Heart transplantation and in‐hospital outcomes in adult congenital heart disease patients with Fontan: A decade nationwide analysis from 2004 to 2014

The majority of pediatric Fontan patients have excellent post-transplant survival

OBJECTIVE

Many pediatric Fontan patients require heart transplant, but this cohort is understudied given the difficulty in identifying these patients in national registries. We sought to characterize survival post-transplant in a large cohort of pediatric patients undergoing the Fontan.

METHODS

The United Network for Organ Sharing and Pediatric Health Information System were used to identify Fontan heart transplant recipients aged less than 18 years (n = 241) between 2005 and 2022. Decompensation was defined as the presence of extracorporeal membrane oxygenation, ventilation, hepatic/renal dysfunction, paralytics, or total parenteral nutrition at transplant.

RESULTS

Median age at transplant was 9 (interquartile range, 5-12) years. Median waitlist time was 107 (37-229) days. Median volume across 32 center was 8 (3-11) cases. Approximately half (n = 107, 45%) of recipients had 1A/1 initial listing status. Sixty-four patients (28%) were functionally impaired at transplant, 10 patients (4%) were ventilated, and 18 patients (8%) had ventricular assist device support. Fifty-nine patients (25%) had hepatic dysfunction, and 15 patients (6%) had renal dysfunction. Twenty-one patients (9%) were dependent on total parenteral nutrition. Median postoperative stay was 24 (14-46) days, and in-hospital mortality was 7%. Kaplan-Meier analysis showed 1- and 5-year survivals of 89% (95% CI, 85-94) and 74% (95% CI, 81-86), respectively. Kaplan-Meier of Fontan patients without decompensation (n = 154) at transplant demonstrated 1- and 5-year survivals of 93% (95% CI, 88-97) and 88% (95% CI, 82-94), respectively. In-hospital mortality was higher in decompensated patients (11% vs 4%, P = .023). Multivariable analysis showed that decompensation predicted worse post-transplant survival (hazard ratio, 2.47; 95% CI, 1.16-5.22; P = .018), whereas older age at transplant predicted superior post-transplant survival (hazard ratio, 0.89/year; 95% CI, 0.80-0.98; P = .019).

CONCLUSIONS

Pediatric Fontan post-transplant outcomes are promising, although early mortality remains high. For nondecompensated pediatric patients at transplant without end-organ disease (>63% of cohort), early mortality is circumvented and post-transplant survival is excellent and similar to all pediatric transplantation.

Cardiac magnetic resonance ventricular parameters correlate with cardiopulmonary fitness in patients with functional single ventricle

Owing to advances in medical and surgical fields, patients with single ventricle (SV) have a greatly improved life expectancy. However, progressive functional deterioration is observed over time, with a decrease in cardiopulmonary fitness. This study aimed to identify, in patients with SV, the association between cardiac magnetic resonance imaging (CMR) parameters and change in cardiopulmonary fitness assessed by cardiopulmonary exercise test (CPET), and if certain thresholds could anticipate a decline in aerobic fitness. Patients with an SV physiology were retrospectively screened from 2011 and 2021 in a single-centre observational study. We evaluated (1) the correlation between baseline CMR and CPET parameters, (2) the association between baseline CMR results and change in peak oxygen uptake (peak VO2), and (3) the cut-off values of end-diastolic and end-systolic volume index in patients with an impaired cardiopulmonary fitness (low peak VO2 and/or high VE/VCO2 slope). 32 patients were included in the study. End-systolic volume index (r = 0.37, p = 0.03), end-diastolic volume index (r = 0.45, p = 0.01), and cardiac index (r = 0.46, p = 0.01) correlated with the VE/VCO2 slope. End-systolic ventricular volume (r = - 0.39, p = 0.01), end-diastolic ventricular volume (r = - 0.38, p = 0.01), and cardiac output (r = - 0.45, p < 0.01) inversely correlated with the peak VO2. In multivariate analysis, the cardiac index obtained from baseline CMR was inversely associated with the change in peak VO2 (p < 0.01). An end-diastolic volume index > 101 ml/m2 and an end-systolic volume index > 47 ml/m2 discriminated patients with impaired cardiopulmonary fitness. CMR parameters correlate with cardiopulmonary fitness in patients with SV and can therefore be useful for follow-up and therapeutic management of these patients.

Mortality and morbidity after combined heart and liver transplantation in the failing Fontan: An updated dual center retrospective study

INTRODUCTION

As the adult Fontan population with Fontan associated liver disease continues to increase, more patients are being referred for transplantation, including combined heart and liver transplantation.

METHODS

We report updated mortality and morbidity outcomes after combined heart and liver transplant in a retrospective cohort series of 40 patients (age 14 to 49 years) with Fontan circulation across two centers from 2006-2022.

RESULTS

The 30-day, 1-year, 5-year and 10-year survival rate was 90%, 80%, 73% and 73% respectively. Sixty percent of patients met a composite comorbidity of needing either post-transplant mechanical circulatory support, renal replacement therapy or tracheostomy. Cardiopulmonary bypass time > 283 min (4.7 h) and meeting the composite comorbidity were associated with mortality by Kaplan Meier analysis.

CONCLUSION

Further study to mitigate early mortality and the above comorbidities as well as the high risk of bleeding and vasoplegia in this patient population is warranted.

Combined Heart-Liver vs Isolated Heart Transplantation in Adults With Congenital Heart Disease

BACKGROUND

Despite an increasing number of adults with congenital heart disease undergoing combined heart-liver transplantation (CHLT), there is a paucity of literature analyzing posttransplant outcomes. We analyzed the incidence and outcomes of congenital heart disease patients undergoing CHLT compared with those undergoing isolated heart transplantation (HT).

METHODS

This was a retrospective analysis of all adult (≥18 years) congenital heart disease patients undergoing CHLT or HT between 2000 and 2020 in the Organ Procurement and Transplantation Network database. The primary outcome was death at 30 days and 1 year after transplantation.

RESULTS

Of 1214 recipients included for analysis, 92 (8%) underwent CHLT and 1122 (92%) underwent HT. Patients undergoing CHLT and HT were similar in the distribution of age, sex, and serum bilirubin. Upon adjusted analysis with HT as the reference, undergoing CHLT was associated with a similar hazard of 30-day mortality between 2000 and 2017 (hazard ratio [HR], 0.51; 95% CI, 0.12-2.08; P = .35) and 2018 and 2020 (HR, 2.32; 95% CI, 0.88-6.13; P = .09). Similarly, there was no difference in the hazard of 1-year mortality for patients undergoing CHLT between 2000 and 2017 (HR, 0.60; 95% CI, 0.22-1.63; P = .32) and 2018 and 2020 (HR, 1.52; 95% CI, 0.66-3.53; P = .33) compared with HT.

CONCLUSIONS

The number of adults undergoing CHLT continues to rise. Given comparable survival outcomes between CHLT and HT, our findings demonstrate the former as a viable option for complex congenital heart disease patients with failing cavopulmonary circulation and associated liver disease. Future studies should delineate factors associated with early hepatic dysfunction to help identify congenital heart disease patients that would benefit from CHLT.

Heart transplantation surgery in children and young adults with congenital heart disease

BACKGROUND

Pediatric cardiac transplantation remains a surgical challenge as a variety of cardiac and vessel malformation are present in patients with congenital heart disease (CHD). Despite limited availability and acceptability of donor hearts, the number of heart transplantations remains on a stable level with improved survival and quality of life.

OBSERVATION

As treatment options for CHD continue to improve and the chances of survival increase, more adult CHD patients are listed for transplantation. This review focuses on the clinical challenges and modified techniques of pediatric heart transplantations.

CONCLUSION

Not only knowledge of the exact anatomy, but above all careful planning, interdisciplinary cooperation and surgical experience are prerequisites for surgical success.

Morbidity and Mortality in Adult Fontan Patients After Heart or Combined Heart-Liver Transplantation

BACKGROUND

An increasing number of adult Fontan patients require heart transplantation (HT) or combined heart-liver transplant (CHLT); however, data regarding outcomes and optimal referral time remain limited.

OBJECTIVES

The purpose of this study was to define survivorship post-HT/CHLT and predictors of post-transplant mortality, including timing of referral, in the adult Fontan population.

METHODS

A retrospective cohort study of adult Fontan patients who underwent HT or CHLT across 15 centers in the United States and Canada was performed. Inclusion criteria included the following: 1) Fontan; 2) HT/CHLT referral; and 3) age ≥16 years at the time of referral. Date of "failing" Fontan was defined as the earliest of the following: worsening fluid retention, new ascites, refractory arrhythmia, "failing Fontan" diagnosis by treating cardiologist, or admission for heart failure.

RESULTS

A total of 131 patients underwent transplant, including 40 CHLT, from 1995 to 2021 with a median post-transplant follow-up time of 1.6 years (Q1 0.35 years, Q3 4.3 years). Survival was 79% at 1 year and 66% at 5 years. Survival differed by decade of transplantation and was 87% at 1 year and 76% at 5 years after 2010. Time from Fontan failure to evaluation (HR/year: 1.23 [95% CI: 1.11-1.36]; P < 0.001) and markers of failure, including NYHA functional class IV (HR: 2.29 [95% CI: 1.10-5.28]; P = 0.050), lower extremity varicosities (HR: 3.92 [95% CI: 1.68-9.14]; P = 0.002), and venovenous collaterals (HR: 2.70 [95% CI: 1.17-6.20]; P = 0.019), were associated with decreased post-transplant survival at 1 year in a bivariate model that included transplant decade.

CONCLUSIONS

In our multicenter cohort, post-transplant survival improved over time. Late referral after Fontan failure and markers of failing Fontan physiology, including worse functional status, lower extremity varicosities, and venovenous collaterals, were associated with post-transplant mortality.

Heart transplant indications, considerations and outcomes in Fontan patients: Age-related nuances, transplant listing and disease-specific indications

In the current era, 5-10% of Fontan patients die or need a transplant in childhood, and approximately 50% will experience the same fate by age 40 years. Heart transplant (HTx) can be successful for selected children and adults with Fontan circulatory failure (FCF) of any mechanism, with a 1-year post-transplant survival approaching 90% in children and 80% in the largest single-centre adult Fontan HTx experience. Protein losing enteropathy and plastic bronchitis can be expected to resolve post-transplant and limited data suggests patients with FALD who survive HTx can expect improvement in liver health. Early Fontan failure, within 12 months of Fontan completion, is not easily rescued by HTx and late referrals / failure to refer adult patients remains problematic. Very little is known about the numbers of patients not referred, turned down following assessment for HTx, or dying on the waiting list which are needed to understand the complete picture of HTx in the Fontan population and to identify where best to focus quality improvement efforts. Recent revisions to listing prioritization in Canada with considerations specific to the Fontan population aim to mitigate the fact that the status listing criteria are not tailored to the congenital heart population. Transplanting high-risk children prior to Fontan completion, developing ACHD transplant centres of expertise which can also offer combined heart-liver transplant when appropriate, and improving single ventricle mechanical support options and criteria for both adults and children may help mitigate the early post-listing mortality.

Complications and management of functional single ventricle patients with Fontan circulation: From surgeon's point of view

Fontan surgery by step-wise completing the isolation of originally mixed pulmonary and systemic circulation provides an operative approach for functional single-ventricle patients not amenable to biventricular repair and allows their survival into adulthood. In the absence of a subpulmonic pumping chamber, however, the unphysiological Fontan circulation consequently results in diminished cardiac output and elevated central venous pressure, in which multiple short-term or long-term complications may develop. Current understanding of the Fontan-associated complications, particularly toward etiology and pathophysiology, is extremely incomplete. What's more, ongoing efforts have been made to manage these complications to weaken the Fontan-associated adverse impact and improve the life quality, but strategies are ill-defined. Herein, this review summarizes recent studies on cardiac and non-cardiac complications associated with Fontan circulation, focusing on significance or severity, etiology, pathophysiology, prevalence, risk factors, surveillance, or diagnosis. From the perspective of surgeons, we also discuss the management of the Fontan circulation based on current evidence, including post-operative administration of antithrombotic agents, ablation, pacemaker implantation, mechanical circulatory support, and final orthotopic heart transplantation, etc., to standardize diagnosis and treatment in the future.

Failures of the Fontan System in Univentricular Hearts and Mortality Risk in Heart Transplantation: A Systematic Review and Meta-Analysis

The Fontan procedure (FP) is the standard surgical treatment for Univentricular heart diseases. Over time, the Fontan system fails, leading to pathologies such as protein-losing enteropathy (PLE), plastic bronchitis (PB), and heart failure (HF). FP should be considered as a transitional step to the final treatment: heart transplantation (HT). This systematic review and meta-analysis aims to establish the risk of death following HT according to the presence of FP complications. There was a total of 691 transplanted patients in the 18 articles, immediate survival 88% (n = 448), survival from 1 to 5 years of 78% (n = 427) and survival from 5.1 to 10 years of 69% (n = 208), >10 years 61% (n = 109). The relative risk (RR) was 1.12 for PLE (95% confidence interval [CI] = 0.89-1.40, p = 0.34), 1.03 for HF (0.7-1.51, p = 0.88), 0.70 for Arrhythmias (0.39-1.24, p = 0.22), 0.46 for PB (0.08-2.72, p = 0.39), and 5.81 for CKD (1.70-19.88, p = 0.005). In patients with two or more failures, the RR was 1.94 (0.99-3.81, p = 0.05). After FP, the risk of death after HT is associated with CKD and with the presence of two or more failures.

Anticoagulation management in adult patients with congenital heart disease: a narrative review

With improvements in treatment of congenital heart disease more paediatric patients are surviving with palliative or corrective interventions during childhood, thus becoming adults with congenital heart disease (ACHD). Overall, the ACHD population is at a higher risk of arrhythmias and stroke. The abnormal structure and function of their corrected hearts suggests that in addition to established stroke risk factors, such as prior stroke or older age, additional stroke risk factors need to be considered to determine the risk and establish the indication for oral anticoagulation (OAC) in ACHD patients. In structurally normal hearts non-vitamin-K oral anticoagulants (NOACs) offer at least equal stroke prevention with a better safety profile compared to vitamin K antagonists (VKA) in patients with atrial fibrillation (AF) or pulmonary embolism. Current guidelines recommend NOACs in ACHD patients with simple lesions and indication for OAC, while there is less certainty about their safety in ACHD patients with moderate or complex congenital heart disease such as patients with transposition of the great arteries (TGA) after atrial switch operation (Senning or Mustard operation), Fontan circulation or congenital corrected transposition of the great arteries (ccTGA). This review summarises the available evidence characterising stroke risk in patients with ACHD and the use of anticoagulants and interventional therapies to reduce that risk.

Improving outcomes for transplantation in failing Fontan—what is the next target?

Objective

To identify the key contributors to postoperative mortality in patients undergoing orthotopic heart transplantation (OHT) for late Fontan failure.

Methods

This retrospective review of failing Fontan patients who underwent OHT in our tertiary care center between 2007 and 2019 included adult patients with congenital heart disease and single ventricle physiology who were palliated with a Fontan circulation for >1 year. We excluded patients undergoing combined heart-liver transplantation.

Results

The study cohort comprised 31 patients, including 18 males (58.1%), with a mean weight of 58.4 kg, median age at Fontan of 6.9 years (interquartile range [IQR], 2-38 years), and a median age at OHT of 27.1 years (IQR, 16.7-53.3). Almost all (93.5%) of the patients were in New York Heart Association class III-IV, and the majority (74.2%) were in Interagency Registry for Mechanically Assisted Circulatory Support class 3. Overall survival at 30 days, 1 year, and 5 years after OHT was 81%, 71%, and 67%, respectively. Major intraoperative bleeding was associated with increased mortality after OHT (odds ratio, 30; 95% confidence interval, 2.8-322; P = .002). Neither preoperative systemic ventricular function nor the development of primary graft dysfunction (PGD) was significantly associated with postoperative death. Nevertheless, PGD determined significant morbidity of this population.

Conclusions

In our cohort, major intraoperative bleeding was the key factor associated with mortality after OHT for late Fontan failure. Novel strategies for the prevention and management of postoperative bleeding will improve outcomes in this group of patients.

Cardiac transplantation in adults with congenital heart disease: A single center case series

BACKGROUND

Adult congenital heart disease (CHD) transplant recipients historically experienced worse survival early after transplantation. We aim to review updated trends in adult CHD transplantation.

METHODS

We performed a single center case series of adult cardiac transplants from January 2013 through July 2020. Outcomes of patients with CHD were compared to non-CHD. The primary outcome was overall survival. Secondary outcomes included a variety of post-operative complications.

RESULTS

18/262 (7%) transplants were CHD recipients. CHD patients were younger with median age 41 (32-47) versus 58 (48-65) (P < .001). Fontan circulation for single ventricle physiology was present in 4/18 (22%) of CHD recipients, while 16/18 (89%) had systemic right ventricles. CHD recipients had higher rates of previous cardiovascular operations (94% vs. 51%, P < .001). 9/18 (50%) of CHD patients required reconstructive procedures at the time of transplant. Operative and cardiopulmonary bypass times were longer for the CHD cohort (7.5 h [6.6-8.5] vs. 5.6 h [4.6-7] P < .001) and (197 min [158-240] vs. 130 [105-167] P < .001), respectively. There were no differences in operative complications or survival between CHD and non-CHD recipients.

CONCLUSIONS

These data highlight the added technical challenges of performing adult CHD transplants. However, similar outcomes can be achieved as for non-CHD recipients.

SUMMARY

Modern advances in palliation of congenital heart defects (CHD) has led to increased survival into adulthood. Many of these patients require heart transplantation as adults. There are limited data on adult CHD transplantation. Historically, these patients have had worse perioperative outcomes with improved long-term survival. We retrospectively analyzed 262 heart transplants at a single center, 18 of which were for adult CHD. Here, we report our series of 18 CHD recipients. We detail the palliative history of all CHD patients and highlight the added technical challenges for each of the 18 patients at transplant. In our analysis, CHD patients had more prior cardiovascular surgeries as well as longer transplant operative and bypass times. Despite this, there were no differences in perioperative and long-term outcomes. We have added patient and institution specific data for transplanting patients with adult CHD. We hope that our experience will add to the growing body of literature on adult CHD transplantation.

The Year in Review: Anesthesia for Congenital Heart Disease 2020

This review focuses on the literature published during the calendar year 2020 that is of interest to anesthesiologists taking care of children and adults with congenital heart disease. Five major themes are discussed, including COVID-19 in children with heart disease, race and outcome disparities in congenital heart disease, Norwood procedure and outcomes, Fontan procedure and outcomes, and neurotoxicity/neurologic outcomes. A total of 59 peer-reviewed articles are discussed.

Biventricular conversion after Fontan completion: A preliminary experience

OBJECTIVE

To assess the feasibility and outcomes of biventricular conversion following takedown of Fontan circulation.

METHODS

Retrospective analysis of patients who had takedown of Fontan circulation and conversion to biventricular circulation at a single center from September 2007 to April 2020. Failing Fontan physiology was defined as Fontan circulation pressure >15 mm Hg and/or the presence of associated complications.

RESULTS

Biventricular conversion was performed in 23 patients at a median age of 10.0 (7.5-13.0) years. Indications included failing Fontan physiology in 15 (65%) and elective takedown in 8 (35%) patients. A subset of patients (n = 6) underwent procedures for staged recruitment of the nondominant ventricle before conversion. Median z score of end-diastolic volume of borderline ventricle before takedown was -2.3 (-3.3, -1.3). Hypoplastic left heart syndrome (P < .01) and sub-/aortic stenosis (P < .01) were more common in these patients. Biventricular conversion with or without staged ventricular recruitment led to a significant increase in indexed end-diastolic volume (P < .01), indexed end-systolic volume (P < .01), and ventricular mass (P < .01) of the nondominant ventricle (14 right, 9 left ventricle). There were 5 (22%) deaths (1 [4%] early death). All who underwent elective biventricular conversion survived, whereas 2-year survival rate for patients with a failing Fontan circulation was 72.7% (95% confidence interval, 37%-90%). The overall, 3-year reoperation-free survival was 86.7% (95% confidence interval, 56%-96%). Left dominant atrioventricular canal defect (P < .01) and early era of biventricular conversion (P = .02) were significant predictors for mortality.

CONCLUSIONS

A primary as well as a staged biventricular conversion is feasible in patients who have had previous Fontan procedure. Although this provides an alternative to transplantation in patients with failing Fontan, outcomes are worse in those with failing Fontan compared with elective takedown of Fontan circulation. Optimal timing needs further evaluation.

Advances in 3D bioprinting technology for cardiac tissue engineering and regeneration

Cardiovascular disease is still one of the leading causes of death in the world, and heart transplantation is the current major treatment for end-stage cardiovascular diseases. However, because of the shortage of heart donors, new sources of cardiac regenerative medicine are greatly needed. The prominent development of tissue engineering using bioactive materials has creatively laid a direct promising foundation. Whereas, how to precisely pattern a cardiac structure with complete biological function still requires technological breakthroughs. Recently, the emerging three-dimensional (3D) bioprinting technology for tissue engineering has shown great advantages in generating micro-scale cardiac tissues, which has established its impressive potential as a novel foundation for cardiovascular regeneration. Whether 3D bioprinted hearts can replace traditional heart transplantation as a novel strategy for treating cardiovascular diseases in the future is a frontier issue. In this review article, we emphasize the current knowledge and future perspectives regarding available bioinks, bioprinting strategies and the latest outcome progress in cardiac 3D bioprinting to move this promising medical approach towards potential clinical implementation.

Technical modifications for transplant in the failing Fontan

INTRODUCTION

Heart transplant after Fontan completion poses a unique surgical challenge. Twenty patients are presented, stressing the technical hints performed in the five anastomoses to match the graft in the recipient.

METHODS

Data are collected from 20 Fontan patients between 2013 and 2019. Age (13 years), weight (37 kg.), and time interval between Fontan and transplant (7 years) are presented as median. Extracardiac conduit (size 18/20) was implanted in 15 patients, whereas atrio-pulmonary connection was performed in 4 and lateral tunnel in 1. Six patients developed protein-losing enteropathy. Seventeen stents had been previously deployed.

RESULTS

The five anastomoses underwent some changes. Left atrium once, aorta 9 times, superior vena cava 7 times, pulmonary branches 15 times, and inferior vena cava 12 times. Follow-up was complete for a median of 42 months (range 6-84). Two patients died. ECMO was needed in six cases for pulmonary hypertension. Four patients had collateral vessels occluded in the cath lab, and stents were placed in superior vena cava (1) and aorta (1) post-transplant. Protein-losing enteropathy was resolved in five patients. Interestingly, one patient was on a systemic assist device before transplant (Levitronix) and right assistance (ECMO) afterwards.

CONCLUSIONS

Transplant in Fontan patients is actually challenging. Hints in every of the five proposed anastomoses must be anticipated, including stents removal. Extra tissue from the donor (innominate vein, aortic arch, and pericardium) is strongly advisable. ECMO for right ventricular dysfunction was needed in nearly one-third of the cases. Overall results can match other transplant cohorts.