Strategies for thromboprophylaxis in Fontan circulation: a meta-analysis

Thromboembolic Events Are Independently Associated with Liver Stiffness in Patients with Fontan Circulation

Background: Thromboembolism (TE) and Fontan-associated liver disease (FALD) are common and lead to significant morbidity in Fontan circulations. Risk factors for TE and the potential link between TE and FALD are not well understood. The objective of this study was to evaluate the association between TE and the severity of FALD based on radiologic liver stiffness. Methods: Using a retrospective cohort study design, 85 Fontan patients (aged 27.7 ± 8.2 years) who had liver stiffness measurement were included. Multivariable logistic regression was used to determine independent associations with TE. Results: Sixteen patients (19%) had a history of TE after the Fontan procedure at a mean age of 21.4 ± 15.0 years. Patients with TE were significantly older at the time of the last evaluation (33.8 ± 11.7 vs. 26.3 ± 6.5 years, p = 0.03). Liver stiffness by MRI and ultrasound was higher in the TE group (5.1 ± 1.4 vs. 4.3 ± 1.2 kPa, p = 0.04 and 2.8 ± 0.4 vs. 2.4 ± 0.5 m/s, p = 0.04, respectively). On multivariable analysis, higher liver stiffness (odds ratio (OR): 2.12, p = 0.03) and older age (OR: 1.11, p = 0.03) were associated with TE. Conclusions: This study found an association between TE, age, and radiologic liver stiffness.

Arterial Ischemic Stroke Secondary to Cardiac Disease in Neonates and Children

OBJECTIVE

We describe the risk factors for peri-procedural and spontaneous arterial ischemic stroke (AIS) in children with cardiac disease.

METHODS

We identified children with cardiac causes of AIS enrolled in the International Pediatric Stroke Study registry from January 2003 to July 2014. Isolated patent foramen ovale was excluded. Peri-procedural AIS (those occurring during or within 72 hours of cardiac surgery, cardiac catheterization, or mechanical circulatory support) and spontaneous AIS that occurred outside of these time periods were compared.

RESULTS

We identified 672 patients with congenital or acquired cardiac disease as the primary risk factor for AIS. Among these, 177 patients (26%) had peri-procedural AIS and 495 patients (74%) had spontaneous AIS. Among non-neonates, spontaneous AIS occurred at older ages (median 4.2 years, interquartile range 0.97 to 12.4) compared with peri-procedural AIS (median 2.4 years, interquartile range 0.35 to 6.1, P < 0.001). About a third of patients in both groups had a systemic illness at the time of AIS. Patients who had spontaneous AIS were more likely to have a preceding thrombotic event (16 % versus 9 %, P = 0.02) and to have a moderate or severe neurological deficit at discharge (67% versus 33%, P = 0.01) compared to those with peri-procedural AIS.

CONCLUSIONS

Children with cardiac disease are at risk for AIS at the time of cardiac procedures but also outside of the immediate 72 hours after procedures. Many have acute systemic illness or thrombotic event preceding AIS, suggesting that inflammatory or prothrombotic conditions could act as a stroke trigger in this susceptible population.

Hypoplastic left heart syndrome: From bedside to bench and back

Hypoplastic Left Heart Syndrome (HLHS) is a complex Congenital Heart Disease (CHD) that was almost universally fatal until the advent of the Norwood operation in 1981. Children with HLHS who largely succumbed to the disease within the first year of life, are now surviving to adulthood. However, this survival is associated with multiple comorbidities and HLHS infants have a higher mortality rate as compared to other non-HLHS single ventricle patients. In this review we (a) discuss current clinical challenges associated in the care of HLHS patients, (b) explore the use of systems biology in understanding the molecular framework of this disease, (c) evaluate induced pluripotent stem cells as a translational model to understand molecular mechanisms and manipulate them to improve outcomes, and (d) investigate cell therapy, gene therapy, and tissue engineering as a potential tool to regenerate hypoplastic cardiac structures and improve outcomes.

Indian guidelines for indications and timing of intervention for common congenital heart diseases: Revised and updated consensus statement of the Working group on management of congenital heart diseases

A number of guidelines are available for the management of congenital heart diseases (CHD) from infancy to adult life. However, these guidelines are for patients living in high-income countries. Separate guidelines, applicable to Indian children, are required when recommending an intervention for CHD, as often these patients present late in the course of the disease and may have coexisting morbidities and malnutrition. Guidelines emerged following expert deliberations at the National Consensus Meeting on Management of Congenital Heart Diseases in India, held on August 10 and 11, 2018, at the All India Institute of Medical Sciences. The meeting was supported by Children's HeartLink, a nongovernmental organization based in Minnesota, USA. The aim of the study was to frame evidence-based guidelines for (i) indications and optimal timing of intervention in common CHD; (ii) follow-up protocols for patients who have undergone cardiac surgery/catheter interventions for CHD; and (iii) indications for use of pacemakers in children. Evidence-based recommendations are provided for indications and timing of intervention in common CHD, including left-to-right shunts (atrial septal defect, ventricular septal defect, atrioventricular septal defect, patent ductus arteriosus, and others), obstructive lesions (pulmonary stenosis, aortic stenosis, and coarctation of aorta), and cyanotic CHD (tetralogy of Fallot, transposition of great arteries, univentricular hearts, total anomalous pulmonary venous connection, Ebstein's anomaly, and others). In addition, protocols for follow-up of postsurgical patients are also described, disease wise. Guidelines are also given on indications for implantation of permanent pacemakers in children.

Thromboprophylaxis strategies for children with single-ventricle circulations (superior or total cavo-pulmonary connections) after stent implantation

OBJECTIVE

To define optimal thromboprophylaxis strategy after stent implantation in superior or total cavopulmonary connections.

BACKGROUND

Stent thrombosis is a rare complication of intravascular stenting, with a perceived higher risk in single-ventricle patients.

METHODS

All patients who underwent stent implantation within superior or total cavopulmonary connections (caval vein, innominate vein, Fontan, or branch pulmonary arteries) were included. Cohort was divided into aspirin therapy alone versus advanced anticoagulation, including warfarin, enoxaparin, heparin, or clopidogrel. Primary endpoint was in-stent or downstream thrombus, and secondary endpoints included bleeding complications.

RESULTS

A total of 58 patients with single-ventricle circulation underwent 72 stent implantations. Of them 14 stents (19%) were implanted post-superior cavopulmonary connection and 58 (81%) post-total cavopulmonary connection. Indications for stenting included vessel/conduit stenosis (67%), external compression (18%), and thrombotic occlusion (15%). Advanced anticoagulation was prescribed for 32 (44%) patients and aspirin for 40 (56%) patients. Median follow up was 1.1 (25th-75th percentile, 0.5-2.6) years. Echocardiograms were available in 71 patients (99%), and advanced imaging in 44 patients (61%). Thrombosis was present in two patients on advanced anticoagulation (6.3%) and none noted in patients on aspirin (p = 0.187). Both patients with in-stent thrombus underwent initial stenting due to occlusive left pulmonary artery thrombus acutely post-superior cavopulmonary connection. There were seven (22%) significant bleeding complications for advanced anticoagulation and none for aspirin (p < 0.001).

CONCLUSIONS

Antithrombotic strategy does not appear to affect rates of in-stent thrombus in single-ventricle circulations. Aspirin alone may be sufficient for most patients undergoing stent implantation, while pre-existing thrombus may warrant advanced anticoagulation.

Rivaroxaban, a direct Factor Xa inhibitor, versus acetylsalicylic acid as thromboprophylaxis in children post-Fontan procedure: Rationale and design of a prospective, randomized trial (the UNIVERSE study)

BACKGROUND

The Fontan procedure is the final step of the 3-stage palliative procedure commonly performed in children with single ventricle physiology. Thrombosis remains an important complication in children after this procedure. To date, guideline recommendations for the type and duration of thromboprophylaxis after Fontan surgery are mainly based on extrapolation of knowledge gained from adults at risk for thrombosis in other clinical settings. Warfarin is being used off-label, and because of its multiple interactions with other drugs and food, a new alternative is highly desirable. Rivaroxaban, a direct Factor Xa inhibitor with a predictable pharmacokinetic profile, is a candidate to address this medical need.

STUDY DESIGN

The UNIVERSE study is a prospective, open-label, active-controlled, multicenter study in children 2 to 8 years of age who have single ventricle physiology and had the Fontan procedure within the 4 months preceding enrollment. This study consists of 2 parts. In Part A, rivaroxaban pharmacokinetics, pharmacodynamics, safety, and tolerability are assessed to validate the pediatric dosing selected. In Part B, safety and efficacy of rivaroxaban versus acetylsalicylic acid are evaluated for thromboprophylaxis in children post-Fontan procedure. Children in each part will receive study drug for 12 months. Part A has been completed with 12 children enrolled. Enrollment into Part B is currently ongoing.

CONCLUSIONS

The UNIVERSE study aims to provide dosing, pharmacokinetics/pharmacodynamics, safety, and efficacy information on the use of rivaroxaban, an oral anticoagulant, versus acetylsalicylic acid, an antiplatelet agent, in children with single ventricle physiology after the Fontan procedure.

Guidelines for the management of common congenital heart diseases in India: A consensus statement on indications and timing of intervention

INTRODUCTION

A number of guidelines are available for management of congenital heart diseases from infancy to adult life. However, these guidelines are for patients living in high-income countries. Separate guidelines, applicable to Indian children, are required when recommending an intervention for congenital heart diseases, as often these patients present late in the course of the disease and may have co-existing morbidities and malnutrition.

PROCESS

Guidelines emerged following expert deliberations at the National Consensus Meeting on Management of Congenital Heart Diseases in India, held on the 10th and 11th of August, 2018 at the All India Institute of Medical Sciences.

OBJECTIVES

The aim of the study was to frame evidence-based guidelines for (i) indications and optimal timing of intervention in common congenital heart diseases and (ii) follow-up protocols for patients who have undergone cardiac surgery/catheter interventions for congenital heart diseases.

RECOMMENDATIONS

Evidence-based recommendations are provided for indications and timing of intervention in common congenital heart diseases, including left-to-right shunts, obstructive lesions, and cyanotic congenital heart diseases. In addition, protocols for follow-up of postsurgical patients are also described.

Assessment of Late Thromboembolic Complications Post-Fontan Procedure in Relation to Different Antithrombotic Regimens: 30-Years' Follow-up Experience

Background: The current CHEST guidelines recommend the use of antithrombotic therapy, either aspirin or warfarin, as a primary thromboembolic complications (TECs) prophylaxis in patients who undergo Fontan procedure, without specification on drug selection or duration of therapy. Objective: To investigate the incidence rate of late TECs, occurring after 1-year post-Fontan procedure and to assess the difference in rate of late TECs between warfarin and aspirin. Methods: A retrospective cohort study included patients who had Fontan procedures between 1985-2010 at our institution. Patients were stratified according to the antithrombotic regimen-warfarin, aspirin, or no therapy-at the time of TECs. Results: We screened 499 patients who underwent Fontan procedures; 431 procedures met the inclusion criteria. Over a median follow-up of 13.6 years (IQR= 8.7), freedom from late TECs at 5, 10, 15, and 20 years was 97.54%, 96.90%, 90.78%, and 88.07%, respectively. There was no difference in late TEC incidence rates per 1000 patient-years between warfarin and aspirin: 7.82 and 5.83 events, respectively; rate ratio= 1.34 (95% CI= 0.68-2.60). Warfarin was associated with a higher major bleeding incidence rate per 1000 patient-years: 3.70 versus 2.91 events with aspirin; rate ratio= 1.27 (95% CI= 0.49 to 3.29). Conclusion and Relevance: The incidence rate of late clinical TECs post-Fontan procedure in our population is low. Warfarin was not superior to aspirin for prevention of late TECs. Yet warfarin was associated with a higher rate of bleeding. This finding suggests a simpler antithrombotic regimen for prevention of TEC after 1-year post-Fontan procedure.

Endocardial transvenous pacing in patients with surgically palliated univentricular hearts: A review on different techniques, problems and management

Fontan surgery and its modifications have improved survival in various forms of univentricular hearts. A regular atrial rhythm with atrioventricular synchrony is one of the most important prerequisite for the long-term effective functioning of this preload dependent circulation. A significant proportion of these survivors need various forms of pacing for bradyarrhythmias, often due to sinus nodal dysfunction and sometimes due to atrioventricular nodal block. The diversion of the venous flows away from the cardiac chambers following this surgery takes away the simpler endocardial pacing options through the superior vena cava. The added risks of thromboembolism associated with endocardial leads in systemic ventricles have made epicardial pacing as the procedure of choice. However challenges in epicardial pacing include surgical adhesions, increased pacing thresholds leading to early battery depletion and frequent lead fractures. When epicardial pacing fails, endocardial lead placement is equally challenging due to lack of access to the cardiac chambers in Fontan circulation. This review discusses the univentricular heart morphologies that may warrant pacing, issues about epicardial pacing, different techniques for endocardial pacing in patients with disconnected superior vena cava, pacing in different modifications of Fontan surgeries, issues of systemic thromboembolism with endocardial leads, atrioventricular valve regurgitation attributed to pacing leads and device infections. In a vast majority of patients following Glenn shunt and Senning surgery, an epicardial pacing and lead replacement is always feasible though technically very difficult. This article highlights the different options of transatrial and transventricular endocardial pacing.

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Fontan surgery prolongs the mean survival of patients with univentricular hearts beyond 30 years.

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9-20% of survivors need permanent pacing for bradyarrhythmias.

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Epicardial pacing is preferred as the first choice for permanent pacemaker.

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There is 20-40% failure of permanent pacing at 10 years due to high threshold, lead fractures.

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Repeated epicardial pacing with surgical revisions are difficult.

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Endocardial pacing involves special techniques.

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Manoeuvring through fenestrations,venous collaterals, hepatic veins, pulmonary valve or hybrid peratrial routes is needed.

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Systemic thromboembolism, endocarditis and systemic AV valve regurgitation should be prevented by meticulously measures.

Transvenous Versus Epicardial Pacing in Fontan Patients

Up to 10% of Fontan patients require pacemakers; an epicardial approach has historically been used. A transvenous approach can be used but carries risk of Fontan obstruction, thromboembolism, and can be technically challenging. The safety and efficacy of these approaches is not well described. The aim of this study was to compare epicardial and transvenous pacemaker outcomes in Fontan patients, specifically, device performance and adverse event rate. A retrospective review was performed on Fontan pacemaker patients followed at a single institution. Thirty-one Fontan pacemaker patients were identified between 1985 and 2017. Twenty-six had an epicardial system, five transvenous, and three converted from epicardial to transvenous. Average atrial lead sensing at placement was 3.23 versus 2.35 mV (p = 0.52) for epicardial and transvenous leads, respectively. Median atrial and ventricular lead longevity was 86.4 versus 98.8 months (p = 0.56) and 73.2 versus 140 months (p = 0.3) with generator longevity of 65.5 versus 73.9 (p = 0.16) months for epicardial versus transvenous systems, respectively. One major complication occurred in a transvenous patient, and two minor complications occurred in epicardial patients. All transvenous patients received warfarin except one, who converted to dabigatran. Epicardial patients received aspirin (n = 20), warfarin (n = 3) or a warfarin/aspirin combination (n = 3). No thromboembolic events occurred. System revision was required in 13 epicardial and 5 transvenous patients. There were two deaths, none related to the pacemaker system. Transvenous pacemakers can be utilized with equal efficacy compared to epicardial pacemakers with trends toward longer lead longevity in transvenous pacemaker systems.

Long Term Consequences of the Fontan Procedure and How to Manage Them

In 1971, Fontan and Baudet described a surgical technique for successful palliation of patients with tricuspid atresia. Subsequently, this technique has been applied to treat most forms of functional single ventricles and has become the current standard of care for long-term palliation of all patients with single ventricle congenital heart disease. Since 1971, the Fontan procedure has undergone several variations. These patients require lifelong management including a thorough knowledge of their anatomic substrate, hemodynamic status, management of rhythm and ventricular function along with multi organ evaluation. As these patients enter middle age, there is increasing awareness regarding the long-term complications and mortality. This review highlights the long-term outcomes of the Fontan procedure and management of late sequelae.

Thromboprophylaxis in Adults With Atrio-Pulmonary Fontan

BACKGROUND

Although aspirin has been compared to warfarin for thromboembolic prophylaxis in the general Fontan population, little is known about the optimal preventative strategy for the atriopulmonary right atrium-pulmonary artery [RA-PA]) Fontan particularly.

METHODS

A retrospective cohort study was performed including adult patients identified in the Ahmanson/UCLA Adult Congenital Heart Disease Center database with a history of RA-PA Fontan and use of either aspirin or warfarin as most recent primary prophylaxis against thromboembolism. Primary outcome was incident thromboembolism, defined as space-occupying lesion on imaging consistent with thrombus within the Fontan or pulmonary arterial circuit. Secondary outcomes were death, transplantation, Fontan conversion, and bleeding requiring either transfusion or invasive intervention. Follow-up was terminated upon achievement of a primary outcome or achievement of a secondary outcome other than bleeding. Kaplan-Meier analysis of freedom from thrombosis was performed.

RESULTS

Twenty-six patients met inclusion criteria. Thirteen (50%) received aspirin as most recent primary prophylaxis and 13 (50%) received warfarin. Tricuspid atresia was the most common underlying diagnosis (42%), followed by double-inlet left ventricle (38%). Median age at Fontan operation was 8.2 years; median age at prophylaxis initiation was 25.9 years. After six years, the aspirin group had 50% ± 35% freedom from thrombosis and the warfarin group 92% ± 8% ( P = .15). Incidences of secondary outcomes were not significantly different between the groups.

CONCLUSION

In this cohort of long-term Fontan survivors with RA-PA Fontan, the risk of thromboembolic complications is high, especially in those taking aspirin rather than warfarin. Larger studies are needed to confirm these findings.

State of the art of the Fontan strategy for treatment of univentricular heart disease

In patients with a functionally univentricular heart, the Fontan strategy achieves separation of the systemic and pulmonary circulation and reduction of ventricular volume overload. Contemporary modifications of surgical techniques have significantly improved survival. However, the resulting Fontan physiology is associated with high morbidity. In this review, we discuss the state of the art of the Fontan strategy by assessing survival and risk factors for mortality. Complications of the Fontan circulation, such as cardiac arrhythmia, thromboembolism, and protein-losing enteropathy, are discussed. Common surgical and catheter-based interventions following Fontan completion are outlined. We describe functional status measurements such as quality of life and developmental outcomes in the contemporary Fontan patient. The current role of drug therapy in the Fontan patient is explored. Furthermore, we assess the current use and outcomes of mechanical circulatory support in the Fontan circulation and novel surgical innovations. Despite large improvements in outcomes for contemporary Fontan patients, a large burden of disease exists in this patient population. Continued efforts to improve outcomes are warranted. Several remaining challenges in the Fontan field are outlined.

Risk of thromboembolic complications in adult congenital heart disease: A literature review

Adult congenital heart disease (ACHD) is a constantly expanding population with challenging issues. Initial medical and surgical treatments are seldom curative, and the majority of patients still experience late sequelae and complications, especially thromboembolic events. These common and potentially life-threating adverse events are probably dramatically underdiagnosed. Better identification and understanding of thromboembolic risk factors are essential to prevent long-term related morbidities. In addition to specific situations associated with a high risk of thromboembolic events (Fontan circulation, cyanotic congenital heart disease), atrial arrhythmia has been recognized as an important risk factor for thromboembolic events in ACHD. Unlike in patients without ACHD, thromboembolic risk stratification scores, such as the CHA₂DS₂-VASc score, may not be applicable in ACHD. Overall, after a review of the scientific data published so far, it is clear that the complexity of the underlying congenital heart disease represents a major risk factor for thromboembolic events. As a consequence, prophylactic anticoagulation is indicated in patients with complex congenital heart disease and atrial arrhythmia, regardless of the other risk factors, as opposed to simple heart defects. The landscape of ACHD is an ongoing evolving process, and specific thromboembolic risk scores are needed, especially in the setting of simple heart defects; these should be coupled with specific trials or long-term follow-up of multicentre cohorts.

Pathophysiology of thrombosis and anticoagulation post Fontan surgery

The Fontan procedure has transformed the lives of children born with single-ventricle physiology, previously deemed inoperable. Worldwide, there are an increasing number of children with Fontan circulation, with the potential for survival into adulthood. Due to the abnormal circulation, Fontan patients have an increased risk of thromboembolic (TE) events, with up to 25% of events leading to death. Despite the importance of preventing TE events in this patient population, there is currently no clinical consensus on the optimal monitoring, thromboprophylaxis therapies, and treatment of these events. This paper reviews the available literature regarding anticoagulation in the pediatric and adult Fontan population, including the mechanisms for thrombosis and current antithrombotic therapies.

Embolic stroke in a postpartum patient with Fontan physiology

In cardiac physiology, single ventricle typically refers to the presence of a dominant systemic ventricle along with a hypoplastic ventricle. The Fontan operation is used to repair the single ventricle by directing deoxygenated systemic venous flow to the pulmonary arterial circulation. Normal pregnancy physiology, particularly increased intravascular volume, increased heart rate, increased cardiac output, hypercoagulability and decreased systemic vascular resistance, can exacerbate cardiac disease in patients with Fontan circulation, leading to pregnancy complications. Despite the known risks, there are limited data addressing the question of anticoagulation in pregnant patients with Fontan physiology. Herein we present the case of a Fontan patient who had a successful pregnancy and delivery, and developed an embolic stroke in the postpartum period.

Diagnosis and Management of Noncardiac Complications in Adults With Congenital Heart Disease: A Scientific Statement From the American Heart Association

Life expectancy and quality of life for those born with congenital heart disease (CHD) have greatly improved over the past 3 decades. While representing a great advance for these patients, who have been able to move from childhood to successful adult lives in increasing numbers, this development has resulted in an epidemiological shift and a generation of patients who are at risk of developing chronic multisystem disease in adulthood. Noncardiac complications significantly contribute to the morbidity and mortality of adults with CHD. Reduced survival has been documented in patients with CHD with renal dysfunction, restrictive lung disease, anemia, and cirrhosis. Furthermore, as this population ages, atherosclerotic cardiovascular disease and its risk factors are becoming increasingly prevalent. Disorders of psychosocial and cognitive development are key factors affecting the quality of life of these individuals. It is incumbent on physicians who care for patients with CHD to be mindful of the effects that disease of organs other than the heart may have on the well-being of adults with CHD. Further research is needed to understand how these noncardiac complications may affect the long-term outcome in these patients and what modifiable factors can be targeted for preventive intervention.

Homoarginine-A prognostic indicator in adolescents and adults with complex congenital heart disease?

Background

Homoarginine (hArg) has been shown to be of prognostic value in patients with chronic left heart failure. The present study aims to assess the clinical utility and prognostic value of hArg levels in patients with complex congenital heart disease (CHD).

Methods

Plasma hArg levels were measured in 143 patients with complex CHD and compared to clinical status, echocardiographic and laboratory parameters as well as the occurrence of adverse cardiac events.

Results

Median hArg levels were 1.5 μmol/l in CHD patients as compared to 1.70 μmol/l in healthy controls (p = 0.051). Median hArg levels were lowest in patients with Fontan palliation (1.27 μmol/l) and Eisenmenger physiology (0.99 μmol/l) and decreased with the severity of adverse cardiac events with lowest values found in patients prior to death or overt heart failure (0.89 μmol/l). According to ROC analysis, the most important predictors of adverse cardiac events were hArg levels (AUC 0.837, p<0.001, CI 0.726–0.947), NYHA class (AUC 0.800, p<0.001, CI 0.672–0.928) and NT-proBNP levels (AUC 0.780, p<0.001, CI 0.669–0.891). The occurrence of overt heart failure or death due to progressive heart failure were best predicted by NYHA class (AUC 0.945, p<0.001, CI 0.898–0.992), hArg levels (AUC 0.911, p<0.001, CI 0.850–0.971) and NT-proBNP levels (AUC 0.877, p<0.001, CI 0.791–0.962), respectively.

Conclusion

In patients with complex CHD, hArg levels can predict adverse cardiac events as reliably as or even better than NT-proBNP levels and thus might be of prognostic value in this subset of patients.

Effect of Fontan-Associated Morbidities on Survival With Intact Fontan Circulation

Although survival after the Fontan operation has improved, little is known about the burden of major medical morbidities associated with the modern total cavopulmonary connection (TCPC). A total of 773 consecutive patients who underwent a first Fontan operation at our institution between 1992 and 2009 were retrospectively reviewed. All subjects underwent TCPC (53% lateral tunnel, 47% extracardiac conduit). Median length of follow-up was 5.3 years (interquartile range 1.4 to 11.2), and 30% had follow-up >10 years. Freedom from a composite medical morbidity outcome (protein-losing enteropathy, plastic bronchitis, serious thromboembolic event, or tachyarrhythmia) was 47% at 20 years (95% confidence interval [CI] 38 to 55). Independent risk factors for morbidity included pre-Fontan atrioventricular valve regurgitation (hazard ratio [HR] 1.7, 95% CI 1.2 to 2.4, p = 0.001), pleural drainage >14 days (HR 1.5, 95% CI 1.01 to 2.2, p = 0.04), and longer cross-clamp time (HR 1.2 per 10 minutes, 95% CI 1.06 to 1.3, p = 0.004) at the time of TCPC. Surgical era, Fontan type, and ventricular morphology were not associated with the composite outcome. Presence of Fontan-associated morbidity was associated with a 36-fold increase in the risk of subsequent Fontan takedown, heart transplantation, or death (95% CI 17 to 76, p <0.001). For patients without any component of the composite outcome, freedom from Fontan failure was 98% at 20 years (95% CI 96 to 99). Medical morbidities after TCPC are common and significantly reduce the longevity of the Fontan circulation. However, for those patients who remain free from the composite morbidity outcome, 20-year survival with intact Fontan circulation is encouraging.

Current Therapy for Hypoplastic Left Heart Syndrome and Related Single Ventricle Lesions

Universally fatal only 4 decades ago, the progress in the 3-stage palliation of hypoplastic left heart syndrome and related single right ventricular lesions has drastically improved the outlook for these patients. Although the stage II operation (hemi-Fontan or bidirectional Glenn) and stage III Fontan procedure have evolved into relatively low-risk operations, the stage I Norwood procedure remains one of the highest-risk and costliest common operations performed in congenital heart surgery. Yet, despite this fact, experienced centers now report hospital survivals of >90% for the Norwood procedure. This traditional 3-stage surgical palliation has seen several innovations in the past decade aimed at improving outcomes, particularly for the Norwood procedure. One significant change is a renewed interest in the right ventricle-to-pulmonary artery shunt as the source of pulmonary blood flow, rather than the modified Blalock-Taussig shunt for the Norwood. The multi-institutional Single Ventricle Reconstruction trial randomly assigned 555 patients to one or the other shunt, and these subjects continue to be followed closely as they now approach 10 years postrandomization. In addition to modifications to the Norwood procedure, the hybrid procedure, a combined catheter-based and surgical approach, avoids the Norwood procedure in the newborn period entirely. The initial hybrid procedure is then followed by a comprehensive stage II, which combines components of both the Norwood and the traditional stage II, and later completion of the Fontan. Proponents of this approach hope to improve not only short-term survival, but also potentially longer-term outcomes, such as neurodevelopment, as well. Regardless of the approach, traditional surgical staged palliation or the hybrid procedure, survivals have vastly improved, and large numbers of these patients are surviving not only through their Fontan in early childhood, but also into adolescence and young adulthood. As this population grows, it becomes increasingly important to understand the longer-term outcomes of these Fontan patients, not only in terms of survival, but also in terms of the burden of disease, neurodevelopmental outcomes, psychosocial development, and quality of life.

The Long-Term Management of Children and Adults with a Fontan Circulation: A Systematic Review and Survey of Current Practice in Australia and New Zealand

Although long-term survival is now the norm, Fontan patients face significant morbidity and premature mortality. Wide variation exists in long-term Fontan management. With an aim of improving their long-term management, we conducted a systematic review to identify best available evidence and gaps in knowledge for future research focus. We also surveyed cardiologists in Australia and New Zealand managing Fontan patients, to determine the alignment of current local practice with best available evidence. A systematic review was conducted using strict search criteria (PRISMA guidelines), pertaining to long-term Fontan management. All adult congenital and paediatric cardiologists registered with The Australia and New Zealand Fontan Registry were invited to respond to an online survey. Reasonable quality evidence exists for non-inferiority of aspirin over warfarin for thromboprophylaxis in standard-risk Fontan patients. No strong evidence is currently available for the routine use of ACE inhibitors, beta blockers or pulmonary vasodilators. Little evidence exists regarding optimal arrhythmia treatment, exercise restriction/prescription, routine fenestration closure, elective Fontan conversion and screening/management of liver abnormalities. Although pregnancy is generally well tolerated, there are high rates of miscarriage and premature delivery. Thirty-nine out of 78 (50 %) cardiologists responded to the survey. Heterogeneity in response was demonstrated with regard to long-term anti-coagulation, other medication use, fenestration closure and pregnancy and contraception counselling. Substantial gaps in our knowledge remain with regard to the long-term management of Fontan patients. This is reflected in the survey of cardiologists managing these patients. We have identified a number of key areas for future research.

Fontan circulation over 30 years. What should we learn from those patients?

Background

This study aimed to evaluate Fontan circulation which was observed over 30 years.

Methods

Forty patients who underwent a Fontan operation between 1974 and 1986 and survived (group S, n = 20) or died in the late period (group LD, n = 20) were evaluated. The median age at operation was 10 years (range 2–32 years). The diagnoses were tricuspid atresia in 21, single ventricle in 9, and others in 10. The Fontan procedure was a right atrium-pulmonary artery graft in 2, atriopulmonary connection in 28, and right atrium-right ventricle anastomosis in 10 (Björk in 4, graft in 6).

Results

Causes of late death were congestive heart failure in 6, sudden death in 4, arrhythmia in 4, and others in 6. Sixteen patients underwent reoperation 23.3 ± 6.5 years after Fontan. Cardiac catheterization was performed at 1 month and 12 years. There were no significant differences in central venous pressure, ventricular ejection fraction, or pulmonary vascular resistance between the two groups. However, changes in ventricular end-diastolic volume suggested volume and pressure overload in group LD. In group S, the latest chest radiographs showed cardiothoracic ratio 51.3% ± 7.6%, oxygen saturation 94% ± 2%, brain natriuretic peptide 153 ± 111 pg ċ mL−1, and Holter monitoring revealed sinus rhythm in 10 patients. New York Heart Association class was I in 12 patients, II in 6, and III in 2.

Conclusions

For long-term Fontan survival, timely total cavopulmonary connection conversion and medication to decrease ventricular volume and pressure load might be important.

Thromboembolism and anticoagulation after Fontan surgery

This review attempts to answer the common questions faced by a clinician regarding thromboembolism and thromboprophylaxis in patients following Fontan surgery. The review is in an easy to understand question and answer format and discusses the currently available literature on the subject in an attempt to arrive at practical clinically relevant solutions. Patients who have undergone the Fontan operation are at a high risk for thromboembolism. Based on available evidence, there is a strong rationale for thromboprophylaxis. However, it is not clear as to which agent should be administered to prevent thromboembolic events. While the available evidence suggests that antiplatelet agents alone may be as good as oral anticoagulants, there is a need for a large multicenter randomized control trial comparing these two common strategies to deliver a clear verdict.

Adult patients with Fontan circulation: What we know and how to manage adults with Fontan circulation?

Most of patients after the Fontan operation can reach their adulthood, however, the management strategy for this complex pathophysiology has not been yet established. In general, elevated central venous pressure (CVP) and low cardiac output (CO) due to impaired ventricular preload characterize the Fontan circulation and the ideal hemodynamics could be a combination of a lower CVP with a higher CO. Thus, preserved functional systemic ventricle with low pulmonary artery resistance is thought to be crucial for better long-term outcome. However, on the other hand, because of the unique hemodynamics, these patients have significantly higher incidence of complications, sequelae, and even mortality. The major complications are supraventricular arrhythmias, heart failure, and Fontan-related problems, including protein-losing enteropathy and pulmonary arteriovenous fistulae, both of which are refractory to the treatments, and most of these "Fontan inconveniences" increase as patients age. In addition, one of the recent emerging problems is Fontan-associated liver disease that includes liver cirrhosis and hepatocellular carcinoma. Furthermore, women with Fontan circulation also reach childbearing age and there have been increasing numbers of reports showing a high incidence of pregnancy-associated complications. All these problems may be a part of "Fontan inconveniences" because most of the current Fontan patients are still "young" i.e. in their twenties or thirties and it may be not surprising that more new Fontan-associated pathophysiology emerges as patients age. Recent evidence reminds us of the concept that adult Fontan pathophysiology is not just a cardiovascular disease, rather, a multiorgan disease with many interactions between cardiovascular and non-cardiovascular organs. Therefore, a multidisciplinary approach is mandatory to take care of and anticipate the better long-term outcome.