVAD undergoing HT. This innovation in preservation technology may be an option for HT candidates at increased risk for PGD.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04141605.

A radiographic score for human donor lungs on ex vivo lung perfusion predicts transplant outcomes

BACKGROUND

Ex vivo lung perfusion (EVLP) is an advanced platform for isolated lung assessment and treatment. Radiographs acquired during EVLP provide a unique opportunity to assess lung injury. The purpose of our study was to define and evaluate EVLP radiographic findings and their association with lung transplant outcomes.

METHODS

We retrospectively evaluated 113 EVLP cases from 2020-21. Radiographs were scored by a thoracic radiologist blinded to outcome. Six lung regions were scored for 5 radiographic features (consolidation, infiltrates, atelectasis, nodules, and interstitial lines) on a scale of 0 to 3 to derive a score. Spearman's correlation was used to correlate radiographic scores to biomarkers of lung injury. Machine learning models were developed using radiographic features and EVLP functional data. Predictive performance was assessed using the area under the curve.

RESULTS

Consolidation and infiltrates were the most frequent findings at 1 hour EVLP (radiographic lung score 2.6 (3.3) and 4.6 (4.3)). Consolidation (r = -0.536 and -0.608, p < 0.0001) and infiltrates (r = -0.492 and -0.616, p < 0.0001) were inversely correlated with oxygenation (∆pO2) at 1 hour and 3 hours of EVLP. First-hour consolidation and infiltrate lung scores predicted transplant suitability with an area under the curve of 87% and 88%, respectively. Prediction of transplant outcomes using a machine learning model yielded an area under the curve of 80% in the validation set.

CONCLUSIONS

EVLP radiographs provide valuable insight into donor lungs being assessed for transplantation. Consolidation and infiltrates were the most common abnormalities observed in EVLP lungs, and radiographic lung scores predicted the suitability of donor lungs for transplant.

Recipient Outcomes With Extended Criteria Donors Using Advanced Heart Preservation: An Analysis of the GUARDIAN-Heart Registry

BACKGROUND

The prevalence of end-stage heart failure and patients who could benefit from heart transplantation requires an expansion of the donor pool, relying on the transplant community to continually re-evaluate and expand the use of extended criteria donor organs. Introduction of new technologies such as the Paragonix SherpaPak Cardiac Transport System aids in this shift. We seek to analyze the impact of the SherpaPak system on recipient outcomes who receive extended criteria organs in the GUARDIAN-Heart Registry.

METHODS

Between October 2015 and December 2022, 1,113 adults from 15 US centers receiving donor hearts utilizing either SherpaPak (n = 560) or conventional ice storage (ice, n = 453) were analyzed from the GUARDIAN-Heart Registry using summary statistics. A previously published set of criteria was used to identify extended criteria donors, which included 193 SherpaPak and 137 ice.

RESULTS

There were a few baseline differences among recipients in the 2 cohorts; most notably, IMPACT scores, distance traveled, and total ischemic time were significantly greater in SherpaPak, and significantly more donor hearts in the SherpaPak cohort had >4 hours total ischemia time. Posttransplant mechanical circulatory support utilization (SherpaPak 22.3% vs ice 35.0%, p = 0.012) and new extracorporeal membrane oxygenation/ventricular assist device (SherpaPak 7.8% vs ice 15.3%, p = 0.033) was significantly reduced, and the rate of severe primary graft dysfunction (SherpaPak 6.2% vs ice 13.9%, p = 0.022) was significantly reduced by over 50% in hearts preserved using SherpaPak. One-year survival between cohorts was similar (SherpaPak 92.9% vs ice 89.6%, p = 0.27).

CONCLUSIONS

This subgroup analysis demonstrates that SherpaPak can be safely used to utilize extended criteria donors with low severe PGD rates.