Improved survival after heart transplant for failed Fontan patients with preserved ventricular function

Heart Transplantation after Univentricular Palliation: Improved Outcomes and Increased Complexity

AIM

Heart transplantation (HT) in patients with failing univentricular circulation is often challenging. This is compounded by the ever-increasing number of patients with prior Norwood-type reconstruction of the aorta, large aortic root, and often dense adhesions from multiple prior operations. We aimed to elucidate differences in outcomes of HT in patients with prior univentricular palliations, with and without prior Norwood-type aortic arch reconstruction (ArchRec).

METHODS

All patients who underwent HT for failed univentricular palliation during the 1990-2022 period were included in the study.

RESULTS

Of 45 patients, 18 had undergone ArchRec. Hospital mortality improved in the recent era (17.4% before 2006 vs 0% after 2006; p=0.11), despite a higher proportion of patients with ArchRec (17.4% before 2006 vs 60.8% after 2006, p=0.002). Patients with ArchRec had a higher number of prior cardiac surgeries (4.1±1.5 vs 3.2±1.3, p=0.04), longer cardiopulmonary bypass time (320±23 vs 242±21 min, p=0.02), more concomitant arch reconstruction (33.3% vs 0%, p=0.02), greater need for post-HT extracorporeal membrane oxygenation (33.3% vs 3.7%; p=0.01) and longer hospital stay (37.1±30.5 days vs 23.6±11.8 days, p=0.04). Freedom from death or retransplantation for all patients was 91%, 73%, 67%, and 53% at 1, 5, 10, and 15-years, respectively. Prior ArchRec, Fontan procedure, and earlier eras were not risk factors for death.

CONCLUSIONS

The outcomes of HT after univentricular palliation have improved in recent times and low operative mortality can be achieved. Despite increased complexity, good similar outcomes can be achieved in patients with and without prior arch reconstruction regardless of the palliation stage.

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.

Contemporary Management of the Failing Fontan

Adult patients with congenital heart disease have now surpassed the pediatric population due to advances in surgery and improved survival. One such complex congenital heart disease seen in adult patients is the Fontan circulation. These patients have complex physiology and are at risk for several complications, including thrombosis of the Fontan pathway, pulmonary vascular disease, heart failure, atrial arrhythmias, atrioventricular valve regurgitation, and protein-losing enteropathy. This review discusses the commonly encountered phenotypes of Fontan circulatory failure and their contemporary management.

Adults with Congenital Heart Disease and Transplant: Challenges, Opportunities, and Policy

The rate of heart transplantation in adults with congenital heart disease (ACHD) is rising, but the 1-year mortality posttransplantation remains higher than non-ACHD patients. A robust pretransplant assessment and operative and postoperative planning can mitigate much of the perioperative risk. Importantly, ACHD patients who survive the first year have significantly better 10-year survival compared with non-ACHD patients. The current allocation system gives ACHD patients a relatively high priority, but providers must use the prespecified exception requests for higher status, especially for patients with the Fontan circulation. It is vital that ACHD patients with end-stage heart failure are cared for at centers with ACHD subspecialty care.

EASL-ERN position paper on liver involvement in patients with Fontan-type circulation

Fontan-type surgery is the final step in the sequential palliative surgical treatment of infants born with a univentricular heart. The resulting long-term haemodynamic changes promote liver damage, leading to Fontan-associated liver disease (FALD), in virtually all patients with Fontan circulation. Owing to the lack of a uniform definition of FALD and the competitive risk of other complications developed by Fontan patients, the impact of FALD on the prognosis of these patients is currently debatable. However, based on the increasing number of adult Fontan patients and recent research interest, the European Association for The Study of the Liver and the European Reference Network on Rare Liver Diseases thought a position paper timely. The aims of the current paper are: (1) to provide a clear definition and description of FALD, including clinical, analytical, radiological, haemodynamic, and histological features; (2) to facilitate guidance for staging the liver disease; and (3) to provide evidence- and experience-based recommendations for the management of different clinical scenarios.

Cardiac transplantation in adult congenital heart disease: a narrative review

Background and Objective

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

Methods

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

Key Content and Findings

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

Conclusions

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

Fontan-associated liver disease after heart transplant

BACKGROUND

Fontan associated liver disease (FALD) potentially impacts Fontan patients undergoing heart transplant. This multi-center study sought to identify pre-transplant risk factors and characterize any post-transplant liver recovery in those patients undergoing heart-alone transplant.

METHODS

Review of Fontan patients at 12 pediatric institutions who underwent heart transplant between 2001-2019. Radiologists reviewed pre and post-transplant liver imaging for fibrosis. Laboratory, pathology and endoscopy studies were reviewed.

RESULTS

156 patients underwent transplant due to decreased ventricular function (49%), protein losing enteropathy (31%) or plastic bronchitis (10%); median age at transplant was 13.6 years (interquartile range IQR 7.8, 17.2) with a median of 9.3 years (IQR 3.2, 13.4) between the Fontan operation and transplant. Few patients had pre-transplant endoscopy (18%), and liver biopsy (19%). There were 31 deaths (20%). The median time from transplant to death was 0.5 years (95% Confidence Interval CI 0.0, 3.6). The five-year survival was 73% (95% CI 64%, 83%). Deaths were related to cardiac causes in 68% (21/31) and infection in 6 (19%). A pre-transplant elevation in bilirubin was a predictor of death. Higher platelet levels were protective. Immediate post-transplant elevations in creatinine, AST, ALT, and INR were predictive of death. Advanced liver fibrosis identified on ultrasound, computed tomography, or magnetic resonance imaging was not predictive of death. Liver imaging suggested some improvement in liver congestion post-transplant.

CONCLUSIONS

Elevated bilirubin, but not fibrosis on liver imaging, was associated with post-heart transplant mortality in Fontan patients in this multicenter retrospective study. Additionally, heart transplant may alter the progression of FALD.

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.

Fontan-associated liver disease: Diagnosis, surveillance, and management

The Fontan operation is a lifesaving procedure for patients with functional single-ventricle congenital heart disease, where hypoplastic left heart syndrome is the most frequent anomaly. Hemodynamic changes following Fontan circulation creation are now increasingly recognized to cause multiorgan affection, where the development of a chronic liver disease, Fontan-associated liver disease (FALD), is one of the most important morbidities. Virtually, all patients with a Fontan circulation develop liver congestion, resulting in fibrosis and cirrhosis, and most patients experience childhood onset. FALD is a distinctive type of congestive hepatopathy, and its pathogenesis is thought to be a multifactorial process driven by increased nonpulsatile central venous pressure and decreased cardiac output, both of which are inherent in the Fontan circulation. In the advanced stage of liver injury, complications of portal hypertension often occur, and there is a risk of developing secondary liver cancer, reported at young age. However, FALD develops with few clinical symptoms, a surprisingly variable degree of severity in liver disease, and with little relation to poor cardiac function. The disease mechanisms and modifying factors of its development are still not fully understood. As one of the more important noncardiac complications of the Fontan circulation, FALD needs to be diagnosed in a timely manner with a structured monitoring scheme of disease development, early detection of malignancy, and determination of the optimal time point for transplantation. There is also a clear need for consensus on the best surveillance strategy for FALD. In this regard, imaging plays an important role together with clinical scoring systems, biochemical workups, and histology. Patients operated on with a Fontan circulation are generally followed up in cardiology units. Ultimately, the resulting multiorgan affection requires a multidisciplinary team of healthcare personnel to address the different organ complications. This article discusses the current concepts, diagnosis, and management of FALD, with special emphasis on the role of different imaging techniques in the diagnosis and monitoring of disease progression, as well as current recommendations for liver disease surveillance.

Outcomes of treatment for right atrial isomerism with functional single ventricle and extracardiac total anomalous pulmonary venous connection beyond neonatal period: Delayed surgical treatment, improving outcomes

Objective

Total anomalous pulmonary venous connection (TAPVC) is frequently associated with right atrial isomerism (RAI), which is commonly complicated with an unbalanced atrioventricular canal with contralateral hypoplasia, complex systemic and pulmonary venous anatomy, and conotruncal abnormalities, resulting in increased risk of mortality. This study aimed to review the outcomes of delayed surgical treatment for patients with RAI complicated with functional single ventricle (FSV) and TAPVC at a single center.

Methods

In this retrospective study, we reviewed the medical records of 24 consecutive patients with RAI complicated with FSV and TAPVC who underwent initial surgical palliation after 5-month old between September 2008 and June 2019. Demographic data, concomitant anomalies, age at initial palliation, and surgical interventions were extracted and analyzed using the Cox proportional hazard model to assess risk factors for mortality and the Kaplan-Meier method to assess survival.

Results

The in-hospital mortality was 12.5% (three out of 24). The causes of death were pulmonary arterial hypertension and low cardiac output syndrome. Average follow-up was 65.2 ± 40.3 months (7-137 months). Another 4 patients died during the follow-up due to low cardiac output syndrome, protein-losing enteropathy and pulmonary arterial hypertension, respectively. Kaplan-Meier estimated survival at 1 and 5 years were 83.1 and 69.4%, respectively. Fontan completion was 45.8% (11/24). The mortality for patients with pulmonary venous obstruction (PVO) was 66.7% (4/6). Cox multivariate regression analysis indicated that preoperative PVO was the only risk factor for mortality (p = 0.032; hazard ratio, 10.000; CI 1.222-81.811).

Conclusion

Outcomes of delayed surgical treatment for patients with RAI complicated with FSV and TAPVC have improved significantly. The survival and Fontan completion were higher. However, preoperative PVO was still the risk factor for mortality.

Failing Fontan cardiovascular support: Review

BACKGROUND

Although all congenital heart defects (CHD) present unique challenges, univentricular CHD are especially challenging given the difficulty of passively perfusing pulmonary blood flow. Three surgical procedures are required within the first years of life, with the final completing a Fontan circulation in which the inferior vena cava is connected to the pulmonary artery and previously connected superior vena cava. This allows passive venous return to the pulmonary circulation then flow into the single ventricle for systemic circulation.

METHODS

Although a Fontan provides successful palliation for two to three decades, many complications can arise as pulmonary resistance must remain low to allow adequate forward flow. Eventually, the failing Fontan circulation requires temporary support as the patient awaits a heart transplant. We reviewed PubMed, Google Scholar, and U. Kentucky library for different techniques evaluated to support a failing Fontan circulation.

RESULTS

Multiple technologies have been developed as a bridge to transplant to decrease morbidity. Innovative types of extracorporeal membrane oxygenation, ventricular assist devices, and total artificial hearts have been attempted in laboratory settings as well as in Fontan patients with varying degrees of success. This article emphasizes the strengths and weaknesses of each technology in the context of Fontan physiology.

CONCLUSION

The end game for these patients remains a heart transplant. Without easy access to donors, each of the options discussed is a potential bridge to limit morbidity and mortality until a suitable donor heart becomes available.

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

Abdominal CT and MRI Findings of Portal Hypertension in Children and Adults with Fontan Circulation

Background Portal hypertension in the Fontan circulation is a function of elevated systemic venous pressure and liver fibrosis. Purpose To quantify the prevalence of radiologic evidence of portal hypertension and elevated VAST score (one point each for varices, ascites, splenomegaly, and thrombocytopenia) of 2 or greater in children and adults with Fontan circulation and to determine the association with hemodynamics and adverse outcomes. Materials and Methods This was a retrospective study of individuals with Fontan circulation who underwent abdominal MRI or CT for focal liver lesion surveillance between January 2012 and December 2019. Portal hypertension was defined as the presence of at least two of the following: varices, ascites, or splenomegaly. Fontan deterioration was defined as a composite of heart failure signs or symptoms requiring diuretic escalation, placement of a ventricular assist device, heart transplant, or death. Relationships between variables and the composite end point were assessed using univariable and multivariable logistic regression. Results A total of 123 patients (age range, 9-55 years; 32 children) were evaluated (median age, 23 years; IQR, 17-30 years; 63 male patients). Median time since diagnosis of Fontan circulation was 16 years (IQR, 12-23 years). Twenty-five of the 123 patients (20%) had radiologic evidence of portal hypertension, and 34 (28%) had a VAST score of 2 or greater. Fontan deterioration occurred in 25 of the 123 patients (20%); median follow-up duration was 0.4 year (IQR, 0.1-3.1 years). Compared with patients who had Fontan circulation without deterioration, patients with Fontan deterioration were more likely to have moderate or severe ventricular systolic dysfunction (P < .01), moderate or severe atrioventricular valve regurgitation (P < .01), higher Fontan pressure (P = .01), radiologic evidence of portal hypertension (P < .01), and VAST score of 2 or greater (P < .01). Conclusion Radiologic evidence of portal hypertension at abdominal imaging in children and adults with Fontan circulation was associated with higher venous pressures and an increased risk for Fontan deterioration. These characteristics may be used to identify patients who warrant comprehensive hemodynamic evaluation. © RSNA, 2022.

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.

Management of circulatory failure after Fontan surgery

With improvement in survival after Fontan surgery resulting in an increasing number of older survivors, there are more patients with a Fontan circulation experiencing circulatory failure each year. Fontan circulatory failure may have a number of underlying etiologies. Once Fontan failure manifests, prognosis is poor, with patient freedom from death or transplant at 10 years of only about 40%. Medical treatments used include traditional heart failure medications such as renin-angiotensin-aldosterone system blockers and beta-blockers, diuretics for symptomatic management, antiarrhythmics for rhythm control, and phosphodiesterase-5 inhibitors to decrease PVR and improve preload. These oral medical therapies are typically not very effective and have little data demonstrating benefit; if there are no surgical or catheter-based interventions to improve the Fontan circulation, patients with severe symptoms often require inotropic medications or mechanical circulatory support. Mechanical circulatory support benefits patients with ventricular dysfunction but may not be as useful in patients with other forms of Fontan failure. Transplant remains the definitive treatment for circulatory failure after Fontan, but patients with a Fontan circulation face many challenges both before and after transplant. There remains significant room and urgent need for improvement in the management and outcomes of patients with circulatory failure after Fontan surgery.

Contemporary Provider Management Practices and Attitudes Toward Referral for Advanced Heart Failure Therapies in Fontan Patients Across North America

BACKGROUND

To date, no reports have described clinicians' management practices for patients with Fontan circulatory failure or their understanding of risk factors for mortality and transplant outcomes in these patients.

METHODS AND RESULTS

A cross-sectional survey of caregivers across North America was conducted from February to September 2020. Responses were compared by primary specialty (heart failure/transplant vs non-heart failure/transplant), years of experience (early, mid, and late career), and Fontan center volume (low, medium, and high). Of 400 responses, the majority were from general cardiologists (111, 28%) followed by heart failure/transplant specialists (93, 23%). Although most agreed that patients with Fontan physiology will have signs/symptoms of heart failure (369 [93%]) and eventuate in heart transplant (286 [72%]), many disagreed (180 [45%]) that routine evaluation by a transplant cardiologist is needed without symptoms. Transplant providers were more likely than non-transplant providers to suggest referral for manifestations of Fontan circulatory failure such as protein-losing enteropathy, plastic bronchitis, liver fibrosis/cirrhosis, and worsening valve regurgitation. Non-transplant providers were more likely to suggest that protein-losing enteropathy, plastic bronchitis, and Fontan-associated liver disease lead to inferior outcomes after transplantation. Early career and transplant providers more favorably viewed ventricular assist device use for Fontan patients failing traditional heart failure therapy (P < .05 for all).

CONCLUSIONS

There is significant variation in the management of Fontan patients, including heterogeneous timing of referral of such patients to the heart failure/transplant team, which may have implications for future outcomes.

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.

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.

Clinical and hemodynamic characteristics of the pediatric failing Fontan

AIM

To describe the clinical and hemodynamic characteristics of Fontan failure in children listed for heart transplant.

METHODS

In a nested study of the Pediatric Heart Transplant Society, 16 centers contributed information on Fontan patients listed for heart transplant between 2005and 2013. Patients were classified into four mutually exclusive phenotypes: Fontan with abnormal lymphatics (FAL), Fontan with reduced systolic function (FRF), Fontan with preserved systolic function (FPF), and Fontan with "normal" hearts (FNH). Primary outcome was waitlist and post-transplant mortality.

RESULTS

177 children listed for transplant were followed over a median 13 (IQR 4-31) months, 84 (47%) were FAL, 57 (32%) FRF, 22 (12%) FNH, and 14 (8%) FPF. Hemodynamic characteristics differed between the 4 groups: Fontan pressure (FP) was most elevated with FPF (median 22, IQR 18-23, mmHg) and lowest with FAL (16, 14-20, mmHg); cardiac index (CI) was lowest with FRF (2.8, 2.3-3.4, L/min/m²). In the entire cohort, 66% had FP >15 mmHg, 21% had FP >20 mmHg, and 10% had CI <2.2 L/min/m². FRF had the highest risk of waitlist mortality (21%) and FNH had the highest risk of post-transplant mortality (36%).

CONCLUSIONS

Elevated Fontan pressure is more common than low cardiac output in pediatric failing Fontan patients listed for transplant. Subtle hemodynamic differences exist between the various phenotypes of pediatric Fontan failure. Waitlist and post-transplant mortality risks differ by phenotype.

A Review of Physiologic Considerations and Challenges in Pediatric Patients With Failing Single- Ventricle Physiology Undergoing Ventricular Assist Device Placement

Advances in surgical techniques and outpatient cardiac care have led to a growing population of pediatric patients surviving well into adulthood with previous single-ventricle palliation. Continued improvement in survival has resulted in subsequent increases in the number of patients with single-ventricle physiology listed for heart transplantations. Some of these patients require mechanical circulatory support as a bridge to transplantation, although establishing successful mechanical circulatory support in these complex patients remains challenging. Only limited published data exist describing the perioperative anesthetic management and key considerations dedicated to patients with failing single-ventricle physiology presenting for ventricular assist devices. This clinical review aims to provide a focused evaluation of the vital perioperative considerations encountered in this novel population.

Perioperative Management of the Fontan Patient for Cardiac and Noncardiac Surgery

The Fontan circulation is the single-ventricle approach to surgical palliation of complex congenital heart disease wherein biventricular separation and function cannot be safely achieved. Incremental improvements in this surgical technique, along with improvements in the long-term medical management of these patients, have led to greater survival of these patients and a remarkably steady increase in the number of adults living with this unusual circulation and physiology. This has implications for healthcare providers who now have a greater chance of encountering Fontan patients during the course of their practice. This has particularly important implications for anesthesiologists because the effects of their interventions on the finely balanced Fontan circulation may be profound. The American Heart Association and American College of Cardiology recommend that, when possible, elective surgery should be performed in an adult congenital heart disease center, although this may not be feasible in the provision of true emergency care. This review article summarizes the pathophysiology pertinent to the provision of anesthesia in this complex patient group and describes important modifications to anesthetic technique and perioperative management.

Fontan-Associated Liver Disease: Screening, Management, and Transplant Considerations

Surgical innovation and multidisciplinary management have allowed children born with univentricular physiology congenital heart disease to survive into adulthood. An estimated global population of 70 000 patients have undergone the Fontan procedure and are alive today, most of whom are <25 years of age. Several unexpected consequences of the Fontan circulation include Fontan-associated liver disease. Surveillance biopsies have demonstrated that virtually 100% of these patients develop clinically silent fibrosis by adolescence. As they mature, there are increasing reports of combined heart-liver transplantation resulting from advanced liver disease, including bridging fibrosis, cirrhosis, and hepatocellular carcinoma, in this population. In the absence of a transplantation option, these young patients face a poor quality of life and overall survival. Acknowledging that there are no consensus guidelines for diagnosing and monitoring Fontan-associated liver disease or when to consider heart transplantation versus combined heart-liver transplantation in these patients, a multidisciplinary working group reviewed the literature surrounding Fontan-associated liver disease, with a specific focus on considerations for transplantation.

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.

Imaging of complications following Fontan circulation in children - diagnosis and surveillance

The Fontan operation is performed for various cardiac lesions with single-ventricle physiology. The survival rate of Fontan patients is increasing for adolescents and young adults, with an expected 30-year survival of >80%. Medical health care providers including specialists in organ systems and pediatric radiologists need to improve their knowledge about the Fontan circulation and the various organ complications to monitor care. In this review the author explains the basic anatomical and functional features of Fontan palliation and gives an overview of the multiple long-term organ complications that might present in the pediatric population. These include decreased physical capacity, ventricular dysfunction, atrioventricular valve regurgitation and arrhythmia, as well as protein-losing enteropathy, plastic bronchitis, growth/bone composition disturbances, renal dysfunction, and the recently recognized and important liver fibrosis (Fontan-associated liver disease). Neuropsychological and behavioral deficits occur frequently. This review focuses on the key role of radiology in making the diagnosis of these complications, monitoring therapy and predicting outcomes in the pediatric age group. The author discusses how and when radiology is important in Fontan patients, as well as how new techniques enabling quantitative measures in imaging with US, MRI and CT are adapted for pediatric use, and how they contribute to urgently needed surveillance strategies.

Transplantation of the failing Fontan

Half a century has passed since the original Fontan palliation. In the interim, surgical and medical advancements have allowed more single ventricle patients to reach Fontan and long-term survival for Fontan patients to improve significantly. However, the risk for Fontan failure and need for heart transplantation remains. In this article we discuss mechanisms of Fontan failure, risk factors and special considerations for Fontan patients in both medical and surgical management around heart transplantation and provide an updated review of survival for Fontan patients after heart transplantation.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

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.

Hypoplastic left heart syndrome: from fetus to fontan

The care of children with hypoplastic left heart syndrome is constantly evolving. Prenatal diagnosis of hypoplastic left heart syndrome will aid in counselling of parents, and selected fetuses may be candidates for in utero intervention. Following birth, palliation can be undertaken through staged operations: Norwood (or hybrid) in the 1st week of life, superior cavopulmonary connection at 4-6 months of life, and finally total cavopulmonary connection (Fontan) at 2-4 years of age. Children with hypoplastic left heart syndrome are at risk of circulatory failure their entire life, and selected patients may undergo heart transplantation. In this review article, we summarise recent advances in the critical care management of patients with hypoplastic left heart syndrome as were discussed in a focused session at the 12th International Conference of the Paediatric Cardiac Intensive Care Society held on 9 December, 2016, in Miami Beach, Florida.

An overview of mechanical circulatory support in single-ventricle patients

The population of people with a single-ventricle is continually increasing due to improvements across the spectrum of medical care. Unfortunately, a proportion of these patients will develop heart failure. Often, for these patients, mechanical circulatory support (MCS) represents the only available treatment option. While single-ventricle patients currently represent a small proportion of the total number of patients who receive MCS, as the single-ventricle patient population increases, this number will increase as well. Outcomes for these complex single-ventricle patients who require MCS has begun to be evaluated. When considering the entire population, survival to hospital discharge is 30-50%, though this must be considered with the significant heterogeneity of the single-ventricle patient population. Patients with a single-ventricle have unique anatomy, mechanisms of failure, indications for MCS and the type of support utilized. This has made the interpretation and the generalizability of the limited available data difficult. It is likely that some subsets will have a significantly worse prognosis and others a better one. Unfortunately, with these limited data, indications of a favorable or poor outcome have not yet been elucidated. Though currently, a database has been constructed to address this issue. While the outcomes for these complex patients is unclear, at least in some situations, they are poor. However, significant advances may provide improvements going forward, including new devices, computer simulations and 3D printed models. The most important factor, however, will be the increased experience gained by the heart failure team to improve patient selection, timing, device and configuration selection and operative approach.

Mechanical Circulatory Support for the Failing Fontan: Conversion to Assisted Single Ventricle Circulation—Preliminary Observations

Background:

Mechanical circulatory support (MCS) of a failing Fontan circulation remains challenging. We hypothesized that MCS can be provided by converting the Fontan circulation into a mechanically assisted single ventricle parallel circulation (MASVC).

Methods:

A porcine model of functionally univentricular circulation was created under cardiopulmonary bypass (CPB) by performing an atrial septectomy, tricuspid valvectomy, and interrupting antegrade pulmonary blood flow. A centrifugal flow pump was placed with inflow from the common atrium. Eight millimeter Dacron grafts anastomosed to the ascending aorta and main pulmonary artery supplied systemic (Qs) and pulmonary (Qp) blood flow. Ultrasonic flow probes were used to measure Qs and Qp after weaning from CPB. The Qp/Qs ratio was regulated using an adjustable clamp. Hemodynamic and laboratory data were recorded.

Results:

All four animals were successfully weaned from CPB onto the MASVC for a duration of two hours. Mechanically assisted single ventricle parallel circulation achieved satisfactory hemodynamics. As anticipated, the arterial oxygen saturation and partial pressure of oxygen in arterial blood were lower in the MASVC compared to baseline biventricular circulation. At the conclusion of the study, there was a trend towards a decrease in the mixed venous saturation with increasing oxygen extraction compared to the baseline. Serum lactate levels increased after weaning from CPB and did not return to baseline after two hours of support.

Conclusion:

Mechanically assisted single ventricle parallel circulation can be established in a single ventricle animal model. This strategy could potentially provide MCS of a single ventricle circulation. Studies with longer duration of support are required to assess adequacy of support and long-term sustainability.

Role of Doppler echocardiography for cardiac output assessment in Fontan patients

BACKGROUND

To determine (1) correlation between Doppler stroke volume index (SVI) and cardiac magnetic resonance imaging (CMRI) SVI and (2) association between Doppler SVI and Fontan-associated diseases (FAD) and Fontan failure.

METHODS

Review of Fontan patients who underwent same-day CMRI and transthoracic echocardiography (TTE), 2005 to 2015. We defined FAD as cardiac thrombus, protein-losing enteropathy, arrhythmia, and hospitalization for heart failure. Fontan failure was defined as Fontan conversion or revision, heart transplantation or listing, or death.

RESULTS

Fifty-three patients with systemic left ventricle (LV) underwent 86 sets of TTE/CMRI. Mean (SD) age 31 (6) years. SVI (45 [16] vs 42 [13] mL/m²), CI (3.0 [1.1] vs 2.8 [0.8] L min^-1 m^-2), and ejection fraction (53 [4]% vs 51 [5]%) were similar for both modalities (P>.05 for all). Doppler SVI correlated with CMRI (r=0.68; P<.001). Sixteen patients had cirrhosis, and these patients had a higher CI (3.9 [0.9] vs 2.8 [1.0] L min^-1 m^-2; P<.01). Among the 37 patients without cirrhosis, Doppler SVI <39 mL/m² was associated with FAD (odds ratio [OR], 2.11; 95% confidence limit, 1.26-3.14; P=.02); Fontan failure was more common in patients with CI was <2.5 L min^-1 m^-2 (3/9 [33%] vs 0/28 [0%], P=.01). Another 11 patients with systemic right ventricle (RV) underwent 17 sets of TTE/CMRI, mean (SD) age 17 (3) years, and CMRI SVI also correlated with Doppler SVI (r=0.75; P<.001).

CONCLUSION

Doppler SVI correlated with CMRI SVI in patients with systemic LV and systemic RV. The association between output measures (SVI and CI) and FAD were seen only in single LV patients (single RV patients not assessed for this outcome due to small numbers). An association between low Doppler CI and Fontan failure was suggested in a small number of single LV patients.

Overview of adult congenital heart transplants

Transplantation for adult patients with congenital heart disease (ACHD) is a growing clinical endeavor in the transplant community. Understanding the results and defining potential high-risk patient subsets will allow optimization of patient outcomes. This review summarizes the scope of ACHD transplantation, the mechanisms of late ventricular dysfunction, the ACHD population at risk of developing heart failure, the indications and potential contraindications for transplant, surgical considerations, and post-transplant outcomes. The findings reveal that 3.3% of adult heart transplants occur in ACHD patients. The potential mechanisms for the development of late ventricular dysfunction include a morphologic systemic right ventricle, altered coronary perfusion, and ventricular noncompaction. The indications for transplant in ACHD patients include systemic ventricular failure refractory medical therapy, Fontan patients failing from chronic passive pulmonary circulation, and progressive cyanosis leading to functional decline. Transplantation in ACHD patients can be quite complex and may require extensive reconstruction of the branch pulmonary arteries, systemic veins, or the aorta. Vasoplegia, bleeding, and graft right ventricular dysfunction can complicate the immediate post-transplant period. The post-transplant operative mortality ranges between 14% and 39%. The majority of early mortality occurs in ACHD patients with univentricular congenital heart disease. However, there has been improvement in operative survival in more contemporary studies. In conclusion, the experience with cardiac transplantation for ACHD patients with end-stage heart failure is growing, and high-risk patient subsets have been defined. Significant strides have been made in developing evidence-based guidelines of indications for transplant, and the intraoperative management of complex reconstruction has evolved. With proper patient selection, more aggressive use of mechanical circulatory support, and earlier referral of patients with failing Fontan physiology, outcomes should continue to improve.

Ventricular assist device use in single ventricle congenital heart disease

As VAD have become an effective therapy for end-stage heart failure, their application in congenital heart disease has increased. Single ventricle congenital heart disease introduces unique physiologic challenges for VAD use. However, with regard to the mixed clinical results presented within this review, we suggest that patient selection, timing of implant, and center experience are all important contributors to outcome. This review focuses on the published experience of VAD use in single ventricle patients and details physiologic challenges and novel approaches in this growing pediatric and adult population.

Pediatric cardiac transplantation

Heart transplantation in pediatric patients generally arises as a treatment option of last resort, that is, the indication is for patients with heart failure of various etiologies, with potential or actual end-organ dysfunction, in whom there are no reasonable, long-term options for life-prolonging therapy. The concept of heart failure is complex in a pediatric population, particularly those with congenital heart disease. While heart failure may refer simply to systolic dysfunction leading to low cardiac output, it can also encompass: diastolic dysfunction in restrictive cardiomyopathy; single ventricle physiology without an option for stable palliation. A good candidate should have a predicted life expectancy less than the median lifetime of a transplanted heart. Significant improvement in survival has been observed over time with 1- and 5-year survival approximately 90% and 80% in the contemporary era.

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.