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

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.

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.

"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.

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.

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.

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.

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.

Association of diet quality and weight increase in adult heart transplant recipients

BACKGROUND

Understanding the quality of the diet of heart transplant recipients (HTRs) is essential to developing effective dietary interventions for weight control, but relevant evidence is scarce. We investigated diet quality and its association with post-transplant increase in weight adjusted for height (body mass index [BMI]) in Australian HTRs.

METHODS

We recruited adult HTRs from Queensland's thoracic transplant clinic, 2020-2021. Study participants completed a 3-day food diary using a smart-phone app. Socio-demographic information was collected by self-administered questionnaire, and height, serial weight and clinical information were obtained from medical records. We calculated the Dietary Approaches to Stop Hypertension (DASH) index based on nine food groups and nutrients (index of 90 indicates highest possible quality), and any changes in BMI (≤ 0 kg m-2 or >0 kg m-2) post-transplantation. Median DASH index values were assessed in relation to sex and BMI change using Mann-Whitney U test.

RESULTS

Among 49 consented HTRs, 25 (51%) completed the food diary (median age 48 years, 52% females). Median BMI at enrolment was 27.2 kg m-2; median BMI change since transplant was +3.7 kg m-2. Fruit, vegetable, and whole grain intakes were generally lower than recommended, giving a low overall median DASH index of 30 with no sex differences. HTRs for which the BMI increased post-transplant had significantly lower median DASH indices than those whose BMI did not increase (30 vs. 45, p = 0.013).

CONCLUSIONS

The diet quality of HTRs appears suboptimal overall, with fruit and vegetable intakes especially low. HTRs whose BMI increased post-transplant had substantially lower quality diets than HTRs whose BMI did not increase.

Use of intraoperative haemoadsorption in patients undergoing heart transplantation: a proof-of-concept randomized trial

AIMS

The aim of this trial was to compare the clinical effects of intraoperative haemoadsorption versus standard care in patients undergoing orthotopic heart transplantation (OHT).

METHODS AND RESULTS

In a randomized, controlled trial, OHT recipients were randomized to receive intraoperative haemoadsorption or standard care. Outcomes were vasoactive-inotropic score (VIS), frequency of vasoplegic syndrome (VS) in the first 24 h; post-operative change in procalcitonin (PCT) and C-reactive protein (CRP) levels; intraoperative change in mycophenolic acid (MPA) concentration; frequency of post-operative organ dysfunction, major complications, adverse immunological events and length of in-hospital stay and 1-year survival. Sixty patients were randomized (haemoadsorption group N = 30, control group N = 25 plus 5 exclusions). Patients in the haemoadsorption group had a lower median VIS and rate of VS (VIS: 27.2 [14.6-47.7] vs. 41.9 [22.4-63.2], P = 0.046, and VS: 20.0% vs. 48.0%, P = 0.028, respectively), a 6.4-fold decrease in the odds of early VS (OR: 0.156, CI: 0.029-0.830, P = 0.029), lower PCT levels, shorter median mechanical ventilation (MV: 25 [19-68.8] hours vs. 65 [23-287] hours, P = 0.025, respectively) and intensive care unit stay (ICU stay: 8.5 [8.0-10.3] days vs. 12 [8.5-18.0] days, P = 0.022, respectively) than patients in the control group. Patients in the haemoadsorption versus control group experienced lower rates of acute kidney injury (AKI: 36.7% vs. 76.0%, P = 0.004, respectively), renal replacement therapy (RRT: 0% vs. 16.0%, P = 0.037, respectively) and lower median per cent change in bilirubin level (PCB: 2.5 [-24.6 to 71.1] % vs. 72.1 [11.2-191.4] %, P = 0.009, respectively) during the post-operative period. MPA concentrations measured at pre-defined time points were comparable in the haemoadsorption compared to control groups (MPA pre-cardiopulmonary bypass: 2.4 [1.15-3.60] μg/mL vs. 1.6 [1.20-3.20] μg/mL, P = 0.780, and MPA 120 min after cardiopulmonary bypass start: 1.1 [0.58-2.32] μg/mL vs. 0.9 [0.45-2.10] μg/mL, P = 0.786). The rates of cardiac allograft rejection, 30-day mortality and 1-year survival were similar between the groups.

CONCLUSIONS

Intraoperative haemoadsorption was associated with better haemodynamic stability, mitigated PCT response, lower rates of post-operative AKI and RRT, more stable hepatic bilirubin excretion, and shorter durations of MV and ICU stay. Intraoperative haemoadsorption did not show any relevant adsorption effect on MPA. There was no increase in the frequency of early cardiac allograft rejection related to intraoperative haemoadsorption use.

Prognosis after heart transplant in patients with hypertrophic and restrictive cardiomyopathy. A nationwide registry analysis

INTRODUCTION AND OBJECTIVES

Posttransplant outcomes among recipients with a diagnosis of hypertrophic cardiomyopathy (HCM) or restrictive cardiomyopathy (RCM) remain controversial.

METHODS

Retrospective analysis of a nationwide registry of first-time recipients undergoing isolated heart transplant between 1984 and 2021. One-year and 5-year mortality in recipients with HCM and RCM were compared with those with dilated cardiomyopathy (DCM).

RESULTS

We included 3703 patients (3112 DCM; 331 HCM; 260 RCM) with a median follow-up of 5.0 [3.1-5.0] years. Compared with DCM, the adjusted 1-year mortality risk was: HCM: HR, 1.38; 95%CI, 1.07-1.78; P=.01, RCM: HR, 1.48; 95%CI, 1.14-1.93; P=.003. The adjusted 5-year mortality risk was: HCM: HR, 1.17; 95%CI, 0.93-1.47; P=.18; RCM: HR, 1.52; 95%CI, 1.22-1.89; P<.001. Over the last 20 years, the RCM group showed significant improvement in 1-year survival (adjusted R2=0.95) and 5-year survival (R2=0.88); the HCM group showed enhanced the 5-year survival (R2=0.59), but the 1-year survival remained stable (R2=0.16).

CONCLUSIONS

Both RCM and HCM were linked to a less favorable early posttransplant prognosis compared with DCM. However, at the 5-year mark, this unfavorable difference was evident only for RCM. Notably, a substantial temporal enhancement in both early and late mortality was observed for RCM, while for HCM, this improvement was mainly evident in late mortality.

3D Printing for Left Ventricular Assist Device Exchange: Insights From Real-World Experience

Left ventricular assist devices (LVADs) are used in end-stage heart failure. Inadequate positioning of the inflow cannula may necessitate replacement of the LVAD. We present the successful use of a three-dimensional printed model used to optimize surgical planning and allow for simulation and training for the LVAD exchange procedure.

Emergency Department Use and Hospital Mortality Among Heart Transplant Recipients in the United States

BACKGROUND

Annual heart transplant (HT) volumes have increased, as have post-HT outpatient care needs. Data on HT-related emergency department (ED) visits are limited.

METHODS AND RESULTS

A retrospective analysis of 177 450 HT patient ED visits from the 2009 to 2018 Nationwide Emergency Department Sample was conducted. HT recipients, primary diagnoses, and comorbidities associated with ED visits were identified via International Classification of Diseases, Ninth Revision (ICD-9) and International Classification of Diseases, Tenth Revision (ICD-10) codes. Multivariable logistic regression was used to predict outcomes of hospital admission and death. HT volumes and HT-related ED visits increased from 2009 to 2018. Infection was the most common primary diagnosis (24%), and cardiac primary diagnoses represented 10% of encounters. Hospital admissions occurred in 48% of visits, but overall mortality was low (1.6%). Length of stay was 3.1 days (interquartile range, 1.6-5.9 days), and comorbidity burden was high: 42% had hypertension, 38% had diabetes, and 31% had ≥2 comorbidities. Those aged ≥65 years had significantly higher odds of admission (odds ratio [OR], 2.14 [95% CI, 1.97-2.33]) and death (OR, 2.06 [95% CI, 1.61-2.62]). Comorbidities increased odds of admission (OR, 1.62 [95% CI, 1.51-1.75]) but not death. Renal primary diagnosis had the highest risk of admission (OR, 4.1 [95% CI, 3.6-4.6]), but cardiac primary diagnosis had the highest odds of death (OR, 11.6 [95% CI, 9.1-14.8]).

CONCLUSIONS

HT-related ED visits increased from 2009 to 2018 with high admission rates but low in-hospital mortality, suggesting an opportunity to improve prehospital care. Older patients and those with cardiac primary diagnoses had the highest risk of death. The observed contrast between predictors of admission and mortality signals a need for further study to improve risk stratification and outpatient care strategies.

Heart Retransplantation Under the 2018 Adult Heart Allocation Policy

BACKGROUND

The purpose of the present study was to characterize the impact of the 2018 adult heart allocation policy change on waiting list and posttransplant outcomes of heart retransplantation in the United States.

METHODS

All adults listed for heart retransplantation from May 2015 to June 2022 were identified using the United Network for Organ Sharing database. Patients were stratified into eras (era 1 and era 2) based on the heart allocation change on October 18, 2018. Competing risks regressions and Cox proportional hazards models were used to assess differences across eras in waiting list outcomes and 1-year posttransplant survival, respectively.

RESULTS

The analysis included 356 repeat heart transplant recipients, with 207 (58%) receiving retransplantation during era 2. Patients who received a retransplant in era 2 were more commonly bridged with extracorporeal membrane oxygenation (21% vs 8%, P < .01) and intra-aortic balloon pump (29% vs 13%, P < .001) and had a lower likelihood of death/deterioration on the waiting list (subdistribution hazard ratio, 0.52; 95% CI, 0.33-0.82) compared with those in era 1. Rates of 30-day mortality (7% vs 7%, P = .99) and 1-year survival (82% vs 87%, P = .27) were not significantly different among retransplantation recipients across eras. After adjustment, retransplantation in era 2 was not associated with an increased hazard of mortality (adjusted hazard ratio, 1.13; 95% CI, 0.55-2.30). The gap in 1-year mortality between primary transplant and retransplant recipients increased from era 1 to 2.

CONCLUSIONS

Heart retransplantation candidates have experienced improved waiting list outcomes after the 2018 adult heart allocation policy, without significant changes to posttransplant survival.

Summary of a consensus conference on heart-liver transplantation

Patients with severe heart disease may have coexisting liver disease from various causes. The incidence of combined heart-liver transplant (CHLT) is increasing as more patients with congenital heart disease survive to adulthood and develop advanced heart failure with associated liver disease from chronic right-sided heart or Fontan failure. However, the criteria for CHLT have not been established. To address this unmet need, a virtual consensus conference was organized on June 10, 2022, endorsed by the American Society of Transplantation. The conference represented a collaborative effort by experts in cardiothoracic and liver transplantation from across the United States to assess interdisciplinary criteria for liver transplantation in the CHLT candidate, surgical considerations of CHLT, current allocation system that generally results in the liver following the heart for CHLT, and optimal post-CHLT management. The conference served as a forum to unify criteria between the different specialties and to forge a pathway for patients who may need dual organ transplantation. Due to the continuing shortage of available donor organs, ethical issues related to multiorgan transplantation were also debated. The findings and consensus statements are presented.

Digital pathology in cardiac transplant diagnostics: from biopsies to algorithms

In the field of heart transplantation, the ability to accurately and promptly diagnose cardiac allograft rejection is crucial. This comprehensive review explores the transformative role of digital pathology and computational pathology, especially through machine learning, in this critical domain. These methodologies harness large datasets to extract subtle patterns and valuable information that extend beyond human perceptual capabilities, potentially enhancing diagnostic outcomes. Current research indicates that these computer-based systems could offer accuracy and performance matching, or even exceeding, that of expert pathologists, thereby introducing more objectivity and reducing observer variability. Despite promising results, several challenges such as limited sample sizes, diverse data sources, and the absence of standardized protocols pose significant barriers to the widespread adoption of these techniques. The future of digital pathology in heart transplantation diagnostics depends on utilizing larger, more diverse patient cohorts, standardizing data collection, processing, and evaluation protocols, and fostering collaborative research efforts. The integration of various data types, including clinical, demographic, and imaging information, could further refine diagnostic precision. As researchers address these challenges and promote collaborative efforts, digital pathology has the potential to become an integral part of clinical practice, ultimately improving patient care in heart transplantation.

Heart transplantation: advances in expanding the donor pool and xenotransplantation

Approximately 65 million adults globally have heart failure, and the prevalence is expected to increase substantially with ageing populations. Despite advances in pharmacological and device therapy of heart failure, long-term morbidity and mortality remain high. Many patients progress to advanced heart failure and develop persistently severe symptoms. Heart transplantation remains the gold-standard therapy to improve the quality of life, functional status and survival of these patients. However, there is a large imbalance between the supply of organs and the demand for heart transplants. Therefore, expanding the donor pool is essential to reduce mortality while on the waiting list and improve clinical outcomes in this patient population. A shift has occurred to consider the use of organs from donors with hepatitis C virus, HIV or SARS-CoV-2 infection. Other advances in this field have also expanded the donor pool, including opt-out donation policies, organ donation after circulatory death and xenotransplantation. We provide a comprehensive overview of these various novel strategies, provide objective data on their safety and efficacy, and discuss some of the unresolved issues and controversies of each approach.

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.

Conversion to tacrolimus alone compared to full immunosuppression following cardiac transplantation (TACTFUL)

BACKGROUND

Cardiac transplantation requires lifelong immunosuppressant medications to prevent rejection. However, some patients may not tolerate multiple immunosuppressants due to adverse effects. At our institution, patients may be converted to monotherapy with tacrolimus if unable to tolerate a combination regimen. This study evaluated the outcomes among patients converted to tacrolimus monotherapy compared with those maintained on combination immunosuppression.

METHODS

This single-center, retrospective cohort study included patients who received heart transplants at Sentara Norfolk General Hospital between January 2015 and July 2021. Patients were classified as receiving tacrolimus monotherapy (Mono) or combination immunosuppression (Combo). The primary outcome was all-cause mortality with key secondary outcomes including incidence of 2R/3R rejection, necessity for renal replacement therapy, and infection.

RESULTS

112 patients were included (Mono = 25, Combo = 87). Median age at transplant was 53.8 years (Mono) and 52.1 years (Combo). The most common reasons for conversion to monotherapy were leukopenia, infection, and gastrointestinal (GI) distress. There was no difference in mortality (0 in Mono, 11 in Combo; p = .09) or percentage of patients with 2R/3R rejection (24% in Mono, 32.2% in Combo; p = .43). No Mono group patients experienced rejection after converting from combination therapy. 24% of Mono group patients resumed at least one additional immunosuppressive medication during the study period. Median time to monotherapy was 9.0 months, with a total median duration on monotherapy of 16.0 months. A median of 3.3 years of follow-up was observed for patients in Mono and 3.4 years in Combo (p = .29).

CONCLUSION

Selected patients who do not tolerate combination immunosuppression can be safely transitioned to tacrolimus monotherapy as a means of controlling adverse events without an increased risk of mortality or rejection.

Impact of Type 2 Diabetes on the Outcomes of Solid Organ Transplantations in the U.S.: Data From a National Registry

OBJECTIVE

Type 2 diabetes (T2D) is a major driver of chronic diseases around the globe. The aim was to assess the impact of T2D on the outcomes of solid organ transplantations.

RESEARCH DESIGN AND METHODS

We used the Scientific Registry of Transplant Recipients from 2006 to 2021 to collect data for all patients age ≥18 years who received a lung, heart, liver, or kidney transplant in the U.S.

RESULTS

We included 462,692 solid organ transplant recipients: 31,503 lung, 38,004 heart, 106,639 liver, and 286,440 kidney transplantations. The prevalence of pretransplantation T2D was 15% in lung, 26% in heart, 25% in liver, and 30% in kidney transplant recipients, increasing over time. Posttransplantation mortality was significantly higher among transplant recipients with T2D versus those without T2D (lung 32.1% vs. 29.3% [3 years], 46.4% vs. 42.6% [5 years]; P < 0.01; heart 11.2% vs. 9.1% [1 year], 24.4% vs. 20.6% [5 years]; P < 0.0001; liver 10.6% vs. 8.9% [1 year], 26.2% vs. 22.0% [5 years]; P < 0.0001; kidney 5.3% vs. 2.5% [1 year], 20.8% vs. 10.1% [5 years]; P < 0.0001). Independent association of pretransplantation T2D with higher posttransplantation mortality was significant after adjustment for clinicodemographic confounders (adjusted hazard ratio in lung transplant recipients 1.08 [95% CI 1.03-1.13]; heart 1.26 [1.20-1.32]; liver 1.25 [1.21-1.28]; kidney 1.65 [1.62-1.68]; P < 0.01).

CONCLUSIONS

The prevalence of T2D in solid organ transplantation candidates is increasing. In all solid organ transplantations, pretransplantation T2D was independently associated with higher posttransplantation mortality, most profoundly in kidney transplantations.

Improved donor lung size matching by estimation of lung volumes based on chest X-ray measurements

RATIONALE

Organ size matching is an important determinant of successful allocation and outcomes in lung transplantation. While computed tomography (CT) is the gold standard, it is rarely used in an organ-donor context, and chest X-ray (CXR) may offer a practical and accurate solution in estimating lung volumes for donor and recipient size matching. We compared CXR lung measurements to CT-measured lung volumes and traditional estimates of lung volume in the same subjects.

METHODS

Our retrospective study analyzed clinically obtained CXR and CT lung images of 250 subjects without evidence of lung disease (mean age 9.9 ± 7.8 years; 129 M/121F). From CT, each lung was semi-automatically segmented and total lung volumes were quantified. From anterior-posterior CXR view, each lung was manually segmented and areas were measured. Lung lengths from the apices to the mid-basal regions of each lung were measured from CXR. Quantified CT lung volumes were compared to the corresponding CXR lung lengths, CXR lung areas, height, weight, and predicted total lung capacity (pTLC).

RESULTS

There are strong and significant correlations between CT volumes and CXR lung areas in the right lung (R2  = .89, p < .0001), left lung (R2  = .87, p < .0001), and combined lungs (R2  = .89, p < .0001). Similar correlations were seen between CT volumes and CXR measured lung lengths in the right lung (R2  = .79, p < .0001) and left lung (R2  = .81, p < .0001). This correlation between anatomical lung volume (CT) and CXR was stronger than lung-volume correlation to height (R2  = .66, p < .0001), weight (R2  = .43, p < .0001), or pTLC (R2  = .66, p < .0001).

CONCLUSION

CXR measures correlate much more strongly with true lung volumes than height, weight, or pTLC. The ability to obtain efficient and more accurate lung volume via CXR has the potential to change our current listing practices of using height as a surrogate for lung size, with a case example provided.

Major adverse kidney events predict reduced survival in ventricular assist device supported patients

AIMS

There is limited data describing major adverse kidney events (MAKE) in patients supported with ventricular assist devices (VAD). We aim to describe the association between MAKE and survival, risk factors for MAKE, and renal trajectory in VAD supported patients.

METHODS AND RESULTS

We conducted a single-centre retrospective analysis of consecutive VAD implants between 2010 and 2019. Baseline demographics, biochemistry, and adverse events were collected for the duration of VAD support. MAKE was defined as the first event to occur of sustained drop (>50%) in estimated glomerular filtration rate (eGFR), progression to stage V chronic kidney disease, initiation or continuation of renal replacement therapy beyond implant admission or death on renal replacement therapy at any time. One-hundred and seventy-three patients were included, median age 56.8 years, 18.5% female, INTERMACS profile 1 or 2 in 75.1%. Thirty-seven patients experienced MAKE. On multivariate analysis, post-implant clinical right ventricular failure and the presence of chronic haemolysis, defined by the presence of schistocytes on blood film analysis, were significantly associated with increased risk of MAKE (adjusted odds ratio 9.88, P < 0.001 and adjusted odds ratio 3.33, P = 0.006, respectively). MAKE was associated with reduced survival (hazard ratio 4.80, P < 0.001). Patients who died or experienced MAKE did not demonstrate the expected transient 3-month improvement in eGFR, seen in other cohorts.

CONCLUSIONS

MAKE significantly impacts survival. In our cohort, MAKE was predicted by post-implant right ventricular failure and chronic haemolysis. The lack of early eGFR improvement on VAD support may indicate higher risk for MAKE.

Advanced Heart Failure Characteristics and Outcomes in Commercially Insured U.S. Adults

BACKGROUND

The characteristics and outcomes of patients with advanced heart failure (HF) have been poorly defined due to challenges in applying the complex advanced HF definition broadly to populations.

OBJECTIVES

In this study, the authors sought to apply a validated advanced HF algorithm to a large U.S. administrative claims database and describe the population and use of advanced HF therapies.

METHODS

This study included adults with advanced HF identified in the OptumLabs Data Warehouse from 2009 to 2019. The algorithm for advanced HF required 2 hospitalizations for HF plus 1 additional sign of advanced HF in a 12-month period. The association of baseline characteristics with mortality was examined with the use of Cox proportional hazards models. Associations of patient characteristics with advanced therapies were estimated with the use of cause-specific Cox proportional hazard models.

RESULTS

In 60,197 patients identified with advanced HF, the mean age was 73 years, 51.5% were men, and 64.3% were non-Hispanic White, 1.9% Asian, 21.2% Black, and 8.2% Hispanic. The median survival with advanced HF was 2.0 years (IQR: 0.4-5.5 years). Differences in mortality and use of advanced therapies by age, sex, and race/ethnicity were observed. Adjusted mortality was higher in patients who were older, male, non-Hispanic White, and from rural areas (P < 0.05 for all). Advanced therapies were used less in older patients and women (P < 0.05 for both). Black patients were more likely to be treated with a left ventricular assist device (P = 0.010) but less likely to receive a heart transplant compared with White patients (P = 0.034).

CONCLUSIONS

In U.S. adults with advanced HF, variation in outcomes and use of advanced therapies exist by age, sex, and race/ethnicity.

Conversion between sirolimus and everolimus in heart transplant recipients

BACKGROUND

Sirolimus and everolimus are mechanistic target of rapamycin inhibitors (mTORi) that may be included in immunosuppression regimens for orthotopic heart transplant (OHT) recipients. mTORi play a role in slowing progression of cardiac allograft vasculopathy; however, they have poor tolerability, sometimes necessitating a change between agents or therapies. The literature surrounding a conversion between mTORi are incongruent, thus this study was designed to assess the concentration/dose ratio for each medication around the time of conversion to provide guidance for a conversion strategy between mTORi.

METHODS

We conducted a retrospective study of adult OHT recipients who were maintained on both sirolimus- and everolimus-based immunosuppression regimens. The primary outcome was the concentration/dose (C/d) ratio of sirolimus to everolimus. Secondary outcomes included changes in hematologic and lipid labs and patient-reported intolerances.

RESULTS

The C/d ratio of sirolimus was 4.42, whereas the everolimus ratio was 2.23, resulting in a sirolimus: everolimus ratio of 1.98. Secondarily, after converting between mTORi, 93% of patients who reported intolerance(s) to one agent had a resolution of that intolerance. In our patient population, everolimus appeared better tolerated than sirolimus, with significantly more patients having no reported intolerances and significantly fewer patients experiencing edema. Other lab values were similar between patients receiving sirolimus and everolimus, except for an increased hemoglobin level in those receiving everolimus.

CONCLUSIONS

The conversion ratio of 1:2 observed in our population suggests OHT recipients may require an increased dose of EVL compared with SRL to maintain the same goal trough levels. A conversion between mTORi appeared to improve tolerability and did not lead to clinically significant worsening of any measured lab value.

Technology Usage, Physical Activity, and Motivation in Patients With Heart Failure and Heart Transplantation

The cross-sectional study enrolled 231 patients with heart failure (n = 115; 60.87% were men; mean age, 74.34 ± 12.70 years) and heart transplantation (n = 116; 72.41% were men; mean age, 56.85 ± 11.87 years) who self-reported their technology usage, physical activity, and source of motivation for exercise. Patients with heart failure were significantly older ( P = .0001) than patients with heart transplantation. Physical activity levels in patients with heart failure decreased as the New York Heart Association classification increased. Patients with heart failure reported significantly lower physical activity than patients with heart transplantation ( P = .0008). Smartphones were the most widely used electronic device to access the Internet in both groups. Patients with heart transplantation seemed to use more than one device to access the Internet. In both groups, patients reporting more technology usage also reported higher levels of physical activity. Patients who accessed the Internet daily reported lower levels of physical activity. Whereas patients with heart failure identified encouragement by family members as a source of motivation for exercise, patients with heart transplantation reported that they were likely to exercise if motivated by their healthcare provider. Patients with heart failure and heart transplantation have unique technological and motivational needs that need consideration for mobile health-driven interventions.

The impact of obesity and LVAD-bridging on heart transplant candidate outcomes: a linked STS INTERMACS - OPTN/UNOS data analysis

BACKGROUND

Limited data integrating waitlist and postheart transplant (HT) mortality have evaluated outcomes of left ventricular assist device (LVAD)-bridged strategy vs no LVAD according to patient characteristics. We evaluated waitlist and post-HT mortality in LVAD-bridged vs nonbridged patients based on body mass index (BMI).

METHODS

We included linked adults listed for HT in Organ Procurement and Transplant Network/United Network for Organ Sharing and patients receiving durable LVAD as bridge to HT or candidacy in Society of Thoracic Surgeons/Interagency Mechanical Circulatory Support databases (2010-2019). Using BMI at listing or LVAD implant, we categorized patients as underweight (<18.5 kg/m2), normal weight (18.5-24.99 kg/m2), overweight (25-29.99 kg/m2), and obese (≥30 kg/m2). Kaplan-Meier analysis and multivariable Cox proportional hazards models informed the effect of LVAD-bridged and nonbridged strategy by BMI on waitlist, post-HT, and overall mortality (including waitlist and post-HT mortality).

RESULTS

Among 11,216 LVAD-bridged and 17,122 nonbridged candidates, bridged candidates were more frequently obese (37.3% vs 28.6%) (p < 0.001). Multivariable analysis indicated increased waitlist mortality in LVAD-bridged vs nonbridged with overweight (Hazard ratio (HR) 1.18, 95% confidence interval (CI) 1.02-1.36) or obesity (HR 1.35, 95%CI 1.17-1.56) in comparison to normal weight candidates (HR 1.02, 95%CI 0.88-1.19) (p-interaction < 0.001). Post-transplant mortality was not statistically different in LVAD-bridged vs nonbridged patients across BMI categories (p-interaction = 0.26). There was a nonsignificant graded increase in overall mortality in LVAD-bridged with overweight (HR 1.53, 95%CI 1.39-1.68) or obesity (HR 1.61, 95%CI 1.46-1.78) compared to nonbridged patients (p-interaction = 0.13).

CONCLUSIONS

LVAD-bridged candidates with obesity had higher waitlist mortality compared to nonbridged candidates with obesity. Post-transplant mortality was similar in LVAD-bridged and nonbridged patients, but obesity remained associated with increased mortality in both groups. This study may aid clinicians and advanced heart failure patients with obesity in decision-making.

Perioperative Management of Heart Transplantation: A Clinical Review

In this clinical review, the authors summarize the perioperative management of heart transplant patients with a focus on hemodynamics, immunosuppressive strategies, hemostasis and hemorrage, and the prevention and treatment of infectious complications.

Three year post heart transplant outcomes of desensitized durable mechanical circulatory support patients

BACKGROUND

The risks and benefits of desensitization therapy (DST) in highly sensitized mechanical circulatory support (MCS) patients are not well known. We investigated 3 year post-transplant outcomes of desensitized durable MCS patients.

METHODS

Among 689 consecutively enrolled heart transplantation recipients between 2010 and 2016, we categorized them into Group A (desensitized MCS patients, n = 21), Group B (desensitized non-MCS patients, n = 28) and Group C (all nondesensitized patients, n = 640). Post-transplant outcomes included the incidence of primary graft dysfunction, 3-year survival, freedom from cardiac allograft vasculopathy, nonfatal major adverse cardiac events, any treated rejection, acute cellular rejection, antibody mediated rejection (AMR) and infectious complications.

RESULTS

The types of DST in Groups A and B were similar and included combinations of rituximab/intravenous immunoglobulin and plasmapheresis/bortezomib. Group A, compared with Group B, showed significantly higher pre-DST panel reactive antibody (PRA) (92.2 ± 9.8 vs. 83.3 ± 15.6, P = 0.007) and higher PRA reduction after DST (-22.2 ± 26.9 vs. -6.3 ± 7.5, P = 0.015). Groups A and C showed comparable primary graft dysfunction, 3-year survival, freedom from cardiac allograft vasculopathy, nonfatal major adverse cardiac events, any treated rejection, acute cellular rejection, and AMR. Although statistically not significant, Group A showed numerically higher 3-year freedom from AMR than Group B. Infectious complications were similar in both Groups A and B.

CONCLUSIONS

DST for MCS patients showed significant PRA reduction, resulting in an expansion of the donor pool. The post-transplant outcome of desensitized MCS patients showed comparable clinical outcomes to non-desensitized control patients in the same study period, revealing the safety and efficacy of DST.

Cardiac transplantation in adult congenital heart disease: a narrative review

Background and Objective

As more children with congenital heart disease survive to adulthood, adult congenital heart disease (ACHD) prevalence will increase (currently ~1 million US patients). Heart failure (HF) accounts for 26-42% of ACHD deaths. The rate of ACHD heart transplantations (ACHD HTx) is also increasing. We describe the ACHD HTx recipient/candidate cohort, analyze ACHD HTx outcomes, identify ACHD HTx specific challenges, and discuss opportunities to better serve more patients with ACHD HF.

Methods

PubMed literature search including articles published from 2010-2023. Reviewed 89 studies, 67 included. Our search focused on the challenges of ACHD HTx and potential solutions.

Key Content and Findings

ACHD HTx recipients are young [median age 35 years, interquartile range (IQR): 24-46 years]. 87-95% of ACHD HTx recipients had prior cardiac surgery. The most common underlying diagnoses include transposition of the great arteries (31%) and Fontan/Glenn circulation (28%). 63% of listed ACHD HTx candidates received a transplant within one year of listing. Post-transplant 1-year survival is 80%, 5-year survival 74%, and 10-year survival 59%. There are 4 unique ACHD HTx challenges: (I) difficulty in assessing pulmonary hypertension, resulting in some centers selecting oversized donor hearts. However, selecting oversized hearts does not improve post-operative mortality and could prolong waitlist time. (II) Increased immunologic sensitization, increasing rejection risk. Desensitization therapy has enabled sensitized HTx recipients to enjoy outcomes similar to non-sensitized recipients. (III) Procedural complexity with ~30% of cases requiring additional surgical reconstruction. Detailed multidisciplinary planning, extensive imaging, and transferring the patient into the operating room early can help manage the complexities and reduce organ ischemic time. (IV) Increased intraoperative bleeding due to patients' surgical histories and circulatory collaterals. Preoperative collateral coil embolization and select utilization of hypothermic circulatory arrest can help reduce bleeding. Additional Fontan specific challenges include extensive great artery repair, liver failure, plastic bronchitis, and protein loss enteropathy. Finally, given limited donor heart availability, mechanical circulatory support is a promising technology for patients with ACHD HF.

Conclusions

The prevalence of ACHD HTx is slowly but steadily increasing. The operational complexity of ACHD HTx can be managed, and the majority of recipients have excellent outcomes (59% 10-year survival).

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

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

Unsupervised mRNA-seq classification of heart transplant endomyocardial biopsies

BACKGROUND

Endomyocardial biopsy (EMB) is currently considered the gold standard for diagnosing cardiac allograft rejection. However, significant limitations related to histological interpretation variability are well-recognized. We sought to develop a methodology to evaluate EMB solely based on gene expression, without relying on histology interpretation.

METHODS

Sixty-four EMBs were obtained from 47 post-heart transplant recipients, who were evaluated for allograft rejection. EMBs were subjected to mRNA sequencing, in which an unsupervised classification algorithm was used to identify the molecular signatures that best classified the EMBs. Cytokine and natriuretic peptide peripheral blood profiling was also performed. Subsequently, we performed gene network analysis to identify the gene modules and gene ontology to understand their biological relevance. We correlated our findings with the unsupervised and histological classifications.

RESULTS

Our algorithm classifies EMBs into three categories based solely on clusters of gene expression: unsupervised classes 1, 2, and 3. Unsupervised and histological classifications were closely related, with stronger gene module-phenotype correlations for the unsupervised classes. Gene ontology enrichment analysis revealed processes impacting on the regulation of cardiac and mitochondrial function, immune response, and tissue injury response. Significant levels of cytokines and natriuretic peptides were detected following the unsupervised classification.

CONCLUSION

We have developed an unsupervised algorithm that classifies EMBs into three distinct categories, without relying on histology interpretation. These categories were highly correlated with mitochondrial, immune, and tissue injury response. Significant cytokine and natriuretic peptide levels were detected within the unsupervised classification. If further validated, the unsupervised classification could offer a more objective EMB evaluation.

Heart Transplantation: Indications, Surgical Techniques, and Complications

Heart transplantation has been increasingly performed for patients with end-stage heart failure most commonly related to ischemic and non-ischemic cardiomyopathies. The major complications are procedure-related complications, infection, acute rejection, cardiac allograft vasculopathy, and malignancy. Radiologists have an important role in the evaluation of transplant candidates and early detection of postoperative complications.

Comparison of Veno-arterial Extracorporeal Membrane Oxygenation Configurations for Patients Listed for Heart Transplantation

BACKGROUND AND OBJECTIVES

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as a bridge to eventual heart transplantation (HT) is increasingly used worldwide. However, the effect of different VA-ECMO types on HT outcomes remains unclear.

METHODS

This was a retrospective observational study of 111 patients receiving VA-ECMO and awaiting HT. We assessed 3 ECMO configuration groups: peripheral (n=76), central (n=12), and peripheral to central ECMO conversion (n=23). Cox proportional hazards regression and landmark analysis were conducted to analyze the effect of the ECMO configuration on HT and in-hospital mortality rates. We also evaluated adverse events during ECMO support.

RESULTS

HT was performed in the peripheral (n=48, 63.2%), central (n=10, 83.3%), and conversion (n=11, 47.8%) ECMO groups (p=0.133) with a median interval of 10.5, 16, and 30 days, respectively (p<0.001). The cumulative incidence of HT was significantly lower in the conversion group (hazard ratio, 0.292, 95% confidence interval, 0.145-0.586, p=0.001). However, there was no difference in in-hospital mortality (log-rank p=0.433). In the landmark analysis, in-hospital mortality did not differ significantly among the 3 groups. Although we did note a trend toward lower HT in the conversion group, the difference was not statistically significant. Surgical site bleeding occurred mainly in the central, while limb ischemia occurred mainly in the peripheral groups.

CONCLUSIONS

We suggest that if patients are being stably supported with their initial ECMO configuration, whether it is central or peripheral, it should be maintained, and ECMO conversion should only be cautiously performed when necessary.

European multicenter study on the real-world use and clinical impact of extracorporeal photopheresis after heart transplantation

BACKGROUND

Aim of this study was to describe the real-world use of extracorporeal photopheresis (ECP) and assess its impact on clinical outcomes in the modern era of heart transplantation.

METHODS

Seven transplant centers from 5 European countries participated in this retrospective, observational, single-arm chart review study. All patients received ECP after heart transplantation in 2015 or later. Data were extracted from medical records between November 2020 and December 2021.

RESULTS

Overall, 105 patients were enrolled and followed for an average of 2 years after initiation of ECP. Reasons to start ECP were acute cellular rejection (35.2%), rejection prevention (32.4%), mixed rejection (18.1%), and antibody-mediated rejection (14.3%). Rejection ISHLT grades improved from start to end of ECP treatment in 92% of patients treated with ECP for rejection. Of patients who started ECP to prevent rejection, 88% remained free from any rejection despite a reduction of calcineurin inhibitors. Overall survival was 95%, and no deaths were related to ECP. Safety events occurred in 18 patients, of which 13 experienced complications with venous access.

CONCLUSIONS

This study, the largest European ECP study in heart transplantation, demonstrates that ECP can effectively be used to treat different rejection types and to prevent rejection in the modern era of immunosuppression. Patients with rejections who have received ECP have shown high response as measured by histological improvements in ISHLT classification. A high percentage of patients in the prevention group remained free from rejection despite reduction in immunosuppression, in particular calcineurin inhibitors.

Heart transplantation from donation after circulatory death: Impact on waitlist time and transplant rate

The effect of using donation after circulatory death (DCD) hearts on waitlist outcomes has not been substantiated. We retrospectively analyzed 184 heart transplant (HT) candidates at our institution from 2019 to 2021. Patients were stratified into 2 observation periods centered on September 12, 2020, when the adult DCD HT program officially began. The primary outcome was a comparison of transplant rate between period 1 (pre-DCD) and period 2 (post-DCD). Secondary outcomes included waitlist time-to-transplant, waitlist mortality rate, independent predictors of incidence of HT, and posttransplant outcomes. A total of 165 HTs (n = 92 in period 1 and n = 73 in period 2) were performed. The median waitlist time-to-transplant decreased from 47.5 to 19 days in periods 1 and 2, respectively (P = .004). The transplant rate increased from 181 per 100 patient-years in period 1 to 579 per 100 patient-years in period 2 (incidence rate ratio, 1.87; 95% CI, 1.04-3.38; P = .038). There were no statistical differences in waitlist mortality rate (P = .566) and 1-year survival (P = .699) between the 2 periods. DCD HTs (n = 36) contributed to 49.3% of overall HT activity in period 2. We concluded that utilization of DCD hearts significantly reduced waitlist time and increased transplant rate. Short-term posttransplant outcomes were comparable between the pre-DCD and post-DCD periods.

Heart retransplant recipients with renal dysfunction benefit from simultaneous heart-kidney transplantation

BACKGROUND

Given ongoing donor shortages, appropriate patient selection for dual-organ transplantation is critical. We evaluated outcomes of heart retransplant with simultaneous kidney transplant (HRT-KT) vs isolated heart retransplant (HRT) across varying levels of renal dysfunction.

METHODS

The United Network for Organ Sharing database identified 1189 adult patients undergoing heart retransplantation between 2005 and 2020. Recipients undergoing HRT-KT (n = 251) were compared to those undergoing HRT (n = 938). The primary outcome was 5-year survival; subgroup analyses and multivariable adjustment were performed utilizing the following 3 estimated glomerular filtration (eGFR) groups: <30 ml/min/1.73m2, 30-45 ml/min/1.73m2, and >45 ml/min/1.73m2.

RESULTS

HRT-KT recipients were older and had longer waitlist times, longer inter-transplant periods, and lower eGFR levels. HRT-KT recipients were less likely to require pretransplant ventilator (1.2% vs 9.0%, p < 0.001) or ECMO (2.0% vs 8.3%, p < 0.001) support but were more likely to have severe functional limitation (63.4% vs 52.6%, p = 0.001). After retransplantation, HRT-KT recipients had less treated acute rejection (5.2% vs 9.3%, p = 0.02) and more dialysis requirement (29.1% vs 20.2%, p < 0.001) before discharge. Survival at 5-years was 69.1% after HRT and 80.5% after HRT-KT (p < 0.001). After adjustment, HRT-KT was associated with improved 5-year survival among recipients with eGFR <30 ml/min/1.73m2 (HR:0.42, 95% CI: 0.26-0.67) and 30 to 45 ml/min/1.73m2 (HR:0.29, 95% CI 0.13-0.65), but not among those with eGFR>45 ml/min/1.73sm2 (HR 0.68, 95% CI 0.30-1.54).

CONCLUSION

Simultaneous kidney transplantation is associated with improved survival following heart retransplantation in patients with eGFR <45 ml/min/1.73m2 and should be strongly considered to optimize organ allocation stewardship.