Heart Transplantation for Adults With Congenital Heart Disease: Analysis of the United Network for Organ Sharing Database

Utilization and Outcomes of Expanded Criteria Donors in Adults with Congenital Heart Disease

BACKGROUND

Use of donation after circulatory death(DCD) and hepatitis C virus(HCV) positive donors in heart transplantation have increased the donor pool. Given poor waitlist outcomes in the adult congenital heart disease(ACHD) population, we investigated waitlist outcomes associated with willingness to consider DCD and HCV+ offers and post-transplant outcomes following HCV+ and DCD transplantation for these candidates.

METHODS

Using the United Network for Organ Sharing database, we identified adult ACHD candidates and recipients listed or transplanted, respectively, between 01/01/2016-09/30/2023 for the HCV analysis and between 12/01/2019-09/30/2023 for the DCD analysis. Among candidates, we compared the cumulative incidence of transplant, with waitlist death/deterioration as a competing risk, by willingness to consider HCV+ and DCD offers. Among recipients of HCV+ (vs. HCV-) and DCD (vs. brain death[DBD]) transplants, we compared perioperative outcomes and post-transplant survival.

RESULTS

Of 1,436 ACHD candidates from 01/01/2016-09/30/2023, 37.0% were willing to consider HCV+ heart offers. Of 886 ACHD candidates from 12/01/2019-09/30/2023, 15.5% were willing to consider DCD offers. On adjusted analysis, willingness to consider HCV+ offers was associated with 84% increased likelihood of transplant, and willingness to consider DCD offers was associated with 56% increased likelihood of transplant. Of 904 transplants between 01/01/2016-09/30/2023, 6.4% utilized HCV+ donors, and of 540 transplants between 12/01/2019-09/30/2023, 6.9% utilized DCD donors. Recipients of HCV+ (vs. HCV-) and DCD (vs. DBD) heart transplants had similar likelihood of perioperative outcomes and 1-year survival.

CONCLUSIONS

ACHD candidates who were willing to consider HCV+ and DCD offers were more likely to be transplanted and had similar post-transplant outcomes compared to recipients of HCV- and DBD organs.

The Impact of Local Programmatic Decisions on Outcomes in Transplant-Listed Adults With Congenital Heart Disease

BACKGROUND

We investigated variables impacting waitlist times and negative waitlist outcomes in adults with congenital heart disease (ACHD) who were waiting for orthotopic heart transplant (OHT) after the 2018 allocation change.

METHODS

Adult candidates for OHT who were listed between 10/18/2018 and 12/31/2022 in the United Network for Organ Sharing database were categorized as ACHD vs non-ACHD. Waitlist time and time to upgrade for those upgraded into status 1-3 were compared by using rank-sum tests. Death/delisting for deterioration was assessed by using Fine-Gray subdistribution hazard ratios (SHRs).

RESULTS

Of 15,424 OHT candidates, 589 (3.8%) were ACHD. ACHD vs non-ACHD candidates had less urgent status at initial listing (4.2% vs 4.7% listed at status 1; 17.2% vs 23.7% listed at status 2; P < 0.001), but not final listing (5.9% vs 7.6% final status 1; 35.6% vs 36.8% final status 2; P < 0.001). ACHD vs non-ACHD candidates upgraded into status 1 (65.0 vs 30.0 days; P = 0.09) and status 2 (113.0 vs 64.0 days; P = 0.003) spent longer times on the waitlist. ACHD vs non-ACHD candidates spent longer times waiting for an upgrade into status 1 (51.4 vs 17.6 days; P = 0.027) and status 2 (76.7 vs 34.7 days; P = 0.003). Once upgraded, there was no difference between groups in waitlist time to status 1 (9.7 vs 5.5 days = 0.66). ACHD vs non-ACHD candidates with a final status of 1 (20.0% vs 8.6%; SHR 2.47 [95%CI = 1.19-5.16]; P = 0.02) and 2 (8.9% vs 2.3%; SHR 3.59 [95%CI = 2.18-5.91]; P < 0.001) experienced higher rates of death and deterioration.

CONCLUSIONS

ACHD candidates have longer waitlist times, have lower priority status at initial listing, wait longer for upgrades, and have higher mortality rates at the same final status as non-ACHD candidates, suggesting that they are being upgraded too late.

Characteristics and Outcomes of a Single-Centre Cohort of Adult Congenital Heart Disease Patients Referred for Heart Transplant

BACKGROUND

Adult congenital heart disease (ACHD) services increasingly encounter heart failure (HF) in the ageing ACHD population. Optimal timing of referral for heart transplant (HTx) evaluation in this heterogeneous population is complex and ill-defined. We aim to outline the characteristics and outcomes of ACHD patients referred for HTx from a large Australian ACHD centre.

METHOD

Retrospective review of ACHD patients referred for HTx from a primary ACHD centre (1992-2021). Database analysis of patient demographics, characteristics, wait-listing, and transplantation outcomes was performed.

RESULTS

A total of 45 patients (mean age 37±9.9 years old; 69% male) were referred for HTx with a mean follow-up of 5.9±6.3 years. Of these, 22 of 45 (49%) were listed and transplanted, including one heart-lung transplant. The commonest diagnosis was dextro-transposition of the great arteries (13/45, 29%). Most patients, 33 of 45 (73.3%) had undergone at least one cardiac surgery in childhood. Indications for HTx referral included HF in 34 of 45 (75%), followed by pulmonary hypertension in 7 of 45 (11%). Median transplant wait-list time was 145 days (interquartile range, 112-256). Of the 23 patients not wait-listed, the reasons included clinical stability in 13 of 45 (29%), psychosocial factors in 2 of 45 (4.4%) and prohibitive surgical risk, including multiorgan dysfunction, in 8 of 45 (17.7%). Transplant was of a single organ in most, 21 of 22 (95.5%). Overall mortality was 5 of 22 (22.7%) in those after HTx, and 14 of 23 (60.9%) in those not listed (p=0.0156).

CONCLUSIONS

Increasingly, ACHD patients demonstrate the need for advanced HF treatments. HTx decision-making is complex, and increased mortality is seen in those not wait-listed. Ultimately, the referral of ACHD patients for HTx is underpinned by local decision-making and experience, wait-list times and outcomes.

Pulmonary Hypertension in Adult Congenital Heart Disease-Related Heart Failure

Already a challenging condition to define, adult congenital heart disease (ACHD) -associated heart failure (HF) often incorporates specific anatomies, including intracardiac and extracardiac shunts, which require rigorous diagnostic characterization and heighten the importance of clinicians proactively considering overall hemodynamic impacts of using specific therapies. The presence of elevated pulmonary vascular resistance dramatically increases the complexity of managing patients with ACHD-HF. Total circulatory management in patients with ACHD-HF requires input from multidisciplinary care teams and thoughtful and careful utilization of medical, interventional, and surgical approaches.

Trends and outcomes of heart transplantation in adults with congenital heart disease

OBJECTIVES

Heart transplantation for adult congenital heart disease is complicated and associated with challenging pretransplant support, long waiting and high early post-transplant mortality. We explored if surgical and medical advances and allocation system changes have affected outcomes.

METHODS

From United Network for Organ Sharing database, adults with congenital heart disease listed for heart transplantation were queried. To explore practice and outcome trends, patients were divided into 4 eras (eras 1-3: nearly 3 equal periods from 1992 to 2018, era 4: after 2018, corresponding with new allocation system). Univariate and multivariable analysis was performed to evaluate outcomes.

RESULTS

A total of 2737 patients were listed. There was gradual increase in listed and transplanted patients, along with significant increase in use of mechanical support, simultaneous kidney and liver transplantation. While proportion of transplanted remained constant, there was decrease in proportion delisted/died after listing (P = 0.01) and waiting list duration (P = 0.01), especially in era 4. Thirty-day post-transplant mortality remains high; however, it has significantly improved starting era 3 (P = 0.01). Current survival at 1-year and 5-years is 85% and 65%, with improvement mainly related to decreased early death. On multivariable analysis, factors associated with survival were lower glomerular filtration rate (hazard ratio = 0.99, P = 0.042), bilirubin (hazard ratio = 1.17, P<0.001) and mechanical ventilation (hazard ratio = 2.3, P=0.004).

CONCLUSIONS

Heart transplantation in adults with congenital heart disease is increasing, along with added complexity, higher usage of pretransplant mechanical support and simultaneous organ transplantation. Despite that, more complex patients do not experience worse outcomes. Early mortality improved but remains high. New donor allocation system allowed shorter waiting time and higher proportion transplanted without altering early mortality.

Survival After Cardiac Transplantation in Adults With Single-Ventricle Congenital Heart Disease

BACKGROUND

Without large-scale analyses of adults with single-ventricle congenital heart disease (CHD) undergoing heart transplantation, little evidence exists to guide listing practices and patient counseling.

OBJECTIVES

This study aims to evaluate survival after heart transplantation in adults with single and biventricular CHD and compare it to that of non-CHD transplant recipients.

METHODS

In this 15-year (2005-2020) retrospective analysis, outcome-blinded investigators used probability-linkage to merge the National (Nationwide) Inpatient Sample and Organ Procurement and Transplantation Network data sets.

RESULTS

Of 382 adult (≥18 years of age) heart transplant recipients with CHD, 185 (48%) had single-ventricle physiology. Compared to biventricular CHD, single-ventricle patients showed significantly reduced survival at 1 (80% vs 91%; HR: 2.50; 95% CI: 1.40-4.49; P = 0.002) and 10 years (54% vs 71%; HR: 2.10; 95% CI: 1.38-3.18; P < 0.001). Among patients who survived the first post-transplantation year, biventricular CHD patients exhibited similar 10-year survival as single-ventricle patients, except for those with hypoplastic left heart syndrome (79% vs 71%; HR: 1.58; 95% CI: 0.85-2.92; P = 0.15). Additionally, biventricular CHD transplant recipients showed significantly better 10-year conditional survival compared to their non-CHD counterparts (79% vs 68%; HR: 0.73; 95% CI: 0.59-0.90; P = 0.003).

CONCLUSIONS

Among adult CHD transplant recipients, single-ventricle physiology correlated with higher short-term mortality. However, 10-year conditional survival was similar for biventricular and most single-ventricle CHD patients, and notably better for biventricular CHD patients compared to non-CHD heart transplant recipients. These findings have significant implications towards patient selection and listing strategies, easing concerns related to heart transplantation in adults with CHD and destigmatizing most subtypes of single-ventricle CHD.

Synthesizing secondary data into survival analysis to improve estimation efficiency

The accelerated failure time (AFT) model and Cox proportional hazards (PH) model are broadly used for survival endpoints of primary interest. However, the estimation efficiency from those models can be further enhanced by incorporating the information from secondary outcomes that are increasingly available and highly correlated with primary outcomes. Those secondary outcomes could be longitudinal laboratory measures collected from doctor visits or cross-sectional disease-relevant variables, which are believed to contain extra information related to primary survival endpoints to a certain extent. In this paper, we develop a two-stage estimation framework to combine a survival model with a secondary model that contains secondary outcomes, named as the empirical-likelihood-based weighting (ELW), which comprises two weighting schemes accommodated to the AFT model (ELW-AFT) and the Cox PH model (ELW-Cox), respectively. This innovative framework is flexibly adaptive to secondary outcomes with complex data features, and it leads to more efficient parameter estimation in the survival model even if the secondary model is misspecified. Extensive simulation studies showcase more efficiency gain from ELW compared to conventional approaches, and an application in the Atherosclerosis Risk in Communities study also demonstrates the superiority of ELW by successfully detecting risk factors at the time of hospitalization for acute myocardial infarction.

Special Considerations in Critical Care of the Congenital Heart Disease Patient

Outcomes of congenital heart disease have improved markedly over the past 20 years, with survival to adulthood now close to 90%. The mean age of admission to an intensive care unit (ICU) is 40 years. The incidence of hospital and critical care admissions have increased significantly as a consequence of this improved survival. Intensivists are now confronted with the management not only of complex adult congenital heart disease (ACHD) lesions from a cardiac perspective, but also of extracardiac organ consequences of years of abnormal circulation after surgical or palliative correction. Kidney and liver dysfunction and respiratory and hematologic abnormalities are very common in this population. ACHD patients can present to the ICU for a vast number of reasons, classified in this review as medical noncardiac, medical cardiac, and surgical. Community/hospital-acquired infections, cerebrovascular accidents, and respiratory failure, alongside arrhythmias and heart failure, are responsible for medical admissions. Surgical admissions include postoperative management after correction or palliation, but also medical optimisation and work-up for advanced therapies. ICU management of this large heterogeneous group requires a thorough understanding of the pathophysiology in order to apply conventional adult critical care modalities; left ventricular or right ventricular dysfunction, pulmonary hypertension, intracardiac, extracardiac, and palliative surgical shunts can be present and require additional consideration. This review focuses on the pathophysiology, long-term sequelae, and different treatment modalities to supply a framework for the ICU physician caring for these patients. Successful outcome, especially in complex lesions, depends on early involvement of specialised ACHD centres.

Machine learning-based prediction of mortality after heart transplantation in adults with congenital heart disease: A UNOS database analysis

BACKGROUND

Machine learning (ML) is increasingly being applied in Cardiology to predict outcomes and assist in clinical decision-making. We sought to develop and validate an ML model for the prediction of mortality after heart transplantation (HT) in adults with congenital heart disease (ACHD).

METHODS

The United Network for Organ Sharing (UNOS) database was queried from 2000 to 2020 for ACHD patients who underwent isolated HT. The study cohort was randomly split into derivation (70%) and validation (30%) datasets that were used to train and test a CatBoost ML model. Feature selection was performed using SHapley Additive exPlanations (SHAP). Recipient, donor, procedural, and post-transplant characteristics were tested for their ability to predict mortality. We additionally used SHAP for explainability analysis, as well as individualized mortality risk assessment.

RESULTS

The study cohort included 1033 recipients (median age 34 years, 61% male). At 1 year after HT, there were 205 deaths (19.9%). Out of a total of 49 variables, 10 were selected as highly predictive of 1-year mortality and were used to train the ML model. Area under the curve (AUC) and predictive accuracy for the 1-year ML model were .80 and 75.2%, respectively, and .69 and 74.2% for the 3-year model, respectively. Based on SHAP analysis, hemodialysis of the recipient post-HT had overall the strongest relative impact on 1-year mortality after HΤ, followed by recipient-estimated glomerular filtration rate, age and ischemic time.

CONCLUSIONS

ML models showed satisfactory predictive accuracy of mortality after HT in ACHD and allowed for individualized mortality risk assessment.

Adult Renal Transplantation in a Patient 28 Years after Heart Transplantation as a Neonate for Hypoplastic Left Heart Syndrome

We present a case of kidney transplantation in a 28-year-old patient who received a heart transplant at 7 weeks of age due to hypoplastic left heart syndrome. The patient's renal insufficiency was the result of chronic immunosuppression and hypertension. The almost 28-year-old graft demonstrated very good function. This patient represents as one of the longest pediatric cardiac graft recipients living without any significant functional limitations.

Impact of the new UNOS donor heart allocation system on waitlist outcomes and early posttransplant mortality among adults with congenital heart disease

Adults with congenital heart disease (ACHD) experience worse waitlist outcomes and higher early posttransplant mortality compared to non-ACHD patients. On October 18, 2018; the UNOS donor heart allocation system was redesigned giving unique listing status to ACHD patients. The impact of this change on outcomes in transplant-listed patients is unstudied. Using the Scientific Registry of Transplant Recipients (SRTR) we compared ACHD patients listed for the first-time for heart transplantation from two eras of equal duration. We analyzed waitlist outcomes, posttransplant mortality and length of stay among ACHD patients in both eras and between ACHD and non-ACHD patients in the new era. Of 12 723 listed patients, 535 had ACHD (293 in the new era) and 12 188 did not (6258 in the new era). A total of 163 (56%) ACHD patients in the new era versus 150 (62%) in the prior era were transplanted; 11 (3.8%) versus 15 (6.2%) died on the waitlist; 32 (11%) versus 35 (14%) were delisted and 15 (9.2%) versus 19 (12.7%) died within 30 days of transplant, respectively. The new UNOS donor heart allocation system improved waitlist time and decreased the proportion not transplanted during the first 300 days after listing among ACHD patients without altering early posttransplant outcomes or significantly changing the gap in outcomes compared to non-ACHD patients.

Contemporary outcomes of durable ventricular assist devices in adults with congenital heart disease as a bridge to heart transplantation

OBJECTIVES

This study aimed to compare the clinical characteristics, risk factors, and overall survival outcomes in adults with congenital heart disease (ACHD) bridged to transplantation with a ventricular assist device (VAD) versus no-VAD.

METHODS

The study included 894 ACHD patients aged ≥18 years listed for primary heart transplantation between 2010 and 2019 from the United Network for Organ Sharing database. Primary outcomes were waitlist and 1-year post-transplant mortality between VAD and no-VAD ACHD patients.

RESULTS

Of 894 ACHD patients included in the study, 91(10.1%) had VAD support at the time of listing. Patients who needed VAD support were mostly males, heavier, and had higher pulmonary artery pressure than the no-VAD group at the listing. The overall waitlist mortality was 38% in the VAD group than 17% in the no-VAD group (p < 0.01). ECMO use was associated with significantly higher mortality than either group. There was no significant difference in 1-year post-transplant mortality between VAD versus no-VAD at the time of transplant (15% vs. 17%; p = 0.66). Multivariate regression analysis found that BMI <20 kg/m² (hazard ratio (HR) 1.1; p = 0.01), bilirubin >2 mg/dl (HR 1.1; p = 0.03), creatinine >2 mg/dl (HR 1.3; p = 0.04) and ECMO at transplant (HR 1.4; p = 0.03) increased early post-transplant mortality.

CONCLUSIONS

The one-year post-transplant mortality rate was no different for ACHD patients that received VAD versus no-VAD. These findings suggest that a VAD should be considered an option to support ACHD patients as a bridge to heart transplantation.

Heart transplantation in adults with congenital heart disease: a 17-year single center experience

BACKGROUND

Heart transplantation (HTx) in adults with congenital heart disease (ACHD) remains challenging because of structural anomalies and often previous procedure. The aim of this retrospective study was to describe the outcomes of heart transplantation (HTx) in a cohort of ACHD patients at our tertiary centre.

PATIENTS AND METHODS

Between January 1993 and December 2010, 223 consecutive adult patients (age > 18 years) underwent HTx at our institution. Fifteen (6.7%) were ACHD patients. Outcomes were reviewed using our institution's HTx database. We looked at 30-day, 1, 5 and 10-years survival, as well as post-transplantation complications.

RESULTS

The mean age at HTx of the groups of ACHD was 42 ± 14.4 years, vs 54.2 ± 9.8 years for the non-CHD patients. Prior to transplant, thirteen of the fifteen ACHD had undergone one or more surgical procedures including palliative or corrective open-heart procedures in 66.6% of them. Seven of the fifteen ACHD (47%) required additional surgical procedures at transplantation. The mean follow-up was 95,44 ± 84.3 months. There was no significant difference in survival (ACHD vs non-CHD) at 30 days (87% vs. 90%), 1 year (73% vs. 74.5%) or 5 years (53% vs. 55%). Survival at 10 years was respectively 53% and 41% for ACHD patients and non-CHD patients.

CONCLUSION

Despite the surgical challenge, HTx in ACHD has a good long-term result. However, the small sample size of our cohort limits any definitive conclusions.

Advanced heart failure and heart transplantation in adult congenital heart disease in the current era

BACKGROUND

Adults with congenital heart disease (ACHD) may undergo heart transplantation (HTx) despite increased risk of poor short-term outcomes due to factors including surgical complexity and antibody sensitization. We assessed the clinical characteristics and outcomes of patients with ACHD in the current era referred for HTx at a single high-volume transplant center.

METHODS

From 2010-2020, 37 ACHD patients were evaluated for HTx. ACHD HTx recipients were compared to non-ACHD HTx recipients matched for age, sex, listing status, and prior cardiac surgery.

RESULTS

Of the 37 patients with ACHD, 8 (21.6%) were declined for HTx. Of 29 ACHD patients listed, 19 (65.5%) underwent HTx. Compared with non-ACHD HTx controls, the ACHD HTx recipients had more treated cellular (21.1% vs 15.8%, p = 0.010) and antibody-mediated (15.8% vs 10.5%, p = 0.033) rejection. There was no difference in hospital readmission or allograft vasculopathy at 1 year. There was a nonsignificant higher 1-year mortality in ACHD HTx recipients (21.1% vs 7.9%, p = 0.21).

CONCLUSION

At a high-volume transplant center, ACHD patients undergoing HTx appear to have a marginally higher risk of rejection, but no significant increase in 1-year mortality. With careful selection and management, HTx for patients with ACHD may be feasible in the current era. This article is protected by copyright. All rights reserved.

Transplantation for Congenital Heart Disease: Focus on the Impact of Functionally Univentricular Versus Biventricular Circulation

BACKGROUND

Varying single center data exist regarding the posttransplant outcomes of patients with single ventricle circulation, particularly following the Fontan operation. We sought to better elucidate these results in patients with congenital heart disease (CHD) through combining two national databases.

METHODS

The United Network for Organ Sharing (UNOS) transplantation database was merged with the Pediatric Health Information System (PHIS), an administrative database with 71% of UNOS patients matched. Patients undergoing transplantation at a PHIS hospital from 2006 to 2017 were categorized as single ventricle or biventricular strategy based on their diagnoses and procedures in 90% of patients. When known, single ventricle patients were further analyzed by their palliative stage post-Glenn or post-Fontan (known in 31%).

RESULTS

A total of 1,517 CHD transplantations were identified, 67% with single ventricle strategy (1,016). Single ventricle, biventricular, and indeterminate patients had similar survival (log-rank P > .1). Risk factors for mortality in patients with CHD were extracorporeal membrane oxygenation (ECMO) support at transplant (hazard: 2.27), ABO blood type incompatibility (hazard: 1.61), African American recipient (hazard 1.42), and liver dysfunction (hazard 1.29). A total of 130 confirmed Fontan and 185 confirmed bidirectional Glenn patients underwent transplantation, each with survival equivalent to biventricular patients (log-rank P > .500). For Fontan patients, renal dysfunction (hazard: 5.40) and transplant <1 year after Fontan (hazard 2.82) were found to be associated with mortality.

CONCLUSIONS

Single ventricle patients, as a group, experience similar outcomes as biventricular patients with CHD undergoing transplantation, and this extends to Fontan patients. Risk factors for mortality correlate with end-organ dysfunction as well as race and ABO blood type incompatibility in the CHD population.

Cardiac transplantation in adult congenital heart disease with prior sternotomy

BACKGROUND

Adult congenital heart disease (ACHD) patients who require orthotopic heart transplantation are surgically complex due to anatomical abnormalities and multiple prior surgeries. In this study, we investigated these patients' outcomes using our institutional database.

METHODS

ACHD patients who had prior intracardiac repair and subsequent heart transplant were included (2008-2018). Adult patients without ACHD were extracted as a control. A comparison of patients with functional single ventricular (SV) and biventricular (BV) hearts was performed.

RESULTS

There were 9 SV and 24 BV patients. The SV group had higher central venous pressure/pulmonary capillary wedge pressure (P = .028), hemoglobin concentration (P = .010), alkaline phosphatase (P = .022), and were more likely to have liver congestion (P = .006). Major complications included infection in 16 (48.5%), temporary dialysis in 12 (36.4%), and graft dysfunction requiring perioperative mechanical support in 7 (21.2%). Overall in-hospital mortality was 15.2%. Kaplan-Meier analysis showed a higher, but not statistically significant, survival after 10 years between the ACHD and control groups (ACHD 84.9% vs. control 67.5%, P = .429). There was no significant difference in 10-year survival between SV and BV groups (78% vs. 88%, P = .467).

CONCLUSIONS

Complex ACHD cardiac transplant recipients have a high incidence of early morbidities after transplantation. However, long-term outcomes were acceptable.

No survival benefit associated with waiting for non-lung donor heart transplants for adult recipients with congenital heart disease

BACKGROUND

Adults with congenital heart disease (CHD) awaiting heart transplant (HT) have higher mortality and waitlist removal due to clinical deterioration than those without CHD. The selective use of non-lung donors (NLD) to recover donor pulmonary vasculature to assist in graft implantation may be a contributing factor and is supported by consensus statements despite the recent use of pericardium or graft material as an alternative in pulmonary vascular reconstruction. The impact of selecting NLD for CHD recipients on wait time and mortality has not been evaluated.

METHODS/RESULTS

In the United Network for Organ Sharing (UNOS) Registry, 1271 HT recipients age ≥ 18 with CHD were identified between 1987 and 2016, 68% of which had NLDs. Prior to HT, NLD recipients were significantly less likely to be listed UNOS Status 1A, require mechanical ventilation, or intra-aortic balloon pump support. There was no difference in mean waitlist time (254 vs. 278 days, p = .31), 1-year mortality (82% vs. 80%, p = .81; adjusted odds ratio 1.32, 95% confidence interval [CI] 0.96-1.83, p = .08), or overall mortality (adjusted hazard ratio 1.08, 95% CI 0.86-1.36, p = .48) between recipients from NLD and concomitant lung donors.

CONCLUSIONS

Adult CHD patients who are less critically ill or listed at a lower status are more likely to receive HT from NLD. There is no overall mortality benefit associated with this practice. While specific cases may necessitate waiting for NLD, programs need to re-evaluate whether this should remain a more widespread practice among CHD patients.

Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement on Heart Transplantation: Patient Eligibility, Selection, and Post-Transplantation Care

Significant practice-changing developments have occurred in the care of heart transplantation candidates and recipients over the past decade. This Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement provides evidence-based, expert panel recommendations with values and preferences, and practical tips on: (1) patient selection criteria; (2) selected patient populations; and (3) post transplantation surveillance. The recommendations were developed through systematic review of the literature and using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The evolving areas of importance addressed include transplant recipient age, frailty assessment, pulmonary hypertension evaluation, cannabis use, combined heart and other solid organ transplantation, adult congenital heart disease, cardiac amyloidosis, high sensitization, and post-transplantation management of antibodies to human leukocyte antigen, rejection, cardiac allograft vasculopathy, and long-term noncardiac care. Attention is also given to Canadian-specific management strategies including the prioritization of highly sensitized transplant candidates (status 4S) and heart organ allocation algorithms. The focus topics in this position statement highlight the increased complexity of patients who undergo evaluation for heart transplantation as well as improved patient selection, and advances in post-transplantation management and surveillance that have led to better long-term outcomes for heart transplant recipients.

Heart transplantation at a single tertiary adult congenital heart disease centre: Too little, too late?

BACKGROUND

Heart failure (HF) is the leading cause of death in adults with congenital heart disease (ACHD). Heart transplantation can be an effective therapy for them, albeit unfavourable anatomy, end-organ damage, pulmonary vascular disease, HLA sensitization and lack of robust selection criteria currently limit its application.

METHODS

Consecutive CHD patients considered for heart or combined heart and lung transplantation at our tertiary ACHD centre between 2000 and 2018 constitute our study population. Baseline characteristics and outcome, including transplantation and death, were obtained for all patients from designated databases, medical records and the UK Office for National Statistics.

RESULTS

From a total of more than 9000 active ACHD patients under follow-up, 166 (median age 40.4 years) fulfilled inclusion criteria, with a broad spectrum of underlying diagnosis: univentricular heart 22.3%, systemic right ventricle 22.3%, systemic-to-pulmonary shunts and Eisenmenger syndrome 16.3%, left sided valvular lesions 14.5%, tetralogy of Fallot 12.7%, CHD associated with cardiomyopathy 4.8% and other 7.2%. There was a high overall mortality with 39.2% of patients dying over a median follow-up of 2.7 years. A minority of patients (22.9%) were eventually listed and only 13.3% from the 166 patients were actually transplanted. Survival at 1 year after transplantation was 81.8% and remained high long-term (65.5% at 15 years). We describe herewith in detail characteristics and outcome of our cohort and present the transplantation pathway followed.

CONCLUSION

Of the small number of patients with ACHD considered for heart transplantation at a large tertiary centre, there was high overall mortality, with only a fraction of patients being actually transplanted. Patients who received transplantation, however, had a good outcome. Better patient selection and timing are clearly warranted so that more ACHD patients are considered and potentially benefit from this effective form of therapy.

A Risk Score for Adults With Congenital Heart Disease Undergoing Heart Transplantation

BACKGROUND

This study derived and validated a risk score for 1-year mortality in patients with adult congenital heart disease (ACHD) undergoing orthotopic heart transplantation (OHT).

METHODS

The United Network for Organ Sharing registry identified patients with ACHD (≥18 years of age) who underwent OHT between 1987 and 2018. The primary outcome was 1-year mortality. Associated covariates (univariate P < .2) were entered into a multivariable logistic regression model. Variable inclusion in the model was assessed by improvement in the McFadden pseudo-R², likelihood ratio test, and C-index. A risk score was created using the absolute magnitude of the odds ratios from the derivation cohort, and its ability to predict 1-year mortality was tested in the validation cohort.

RESULTS

A total of 1388 recipients were randomly divided into derivation (66.7%, n = 950) and validation (33.3%, n = 438) cohorts. A 13-point risk score incorporating 4 pretransplant variables (age, dialysis dependence, serum bilirubin level, and mechanical ventilation) was created. The predicted 1-year mortality ranged from 14.6% (0 points) to 49.9% (13 points) (P < .001). In weighted regression analysis, there was a strong correlation between predicted 1-year mortality and observed 1-year mortality in the validation cohort (r = 0.85, P < .001). Logistic regression also demonstrated a significant association (odds ratio, 1.18; 95% confidence interval, 1.1-1.3; P = .004). The Brier score of the composite score in the validation cohort was 0.14. Kaplan-Meier analysis demonstrated that risk scores of 4 points or higher portended worse survival at 1-year posttransplant (P < .001).

CONCLUSIONS

This 13-point risk score for ACHD is predictive of mortality within 1 year after OHT and has potential utilization in improving recipient selection for OHT in adult patients with CHD.

A Review of Heart Transplantation for Adults With Congenital Heart Disease

As techniques for corrective and palliative surgery in congenital heart disease improve, the number of patients surviving to become adults with congenital heart disease (ACHD) has increased. A significant proportion of these patients will progress to develop advanced heart failure, the symptoms of which vary, complicating prediction of life expectancy. Unlike acquired heart failure, there is a lack of evidence-based treatments with which to relieve symptoms and prolong survival. As a result, a number of ACHD patients will proceed to heart transplantation. Referral for transplantation should be considered early, given the difficulties with prognostication, and should take place in a center with surgical and medical expertise in the management of ACHD patients and transplantation. In addition to assessing contraindications to heart transplantation for the general population, factors specific to ACHD should be considered. These include pulmonary hypertension, cyanosis, liver disease, previous surgeries, and the degree of allosensitization. Once listed for transplantation, ACHD patients spend longer on the waitlist, and are more likely to die or be delisted than their non-ACHD counterparts. Mechanical circulatory support is used less commonly as a bridge to transplantation given the difficulties with implantation and unfamiliarity of use. Recent evidence suggests that with increased experience and early consideration, mechanical circulatory support can be used successfully as a bridging therapy. Despite a higher early mortality, long-term survival is greater for ACHD patients after transplant due to younger age and relative lack of comorbidities. With early referral, careful assessment of each individual's unique anatomy and physiology, and care in a center experienced with ACHD patients and transplantation, outcomes will continue to improve.

Transplant and mechanical circulatory support in patients with adult congenital heart disease

Advances in surgery and pediatric care over the past decades have achieved improved survival for children born with congenital heart disease (CHD) and have produced a large, growing population of patients with adult congenital heart disease (ACHD). Heart failure has emerged as the leading cause of death and a major cause of morbidity among the ACHD population, while as little evidence supports the efficacy of guideline-directed medical therapies in this population. It is increasingly important that clinicians caring for these patients understand how to utilize mechanical circulatory support (MCS) in ACHD. In this review, we summarize the data on transplantation and MCS in the ACHD-heart failure population and provide a framework for how ACHD patients may benefit from advanced heart failure therapies like transplantation and MCS.

Post-transplant survival in adult congenital heart disease patients as compared to dilated and ischemic cardiomyopathy patients; an analysis of the thoracic ISHLT registry

Previous studies have shown that adult congenital heart disease (ACHD) is associated with high early post-transplant mortality but improved long-term survival in comparison to the overall heart transplant population. We aimed to evaluate survival outcomes of ACHD in adult transplant recipient patients as specifically compared to ischemic (ICM) and dilated cardiomyopathy (DCM) groups. Adult heart transplant recipients between 2004 and 2014 were identified from the ISHLT registry. We used Kaplan-Meier analysis to evaluate overall survival, 1-year survival, and 1-year conditional survival among etiology groups and multivariable Cox proportional hazard (PH) models to assess the association between etiology of cardiomyopathy and 1-year and long-term all-cause mortality and cause-specific mortality. We included 30 130 heart transplant recipients. One-year survival was 78.3% in ACHD, 84.3% in ICM, and 86.2% in DCM patients (P < .001). By multivariable analysis, during first post-transplant year, ACHD and ICM patients were at significantly higher mortality risk than DCM. Adjusted post-transplant mortality risk, conditional on 1-year survival, was not statistically different in ACHD and DCM while ICM patients had 17% higher long-term mortality risk than DCM patients leading to overall worse outcomes in ICM patients. Therefore, ICM patients have poorer outcomes in comparison to both DCM and ACHD patients.

Comparison of Heart Transplantation Outcomes: Adult Congenital Heart Disease vs Matched Cardiac Patients in a Quaternary Reference Centre

BACKGROUND

The number of transplantations performed for adult congenital heart disease (ACHD) patients is increasing. We sought to compare survival and post-transplantation complications, including graft failure, rejection, dialysis, and use of a right ventricular assist device, between ACHD and a cohort of dilated (DCM) and ischemic (ICM) cardiomyopathy patients matched by age and year of transplantation.

METHODS

We retrospectively reviewed our single-institution heart transplantation database and selected all patients who had surgery from 1988 to 2017. In our primary analysis, we looked at survival and post-transplantation complications across cardiomyopathy groups. Our secondary analysis was matched to mitigate era effects as well as differences in age at transplant.

RESULTS

We analyzed a cohort consisting of 303 heart transplant patients with cardiomyopathy due to either 1) ACHD (n = 38), 2) ICM (n = 110), or 3) DCM (n = 155). Kaplan-Meier analysis and a multivariable Cox proportional hazard regression model were used for all-cause mortality, and cause-specific hazard regression for cause-specific mortality and morbidity. There was no statistically significant survival difference across groups. The 1-year survival was 68.5% for ACHD, 85.4% for ICM, and 85.5% for DCM. In multivariable analysis, ICM and DCM patients showed a 66% lower risk of death relative to the ACHD group. The matched analysis showed no significant difference in survival across groups.

CONCLUSIONS

ACHD patients represent a growing high-risk patient cohort referred for transplantation. To improve survival outcomes we need to address modifiable risk factors.

Adult Congenital Heart Disease: Current Early Expectations After Cardiac Transplantation

BACKGROUND

Early mortality has plagued the otherwise good outcomes of heart transplantation in patients with adult congenital heart disease (ACHD), but perioperative care is improving. This study sought to identify risk factors for 1-year mortality currently and examine the results of patients without those risk factors compared with patients who did not have ACHD (nACHD).

METHODS

The United Network of Organ Sharing database was searched for all adult (>17 years of age) heart transplant recipients from 2000 to 2018. They were divided into an early era and a late era. A multivariate analysis identified risk factors for 1-year mortality in the late era. Patients without these risk factors were compared with the nACHD group by Kaplan-Meier analysis.

RESULTS

A total of 495 patients with ACHD were identified from 2000 to 2008, and 666 were identified from 2009 to 2018. The recent era had better 1-year survival (P <.001) and overall survival (P = .003) than did the era from 2000 to 2008. Patients with ACHD were different from the nACHD population in age (37 years vs 57 years), body mass index greater than 25 kg/m² (45% vs 66%), incidence of renal dysfunction (23% vs 28%) and liver dysfunction (29% vs 23%), sensitization (38% vs 29%), and ischemic times (3.5 hours vs 3.1 hours). Multivariate analysis identified body mass index greater than 25 kg/m² (hazard ratio [HR], 1.79), renal dysfunction (HR, 1.85), liver dysfunction (HR, 1.69), and longer ischemic time (HR, 1.46) as risk factors for early mortality. Patients with only 1 of the first 3 categorical risk factors had 1-year survival comparable to that reported in patients with nACHD.

CONCLUSIONS

Patients with ACHD had better early and long-term outcomes in the recent era. When only 1 of 3 pretransplant risk factors for early mortality was present, patients had survival equal to that of nACHD patients and perhaps better long-term survival.

Heart Failure in Adult Congenital Heart Disease: From Advanced Therapies to End-of-Life Care

There is mounting recognition that some of the most urgent problems of adult congenital heart disease (ACHD) are the prevention, diagnosis, and management of heart failure (HF). Recent expert consensus and position statements not only emphasize a specific and pressing need to tackle HF in ACHD (ACHD-HF) but also highlight the difficulty of doing so given a current sparsity of data. Some of the challenges will be addressed by this review. The authors are from 3 different centres; each centre has an established subspeciality ACHD-HF clinic and is able to provide heart transplant, multiorgan transplant, and mechanical support for patients with ACHD. Appropriate care of this complex population requires multidisciplinary ACHD-HF teams evaluate all possible treatment options. The risks and benefits of nontransplant ACHD surgery, percutaneous structural and electrophysiological intervention, and ongoing conservative management must be considered alongside those of transplant strategies. In our approach, advanced care planning and palliative care coexist with the consideration of advanced therapies. An ethos of shared decision making, guided by the patient's values and preferences, strengthens clinical care, but requires investment of time as well as skilled communication. In this review, we aim to offer practical real-world advice for managing these patients, supported by scientific data where it exists.

Natural history of a systemic right ventricle

The natural history of a systemic right ventricle after an atrial switch procedure has yet to be fully characterised. We describe the case of the longest surviving patient at our institution who underwent a Mustard Baffle correction for dextro-transposition of great arteries in childhood. Over following decades he was reviewed regularly with deteriorating systemic right ventricle function. At around 50 years of age he developed worsening heart failure on maximal medical therapy. He was subsequently assessed for cardiac transplantation which he underwent successfully at the age of 55 years.

Pulmonary arterial hypertension in adults with systemic right ventricles referred for cardiac transplantation

BACKGROUND

Systemic right ventricular (RV) failure may progress necessitating referral for orthotropic heart transplantation (OHT). Pulmonary hypertension (PH) frequently coexists in adult congenital heart disease and can complicate the assessment for OHT.

METHODS

Single-center case series of six patients (median age 34.9 years [IQR, 31.9-42.4]) with systemic RV physiology with PH referred for OHT evaluation from 2008 to 2017.

RESULTS

One-third (n = 6) of 18 patients with systemic RV physiology referred for OHT evaluation had pulmonary arterial hypertension (PAH) defined as mean pulmonary artery pressure (mPAP) > 25 mm Hg and pulmonary vascular resistance (PVR) > 3 Wood Units. Two of the six patients were considered OHT-ineligible due to PH and comorbidities. Of the remaining four, two had pre-capillary PH and underwent heart-lung transplant (HLTx). The other two demonstrated reversibility of PVR with vasodilator testing and underwent OHT alone, one of whom died post-transplant from PH crisis.

CONCLUSIONS

Pulmonary arterial hypertension is common in systemic RV patients referred for OHT. Systemic RV dysfunction places these patients at risk for post-capillary PH but pre-capillary PH can exist. Despite management with selective pulmonary vasodilators and afterload reduction, criteria for listing patients for HLTx vs OHT are not known and need further elucidation.

Heart Transplantation and Mechanical Circulatory Support in Adults with Congenital Heart Disease

PURPOSE OF REVIEW

To assess current management strategies for advanced heart failure in adults with congenital heart disease, including heart transplantation and mechanical circulatory support.

RECENT FINDINGS

Current data demonstrate that adults with CHD generally experience higher short-term mortality after heart transplantation and MCS implantation, but enjoy superior long-term survival. Such patients are nonetheless less likely to receive a transplant than non-ACHD peers due to a variety of factors, including lack of applicability of current listing criteria to HF in ACHD. MCS is underutilized in ACHD, but provides similar quality of life benefits for ACHD and non-ACHD patients alike. Heart failure in ACHD is complex and difficult to treat, and both heart transplantation and mechanical circulatory support are often challenging to implement in this patient population. However, long-term results are encouraging, and existing data supports increasing use of MCS and transplant earlier in their disease course. Multidisciplinary care is critical to success in these complex patients.

Administrative health databases for addressing emerging issues in adults with CHD: a systematic review

The need for population-based studies of adults with CHD has motivated the growing use of secondary analyses of administrative health data in a variety of jurisdictions worldwide. We aimed at systematically reviewing all studies using administrative health data sources for adult CHD research from 2006 to 2016. Using PubMed and Embase (1 January, 2006 to 1 January, 2016), we identified 2217 abstracts, from which 59 studies were included in this review. These comprised 12 different data sources from six countries. Of these, 55% originated in the United States of America, 28% in Canada, and 17% in Europe and Asia. No study was published before 2007, after which the number of publications grew exponentially. In all, 41% of the studies were cross-sectional and 25% were retrospective cohort studies with a wide variation in the availability of patient-level compared with hospitalisation-level episodes of care; 58% of studies from eight different data sources linked administrative data at a patient level; and 37% of studies reported validation procedures. Assessing resource utilisation and temporal trends of relevant epidemiological and outcome end points were the most reported objectives. The median impact factor of publication journals was 4.04, with an interquartile range of 3.15, 7.44. Although not designed for research purposes, administrative health databases have become powerful data sources for studying adult CHD populations because of their large sample sizes, comprehensive records, and long observation periods, providing a useful tool to further develop quality of care improvement programmes. Data linkage with electronic records will become important in obtaining more granular life-long adult CHD data. The health services nature of the data optimises the impact on policy and public health.

Predictors of 1-year mortality in heart transplant recipients: a systematic review and meta-analysis

Objective

A systematic summary of the observational studies informing heart transplant guideline recommendations for selection of candidates and donors has thus far been unavailable. We performed a meta-analysis to better understand the impact of such known risk factors.

Methods

We systematically searched and meta-analysed the association between known pretransplant factor and 1-year mortality identified by multivariable regression models. Our review used the Grading of Recommendations, Assessment, Development and Evaluation for assessing the quality of assessment. We pooled risk estimates by using random effects models.

Results

Recipient variables including age (HR 1.16 per 10-year increase, 95% CI 1.10–1.22, high quality), congenital aetiology (HR 2.35, 95% CI 1.62 to 3.41, moderate quality), diabetes (HR 1.37, 95% CI 1.15 to 1.62, high quality), creatinine (HR 1.11 per 1 mg/dL increase, 95% CI 1.06 to 1.16, high quality), mechanical ventilation (HR 2.46, 95% CI 1.48 to 4.09, low quality) and short-term mechanical circulatory support (MCS) (HR 2.47, 95% CI 1.04 to 5.87, low quality) were significantly associated with 1-year mortality. Donor age (HR 1.20 per 10-year increase, 95% CI 1.14 to 1.26, high quality) and female donor to male recipient sex mismatch (HR 1.38, 95% CI 1.06 to 1.80, high quality) were significantly associated with 1-year mortality. None of the operative factors proved significant predictors.

Conclusion

High-quality and moderate-quality evidence demonstrates that recipient age, congenital aetiology, creatinine, pulsatile MCS, donor age and female donor to male recipient sex mismatch are associated with 1-year mortality post heart transplant. The results of this study should inform future guideline and predictive model development.

Application and interpretation of histocompatibility data in thoracic (heart and lung) transplantation

PURPOSE OF REVIEW

The purpose of the review is to update our current understanding and utilization of immunogenetic tools in heart and lung transplant.

RECENT FINDINGS

Increasingly, complex patients have been managed perioperatively for heart and lung transplant using a variety of tests and techniques. Recent treatment regimens and listing strategies have exploited recent laboratory advances. However, the better characterization has led to an even more complex description of sensitized heart and lung candidates. Several recent studies have examined antibody strengths and behavior to guide clinical decision-making and examine postoperative outcomes. Finally, non-human leukocyte antigen antibodies have emerged as possible determinants of allograft outcome in heart and lung transplant.

SUMMARY

Heart and lung transplant candidates with preformed and de-novo posttransplant antibodies continue to represent a challenging and high-risk group of patients. Modern immunogenetic techniques have broadened our understanding and have revealed an even more complex relationship between antibodies, allografts, and outcomes.

Heart transplantation for adults with congenital heart disease: current status and future prospects

Increased survival rates after corrective or palliative surgery for complex congenital heart disease (CHD) in infancy and childhood are now being coupled with increased numbers of patients who survive to adulthood with various residual lesions or sequelae. These patients are likely to deteriorate in cardiac function or end-organ function, eventually requiring lifesaving treatment including heart transplantation. Although early and late outcomes of heart transplantation have been improving for adult survivors of CHD, outcomes and pretransplant management could still be improved. Survivors of Fontan procedures are a vulnerable cohort, particularly when single ventricle physiology fails, mostly with protein-losing enteropathy and hepatic dysfunction. Therefore, we reviewed single-institution and larger database analyses of adults who underwent heart transplantation for CHD, to enable risk stratification by identifying the indications and outcomes. As the results, despite relatively high early mortality, long-term results were encouraging after heart transplantation. However, further investigations are needed to improve the indication criteria for complex CHD, especially for failed Fontan. In addition, the current system of status criteria and donor heart allocation system in heart transplantation should be arranged as suitable for adults with complex CHD. Furthermore, there is a strong need to develop ventricular assist devices as a bridge to transplantation or destination therapy, especially where right-sided circulatory support is needed.

B-type natriuretic peptide: powerful predictor of end-stage chronic heart failure in individuals with systolic dysfunction of the systemic right ventricle

AIM

To assess whether B-type natriuretic peptide (BNP) can serve as a predictor of end-stage chronic heart failure (CHF) in patients with severe systolic dysfunction of the systemic right ventricle (SRV).

METHODS

We performed a retrospective analysis in 28 patients with severe systolic dysfunction of the SRV (ejection fraction 23 ± 6%) who were evaluated as heart transplant (HTx) candidates between May 2007 and October 2014. The primary endpoints of the study (end-stage CHF) were progressive CHF, urgent HTx, and ventricular assist device (VAD) implantation. Plasma BNP levels were measured using a chemiluminescent immunoassay.

RESULTS

During median follow-up of 29 months (interquartile range, 9-50), 3 patients died of progressive CHF, 5 patients required an urgent HTx, and 6 patients underwent VAD implantation. BNP was a strong predictor of end-stage CHF (hazard ratio per 100 ng/L: 1.079, 95% confidence interval, 1.042-1.117, P<0.001). The following variables with corresponding areas under the curve (AUC) were identified as the most significant predictors of end-stage CHF: BNP (AUC 1.00), New York Heart Association functional class class III or IV (AUC 0.98), decompensated CHF in the last year (AUC 0.96), and systolic dysfunction of the subpulmonal ventricle (AUC 0.96).

CONCLUSION

BNP is a powerful predictor of end-stage CHF in individuals with systolic dysfunction of the SRV.

HeartWare Ventricular Assist Device Implantation in Patients With Fontan Physiology

We aim to describe the clinical course of a series of patients with hypoplastic left heart syndrome and refractory systolic heart failure supported with a HeartWare ventricular assist device (HVAD) following Fontan palliation. This is a retrospective review of three consecutive patients supported with a HVAD following Fontan palliation through February 2016. Data include patient characteristics, operative variables, postimplantation hemodynamic/device parameters, event outcomes, and duration of HVAD support. Patient ages were 11.7, 13.5, and 17.5 years, respectively, at the time of HVAD implant. The duration of HVAD support was 148, 272, and 271 days, respectively, of which 86, 222, and 211 were outpatient days. Inflow cannula position was the morphologic right ventricle with depth adjustment and manipulation of the tricuspid subvalvar apparatus to ensure good inflow. Echocardiographic, hemodynamic, and noninvasive oximetric monitoring resulted in high RPM settings for all patients. Despite various complications, all patients were successfully transplanted and discharged home alive. We present three patients bridged to transplantation using the HVAD following Fontan palliation. We demonstrate potential for durable support with transition to outpatient care while awaiting heart transplantation in a subset of patients status post Fontan surgery.

Current Expectations for Cardiac Transplantation in Patients With Congenital Heart Disease

Congenital heart disease accounts for 40% of pediatric heart transplants and presents unique challenges to the transplant team. Suitability for transplantation is defined in part by degree of sensitization, pulmonary vascular resistance, and hepatic reserves. The incremental transplant risk for patients with congenital heart disease occurs within the first 3 months, after which survival is equivalent to transplantation for cardiomyopathy. Single ventricle with prior palliation, and especially the failing Fontan, carry the highest risk for transplantation and are least amenable to bridging with mechanical circulatory support. More effective bridging to transplant with mechanical circulatory support will require improvements in the adverse event profile of available pumps and the introduction of miniaturized continuous flow technology. The major barriers to routine long-term survival are chronic allograft failure and allograft vasculopathy. Despite these many challenges, continuing improvements in the care of pediatric heart transplant patients have pushed the median posttransplant survival past 15 years for children and to 20 years for infants.