Atrial tachyarrhythmias late after Fontan operation are related to increase in mortality and hospitalization

Long-Term Outcomes and Predictors of Recurrence in Atrial Arrhythmia Ablations Post-Fontan Procedure: A Retrospective Analysis

Background

Supraventricular tachycardia (SVT) is common in patients who have undergone a Fontan procedure and is poorly tolerated. SVT recurrence rates after catheter ablations are high. Recent data on the outcomes of SVT ablation and the predictors of recurrence in this population are limited.

Methods

Electronic medical records of patients who had undergone a Fontan procedure and SVT ablation between January 1, 1995, and October 1, 2023, at a tertiary care center were reviewed. Demographic, clinical, and outcome variables over 5 years were compared between patients with and without SVT recurrence.

Results

Twenty-five patients (56% male, mean age 31.5 ± 7.2 years) with a mean age of 6.1 ± 3.6 years at Fontan surgery were included. Ablation success rate was 92%. Recurrence occurred in 12 (48%) patients, of whom 7 (28%) required repeat ablations. Thirteen (59%) patients had a cardiac hospitalization, and one patient died in the 5-year follow-up period. Atypical (71%) and typical (33%) right atrial flutter were the most common SVTs. Higher brain natriuretic peptide (BNP) levels pre- (1,702 vs. 242, P = 0.028) and post-ablation (862 vs. 112, P = 0.017) were associated with recurrence. Atriopulmonary (AP) Fontan type (91% vs. 17%, P = 0.0006), number of radiofrequency (RF) applications (48 vs. 14, P = 0.045), post-ablation cardiovascular (CV) hospitalizations (82% vs. 36% P = 0.030), and post-ablation antiarrhythmic prescriptions (1.8 vs. 1.2, P = 0.0256) were more prevalent in patients with recurrence.

Conclusion

Catheter ablation of SVT in patients with Fontan physiology is associated with a high success rate and a high long-term recurrence rate. Recurrence of SVT is associated with markers of severe heart disease and type of Fontan.

Are Arrhythmias Adequately Incorporated into Studies on Long-Term Outcomes After the Fontan Operation?

Arrhythmias are common after the Fontan operation and increase risk of morbidity and mortality. Their impact on late outcomes remains poorly understood. Our objective was to assess whether long-term studies after the Fontan incorporated the impact of arrhythmia characteristics on outcome. We reviewed the literature since 2005 for studies evaluating the impact of multiple risk factors on long-term outcomes and mortality after the Fontan. Studies focusing only on one or two risk factors (including arrhythmias) and those with a mean follow-up < 10 years were excluded. Of the 17 studies analyzed, only six mentioned rhythm at follow-up. Nine lumped all arrhythmias (tachyarrhythmia, bradyarrhythmia, paced rhythm, early and late arrhythmia) into one single category. Only eight of the 17 studies reported the incidence of tachyarrhythmias in detail and only two studies described bradyarrhythmias in detail as sinus or atrioventricular (AV) node dysfunction subgroups. Five studies reported on treatment of tachyarrhythmias including Fontan revision surgeries, catheter ablation, pacemaker placement and or the use of antiarrhythmic drugs. However, only one included information on the impact of treatment on outcomes. Out of 15 studies that conducted a multivariate analysis of Fontan outcomes, arrhythmia was included in the univariate model in 14 and in the multivariate model in 9. Overall, we found most studies on late outcomes after the Fontan do not include rhythm and arrhythmia characteristics in data collection and analysis. Incorporating more granular rhythm information in large databases and in multivariate analyses will help better determine and contextualize the impact of arrhythmias on outcomes after the Fontan.

Review of rhythm disturbances in patient after fontan completion: epidemiology, management, and surveillance

Purpose

The Fontan operation is commonly associated with alterations in heart rhythms, both tachycardic and bradycardic. Despite modifications to attempt to mitigate these complications, arrythmias still frequently occur. The purpose of this review is to examine the literature regarding the scope of the problem, therapeutic options, and current recommendations regarding screening and surveillance.

Recent findings

Modifications to the original Fontan procedure, antiarrhythmic medications, and improvements in catheter ablation procedures have improved the management of patients with arrhythmias following Fontan palliation. There is growing interest in the role of junctional rhythm in the role of Fontan dysfunction. While chronotropic incompetence has often been blamed for poor exercise testing, there is evidence that decreased performance may be related to ventricular filling and Fontan hemodynamics.

Summary

Tachyarrhythmias are an important cause of mortality and morbidity after the Fontan operation. Prompt and aggressive management of arrhythmias with the goal of maintaining sinus rhythm is vital. Management strategies such as anti-arrhythmic medications, ablation, anti-tachycardia pacing and Fontan conversion should be seen as complementary and used early to prevent hemodynamic deterioration. Bradyarrythmias likely also contribute to Fontan failure. Pacing is the primary management strategy with evidence supporting use of atrial pacing. However, ventricular pacing seems to often lead to deleterious effects. Current guidelines recommend surveillance with Holter monitor every 2-3 years in adolescents and every 1-2 years in adults. Future directions for research include further assessment of junctional rhythm and its management as well as further identifying patients in which pacing would be beneficial.

Late development of intra-atrial reentrant tachycardia in lateral tunnel Fontan patients and the preventive role of prophylactic cryoablation

OBJECTIVE

Intra-atrial reentrant tachycardia is an important late-onset complication in patients undergoing the Fontan procedure. However, the protective effects of prophylactic cryoablation against late-onset intra-atrial reentrant tachycardia are unclear. This study investigated the late development of intra-atrial reentrant tachycardia in patients undergoing the lateral tunnel Fontan procedure and the role of prophylactic cryoablation.

METHODS

This was a single-center retrospective cohort study of patients who underwent the lateral tunnel Fontan procedure between 1988 and 2003. Univariate and multivariable competing risks regression models were used to determine the associations of prophylactic cryoablation and covariates with the outcomes of interest: late-onset intra-atrial reentrant tachycardia, all-cause mortality, and cardiovascular mortality.

RESULTS

In total, 130 patients who underwent the lateral tunnel Fontan procedure, 30 of whom had undergone prophylactic cryoablation, were included in this study and followed up for a median of 23.6 years (interquartile range, 17.7-26.5). Intra-atrial reentrant tachycardia was identified in 14 patients (10.8%), none of whom underwent prophylactic cryoablation. The median Fontan-to-intra-atrial reentrant tachycardia time was 17.2 years (interquartile range, 11.1-23.1). Prophylactic cryoablation was protective against late-onset intra-atrial reentrant tachycardia (P < .0001) and cardiovascular mortality (P < .0001) in the type 3 test.

CONCLUSIONS

None of the patients who underwent prophylactic cryoablation developed late-onset intra-atrial reentrant tachycardia during a median follow-up time of 22.9 years. Our study demonstrated that prophylactic cryoablation was effective in preventing late-onset intra-atrial reentrant tachycardia and cardiovascular mortality in patients undergoing the lateral tunnel Fontan.

Morbidity and mortality in adults with a Fontan circulation beyond the fourth decade of life

AIMS

To evaluate the late outcomes of adults (above 35 years) with a Fontan-type circulation, for whom current data on morbidity and mortality are lacking.

METHODS AND RESULTS

Data were collected retrospectively on consecutive patients with Fontan circulation above the age of 35 years followed in three European specialist centres. Overall, 115 Fontan patients were included [median age 35 (range 35-48) years, 47.8% female]. The most common underlying congenital heart disease diagnosis was tricuspid atresia (n = 58, 50.4%), and the age at first Fontan completion was 9.1 (interquartile range 5.0-15.8) years. Almost two-thirds (61.7%) of patients had undergone an atriopulmonary Fontan, and 23.5% had received a total cavopulmonary connection. One-third required repeat surgery or intervention. Most patients (55.9%) were in New York Heart Association functional class II or class I (30.6%), 76 (66.1%) patients had experienced at least one arrhythmia, and eight (7.0%) protein-losing enteropathy. At a median follow-up of 5.0 (2.4-10.3) years, 15 (13.0%) patients were referred for transplantation assessment and 19 (16.5%) patients died, mainly from heart failure (84.2%). Univariable predictors of death or transplantation included lower serum albumin level [hazard ratio (HR) 1.09 per g/L decrease, 95% confidence interval (CI): 1.04-1.15, P = 0.0009], prior heart failure admission (HR 4.28, 95% CI:1.75-10.44, P = 0.001), prior atrial tachycardia or flutter (HR 3.02, 95% CI: 1.23-7.38, P = 0.02), and baseline pulmonary vasodilator therapy (HR 8.59, 95% CI:1.05-70.13, P = 0.04). Lower serum albumin and prior atrial tachycardia or flutter remained significant on bivariable analysis.

CONCLUSION

Our study highlights the significant morbidity and mortality in older adults with a Fontan-type circulation, emphasizing the need for lifelong specialist surveillance with frequent risk stratification, close monitoring, and early consideration for transplantation assessment.

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.

Arrhythmias in Adult Congenital Heart Disease Heart Failure

Heart failure and arrhythmias represent 2 major causes of mortality and morbidity in adults with congenital heart disease. Arrhythmias and heart failure are interdependent, and one may exacerbate the other. Treatment of one also has a positive impact on the other. Management approaches need to be multifaceted, including pharmacotherapy, optimization of hemodynamic status with catheter-based or surgical interventions, and specific management of arrhythmia with device or catheter ablation therapy.

Ablation of atrial flutter in a patient after Fontan procedure: a case report of challenging access to the common atrium

Background

In patients with a total cavopulmonary connection in Fontan circulation, the access to the common atrium (CA) during a catheter ablation can be challenging, even in the presence of fenestration in an intra-atrial lateral tunnel (IALT). In our department, the fenestration is typically marked with metal clips (MCs). To the best of our knowledge, there is no previous report of balloonoplasty of clipped fenestration.

Case summary

A 19-year-old male with hypoplastic left heart syndrome (HLHS) was scheduled for catheter ablation of recurrent atrial tachycardia. He was diagnosed with HLHS prenatally and underwent a stepwise surgical palliation. Fontan circulation was completed with the creation of a fenestrated IALT. The fenestration was marked by four MCs. During the ablation procedure, the passage of the steerable sheath with mapping catheter to the CA was prevented by a small fenestration size and rigidness of the edges of the fenestration caused by the MCs. Multiple attempts to dilate the fenestration using a peripheric angioplasty balloon failed. Only angioplasty with the 'balloon-against-dilator' technique was finally successful. Activation map showed a counterclockwise atrial flutter in the CA; successful ablation was performed.

Discussion

We present a case of challenging access to the CA through a clipped fenestration in a polytetrafluoroethylene baffle for atrial tachycardia ablation. Even though a tunnel fenestration in Fontan patients facilitates access to the CA, the passage of a steerable introducer with a mapping catheter may be challenging due to diameter mismatch and the rigidity of its edges caused by MCs. The balloon-against-dilator technique might be helpful when conventional balloon angioplasty fails.

Complex Congenital Heart Disease in the Adult

Congenital heart disease (CHD), a heterogeneous group of structural abnormalities of the cardiovascular system, is the most frequent cause of severe birth defects. Related to improved pediatric outcomes, there are now more adults living with CHD, including complex lesions, than children. Adults with CHD are at high risk for complications related to their underlying anatomy and past surgical palliative interventions. Adults with CHD require close monitoring and proactive management strategies to improve outcomes.

Arrhythmias in Patients with Congenital Heart Disease: An Ongoing Morbidity

With the aging of congenital heart disease (CHD) patients, the burden of arrhythmias is expanding. Atrial arrhythmias, especially intra-atrial reentrant tachycardia and atrial fibrillation, are the most prevalent forms of arrhythmia. Managing comorbidities, such as obesity, using pharmacotherapy, including antiarrhythmics and anticoagulants, and ablation therapy has become the cornerstone of arrhythmia management. Ventricular tachycardias are also not rare; however, except for tetralogy of Fallot patients, recommendations for the use of implantable cardioverter defibrillators for primary prevention in other CHD patients are still not well established. Patients with CHD might also present with atrioventricular blockages because of their anatomy or following a surgical procedure. The scope of this article is to review the current knowledge and discuss the future directions regarding arrhythmia management in CHD patients.

Five decades of Fontan palliation: What have we learned? What should we expect?

The Fontan procedure is the final palliative surgery in a series of staged surgeries to reroute the systemic venous blood flow directly to the lungs, with the ventricle(s) pumping oxygenated blood to the body. Advances in medical and surgical techniques have improved patients' overall survival after the Fontan procedure. However, Fontan-associated chronic comorbidities are common. In addition to chronic cardiac dysfunction and arrhythmias, complications involving other organs such as the liver, lungs, intestine, lymphatic system, brain, and blood frequently occur. This narrative review focuses on the immediate and late consequences in children, pregnant women, and other adults with Fontan circulation. In addition, we describe the technical advancements that might change the way single-ventricle patients are managed in future.

Atrial Arrhythmias in Adults with Fontan Palliation

Single ventricle physiology is a rare form of congenital heart disease and was, historically, a uniformly lethal condition. However, the atriopulmonary Fontan operation, and its successive iterations, the lateral tunnel and extracardiac conduit Fontan, became the fundamental approach to treating single ventricle heart disease. Over time, dysrhythmias are some of the most common complications with Fontan physiology, compounding morbidity and mortality. Atrial arrhythmias are prevalent in the Fontan population and occur in about 15-60% of patients with Fontan palliation, increasingly with age. Diagnosing atrial arrhythmias in patients with Fontan palliation may be challenging because of low voltage amplitudes arising from myopathic atrial tissue making it difficult to clearly assess atrial depolarization on surface electrocardiograms (ECG), vague symptoms not suggestive of tachyarrhythmia, or atrial arrhythmia with ventricular rates below 100 beats per minute. Intra-atrial reentrant tachycardia (IART) is the most common type of supraventricular tachycardia in adults with Fontan palliation. Acute management of atrial arrhythmias in patients with Fontan palliation involves prompt assessment of a patient's hemodynamic stability, anticoagulation and thrombosis risk, systemic ventricular function, and risk of sedation or anesthesia if needed. Long-term management of atrial arrhythmias is often multifactorial and may include long-term anti-arrhythmic therapy, permanent pacing, and ablation. The best approach for the management of atrial arrhythmias in adults with Fontan palliation is patient-specific and involves collaboration between congenital electrophysiologists, adult congenital cardiologists, and the patient.

Atrial Flutters in Adults with Congenital Heart Disease

The macroreentrant atrial tachycardia is very frequent in the adults with congenital heart disease. The impact of the arrhythmias on this type of patients is related to several factors: the anatomy and physiopathology of the specific congenital heart disease (CHD), the sequelae of the corrective surgery or surgical palliation, the presence of residual lesions (shunt, regurgitation), and the age and the clinical status of the patient and the comorbidities. In turn, the mechanism of the MAT depends on the peculiar features of the conduction's system in the CHD and native and acquired (post-surgery) substrates.

Diuretic use in the adult Fontan

Objectives

To explore diuretic use in Fontan patients and its association with clinical features and adverse outcomes.

Background

In Fontan circulatory failure, ventricular dysfunction, chronically elevated systemic venous pressures, lymphatic abnormalities, and preload deprivation lead to volume expansion, prompting initiation of diuretics, yet use of diuretics has not been widely studied in the adult Fontan patient.

Methods

Single center retrospective review of Fontan patients ≥18 years between 2005 and 2018. Descriptive statistics compared Fontan patients by diuretic. Univariate logistic regression analyses were performed. Variables with a p value < 0.05 were selected to create multivariable model using backwards stepwise regression. Kaplan-Meier product-limit estimates stratified by diuretic use were used to find estimates of transplant and death rates. Log-rank tests were used to compare the time to outcome by diuretic use and Cox Proportional Hazards models examined the risk of transplant or death based on diuretic use.

Results

Of 206 Fontan patients, 96 (47%) were taking diuretics. Multivariable analysis demonstrated the following associated with diuretic use: age (Adjusted Odds Ratio [AOR] 1.06; p = 0.02); cyanosis (AOR 3.59; p=<0.01); tachyarrhythmia (AOR 2.64; p=<0.01); pacemaker (AOR 2.48; p = 0.02); ≥ moderate atrioventricular (AV) valve regurgitation (AOR 2.88; p=<0.05); New York Heart Association Class II-IV (AOR 3.41; p < 0.01). Diuretic use was associated with a 17-fold increased risk of transplant or death (95% CI 2.3-131.9; p=<0.01).

Conclusion

Diuretic use is common in adult Fontan patients. Multiple clinical correlates of heart failure were associated with diuretic use. Transplant-free survival was significantly reduced in those taking diuretics.

Catheter ablation of atrial arrhythmias in patients post-Fontan

Atrial arrhythmias are highly prevalent in the aging Fontan population and contribute importantly to morbidity and mortality. Although the most common arrhythmia is scar-based intra-atrial re-entrant tachycardia, various other arrhythmias may occur including focal atrial tachycardia, atrioventricular node-dependent tachycardias, and atrial fibrillation. The type and prevalence of atrial arrhythmia is determined, in part, by the underlying congenital defect and variant of Fontan surgery. While the cumulative incidence of atrial tachyarrhythmias has decreased substantially from the atriopulmonary anastomosis to the more recent total cavopulmonary connection Fontan, the burden of atrial arrhythmias remains substantial. Management is often multi-faceted and can include anticoagulation, anti-arrhythmic drug therapy, pacing, and cardioversion. Catheter ablation plays a key role in arrhythmia control. Risks and benefits must be carefully weighed. Among the important considerations are the clinical burden of arrhythmia, ventricular function, hemodynamic stability in tachycardia, suspected arrhythmia mechanisms, risks associated with anaesthesia, venous access, approaches to reaching the pulmonary venous atrium, and accompanying co-morbidities. Careful review of surgical notes, electrocardiographic tracings, and advanced imaging is paramount, with particular attention to anatomic abnormalities such as venous obstructions and displaced conduction systems. Despite numerous challenges, ablation of atrial arrhythmias is effective in improving clinical status. Nevertheless, onset of new arrhythmias is common during long-term follow-up. Advanced technologies such as high-density mapping catheters and remote magnetic guided ablation carry the potential to further improve outcomes. Fontan patients with atrial arrhythmias should be referred to centers with dedicated expertise in congenital heart disease including catheter ablation, anaesthesia support, and advanced imaging.

The Adult Congenital Heart Disease Anatomic and Physiological Classification: Associations with Clinical Outcomes in Patients with Atrial Arrhythmias

The implications of the adult congenital heart disease anatomic and physiological classification (AP-ACHD) for risk assessment have not been adequately studied. A retrospective cohort study was conducted using data from an ongoing national, multicentre registry of patients with ACHD and atrial arrhythmias (AA) receiving apixaban (PROTECT-AR study, NCT03854149). At enrollment, patients were stratified according to Anatomic class (AnatC, range I to III) and physiological stage (PhyS, range B to D). A follow-up was conducted between May 2019 and September 2021. The primary outcome was a composite of death from any cause, any major thromboembolic event, major or clinically relevant non-major bleeding, or hospitalization. Cox proportional-hazards regression modeling was used to evaluate the risks for the outcome among AP-ACHD classes. Over a median 20-month follow-up period, 47 of 157 (29.9%) ACHD patients with AA experienced the composite outcome. Adjusted hazard ratios (aHR) with 95% confidence intervals (CI) for the outcome in PhyS C and PhyS D were 1.79 (95% CI 0.69 to 4.67) and 8.15 (95% CI 1.52 to 43.59), respectively, as compared with PhyS B. The corresponding aHRs in AnatC II and AnatC III were 1.12 (95% CI 0.37 to 3.41) and 1.06 (95% CI 0.24 to 4.63), respectively, as compared with AnatC I. In conclusion, the PhyS component of the AP-ACHD classification was an independent predictor of net adverse clinical events among ACHD patients with AA.

Current Treatment Options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations, where biventricular repair is unsuitable, the Fontan procedure has provided a long-term palliation strategy with improved outcomes compared to the initially developed procedures. Despite these improvements, several complications merely due to a failing Fontan circulation, including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein-losing enteropathy, hepatic dysfunction, plastic bronchitis, and thrombo-embolism, may occur, thereby limiting the life-expectancy in this patient cohort. This review provides an overview of the most common complications of Fontan circulation and the currently available treatment options.

Impact of 3D Printing on Short-Term Outcomes of Biventricular Conversion From Single Ventricular Palliation for the Complex Congenital Heart Defects

Background: Although Fontan palliation seems to be inevitable for many patients with complex congenital heart defects (CHDs), candidates with appropriate conditions could be selected for biventricular conversion. We aimed to summarize our single-center experience in patient selection, surgical strategies, and early outcomes in biventricular conversion for the complex CHD.

Methods: From April 2017 to June 2021, we reviewed 23 cases with complex CHD who underwent biventricular conversion. Patients were divided into two groups according to the development of the ventricles: balanced ventricular group (15 cases) and imbalanced ventricular group (8 cases). Early and short-term outcomes during the 30.2 months (range, 4.2–49.8 months) follow-up period were compared.

Results: The overall mortality rate was 4.3% with one death case. In the balanced ventricular group, 6 cases received 3D printing for pre-operational evaluation. One case died because of heart failure in the early postoperative period. One case received reoperation due to the obstruction of the superior vena cava. In the imbalanced ventricular group, the mean left ventricular end-diastolic volume was (33.6 ± 2.1) ml/m2, the mean left ventricular end-diastolic pressure was 9.1 ± 1.9 mmHg, and 4 cases received 3D printing. No death occurred while one case implanted a pacemaker due to a third-degree atrioventricular block. The pre-operational evaluation and surgery simulation with a 3D printing model helped to reduce bypass time in the balanced group (p &lt; 0.05), and reduced both bypass and aorta clamp time in the imbalanced group (p &lt; 0.05). All patients presented great cardiac function in the follow-up period.

Conclusion: Comprehensive evaluation, especially 3D printing technique, was conducive to finding the appropriate cases for biventricular conversion and significantly reduced surgery time. Biventricular conversion in selected patients led to promising clinical outcomes, albeit unverified long-term results.

Prediction Models and Scores in Adult Congenital Heart Disease

Nowadays, most patients with congenital heart disease survive to adulthood due to advances in pediatric cardiac surgery but often present with various comorbidities and long-term complications, posing challenges in their management. The development and clinical use of risk scores for the prediction of morbidity and/or mortality in adults with congenital heart disease (ACHD) is fundamental in achieving optimal management for these patients, including appropriate follow-up frequency, treatment escalation, and timely referral for invasive procedures or heart transplantation. In comparison with other fields of cardiovascular medicine, there are relatively few studies that report prediction models developed in the ACHD population, given the small sample size, heterogeneity of the population, and relatively low event rate. Some studies report risk scores originally developed in pediatric congenital or non-congenital population, externally validated in ACHD with variable success. Available risk scores are designed to predict heart failure or arrhythmic events, all-cause mortality, post-intervention outcomes, infective endocarditis, or atherosclerosis-related cardiovascular disease in ACHD. A substantial number of these scores are derived from retrospective studies and are not internally or externally validated. Adequately validated risk scores can be invaluable in clinical practice and an important step towards personalized medicine. Multicenter collaboration, adequate study design, and the potential use of artificial intelligence are important elements in the effort to develop reliable risk scores for the ACHD population.

Ventricular Assist Device Therapy in the Fontan Circulation

The number of Fontan patients with circulatory failure and systolic dysfunction is growing rapidly. The last decade has demonstrated that ventricular assist device (VAD) is an effective therapy in properly selected patients. Herein, we discuss the current approach to patient selection, implantation, and patient management.

Neurologic complications of congenital heart disease in adults

Congenital heart disease (CHD) is a heterogeneous group of structural abnormalities of the cardiovascular system that are present at birth. Advances in childhood medical and surgical treatment have led to increasing numbers of adults with CHD. Neurological complications of CHD in adults are varied and can include an increased risk of stroke not only related to the underlying congenital defect and its surgical management but also due to atherosclerotic disease associated with advancing age. In addition to cerebrovascular events, CHD in adults is also associated with an increased risk of neurodevelopmental disorders, cognitive impairment, psychiatric disease, and epilepsy. Collaborative multidisciplinary care with contributions from neurologists and cardiologists with expertise in adult CHD is necessary to provide optimal long-term care for this complex and rapidly evolving population.

Non-Vitamin K Oral Anticoagulants in Adults with Congenital Heart Disease: A Systematic Review

Adults with congenital heart disease (ACHD) experience more thromboembolic complications than the general population. We systematically searched and critically appraised all studies on the safety and efficacy of non-vitamin-K oral anticoagulants (NOACs) in adult patients with various forms of congenital heart disease. PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) were used, with duplicate extraction of data and risk of bias assessment. The Newcastle-Ottawa quality assessment scale was used to assess study quality. Three studies fulfilled the inclusion criteria and were analyzed. The total number of participants was 766, with a total follow-up of 923 patient-years. The majority of patients (77%) received a NOAC for atrial arrhythmias, while the remainder were prescribed NOACs for secondary (19%) or primary (4%) thromboprophylaxis. The annual rate of thromboembolic and major bleeding events was low: 0.98% (95% CI: 0.51-1.86) and 1.74% (95% CI: 0.86-3.49) respectively. In Fontan patients, the annual rate of thromboembolic and major bleeding events was 3.13% (95% CI: 1.18-8.03) and 3.17% (95% CI: 0.15-41.39) respectively. NOACs appear safe and effective in ACHD without mechanical prostheses. Additional studies are, however, needed to confirm their efficacy in complex ACHD, especially those with a Fontan-type circulation.

Atrioventricular Valve Regurgitation in Single Ventricle Heart Disease: A Common Problem Associated With Progressive Deterioration and Mortality

The Fontan procedure has provided patients with single ventricle physiology extended survival into adulthood and in many cases has improved their quality of life. Atrioventricular valve regurgitation (AVVR) is common in single ventricle patients and is associated with increased risk of mortality. AVVR is more common in patients with a systemic tricuspid or common atrioventricular valve but is generally progressive irrespective of underlying valve morphology. AVVR can be attributable to diverse structural and functional abnormalities at multiple levels of the valvar apparatus, as well as ventricular dysfunction and dilation. Multiple imaging modalities including recent advances in 3‐dimensional echocardiography and cross‐sectional imaging have been used to further understand AVVR. Surgery to address AVVR must be tailored to the underlying mechanism and the timing of surgical repair should be chosen carefully. In this review, we discuss the etiologies, treatment options, surgical timing, and outcomes of valve repair or replacement for AVVR in patients with single ventricle congenital heart disease, with a focus on those with a Fontan circulation as AVVR is associated with increased risk for Fontan failure and mortality. In‐depth understanding of the current literature will help guide clinicians in their approach and management of AVVR in this population.

Biomarker profile in stable Fontan patients

BACKGROUND

As the population of adults with congenital heart disease (CHD) grows, cardiologists continue to encounter patients with complex anatomies that challenge the standard treatment of care. Single ventricle Fontan palliated patients are the most complex within CHD, with a high morbidity and mortality burden. Factors driving this early demise are largely unknown.

METHODS AND RESULTS

We analyzed biomarker expression in 44 stable Fontan outpatients (29.2 ± 10.7 years, 68.2% female) seen in the outpatient Emory Adult Congenital Heart Center and compared them to 32 age, gender and race matched controls. In comparison to controls, Fontan patients had elevated levels of multiple cytokines within the inflammatory pathway including Tumor Necrosis Factor-α (TNF-α) (p < 0.001), Interleukin-6 (IL-6) (p < 0.011), Growth Derived Factor-15 (GDF-15) (p < 0.0001), β2-macroglobulin, (p = 0.0006), stem cell mobilization: Stromal Derived Factor-1∝ (SDF-1α) (p = 0.006), extracellular matrix turnover: Collagen IV (p < 0.0001), neurohormonal activation: Renin (p < 0.0001), renal dysfunction: Cystatin C (p < 0.0001) and Urokinase Receptor (uPAR) (p = 0.022), cardiac injury: Troponin-I (p < 0.0004) and metabolism: Adiponectin (p = 0.0037). Within 1 year of enrollment 50% of Fontan patients had hospitalizations, arrhythmias or worsening hepatic function. GDF-15 was significantly increased in Fontan patients with clinical events (p < 0.0001). In addition, GDF-15 moderately correlated with longer duration of Fontan (r = 0.55, p = 0.01) and was elevated in atriopulmonary (AP) Fontan circulation. Finally, in a multivariate model, VEGF-D and Collagen IV levels were found to be associated with a change in MELDXI, a marker of liver dysfunction.

CONCLUSION

Multiple clinical and molecular biomarkers are upregulated in Fontan patients, suggesting a state of chronic systemic dysregulation.

Ultra-high density mapping of intra-atrial reentrant tachycardia in a patient after a lateral tunnel total cavopulmonary connection

We report a case of an 18-year-old male with a postsurgical lateral tunnel (LT) total cavopulmonary connection (TCPC) and supraventricular tachycardia (SVT). Patients after an LT TCPC have complicated suture lines and a considerable area of damaged myocardium in the LT, which could become a complex arrhythmogenic substrate of tachycardias. Detailed three-dimensional (3D) mapping of the LT and atrium is important for a successful ablation. In this patient, successful catheter ablation of two types of complex tachycardias was accomplished using an ultra-high density 3D mapping system inside the LT.

Predictors of Early Postoperative Supraventricular Tachyarrhythmias in Children After the Fontan Procedure

Postoperative arrhythmias are a frequent and fatal complication after the Fontan operation. However, clinical evidence demonstrating early postoperative arrhythmias in children undergoing the Fontan operation is limited. This study aimed to evaluate the prevalence of arrhythmias and identify the predictors of early postoperative supraventricular tachyarrhythmias (SVTs) after the Fontan procedure.Data were analyzed from 80 pediatric patients who underwent Fontan procedures between April 2000 and December 2017 in a single-center retrospective study. Early postoperative SVTs were defined as arrhythmias within 30 days after the Fontan procedure. We divided the patients into two groups, with or without early postoperative arrhythmias, and the predictors of early postoperative arrhythmias were analyzed. A multivariate logistic regression analysis was performed to determine independent predictors of early postoperative SVTs after the Fontan procedure.Early postoperative SVTs were observed in 21 patients (26.3%). The most common arrhythmia was junctional ectopic tachycardia. After an adjustment, an atrioventricular valve regurgitation (AVVR) grade of ≥2 (odds ratio 10.54, 95% confidence interval 2.52 to 44.17, P = 0.001) and preoperative arrhythmias (odds ratio 26.49, 95% confidence interval 1.64 to 428.62, P = 0.021) were significant predictors of early postoperative SVTs after the Fontan operation.An AVVR grade ≥2 and preoperative arrhythmia were significant predictors associated with early postoperative SVTs. Intervention for AVVR may provide clinical benefit for preventing early postoperative arrhythmias after the Fontan operation.

Micro-RNA 150-5p predicts overt heart failure in patients with univentricular hearts

Background

In patients with left heart failure, micro-RNAs (miRNAs) have been shown to be of diagnostic and prognostic value. The present study aims to identify those miRNAs in patients with univentricular heart (UVH) disease that may be associated with overt heart failure.

Methods

A large panel of human miRNA arrays were used to determine miRNA expression profiles in the blood of 48 UVH patients and 32 healthy controls. For further selection, the most abundantly expressed miRNA arrays were related to clinical measures of heart failure and selected miRNAs validated by polymerase chain reaction were used for the prediction of overt heart failure and all-cause mortality.

Results

According to microarray analysis, 50 miRNAs were found to be significantly abundant in UVH patients of which miR-150-5p was best related to heart failure parameters. According to ROC analysis, NT-proBNP levels (AUC 0.940, 95% CI 0.873–1.000; p = 0.001), miR-150-5p (AUC 0.905, 95% CI 0.779–1.000; p = 0.001) and a higher NYHA class ≥ III (AUC 0.893, 95% CI 0.713–1.000; p = 0.002) were the 3 most significant predictors of overt heart failure. Using a combined biomarker model, AUC increased to 0.980 indicating an additive value of miR-150-5p. Moreover, in the multivariate analysis, a higher NYHA class ≥ III (p = 0.005) and miR-150-5p (p = 0.006) turned out to be independent predictors of overt heart failure.

Conclusion

In patients with UVH, miR-150-5p is an independent predictor of overt heart failure and thus may be used in the risk assessment of these patients.

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.

Clinical Outcomes in Adolescents and Adults After the Fontan Procedure

BACKGROUND

Long-term outcomes of Fontan patients who survive to age ≥16 years have not been well characterized. The Australian and New Zealand Fontan Registry (ANZFR) provides a unique opportunity to understand survival and complication rates in Fontan patients who transition to adult congenital heart disease centers.

OBJECTIVES

This study sought to describe the survival and complications of adult patients who have had a Fontan procedure.

METHODS

The study analyzed outcomes in patients ≥16 years of age who were prospectively enrolled in the ANZFR.

RESULTS

Data from all 683 adult survivors from the ANZFR were analyzed. Mortality status was confirmed from the National Death Index. There were 201 atriopulmonary (AP) connections and 482 total cavopulmonary connections (249 lateral tunnels and 233 extracardiac conduits). For these subjects, the survival rate at age 30 years was 90% (95% CI: 87% to 93%), and it was 80% (95% CI: 75% to 87%) at 40 years of age. Survival at age 30 years was significantly worse for the patients with AP connections (p = 0.03). At latest follow-up, only 53% of patients were in New York Heart Association functional class I. After the age of 16 years, 136 (20%) had experienced at least 1 new arrhythmia, 42 (6%) required a permanent pacemaker, 45 (7%) had a thromboembolic event, and 135 (21%) required a surgical reintervention. Only 41% (95% CI: 33% to 51%) of Fontan patients were free of serious adverse events at 40 years of age.

CONCLUSIONS

This comprehensively followed cohort showed that a variety of morbid complications is common in Fontan adults, and that there is a substantial incidence of premature death, particularly in patients with AP connections.

Calcium-handling abnormalities underlying atrial arrhythmogenesis in a Fontan operation canine model

BACKGROUND

Atrial tachyarrhythmia (AT) is a common complication in patients who have undergone a Fontan operation. In this study, we investigated whether abnormal Ca²⁺ handling contributes to the Fontan operation-related atrial arrhythmogenic substrate.

METHODS

Mongrel dogs were randomly assigned to sham and Fontan groups. The Fontan operation model was developed by performing an atriopulmonary anastomosis. After 14 days, an electrophysiological study was performed to evaluate the AT vulnerability. Ca²⁺ handling properties were measured by loading atrial cardiomyocytes (CMs) with fura-2 AM. The L-type Ca²⁺ (I_Ca-L) and Na⁺-Ca²⁺ exchanger (I_NCX) currents of the CMs were recorded by the whole-cell patch-clamp technique. The key Ca²⁺ handling proteins expression was assessed by Western blotting.

RESULTS

The AT inducibility was higher in the Fontan group than in the sham group (85.71 vs. 14.29%, P < 0.05). The Fontan operation resulted in decreased Ca²⁺ transient (CaT) amplitude and sarcoplasmic reticulum (SR) Ca²⁺ content, but in enhanced diastolic intracellular Ca²⁺ concentration and SR Ca²⁺ leak in the atrial CMs. The spontaneous CaT events, triggered ectopic activity and I_NCX density were increased, but I_Ca-L density was reduced in CMs from the Fontan atria (all P < 0.05). Additionally, the Fontan operation resulted in decreased SR Ca²⁺ ATPase expression and Cav1.2 expression, but in increased NCX1 and Ser2814-phosphorylated ryanodine receptor 2. The calmodulin-dependent protein kinase II expression and function were markedly enhanced in the Fontan atria.

CONCLUSION

The Fontan operation caused atrial CM Ca²⁺ handling abnormalities that produced arrhythmogenic-triggered activity and increased vulnerability to AT in experimental Fontan dogs.

Mode of death and predictors of mortality in adult Fontan survivors: A Japanese multicenter observational study

BACKGROUND

Mortality rates may be high in adult Fontan patients; however, the clinical determinants remain unclear.

PURPOSE

We conducted a prospective multicenter study of adult Fontan survivors to determine the 5-year mortality rate and clarify the determinants.

METHOD AND RESULTS

We followed 600 adult Fontan survivors from 40 Japanese institutions (307 men, 28 ± 7 years old, follow-up: 18 ± 6 years). The New York Heart Association (NYHA) functional class I and II was 51% and 42%, respectively. During the follow-up period of 4.1 ± 1.6 years, 33 patients died, and the 5-year survival rate was 93.5%. The mode of death was heart failure in 11 patients (34%), arrhythmia or sudden death in 8 (24%), cancer in 5 (15%), perioperative problems and hemostatic problems in 4 each (12% for each), and infection in 1 (3%). Left isomerism, prior hospitalization, protein losing enteropathy (PLE), pulmonary arteriovenous fistulae, NYHA functional class, impaired hemodynamics, hyponatremia, hepatorenal dysfunction, and use of diuretics were associated with a high mortality rate (p < 0.05-0.0001). Further, PLE (hazard ratio [HR]: 14.4), left isomerism (HR: 3.5), and NYHA (HR: 2.4) independently predicted a high 5-year high mortality (p < 0.05 for all). The incidence of cancer-related mortality increased markedly with age >40 years.

CONCLUSIONS

Majority of the Japanese adult Fontan survivors had good functional status, with an acceptable 5-year survival rate. However, the significant prevalence of non-cardiac mortality highlights Fontan pathophysiology as a multi-organ disease that requires a multidisciplinary management strategy to improve the long-term outcome.

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.

Life After Surviving Fontan Surgery: A Meta-Analysis of the Incidence and Predictors of Late Death

AIM

We now know that 20-40% of patients with a single ventricle will develop heart failure after the second decade post-Fontan surgery. However, we remain unable to risk-stratify the cohort to identify patients at highest risk of late failure and death. We conducted a systematic review of all reported late outcomes for patients with a Fontan circulation to identify predictors of late death.

METHODS

We searched MEDLINE, Embase and PubMed with subject terms ("single ventricle", "Hypoplastic left heart syndrome", "congenital heart defects" or "Fontan procedure") AND ("heart failure", "post-operative complications", "death", "cause of death", "transplantation" or "follow-up studies") for relevant studies between January 1990 and December 2015. Variables identified as significant predictors of late death on multivariate analysis were collated for meta-analysis. Survival data was extrapolated from Kaplan-Meier survival curves to generate a distribution-free summary survival curve.

RESULTS

Thirty-four relevant publications were identified, with a total of 7536 patients included in the analysis. Mean follow-up duration was 114 months (range 24-269 months). There were 688 (11%) late deaths. Predominant causes of death were late Fontan failure (34%), sudden death (19%) and perioperative death (16%). Estimated mean survival at 5, 10 and 20 years post Fontan surgery were 95% (95%CI 93-96), 91% (95%CI 89-93) and 82% (95%CI 77-85). Significant predictors of late death include prolonged pleural effusions post Fontan surgery (HR1.18, 95%CI 1.09-1.29, p<0.001), protein losing enteropathy (HR2.19, 95%CI 1.69-2.84, p<0.001), increased ventricular end diastolic volume (HR1.03 per 10ml/BSA increase, 95%CI 1.02-1.05, p<0.001) and having a permanent pacemaker (HR12.63, 95%CI 6.17-25.86, p<0.001).

CONCLUSIONS

Over 80% of patients who survive Fontan surgery will be alive at 20 years. Developing late sequelae including protein losing enteropathy, ventricular dysfunction or requiring a pacemaker predict a higher risk of late death.

Twenty-Five Year Outcomes of the Lateral Tunnel Fontan Procedure

The objective of this study was to characterize late outcomes of the lateral tunnel (LT) Fontan procedure. The outcomes of all patients who underwent an LT Fontan procedure in Australia and in New Zealand were analyzed. Original files were reviewed and outcomes data were obtained through a binational registry. Between 1980 and 2014, a total of 301 patients underwent an LT Fontan procedure across 6 major centers. There were 13 hospital mortalities, 21 late deaths, 8 Fontan conversions and revisions, 8 Fontan takedowns, and 4 heart transplantations. Overall survival at 15 and 25 years was 90% (95% confidence interval [CI]: 86%-93%) and 80% (95% CI: 69%-91%), respectively. Protein-losing enteropathy or plastic bronchitis was observed in 14 patients (5%). Freedom from late failure at 15 and 25 years was 88% (95% CI: 84%-92%) and 82% (95% CI: 76%-87%), respectively. Independent predictors of late Fontan failure were prolonged pleural effusions post Fontan operations (hazard ratio [HR] 3.06, 1.05-8.95, P = 0.041), age >7 years at Fontan (vs 3-5 years, HR 9.7, 2.46-38.21, P = 0.001) and development of supraventricular tachycardia (HR 4.67, 2.07-10.58, P < 0.001). Freedom from tachy- or bradyarrhythmias at 10 and 20 years was 87% (95% CI: 83%-91%) and 72% (95% CI: 66%-79%), respectively. Thromboembolic events occurred in 45 patients (16%, 26 strokes), and freedom from symptomatic thromboembolism at 10 and 20 years was 93% (95% CI: 89%-96%) and 80% (95% CI: 74%-86%), respectively. Over a 25-year period, the LT technique has achieved excellent late survival. As this population ages, it is at an increasing risk of failure and adverse events. We are likely to see an increasing proportion requiring heart transplantation and late reintervention.

Arrhythmia Surgery for Adults with Congenital Heart Disease

Patients with repaired or unrepaired congenital heart anomalies are at increased risk for arrhythmia development throughout their lives, often paralleling the need for reoperations for hemodynamic residua. The ability to incorporate arrhythmia surgery into reoperations can result in improvement in functional class and decreased need for antiarrhythmic medications. Every reoperation for congenital heart disease can be viewed as an opportunity to assess the electrical and arrhythmia substrates and to intervene to improve the arrhythmias and the hemodynamic condition of the patient. The authors review and summarize the operative techniques for arrhythmia surgery that are based on the arrhythmia mechanisms.

Outcomes in adult Fontan patients with atrial tachyarrhythmias

BACKGROUND

The optimal management strategy for atrial tachyarrhythmia in the Fontan population is unknown.

METHODS

Retrospective review of 264 adult Fontan patients with atrial tachyarrhythmia evaluating 3 clinically adopted scenarios: antiarrhythmic drug (AAD) therapy, catheter ablation (CA), and Fontan conversion (FC). These patients were followed up at Mayo Clinic from 1994 to 2014. The study objective was to compare freedom from atrial tachyarrhythmia recurrence (AR) and occurrence of composite adverse events (stroke, heart failure hospitalization, death, or heart transplant) between treatment groups.

RESULTS

The age of atrial tachyarrhythmia onset was 25 ± 4 years, time from Fontan operation was 13 ± 6 years, follow-up was 74 ± 18 months, atriopulmonary Fontan was 215 (81%), and atrial flutter/intra-atrial reentry tachycardia was 173 (65%). In those managed with AAD (n = 110), freedom from AR was 7% at 60 months. Catheter ablation (n = 31) was associated with an acute procedural success of 94%, and freedom from AR was 41% at 60 months. Fontan conversion (n = 33) resulted in a perioperative mortality of 3%, and freedom from AR was 51% at 60 months. Fontan conversion and CA were similar with regard to AR (P = .14) and significantly better compared with AAD (P < .0001). Adverse events were found to occur more frequently in the patients with AR (P < .0001) and the patients treated with AAD only (P < .0001).

CONCLUSIONS

Catheter ablation and FC operations are associated with less recurrence of atrial tachyarrhythmia compared with AAD. Atrial tachyarrhythmias are more likely to recur in patients with a longer history of the arrhythmia and are associated with more adverse events. Early referral to a specialty center for these interventions should be considered.

Management of 1-Lung Ventilation in a Patient With Failing Fontan Circulation

The number of patients reaching adulthood after undergoing Fontan palliation for the repair of a congenital heart defect continues to increase. In this case report, we present the anesthetic management of a patient with a history of tricuspid atresia treated with palliative Fontan repair who had developed clinical evidence of Fontan failure. He presented with septic shock secondary to streptococcal toxic shock syndrome complicated by a loculated pleural effusion. He underwent open thoracic decortication under 1-lung ventilation. Discussion focuses on the management of volume status and pulmonary vascular resistance as well as surgical implications of Fontan physiology in thoracic surgery.