Association of recipient age and causes of heart transplant mortality: Implications for personalization of post-transplant management—An analysis of the International Society for Heart and Lung Transplantation Registry

Implications of Preoperative C-Reactive Protein Levels in Heart Transplant Patients-A Single-Center Retrospective Study

Background: Heart transplant is the final therapeutic option for end-stage heart failure patients. It has been used with increasing success as a surgical procedure, greatly influenced by advances in diagnostic and prognostic tools. The aim of this paper was to study potential implications of C-reactive protein (CRP) in patients who underwent heart transplants. Methods: Our cohort included 43 adult patients from the Emergency Institute for Cardiovascular Diseases and Transplant of Târgu Mureș who underwent heart transplants in our center between 2011 and 2023. Correlations between CRP levels and different characteristics of the patients were investigated, and the optimal cut-off value for CRP levels in relation to the 6-month mortality rate was determined. The central tendencies of the baseline characteristics of patients who had a CRP value lower than the cut-off and those with a value higher than it were compared using parametric or nonparametric tests. Results: Significant correlations between the preoperative CRP levels and 6-month mortality rate (r = 0.35; 95%CI: 0.05-0.60; p = 0.02), as well as previous cardiac resynchronization therapy (CRT) and preoperative CRP levels (r = -0.37; 95%CI: -0.61--0.07, p = 0.01) were highlighted. A value for CRP > 1.66 mg/dL was found to be associated with 6-month mortality (OR = 18.00; 95%CI: 1.90-170.33, p < 0.01). Moreover, the patients who received CRT before transplantation had significantly lower levels of CRP when compared to those who did not receive CRT (p = 0.01). Conclusions: Preoperative CRP levels could represent a valuable asset in the follow-up algorithm of heart transplant patients. The lower levels of CRP in patients who benefited from CRT before transplantation highlights the importance of understanding the complex mechanisms of inflammation and increasing focus on device therapy for future transplant recipients. Further prospective studies with larger cohorts are needed for validation.

A gift of life, not immortality: Evaluation of a strategy of heart transplant listing in the older patient with advanced heart failure

Patients 65 years of age or older represent the fastest-growing demographic group added to the U.S. heart transplant (HT) list. While post-HT outcomes appear acceptable, immortal time bias is introduced if adverse outcomes that occur while waiting for HT are not considered. Recent durable left ventricular assist device (dLVAD) technological innovations have engendered the question of whether this patient subgroup would achieve equivalent survival from a strategy of primary dLVAD implant as opposed to HT listing. We identified adults ≥65 years of age listed for HT between 2018-2021, excluding persons with dLVAD support and/or multi-organ listing. Among 1176 patients, 2-year survival from HT listing was 78.4 ± 1.2%, similar to the 71% to 75% reported in The Society of Thoracic Surgeons (STS) Intermacs National Database for older adults. Linkage of the Scientific Registry of Transplant Recipients with STS Intermacs would enable comparative effectiveness analyses of surgical heart failure therapeutic strategies in high-risk patient cohorts.

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.

Donor Age More Than 20 Years Greater Than Recipient Age Is Associated With Worse 5-Year Survival in Young Adult Heart Transplantation

Prior studies indicate donor age-recipient age (DA-RA) difference may be of prognostic value in adolescents, although not adults. We aim to analyze the relationship between DA-RA difference and long-term survival of young adult heart transplantation (HTx) recipients. First-time, single-organ HTx recipients aged 18-30 who underwent HTx between 2010 and 2020 were analyzed from the United Network for Organ Sharing (UNOS) registry. Four cohorts were created based on DA-RA difference. The primary outcome was 5 year post-HTx survival. Secondary outcome was post-HTx complications. One thousand eight hundred three donor-recipient pairs were divided into four groups: DA-RA < 0, 0 ≤ DA-RA < 10, 10 ≤ DA-RA < 20, and DA-RA ≥ 20 with 682 (37.8%), 651 (36.1%), 356 (19.7%), 114 (6.3%) pairs in each cohort, respectively. The estimated 5 year survival of the DA-RA ≥ 20 cohort was 66.5% compared to the other three groups at ~75%. After adjustment, DA-RA ≥ 20 was independently associated with worse survival compared to DA-RA < 0 (adjusted hazard ratio [HR] = 1.55; 95% confidence interval [CI] = 1.06-2.27; log-rank p = 0.008). There was no significant difference in complication incidence across cohorts. Among young adults, accepting a donor heart more than 20 years older than the recipient was associated with worse 5 year survival. We did not detect a significant difference up to 20 years. This information may help guide appropriate donor selection in the young adult population.

Donor and Recipient Age Influence Outcomes Following Orthotopic Heart Transplantation in the 2018 US Heart Allocation System

BACKGROUND

This study evaluates the interaction of donor and recipient age with outcomes following heart transplantation under the 2018 heart allocation system.

METHODS

The United Network for Organ Sharing registry was queried to analyze adult primary isolated orthotopic heart transplant recipients and associated donors from August 18, 2018, to June 30, 2021. Both recipient and donor cohorts were grouped according to age: <65 and ≥65 y for recipients and <50 and ≥50 y for donors. The primary outcome was survival. Subanalyses were performed to evaluate the impact of donor age.

RESULTS

A total of 7601 recipients and 7601 donors were analyzed. Of these, 1584 recipients (20.8%) were ≥65 y old and 560 donors (7.4%) were ≥50 y old. Compared with recipients <65, recipients ≥65 had decreased 1-y (88.8% versus 92.3%) and 2-y (85.1% versus 88.5%) survival rates (P < 0.001). The association of recipient age ≥65 with lower survival persisted after adjusting for potential cofounders (hazard ratio, 1.38; 95% confidence interval, 1.18-1.61; P < 0.001). Recipients <65 with donors ≥50 had comparable 1-y and 2-y survival rates to recipients <65 with donors <50 (P =0.997). Conversely, transplantation of older allografts was associated with lower 1-y (84.2% versus 89.4%) and 2-y (79.5% versus 85.8%) survival rates in recipients ≥65 (P = 0.025).

CONCLUSIONS

Recipient age ≥65 continues to be associated with worse survival following heart transplantation in the 2018 heart allocation system compared with younger recipients. Donors ≥50 may be acceptable among recipients <65 with comparable outcomes. However, careful donor age selection should be considered for recipients ≥65, as the use of younger donor allografts appears to improve posttransplantation survival.

Revolutionizing Donor Heart Procurement: Innovations and Future Directions for Enhanced Transplantation Outcomes

Heart failure persists as a critical public health challenge, with heart transplantation esteemed as the optimal treatment for patients with end-stage heart failure. However, the limited availability of donor hearts presents a major obstacle to meeting patient needs. In recent years, the most groundbreaking progress in heart transplantation has been in donor heart procurement, significantly expanding the donor pool and enhancing clinical outcomes. This review comprehensively examines these advancements, including the resurgence of heart donation after circulatory death and innovative recovery and evaluation technologies such as normothermic machine perfusion and thoraco-abdominal normothermic regional perfusion. Additionally, novel preservation methods, including controlled hypothermic preservation and hypothermic oxygenated perfusion, are evaluated. The review also explores the use of extended-criteria donors, post-cardiopulmonary resuscitation donors, and high-risk donors, all contributing to increased donor availability without compromising outcomes. Future directions, such as xenotransplantation, biomarkers, and artificial intelligence in donor heart evaluation and procurement, are discussed. These innovations promise to address current limitations and optimize donor heart utilization, ultimately enhancing transplantation success. By identifying recent advancements and proposing future research directions, this review aims to provide insights into advancing heart transplantation and improving patient outcomes.

Tricuspid Annular Plane Systolic Excursion-to-Systolic Pulmonary Artery Pressure Ratio as a Prognostic Factor in Heart Transplant Patients

Background and Objectives: Heart transplant is currently the final step in treating patients with heart failure. The success of this procedure is strongly connected to potential complications such as postoperative heart failure, infections, graft rejection, graft vasculopathy, and kidney failure. Thus, identifying potential prognostic factors for patients' outcome is of utmost importance. We investigated the prognostic role of the postoperative ratio between the tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary artery pressure (sPAP) in patients who underwent heart transplantation in our center. Materials and Methods: The study included 46 adult patients from the Emergency Institute for Cardiovascular Diseases and Transplant of Târgu Mureș, who underwent heart transplant between January 2011 and April 2023. By the use of receiver operating characteristic (ROC) analysis, we determined an optimal cut-off value for TAPSE/sPAP with regard to survival at 6 months. Differences in central tendencies of baseline characteristics in those who had a value lower than the cut-off value of TAPSE/sPAP and those who presented a value above it were investigated using the corresponding parametric or nonparametric tests. Results: A value for TAPSE/sPAP above 0.47 mm/mmHg was associated with 6-month survival (OR: 59.5, CI: 5.7-616.0). No significant differences in central tendencies for baseline characteristics were found between the patients who had a TAPSE/sPAP ratio below the cut-off and those who had a ratio above it. Conclusions: The TAPSE/sPAP ratio might prove to be valuable in the early identification of at-risk heart transplant patients. Further prospective studies with larger cohorts are required for validation.

Employment Status Following Heart Transplantation: Data From the Danish Nationwide Social Service Payment Register During 20 years

Most studies on vocational rehabilitation after heart transplantation (HTX) are based on self-reported data. Danish registries include weekly longitudinal information on all public transfer payments. We intended to describe 20-year trends in employment status for the Danish heart-transplant recipients, and examine the influence of multimorbidity and socioeconomic position (SEP). Linking registry and Scandiatransplant data (1994-2018), we conducted a study in recipients of working age (19-63 years). The cohort contained 492 recipients (79% males) and the median (IQR) age was 52 years (43-57 years). Five years after HTX, 30% of the survived recipients participated on the labor market; 9% were in a flexible job with reduced health-related working capacity. Moreover, 60% were retired and 10% eligible for labor market participation were unemployed. Recipients with multimorbidity had a higher age and a lower prevalence of employment. Five years after HTX, characteristics of recipients with labor market participation were: living alone (27%) versus cohabitation (73%); low (36%) versus medium-high (64%) educational level; low (13%) or medium-high (87%) income group. Heart-transplant recipients with multimorbidity have a higher age and a lower prevalence of employment. Socioeconomically disadvantaged recipients had a lower prevalence of labor market participation, despite being younger compared with the socioeconomically advantaged.

Special Considerations for Advanced Heart Failure Surgeries: Durable Left Ventricular Devices and Heart Transplantation

Heart transplantation and durable left ventricular assist devices (LVADs) represent two definitive therapies for end-stage heart failure in the modern era. Despite technological advances, both treatment modalities continue to experience unique risks that impact surgical and perioperative decision-making. Here, we review special populations and factors that impact risk in LVAD and heart transplant surgery and examine critical decisions in the management of these patients. As both heart transplantation and the use of durable LVADs as destination therapy continue to increase, these considerations will be of increasing relevance in managing advanced heart failure and improving outcomes.

Role of HLA matching and donor specific antibody development in long-term survival, acute rejection and cardiac allograft vasculopathy

Although there are different data supporting benefits of HLA matching in kidney transplantation, its role in heart transplantation is still unclear. HLA mismatch (MM) between donor and recipient can lead to the development of donor-specific antibodies (DSA) which produces negative events on the outcome of heart transplantation. Moreover, DSAs are involved in the development of antibody-mediated rejection (AMR) and are associated with an increase in cardiac allograft vasculopathy (CAV). In this study it is analyzed retrospectively the influence of HLA matching and anti-HLA antibodies on overall survival, AMR and CAV in heart transplantation. For this retrospective study are recruited heart transplanted patients at the Cardiac Transplantation Centre of Naples between 2000 and 2019. Among the 155 heart transplant patients, the mean number of HLA-A, B, -DR MM (0 to 6) between donor and recipient was 4.5 ± 1.1. The results show a negative association between MM HLA-DR and survival (p = 0.01). Comparison of patients with 0-1 MM at each locus to all others with 2 MM, for both HLA class I and class II, has not showed significant differences in the development of CAV. Our analysis detected DSA in 38.1% of patients. The production of de novo DSA reveals that there is not an influence on survival (p = 0.72) and/or AMR (p = 0.39). Instead, there is an association between the production of DSA class II and the probability of CAV development (p = 0.03). Mean fluorescence intensity (MFI) values were significantly higher in CAV-positive patients that CAV-negative patients (p = 0.02). Prospective studies are needed to evaluate HLA class II matching as an additional parameter for heart allocation, especially considering the increment of waiting list time.

Outcomes of Lung Transplant Candidates Aged ≥70 Years During the Lung Allocation Score Era

BACKGROUND

With the increasing age of lung transplant candidates, we studied waitlist and posttransplantation outcomes of candidates ≥70 years during the Lung Allocation Score era.

METHODS

Adult lung transplant candidates from 2005 to 2020 in the United Network for Organ Sharing database were included and stratified on the basis of age at listing into 18 to 59 years old, 60 to 69 years old, and ≥70 years old. Baseline characteristics, waitlist outcomes, and posttransplantation outcomes were assessed.

RESULTS

A total of 37,623 candidates were included (52.3% aged 18-59 years, 40.6% aged 60-69 years, 7.1% aged ≥70 years). Candidates ≥70 years were more likely than younger candidates to receive a transplant (81.9% vs 72.7% [aged 60-69 years] vs 61.6% [aged 18-59 years]) and less likely to die or to deteriorate on the waitlist within 1 year (9.1% vs 10.1% [aged 60-69 years] vs 12.2% [aged 18-59 years]; P < .001). Donors for older recipients were more likely to be extended criteria (75.7% vs 70.1% [aged 60-69 years] vs 65.7% [aged 18-59 years]; P < .001). Recipients ≥70 years were found to have lower rates of acute rejection (6.7% vs 7.4% [aged 60-69 years] vs 9.2% [aged 18-59 years]; P < .001) and prolonged intubation (21.7% vs 27.4% [aged 60-69 years] vs 34.5% [aged 18-59 years]; P < .001). Recipients aged ≥70 years had increased 1-year (adjusted hazard ratio [aHR], 1.19 [95% CI, 1.06-1.33]; P < .001), 3-year (aHR, 1.28 [95% CI, 1.18-1.39]; P < .001), and 5-year mortality (aHR, 1.29 [95% CI, 1.21-1.38]; P < .001) compared with recipients aged 60 to 69 years.

CONCLUSIONS

Candidates ≥70 years had favorable waitlist and perioperative outcomes despite increased use of extended criteria donors. Careful selection of candidates and postoperative surveillance may improve posttransplantation survival in this population.

Correlation between peripheral endothelial function, oxygen consumption and ventilatory efficiency in heart transplantation recipients

BACKGROUND

Endothelial dysfunction and peak oxygen uptake (VO2peak) are also predictors of increased risk of cardiovascular events in heart transplantation (HTx) recipients. The preservation of endothelial function may contribute to exercise tolerance.

OBJECTIVE

To investigate the correlation between peripheral endothelial function and exercise tolerance through VO2peak and ventilation to carbon dioxide production slope (VE / VCO2 slope) in HTx recipients.

METHODS

A pilot cross-sectional study was conducted with adult individuals aged 18-65 years, HTx ≥ six months after surgery, who had a stable medical condition and no changes over the last three months of immunosuppressive treatment. The patients underwent an assessment of endothelial function through PAT (EndoPAT-2000®) and performed a cardiopulmonary exercise test (CPET).

RESULTS

A total of 41% of the studied population presented endothelial dysfunction. The individuals were divided into two groups: the endothelial dysfunction (GED; n=9) group and the normal endothelial function (GNEF; n=13) group according to the logarithm of the reactive hyperemia index (LnRHI). There was a positive and moderate correlation between the LnRHI and VO2 peak (r=0.659, p=0.013) and a negative and moderate correlation between the LnRHI and VE/VCO2 slope (r= -0.686, p= 0.009) in the GNEF. However, no significant correlations were found in the GED.

CONCLUSION

The results showed that the preservation of peripheral endothelial function is significantly correlated with an increase in exercise tolerance in individuals after HTx. These findings bring important considerations for cardiovascular risk prevention and emphasize that therapeutic strategies with physical training programs must be implemented early.

Textbook outcome: A novel metric in heart transplantation outcomes

OBJECTIVE

Assessing heart transplant program quality using short-term survival is insufficient. We define and validate the composite metric textbook outcome and examine its association with overall survival.

METHODS

We identified all primary, isolated adult heart transplants in the United Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research files from May 1, 2005, to December 31, 2017. Textbook outcome was defined as length of stay 30 days or less; ejection fraction greater than 50% during 1-year follow-up; functional status 80% to 100% at 1 year; freedom from acute rejection, dialysis, and stroke during the index hospitalization; and freedom from graft failure, dialysis, rejection, retransplantation, and mortality during the first year post-transplant. Univariate and multivariate analyses were performed. Factors independently associated with textbook outcome were used to create a predictive nomogram. Conditional survival at 1 year was measured.

RESULTS

A total of 24,620 patients were identified with 11,169 (45.4%, 95% confidence interval, 44.7-46.0) experiencing textbook outcome. Patients with textbook outcome were more likely free from preoperative mechanical support (odds ratio, 3.504, 95% confidence interval, 2.766 to 4.439, P < .001), free from preoperative dialysis (odds ratio, 2.295, 95% confidence interval, 1.868-2.819, P < .001), to be not hospitalized (odds ratio, 1.264, 95% confidence interval, 1.183-1.349, P < .001), to be nondiabetic (odds ratio, 1.187, 95% confidence interval, 1.113-1.266, P < .001), and to be nonsmokers (odds ratio, 1.160, 95% confidence interval,1.097-1.228, P < .001). Patients with textbook outcome have improved long-term survival relative to patients without textbook outcome who survive at least 1 year (hazard ratio for death, 0.547, 95% confidence interval, 0.504-0.593, P < .001).

CONCLUSIONS

Textbook outcome is an alternative means of examining heart transplant outcomes and is associated with long-term survival. The use of textbook outcome as an adjunctive metric provides a holistic view of patient and center outcomes.

Pharmacotherapy in the heart transplant recipient: A primer for nurse clinicians and pharmacists

Heart transplantation (HT) is the definitive treatment for eligible patients with end-stage heart disease. A major complication of HT is allograft rejection which can lead to graft dysfunction and death. The guiding principle of chronic immunosuppression therapy is to prevent rejection of the transplanted organ while avoiding oversuppression of the immune system, which can cause opportunistic infections and malignancy. The purpose of this review is to describe immunosuppressive management of the HT recipient-including agent-specific pharmacology and pharmacokinetics, outcomes data, adverse effects, clinical considerations, and recent guideline updates. We will also provide recommendations for medical prophylaxis of immunosuppressed patients based on the most recent clinical guidelines. Additionally, we highlight the importance of medical therapy adherence and the effect of social determinants of health on the long-term management of HT. HT recipients are a complex and high-risk population. The objective of this review is to describe basic pharmacotherapy in HT and implications for nurses and pharmacists.

Rejection Requiring Treatment within the First Year following Heart Transplantation: The UNOS Insight

(1) Background: Heart failure is an extremely impactful health issue from both a social and quality-of-life point of view and the rate of patients with this condition is destined to rise in the next few years. Transplantation remains the mainstay of treatment for end-stage heart failure, but a shortage of organs represents a significant problem that prolongs time spent on the waiting list. In view of this, the selection of donor and recipient must be extremely meticulous, considering all factors that could predispose to organ failure. One of the main considerations regarding heart transplants is the risk of graft rejection and the need for immunosuppression therapy to mitigate that risk. In this study, we aimed to assess the characteristics of patients who need immunosuppression treatment for rejection within one year of heart transplantation and its impact on mid-term and long-term mortality. (2) Methods: The United Network for Organ Sharing (UNOS) Registry was queried to identify patients who solely underwent a heart transplant in the US between 2000 and 2021. Patients were divided into two groups according to the need for anti-rejection treatment within one year of heart transplantation. Patients' characteristics in the two groups were assessed, and 1 year and 10 year mortality rates were compared. (3) Results: A total of 43,763 patients underwent isolated heart transplantation in the study period, and 9946 (22.7%) needed anti-rejection treatment in the first year. Patients who required treatment for rejection within one year after transplant were more frequently younger (49 ± 14 vs. 52 ± 14 years, p < 0.001), women (31% vs. 23%, p < 0.001), and had a higher CPRA value (14 ± 26 vs. 11 ± 23, p < 0.001). Also, the rate of prior cardiac surgery was more than double in this group (27% vs. 12%, p < 0.001), while prior LVAD (12% vs. 11%, p < 0.001) and IABP (10% vs. 9%, p < 0.01) were more frequent in patients who did not receive anti-rejection treatment in the first year. Finally, pre-transplantation creatinine was significantly higher in patients who did not need treatment for rejection in the first year (1.4 vs. 1.3, p < 0.01). Most patients who did not require anti-rejection treatment underwent heart transplantation during the new allocation era, while less than half of the patients who required treatment underwent transplantation after the new allocation policy implementation (65% vs. 49%, p < 0.001). Patients who needed rejection treatment in the first year had a higher risk of unadjusted 1 year (HR: 2.25; 95% CI: 1.88-2.70; p < 0.001), 5 year (HR: 1.69; 95% CI: 1.60-1.79; p < 0.001), and 10 year (HR: 1.47; 95% CI: 1.41-1.54, p < 0.001) mortality, and this was confirmed at the adjusted analysis at all three time-points. (4) Conclusions: Medical treatment of acute rejection was associated with significantly increased 1 year mortality compared to patients who did not require anti-rejection therapy. The higher risk of mortality was confirmed at a 10 year follow-up. Further studies and newer follow-up data are required to investigate the role of anti-rejection therapy in the heart transplant population.

Use of Donor Hearts ≥50 Years Old for Septuagenarians in Heart Transplantation

BACKGROUND

The impact of using donors ≥50 years old on heart transplantation outcomes of septuagenarians is unknown, which may have a potential to expand the donor pool.

METHODS

From January 2011 to December 2021, 817 septuagenarians received donor hearts <50 years old (DON<50) and 172 septuagenarians received donor hearts ≥50 years old (DON≥50) in the United Network for Organ Sharing database. Propensity score matching was performed using recipient characteristics (167 pairs). The Kaplan-Meier method and Cox proportional hazards model were used to analyze death and graft failure.

RESULTS

The number of heart transplants in septuagenarians has been increasing (54 per year in 2011 to 137 per year in 2021). In a matched cohort, the donor age was 30 years in DON<50 and 54 years in DON≥50. In DON≥50, cerebrovascular disease was the main cause of death (43%), whereas head trauma (38%) and anoxia (37%) were the causes in DON<50 (P < .001). The median heart ischemia time was comparable (DON<50, 3.3 hours; DON≥50, 3.2 hours; P = .54). In matched patients, 1- and 5-year survival rates were 88.0% (DON<50) vs 87.2% (DON≥50) and 79.2% (DON<50) vs 72.3% (DON≥50), respectively (log-rank, P = .41). In the multivariable Cox proportional hazards models, donors ≥50 years old were not associated with death in matched (hazard ratio, 1.05; 95% CI, 0.67-1.65; P = .83) and nonmatched groups (hazard ratio, 1.11; 95% CI, 0.82-1.50; P = .49).

CONCLUSIONS

The use of donor hearts older than 50 years can be an effective option for septuagenarians, thereby potentially increasing organ availability without compromising outcomes.

Outcomes of Combined Heart-Kidney Transplantation in Older Recipients

Objectives

The upper limit of recipient age for combined heart-kidney transplantation (HKT) remains controversial. This study evaluated the outcomes of HKT in patients aged ≥65 years.

Methods

The United Network of Organ Sharing (UNOS) was used to identify patients undergoing HKT from 2005 to 2021. Patients were stratified by age at transplantation: <65 and ≥ 65 years. The primary outcome was one-year mortality. Secondary outcomes included 90-day and 5-year mortality, postoperative new-onset dialysis, postoperative stroke, acute rejection prior to discharge, and rejection within one-year of HKT. Survival was compared using Kaplan-Meier analysis, and risk adjustment for mortality was performed using Cox proportional hazards modeling.

Results

HKT in recipients aged ≥65 significantly increased from 5.6% of all recipients in 2005 to 23.7% in 2021 (p=0.002). Of 2,022 HKT patients in the study period, 372 (18.40%) were aged ≥65. Older recipients were more likely to be male and white, and fewer required dialysis prior to HKT. There were no differences between cohorts in unadjusted 90-day, 1-year, or 5-year survival in Kaplan-Meier analysis. These findings persisted after risk-adjustment, with an adjusted hazard for one-year mortality for age ≥65 of 0.91 (95% CI (0.63-1.29), p=0.572). As a continuous variable, increasing age was not associated with one-year mortality (HR 1.01 (95% CI (1.00-1.02), p=0.236) per year). Patients aged ≥65 more frequently required new-onset dialysis prior to discharge (11.56% vs. 7.82%, p=0.051). Stroke and rejection rates were comparable.

Conclusion

Combined HKT is increasing in older recipients, and advanced age ≥65 should not preclude HKT.

Development and Validation of a Model to Predict Malignancy Within the First Year After Adult Heart Transplantation

Purpose: Malignancy after heart transplantation is associated with poor outcomes. At present, no prediction model exists for any malignancy within the first year after transplant. Methods: We studied adults who underwent heart transplantation included in the multicenter, national Scientific Registry of Transplant Recipients from January 2000 through April 2021. Possible predictors of malignancy were identified based on their known association with malignancy. Multiple imputations were conducted for missing values using predictive mean matching. A multivariable logistic regression model for predicting malignancy development within the first year after transplant was developed and internally validated via 500 bootstrapped samples to estimate the optimism-corrected measures of model accuracy and performance. Results: Among the 47 212 recipients comprising 16% females, 76% whites, 7% with prior malignancy, and a median age of 56 years; 865 (2.3% of those with non-missing data) developed malignancy within the first year after transplant. Prior malignancy, older age at heart transplantation, white race, and nonischemic heart failure etiology were the strongest predictors of new malignancy. The optimism-corrected model had modest discrimination (C-statistic: 0.70, 95% CI: 0.69-0.72) and good calibration and performance (calibration slope: 0.96; Cox-Snell R²: 0.063), particularly at lower predicted risk. A nomogram for the practicing clinician was developed. Conclusions: Using selection variables previously linked to cutaneous malignancy, our model was modestly predictive of the development of any malignancy in the first year after heart transplantation. Future research could identify factors that may improve malignancy prediction, including incorporation of time-to-event data.

Prehabilitation in Adult Solid Organ Transplant Candidates

Purpose of Review

To highlight the importance of biological age in the context of prehabilitation and to present relevant research regarding prehabilitation prior to solid organ transplantation.

Recent Findings

Studies on the effect of prehabilitation have been performed in kidney-, lung-, liver-, and heart transplant patient populations. Prior to kidney transplantation, exercise interventions have been shown to improve cardiopulmonary- and physical fitness and result in a decreased length of hospital stay postoperatively. Among lung transplant candidates, various methods of prehabilitation have been studied including home-based, outpatient and in-patient programs, consisting of physical training, psychological support, education, and nutritional interventions. Overall, prehabilitation seems to improve or maintain quality of life and exercise capacity in this patient population. Patients undergoing liver transplantation seem to benefit from prehabilitation as well. Not only does it seem safe and feasible, but significant improvements in aerobic and functional capacity have also been found. Regarding heart transplant candidates, both inpatient and outpatient, supervised prehabilitation programs show promising results with improvements in exercise capacities and quality of life.

Summary

Prehabilitation is an effective and safe intervention for improving functional outcomes of solid organ transplant patients. Future studies should evaluate whether prehabilitation translates into improved pre- and post-transplant clinical outcomes.

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

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

Risk of recipient age on 1-year mortality after simultaneous heart-lung transplantation

BACKGROUND

Heart-lung transplantation (HLTx) is relatively uncommon, and there is a paucity of literature to suggest an age at which older recipients may be exposed to excess risk for mortality. This analysis aimed to identify a threshold of age that predicts adverse outcomes after HLTx.

METHODS

The United Network of Organ Sharing registry was used to identify adult patients undergoing HLTx from 2005 to 2021. The primary outcome was 1-year mortality. Threshold regression was used to identify the threshold at which age impacts 1-year mortality. Kaplan-Meier analysis was used to model survival, and Cox proportional hazards modeling was used for risk-adjustment.

RESULTS

We identified 453 patients undergoing HLTx. Threshold analysis identified that the risk for 1-year mortality was significantly elevated beyond an age of 58 years, and 47 (10.38%) patients were older than this threshold. On Kaplan-Meier analysis, 1-year survival was significantly lower in patients > 58 years compared to younger recipients (64.7% vs. 82.0%, p = .007). After risk adjustment, the hazard ratio for 1-year mortality in recipients older than 58 years was 2.27 (95% confidence interval [1.21-4.28], p = .011).

CONCLUSION

A threshold for recipient age of 58 years of age may avoid excess 1-year mortality after HLTx. However, patients older than this threshold demonstrate acceptable early and midterm survival, and the majority survive to 1 year. Advanced age should be considered in patient selection for HLTx, but may not be a contraindication for candidacy particularly in the absence of other risk factors.

Preoperative Evaluation and Care of Heart Transplant Candidates

Heart transplantation is recommended for patients with advanced heart failure refractory to medical and device therapy, and who do not have absolute contraindications. When patients become eligible for heart transplantation, they undergo comprehensive evaluation and preparation to optimize their posttransplantation outcomes. This review provides an overview of the processes that are employed to enable the candidates to be transplant-ready when donor hearts are available.

Heart Transplantation With Older Donors: Should There Be an Age Cutoff?

PURPOSE

Heart transplantation remains limited by donor availability. Currently, only some programs accept older donors, and their use remains contentious. We compared outcomes of heart transplant recipients who received donor hearts ≥55 years with those who received donor hearts <55 years.

METHODS

Records of first-time adult heart transplant recipients between 2010 and 2019 were reviewed. Endpoints included 30-day and 1-, 3-, and 5-year survival; freedom from cardiac allograft vasculopathy; freedom from nonfatal major adverse cardiac events; and freedom from any rejections. The effect of donor age ≥55 years was analyzed with Cox proportional hazards modeling, 1:2 propensity score matching, and Kaplan-Meier survival analysis.

RESULTS

Sixty-six patients received donor hearts ≥55 years and 766 received donor hearts <55 years. In the unmatched cohort, there was no significant difference in survival between the 2 groups at 30 days (93.9% vs 97.3%, P = .127), 1 year (87.9% vs 91.6%, P = .325), 3 years (86.4% vs 86.5%, P = .888), or 5 years (78.8% vs 83.8%, P = .497). The ≥55 years group had a significantly lower freedom from cardiac allograft vasculopathy and fatal major adverse cardiac events. In propensity-matched patients, recipients of donors ≥55 years had similar survival and freedom from cardiac allograft vasculopathy but significantly lower 1-year (76.7% vs 88.3%, P = .026), 3-year (68.3% vs 84.2%, P = .010), and 5-year (63.3% vs 83.3%, P = .002) freedom from nonfatal major adverse cardiac events when compared to recipients of younger donors.

CONCLUSIONS

Carefully selected older donors can be considered for a carefully selected group of recipients with acceptable outcomes.

Validation of cause of death classification after heart transplantation and cause-specific life expectancy compared to the general population

BACKGROUND

Post heart-transplant survival has increased, but information is lacking on specific causes of death and life expectancy. We aimed to assess cause-specific loss of life-years compared to the general population, evaluate classification for cause of death after heart transplantation, and assess validity of cause of death data from the International Society of Heart and Lung Transplant (ISHLT) registry.

METHODS

In this single center study, we included 239 heart recipients transplanted between 1988 and 2019 in Lund, Sweden (n = 239, 50% of the transplanted population where the cause of death was available). Two cardiologists retrospectively assigned causes of death according to a published classification (CLASS) in the 91 recipients who died during follow-up. Life expectancy was compared to data from the general population.

RESULTS

Compared to the average Swedish population, life expectancy for heart transplant recipients was 20 years shorter (IQR 12.9-27.2). The largest number of life-years lost were for deaths due to acute (49 years) and chronic rejection (27 years). Primary graft dysfunction (24 years) accounted for 24% of deaths, followed by malignancy (20 years) and infection (17 years), each accounting for ∼20% of deaths. Use of CLASS revealed moderate inter-rater agreement (56%) and moderate agreement with the ISHLT registry (62%).

CONCLUSIONS

Survival after heart transplantation was 20 years lower than in the general population. In the young, more life-years were lost due to acute graft rejection, whereas chronic graft rejection and primary graft failure were more important causes of death in older patients. Agreement was moderate between CLASS and the ISHLT registry classifications.

Characteristics, outcomes, and predictors of de novo malignancy after heart transplantation

Background

Post-transplant malignancy (PTM) causes long-term morbidity and mortality in heart transplant (HTx) recipients. However, the detailed characteristics or predictors of PTM are not well-known. We evaluated the incidence, characteristics, long-term outcomes, and predictors of de novo PTM using a single center large-volume database.

Methods

We retrospectively analyzed the types and characteristics of de novo PTM in 989 patients who underwent HTx. Univariate and multivariate logistic regression analyses were used for the PTM prediction model.

Results

Two hundred and six patients (20.8%) had de novo PTMs (241 cancers) during a median follow-up of 11.5 years. PTM patients were older than non-PTM patients, received immunosuppressive therapy for a longer period, and were more likely to be male and white. Skin cancers were the most frequent types of malignancy (60.6%) followed by prostate (9.5%), lung (7.1%), and breast (4.1%) cancers. Although most cancers (88.8%) were surgically resected at initial presentation, about half (47.3%) recurred or progressed. Patients with skin cancer and non-skin cancer had significantly lower overall survival (P < 0.001) than patients without cancer. Older age (P < 0.001), white race (P = 0.001), and longer time receiving immunosuppressive therapy (P < 0.001) were independent predictors for PTM.

Conclusion

Older age, white race, and longer administration of immunosuppressive therapies were independent risk factors for PTM, which was associated with increased mortality. Further research is necessary for the prevention and early detection of PTM in HTx recipients.

Heart Transplant in Older Adults

Purpose of Review

Older adults with end-stage heart failure may be candidates for heart transplantation (HT) and changing guidelines and institutional policies have increased the availability of HT for septuagenarians. This review explores historical, pre-HT evaluation, and post-HT outcomes for older adult HT recipients.

Recent Findings

Rates of HT in older adults have increased in the past decade and more than 800 septuagenarians have undergone HT. Older adult HT recipients have similar survival, rehospitalization, and graft failure rates when compared to younger patients despite additional comorbidities and higher risk donors.

Summary

HT is feasible in carefully selected older adults. As the number of older adults who are considered for HT increases, additional research into population-specific assessment tools will be needed. Furthermore, age-related immune changes warrant population-specific studies on immunosuppressive regimens.

Immunosenescence as a reason of individualizing immunosuppressive therapy in kidney transplantation

Transplantation in elderly patients is obviously more challenging due to existing underlying diseases, changes in pharmacokinetics of immunosuppressive drugs, polypragmasy, and transformation of immunoreactivity (immunosenescence). Our review presents data on modification of adaptive and innate immunity during aging. It also considers the possibility of both reduced and adapted immunosuppressive therapy in elderly renal transplant recipients in achieving an optimal balance between efficacy and complications.

Clinical outcomes of older adults listed for heart transplantation in the United States

OBJECTIVE

To examine if older age (>70 years) should be a relative contraindication for heart transplantation, we evaluated the characteristics and outcomes of patients with age ≥70 years listed for heart transplantation; and whether post-transplantation survival was inferior to younger counterparts.

DESIGN

Retrospective cohort analysis.

SETTING

The scientific registry of transplant recipients (SRTR).

PARTICIPANTS

Adults (≥18 years) listed for heart transplantation in the SRTR between 2000 and 2018.

INTERVENTIONS

Heart transplantation.

MEASUREMENTS

Characteristics and outcomes were compared for adults ≥70 years and <70 years. We evaluated waitlist mortality and post-transplant 1-year and 5-year survivals.

RESULTS

The study included 57,285 patients (age range 18-79 years) listed for heart transplantation; 1203 (2.1%) age ≥70 years. Of these, 37,135 patients underwent heart transplantation; 806 (2.2%) were age ≥70 years. Yearly listing of those age ≥70 years has consistently increased from 2.5% (n = 30) in 2000 to 11% (n = 132) in 2017 (p < 0.01). As compared with the age <70 years group, those ≥70 years had a similar risk of death while waiting (sub-hazard ratio [SHR] 0.86, 95% confidence interval [HR] 0.68-1.08; p = 0.19) but were more likely to be transplanted (SHR 1.36, 95% CI 1.26-1.48; p < 0.01). Among the older patients, the overall post-transplant 1- and 5-year mortality rate was 10.4% and 19.2%, respectively. Older recipients had lower unadjusted survival compared with younger recipients (log-rank p = 0.03). However, after adjustment for relevant covariates, there was no significant difference in 5-year mortality between both groups (HR 1.06, 95% CI 0.91-1.254; p = 0.43).

CONCLUSIONS

Post-transplant survival up to 5 years among patients of age ≥70 years was similar to that of younger recipients. Older patients who received heart transplantation appear to have lower risk features but receive hearts from higher risk donors. Chronologic age alone should not constitute a contraindication for heart transplantation, although careful patient selection criteria should be applied.

Neurological Complications in Patients with Heart Transplantation

Neurological complications after heart transplantation are common and include cerebrovascular events (ischemic strokes, hemorrhagic strokes, and transient ischemic attacks), seizures, encephalopathy, central nervous system (CNS) infections, malignancies, and peripheral nervous system complications. Although most neurological complications are transient, strokes and CNS infections can result in high mortality and morbidity. Early recognition and timely management of these serious complications are crucial to improve survival and recovery. Diagnosing CNS infections can be challenging because their clinical presentation can be subtle in the setting of immunosuppression. Immunosuppressive medications themselves can cause a broad spectrum of neurological complications including seizures and posterior reversible encephalopathy syndrome. This article provides a review of the diagnosis and management of neurological complications after cardiac transplantation.

Association between cytomegalovirus infection and allograft rejection in a large contemporary cohort of heart transplant recipients

BACKGROUND

Cytomegalovirus (CMV) infection remains a common complication after heart transplantation (HTx). The association between CMV infection and allograft rejection is debated in the era of efficient prophylactic antiviral therapies.

METHODS

This single-center cohort study utilized a highly phenotyped database of HTx recipients (2012-2016). The primary endpoint was the analysis of the association between CMV infection (CMV load ≥ 500 IU/mL whole blood) and the risk of allograft rejection (cellular rejection ≥ 1R1B, antibody-mediated rejection ≥ pAMR1). Secondary endpoints included the analysis of a higher CMV load threshold (≥10 000 IU/mL) and different risk periods after PCR positivity. A mixed-effect logistic regression model with a random intercept was applied. Results were adjusted for important risk factors of rejection.

RESULTS

Overall, 384 patients were included and 6388 CMV loads and 3,494 endomyocardial biopsies were analyzed. CMV infections ≥ 500 IU/mL were diagnosed on 1223 (19.2%) blood samples from 284 (72.1%) patients and allograft rejections on 246 biopsies (7%) from 149 patients (38.8%). We did not find any association between CMV infection ≥ 500 IU/mL and rejection (univariable: OR 0.94, 95% CI [0.61, 1.45], P = .78, multivariable: OR 0.86, 95% CI [0.55, 1.33], P = .85). These results were consistent when analyzing a higher CMV load threshold and different periods of risk, reinforced by internal validation procedures and a posteriori calculation of the power (primary endpoint: power = 0.82, 95% CI [0.79-0.84]) and reproducible across different clinical scenarios.

CONCLUSIONS

CMV infection was not associated with an increased risk of rejection in a contemporary cohort of HTx recipients.

[Pathology of heart transplantation: Where are we now?]

Pathology is still the gold standard for the diagnosis of rejection in heart transplantation. During the last decade, molecular pathology has emerged as a powerful tool for the understanding of the processes implicated in allograft rejection. Transcriptomic analysis of the allograft may also help the pathologist for diagnosis and accurate classification of rejection. This review will describe the recent advances and perspectives of molecular pathology in the field of heart transplantation.

Right ventricular undersizing is associated with increased 1-year mortality

OBJECTIVES

Right heart hemodynamic management is critical, because many post-heart transplantation (HTx) complications are related to right ventricular (RV) failure. However, current guidelines on size and sex matching rely primarily on weight matching, with recent literature using total ventricular mass (TVM), which places less emphasis on the impact of RV mass (RVM) matching. The aim of the present study was to analyze the relationship of RVM matching and survival after HTx.

METHODS

We performed the retrospective analysis using the UNOS database of adult HTx performed between January 1997 and December 2017. Previously validated equations were used to calculate TVM and RVM. The percent difference in ventricular mass in the donor and recipient pair was used for the size mismatch. All donor-recipient pairs were divided into 4 RVM groups by their mismatch ratio. We analyzed RVM matching and explored how RVM undersizing impacted outcomes. The primary outcome measure was 1-year survival; secondary outcomes measured included stroke and dialysis within 1 year and functional status.

RESULTS

A total of 38,740 donor-recipient pairs were included in our study. The 4 RVM match groupings were as follows: <0%, 0% to 20%, 20% to 40%, and >40%. Utilization of donors who were older and of female sex resulted in greater RVM undersizing. Survival analysis demonstrated patients with RVM undersizing had worse 1-year survival (P < .001). RVM undersizing was an independent predictor of higher 1-year mortality (hazard ratio, 1.23; 95% confidence interval, 1.11 to 1.34; P < .001). RVM undersizing was also associated with higher rates of dialysis within 1-year of transplantation and poorer postoperative functional status.

CONCLUSIONS

RVM undersizing is an independent predictor for worse 1-year survival. Donors who are older and female have lower absolute predicted RVM and may be predisposed to RVM undersizing. RVM-undersized transplantation requires careful risk/benefit considerations.

A mortality risk score for heart transplants after contemporary ventricular assist device bridging

BACKGROUND

We sought to derive a risk score for 1-year mortality following orthotopic heart transplantation (OHT) in patients bridged with a contemporary centrifugal left ventricular assist device (LVAD).

METHODS

Adult patients (≥18 years) in the United Network for Organ Sharing database undergoing OHT between 2010 and 2019 who were bridged with a HeartWare or HeartMate III device were included. Derivation and validation cohorts were randomly assigned with a 2:1 ratio. Threshold analysis and multivariable logistic regression were utilized to obtain adjusted odds ratios for 1-year post-OHT mortality. A risk score was generated using these adjusted odds ratios in the derivation cohort and the predictive performance of the composite index was evaluated in the validation set.

RESULTS

A total of 3434 patients were identified. In the derivation cohort, the mean age was 53.5 ± 12.1 years and 1758 (76.8%) were male; 1789 (78.1%) were bridged with a HeartWare device. Multivariable logistic regression revealed that recipient age ≥50 years, bilirubin level ≥2.4 mg/dl, ischemic time ≥4 h, and preoperative hemodialysis predicted 1-year post-transplant mortality. Stratification into risk groups in the validation cohort revealed significant differences in postoperative renal failure, stroke, and short-term mortality. One-year post-transplant mortality was 5%, 6.7%, and 14.8% in the low-, moderate-, and high-risk categories, respectively (p < .001).

CONCLUSIONS

Among patients bridged to OHT with newer generation centrifugal LVADs, older age, increasing bilirubin, longer ischemic time, and pre-OHT dialysis independently predicted post-transplant mortality. The composite risk score based on these factors may assist in patient selection and prognostication in those supported with contemporary LVADs.

Long-term Survival After Heart Transplantation: A Population-based Nested Case-Control Study

BACKGROUND

Heart transplantation is the mainstay of treatment for patients in end-stage heart failure. This study sought to contrast survival after transplantation with that of the general population to quantify standardized mortality rates using a nested case-control study design.

METHODS

Control subjects were noninstitutionalized inhabitants of the United States identified through the National Longitudinal Mortality study. Case subjects were adults who underwent heart transplantation between 1990 and 2007 and identified through the Organ Procurement and Transplantation Network. Propensity-matching (5:1, nearest neighbor, caliper = 0.1) was utilized to identify suitable control subjects based on age, sex, race, and state of permanent residency. The primary study endpoint was 10-year survival.

RESULTS

In all, 31,883 heart transplant recipients were matched to 159,415 noninstitutionalized residents of the United States. The 10-year survival of heart transplant recipients was 53%. The population expected mortality rate was 15.9 deaths per 100 person-years with an observed rate of 45.1 deaths per 100 person-years (standardized mortality rate [SMR] 2.84; 95% confidence interval, 2.82 to 2.87). The broadest gaps between observed and expected survival were evident in female (SMR 3.63), black (SMR 3.67), and Hispanic (SMR 4.12) recipients. Standardized mortality ratios declined over time (1990 to 1995, 3.09; 1996 to 2000, 2.90; 2001 to 2007, 2.58). The long-term standardized survival of older recipients was closest to that expected for their age.

CONCLUSIONS

Heart transplant recipients have considerable long-term survival and have a threefold higher standardized long-term mortality rate than that of the noninstitutionalized population. Long-term mortality rates have consistently declined over time and will likely continue to decrease.

Donor-recipient age interaction and the impact on clinical results after heart transplantation

To evaluate the impact of donor-recipient age matching on clinical outcomes after heart transplantation, a total of 509 patients (January 1990-December 2018, mean follow-up 111 ± 80 months) were stratified into 4 groups (young-R/young-D, young-R/old-D, old-R/young-D, old-R/old-D) according to the recipient (young-R < 60, old-R ≥ 60 years) and the donor (young-D < 50, old-D ≥ 50 years) age. No difference was found among 30-day mortality (P = .11) and postoperative complications between groups. Both unadjusted and adjusted survival was significantly higher for group young-R/young-D than that of other groups, in which survival was similar [adjusted HR for mortality of 2.0(1.2-3.4), 2.1(1.4-3.8) and 2.5(1.6-4.1) for groups old-R/young-D, young-R/old-D, old-R/old-D, respectively]. Compared to other groups, the incidence of grade ≥ 2 CAV was significantly lower in old-R/young-D group [adjusted HR 0.4(0.2-0.7)]. Among young recipients, the rate of acute grade ≥ 2 rejection episodes was higher in those receiving an old donor graft (P = .04). Old recipient groups were more affected by neoplasms and severe renal failure than young recipient groups (P < .01). Employment of hearts from donors ≥50 years of age adversely affects survival in recipients <60 years of age but does not influence outcomes in older recipients. Also, donor and recipient ages seem to have opposite effects on incidence of rejections and CAV of high grade.

Donor and recipient age matching in heart transplantation: analysis of the UNOS Registry

The association of donor and recipient age with survival following adult heart transplantation has not been well characterized. The purpose of this study was to examine the impact of the relationship between donor and recipient age on post-transplant survival. We retrospectively reviewed the 2005-2018 UNOS heart transplant database for all adult recipients undergoing first-time isolated heart transplantation. The impact of donor and recipient age on survival was analyzed with Cox proportional hazards modeling using restricted cubic splines. A total of 25 480 heart transplant donor and recipient pairs met inclusion criteria. Unadjusted and adjusted Cox proportional hazards modeling demonstrated a near-linear association between increasing donor age and decreased survival; in addition, older and younger recipient age was associated with decreased survival. After adjustment, there was no significant interaction between donor and recipient age. Older donors decreased survival similarly in both older and younger recipients. Increasing donor age and both younger and older recipient age are independently associated with worsened post-heart transplant survival. The relationship between donor and recipient age does not significantly affect survival following heart transplant.

Hurdles to Cardioprotection in the Critically Ill

Cardiovascular disease is the largest contributor to worldwide mortality, and the deleterious impact of heart failure (HF) is projected to grow exponentially in the future. As heart transplantation (HTx) is the only effective treatment for end-stage HF, development of mechanical circulatory support (MCS) technology has unveiled additional therapeutic options for refractory cardiac disease. Unfortunately, despite both MCS and HTx being quintessential treatments for significant cardiac impairment, associated morbidity and mortality remain high. MCS technology continues to evolve, but is associated with numerous disturbances to cardiac function (e.g., oxidative damage, arrhythmias). Following MCS intervention, HTx is frequently the destination option for survival of critically ill cardiac patients. While effective, donor hearts are scarce, thus limiting HTx to few qualifying patients, and HTx remains correlated with substantial post-HTx complications. While MCS and HTx are vital to survival of critically ill cardiac patients, cardioprotective strategies to improve outcomes from these treatments are highly desirable. Accordingly, this review summarizes the current status of MCS and HTx in the clinic, and the associated cardiac complications inherent to these treatments. Furthermore, we detail current research being undertaken to improve cardiac outcomes following MCS/HTx, and important considerations for reducing the significant morbidity and mortality associated with these necessary treatment strategies.

Human Leukocyte Antigen-Based Risk Stratification in Heart Transplant Recipients-Implications for Targeted Surveillance

Background

Human leukocyte antigen (HLA) matching isn't routinely performed in heart transplantation. Novel allograft perfusion methods may make HLA matching feasible. The purpose of this study is to reexamine whether HLA mismatch may be used in risk stratification to improve outcomes in heart transplantation.

Methods and Results

We analyzed 34 681 recipients undergoing heart transplantation between 1987 and 2013. We used HLAMatchmaker to quantify HLA eplet mismatches and Cox regression for analysis of time to graft loss. Recipients with 4 mismatched HLA‐DR/DQ alleles and >40 eplets reached an adjusted hazard ratio (HR) for graft loss of 1.17 (95% CI 1.07–1.28) and 1.11 (95% CI 1.03–1.21), respectively. We found significant interaction between recipient age and numbers of HLA‐DR/DQ allele and eplet mismatches resulting in an adjusted HR of 1.78 (95% 1.13–2.80) and 1.82 (95% CI, 1.23–2.70), respectively. HR for both interaction terms was 0.99 (95% CI, 0.98–1.00). Risk of graft loss was more pronounced after 1 year, where recipient <40 years with 4 mismatched HLA‐DR/DQ alleles and >40 eplets had an adjusted HR of 1.51 (95% CI 1.12–2.03) and 1.32 (95% CI 1.02–1.70), respectively. Pre‐sensitized recipients with panel reactive antibodies >10% had an adjusted HR=1.27 (95% CI 1.16–1.40) for graft loss within 1 year but not thereafter. HLA eplet mismatch was independent of panel reactive antibodies on reduction of graft loss within and after 1 year, P (interaction)=0.888 and 0.389.

Conclusions

HLA mismatch may be used in risk stratification for intensified post‐transplant surveillance and therapy.

Temporal Trends of De Novo Malignancy Development After Heart Transplantation

BACKGROUND

Malignancy is a concern in cardiac transplant recipients, but the temporal trends of de novo malignancy development are unknown.

OBJECTIVES

The goal of this study was to describe the temporal trends of the incidence, types, and predictors of de novo malignancy in cardiac transplant recipients.

METHODS

The authors analyzed the temporal trends of post-transplant incidence, types, and predictors of malignancy using 17,587 primary adult heart-only transplant recipients from the International Society for Heart and Lung Transplantation registry. The main study outcomes included the incidence of, types of, and time to de novo malignancy.

RESULTS

The risk of any de novo solid malignancy between years 1 and 5 after transplantation was 10.7%. The cumulative incidence by malignancy type was: skin cancer (7.0%), non-skin solid cancer (4.0%), and lymphoproliferative disorders (0.9%). There was no temporal difference in the time to development according to malignancy type. However, the cumulative incidence of de novo solid malignancy increased from 2000 to 2005 vs. 2006 to 2011 (10.0% vs. 12.4%; p < 0.0001). Survival in patients after de novo malignancy was markedly lower than in patients without malignancy (p < 0.0001). Older recipients and patients who underwent transplantation in the recent era had a higher risk of de novo malignancy.

CONCLUSIONS

More than 10% of adult heart transplant recipients developed de novo malignancy between years 1 and 5 after transplantation, and this outcome was associated with increased mortality. The incidence of post-transplant de novo solid malignancy increased temporally, with the largest increase in skin cancer. Individualized immunosuppression strategies and enhanced cancer screening should be studied to determine whether they can reduce the adverse outcomes of post-transplantation malignancy.

When to intervene for donor-specific antibody after heart transplantation

PURPOSE OF REVIEW

Posttransplant donor-specific human leukocyte antigen (HLA) antibodies (DSA) represent a complex area in heart transplantation with nonstandardized practice and paucity of clinical data to guide optimal management.

RECENT FINDINGS

De novo DSA after heart transplantation is common and associated with rejection, cardiac allograft vasculopathy, allograft failure, and mortality. Advances in methods for HLA antibody detection have enabled identification of DSA with high precision and sensitivity. The detection of HLA antibodies must, however, be interpreted within appropriate laboratory and clinical contexts; it remains unclear which DSA are associated with greatest clinical risk. Increased antibody and clinical surveillance as well as optimization of maintenance immunosuppression are required for all patients with DSA. Antibody-directed therapies are reserved for patients with allograft dysfunction or rejection. Treatment of DSA may also be considered in asymptomatic high-risk patients including those in whom DSA arise de novo posttransplant, is persistent, high titer, or complement activating. The impact of DSA reduction and removal on long-term clinical outcomes remains unknown.

SUMMARY

Despite improvements in DSA detection, identification, and characterization, best therapeutic strategies are unclear. Prospective multicenter studies are needed to develop effective standardized approaches for DSA management in heart transplantation.

Renal Function Changes Under Everolimus Plus Cyclosporine or Everolimus Plus Tacrolimus After Heart Transplantation

Everolimus (EVR) can be used with calcineurin inhibitors to reduce the risk of renal dysfunction, with similar immunosuppressive effect. In this study, we compared renal function after heart transplantation (HT) under EVR with cyclosporine (CSA) or tacrolimus (TAC). Between 2004 and 2014, EVR with CSA or TAC was used in 117 HT at the National Taiwan University Hospital. After HT, all patients received corticosteroid, EVR (C0 target 3-8 ng/mL) and CSA (C0 blood level 100-200 ng/mL), or TAC (Co blood level 5-10 ng/mL). Renal function was evaluated before HT, every month after HT for up to 1 year, and then every 3 months for up to 2 years. Blood-drug levels of EVR, CSA, and TAC were also monitored simultaneously with renal function. The estimated mean glomerular filtration rate (eGFR) was 76.5 mL/min/1.73 m² before HT. After HT, the eGFR was 64 mL/min/1.73 m² at the third month, and 64 mL/min/1.73 m² at the end of first year. The difference was significant between pre-HT and post-HT (P = .00) during the first year. No significant differences were noted between the CSA and TAC groups. Careful monitoring of blood-drug level and renal function is crucial after heart transplantation. It is concluded that under close monitoring blood-drug level and renal function, it is possible to reach acceptable postoperative renal function with no difference of renal function between EVR plus CSA and EVR plus TAC.

Quadriceps Muscle Strength and Body Mass Index Are Associated With Estimates of Physical Activity Postheart Transplantation

BACKGROUND

Although exercise capacity improves postheart transplantation (HTx), it remains unclear if the level of physical activity (PA) shows similar improvement. The purpose of this study was to (1) describe PA levels and (2) identify factors which may be associated with levels of PA post-HTx.

METHODS

A prospective observational cross-sectional study was conducted at a single center HTx outpatient clinic. Medically stable adult recipients 6 months or longer post-HTx were recruited. Physical activity level (PAL) and average daily time spent at least moderately active (≥3 metabolic equivalents) were estimated using a multisensor device. Factors investigated were demographic (age, sex, body mass index [BMI], time post-HTx, and reason for HTx), corticosteroid use, exercise capacity (6-min walk distance), and quadriceps muscle strength corrected for body weight (QS%).

RESULTS

The mean post-HTx time of the 75 participants was 9.2 ± 7.0 years (0.5-26 y). Twenty-seven (36%) participants were classified as extremely inactive (PAL, <1.40), 26 (34.6%) sedentary (1.40 ≤ PAL ≤ 1.69), and 22 (29.3%) active (PAL, ≥1.70). Multivariable analysis showed greater QS% (β = 0.004 (0.002-0.006) P = 0.001) to be independently associated with increased PAL. For increased time, 3 or more metabolic equivalents both greater QS% (β = 0.0164 [0.003-0.029]; P = 0.014) and lower BMI (β = -0.0626 [-0.115 to -0.0099]; P = 0.021) were independently associated.

CONCLUSIONS

The degree of observed sedentary behavior post-HTx is surprising, with the majority of participants not reaching levels of PA recommended for health benefits. QS% and BMI were the only factors found to be independently associated with estimates of PA. Further quality trials are required to demonstrate the long-term benefits of regular PA and investigate ways of increasing adherence to PA post-HTx.

Interaction of Donor and Recipient Age: Do Older Heart Transplant Recipients Require Younger Hearts?

BACKGROUND

Older patients (aged 60 years or more) awaiting heart transplant often have comorbidities that may limit overall survival independent of cardiac status. We hypothesized that these comorbidities have a more-limiting impact on survival than age of donor heart and that older allografts might be utilized in these patients without compromising outcomes.

METHODS

We identified all transplant recipients aged more than 60 years in the United Network for Organ Sharing database. Local regression analysis detected the point above which increasing donor age incurred increasing risk of mortality, above and below which two cohorts were defined. Kaplan-Meier analysis compared cumulative 5-year survival between groups. Cox proportional hazard modeling was then used to determine the hazards of death in the two groups.

RESULTS

An inflection point in posttransplant survival was detected near donor age 50 years. Of 14,113 older recipients studied, 86% received younger donor hearts (less than 50 years of age), and 14% received advanced age allografts (50 years of age or more). Baseline characteristics were comparable between groups except more recipients had left ventricular assist devices at time of transplant in the younger donor group (15% versus 9%, p < 0.001). Five-year survival was significantly lower among recipients receiving advanced age hearts compared with those receiving younger hearts (67% versus 73%, log rank p < 0.001). Adjusting for relevant recipient baseline characteristics, patients receiving advanced age hearts were 30% more likely to die by 5 years compared with patients receiving younger hearts.

CONCLUSIONS

Transplant recipients aged 60 years and more who receive advanced age donor hearts (50 years or more) have a significantly increased risk of mortality. With careful allograft selection, use of donor hearts to age 50 may be acceptable among older transplant recipients.