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

Impact of heart failure on reoperation in adult congenital heart disease: An innovative machine learning model

OBJECTIVES

The study objectives were to evaluate the association between preoperative heart failure and reoperative cardiac surgical outcomes in adult congenital heart disease and to develop a risk model for postoperative morbidity/mortality.

METHODS

Single-institution retrospective cohort study of adult patients with congenital heart disease undergoing reoperative cardiac surgery between January 1, 2010, and March 30, 2022. Heart failure defined clinically as preoperative diuretic use and either New York Heart Association Class II to IV or systemic ventricular ejection fraction less than 40%. Composite outcome included operative mortality, mechanical circulatory support, dialysis, unplanned noncardiac reoperation, persistent neurologic deficit, and cardiac arrest. Multivariable logistic regression and machine learning analysis using gradient boosting technology were performed. Shapley statistics determined feature influence, or impact, on model output.

RESULTS

Preoperative heart failure was present in 376 of 1011 patients (37%); those patients had longer postoperative length of stay (6 [5-8] vs 5 [4-7] days, P < .001), increased postoperative mechanical circulatory support (21/376 [6%] vs 16/635 [3%], P = .015), and decreased long-term survival (84% [80%-89%] vs 90% [86%-93%]) at 10 years (P = .002). A 7-feature machine learning risk model for the composite outcome achieved higher area under the curve (0.76) than logistic regression, and ejection fraction was most influential (highest mean |Shapley value|). Additional risk factors for the composite outcome included age, number of prior cardiopulmonary bypass operations, urgent/emergency procedure, and functionally univentricular physiology.

CONCLUSIONS

Heart failure is common among adult patients with congenital heart disease undergoing cardiac reoperation and associated with longer length of stay, increased postoperative mechanical circulatory support, and decreased long-term survival. Machine learning yields a novel 7-feature risk model for postoperative morbidity/mortality, in which ejection fraction was the most influential.

Long-term follow-up of atrioventricular valve function in Fontan patients: effect of atrioventricular valve surgery

OBJECTIVES

The aim of this study was to evaluate the relationship between atrioventricular valve and ventricular function in Fontan survivors, including the effect of atrioventricular valve surgery.

METHODS

Analysis focused on transplant-free survival and the need for atrioventricular valve surgery in single ventricle patients after Fontan completion. Longitudinal echocardiographic examination of long-term valve and ventricular function was performed.

RESULTS

Fontan completion was performed in 113 patients, having a right univentricular morphology in 33.6%, a left ventricle morphology in 62.8% and ambiguous in 3.6%. Perioperative mortality was 2.7% (n = 3). Within a median follow-up of 16.3 years (interquartile range 10.6-23.6), transplant-free survival was 96.1 ± 1.9% and 90.4 ± 5.8% at 10-25 years. Twenty AV valve procedures were performed in 14 (12.4%) children, respectively, pre-Fontan (n = 10), per-Fontan (n = 8) and post-Fontan (n = 2), resulting in a cumulative incidence of AV valve surgery is 5.7 ± 2.2% and 12.3 ± 3.2% at 1-5 years. Atrio-ventricular valve function deteriorated over time [hazard ratio (HR) 1.112, 95% confidence interval (CI) 1.089-1.138, P < 0.001], without difference for valve morphology (P = 0.736) or ventricular dominance (P = 0.484). AV valve dysfunction was greater in patients requiring AV valve surgery (HR 20.383, 95% CI 6.223-36.762, P < 0.001) but showed a comparable evolution since repair to those without valve surgery (HR 1.070, 95% CI 0.987-1.160, P = 0.099). Progressive time-related ventricular dysfunction was observed (HR 1.141, 95% CI 1.097-1.182, P < 0.001), significantly less in left ventricle-dominance (HR 0.927, 95% CI 0.860-0.999, P = 0.047) but more after AV valve surgery (HR 1.103, 95% CI 1.014-1.167, P = 0.022).

CONCLUSIONS

In a homogeneously treated Fontan population, 25-year transplant-free survival is encouraging. Atrio-ventricular valve surgery was necessary in 12.4%, resulting mostly in a durable valve function. However, a slow time-related decline of atrioventricular valve function as of ventricular function is worrisome, evoking a role for additional heart failure therapy.

Long-term outcomes of tricuspid valve intervention during stage 2 palliation in patients with a single right ventricle

OBJECTIVES

In patients with single ventricle physiology and a systemic right ventricle, tricuspid valve regurgitation increases the risk of adverse outcomes, and tricuspid valve intervention at the time of staged palliation further increases that risk in the postoperative period. However, long-term outcomes of valve intervention in patients with significant regurgitation during stage 2 palliation have not been established. The purpose of this study is to evaluate the long-term outcomes after tricuspid valve intervention during stage 2 palliation in patients with right ventricular dominant circulation in a multicenter study.

METHODS

The study was performed using the Single Ventricle Reconstruction Trial and Single Ventricle Reconstruction Follow-up 2 Trial datasets. Survival analysis was performed to describe the association among valve regurgitation, intervention, and long-term survival. Cox proportional hazards modeling was used to estimate the longitudinal association of tricuspid intervention and transplant-free survival.

RESULTS

Patients with tricuspid regurgitation at stage 1 or 2 had worse transplant-free survival (hazard ratio, 1.61; 95% confidence interval, 1.12-2.32; hazard ratio, 2.3; 95% confidence interval 1.39-3.82). Those with regurgitation who underwent concomitant valve intervention at stage 2 were significantly more likely to die or undergo heart transplantation compared with those with regurgitation who did not (hazard ratio, 2.93; confidence interval, 2.16-3.99). Patients with tricuspid regurgitation at the time of the Fontan had favorable outcomes regardless of valve intervention.

CONCLUSIONS

The risks associated with tricuspid regurgitation in patients with single ventricle physiology do not appear to be mitigated by valve intervention at the time of stage 2 palliation. Patients who underwent valve intervention for tricuspid regurgitation at stage 2 had significantly worse survival compared with patients with tricuspid regurgitation who did not.

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.

Predictors of protein losing enteropathy after Fontan completion: An 8-year retrospective study at Sheikh Khalifa Medical City

BACKGROUND

The Fontan procedure is the final stage of a three-stage palliation process in patients born with a univentricular heart as part of hypoplastic left heart syndrome (HLHS) or other pathologies with a univentricular heart. As essential as this procedure has proven to be for such cases, the Fontan physiology diminishes cardiac output and expands systemic venous pressure, which then leads to venous congestion that can be complicated by protein-losing enteropathy (PLE). This retrospective study aimed to identify the predictors of such complications in all patients who underwent completion of the Fontan procedure at our center (Sheikh Khalifa Medical City/SKMC) in the past eight years.

METHODS

This study examined the medical records of patients who underwent completion of Fontan repair at our center since the inauguration of the cardiac surgery program of SKMC in the United Arab Emirates (UAE) - 01 Jan 2012 to 31 Dec 2020. Exclusion criteria included the absence of any of the undermentioned data in patient files. Patients were divided into two groups: those who developed PLE and those who did not. For each group, the following data were collected: demographics data (current age and age at completion of Fontan), clinical and laboratory data (oxygen saturation, serum albumin), echocardiographic data (classification of original cardiac diagnosis, degree of atrio-ventricular valve regurgitation, ventricular functions), hemodynamic data (mean pressures of superior vena cava and pulmonary arteries before Fontan completion), operative data (type of initial palliation, type of Fontan, presence of fenestrations and its size) and the need for any cardiac intervention prior to Fontan completion, such as atrio-ventricular valve repair, peripheral pulmonary stenting and arch balloon dilatation.

RESULTS

Of the 48 included patients,13 (25%) developed PLE. Multivariate regression analysis proved that the best predictors of PLE were superior vena cava mean pressure (P = 0.012) and the degree of atrio-ventricular valve regurgitation (P = 0.013). An oxygen saturation <83% prior to Fontan completion was 92% sensitive in predicting PLE after Fontan completion.

CONCLUSION

This is a single-center study of the predictors of PLE after Fontan procedure and, as expected from similar studies, SVC pressure higher than 11 mmHg and moderate-to-severe atrio-ventricular valve regurgitation were predictors of Fontan failure. The higher prevalence of PLE in our cohort, as well as lower cut-offs of SVC pressure that can predict complications, may be related to the predominance of hypoplastic left heart in the operated patients, which has been the main referral center for cardiac surgeries in UAE in the last decade.

Valvular Regurgitation in Adults with Congenital Heart Disease and Heart Failure: Current Status and Potential Interventions

The great majority of patients born with congenital heart disease (CHD) are living well into adulthood, yet they often have residual hemodynamic lesions, including valvar regurgitation. As these complex patients grow older, they are at risk of developing heart failure, which can be exacerbated by the underlying valvular regurgitation. In this review, we describe the etiologies of heart failure related to valvular regurgitation in the CHD population and discuss potential interventions.

Ex Vivo Modeling of Atrioventricular Valve Mechanics in Single Ventricle Physiology

Single ventricle physiology (SVP) is used to describe any congenital heart lesion that is unable to support independent pulmonary and systemic circulations. Current treatment strategies rely on a series of palliation surgeries that culminate in the Fontan physiology, which relies on the single functioning ventricle to provide systemic circulation while passively routing venous return through the pulmonary circulation. Despite significant reductions in early mortality, the presence of atrioventricular valve (AVV) regurgitation is a key predictor of heart failure in these patients. We sought to evaluate the biomechanical changes associated with the AVV in SVP physiologies. Left and right ventricles were sutured onto patient-derived 3D-printed mounts and mounted into an ex vivo systemic heart simulator capable of reproducing Norwood, Glenn, Fontan and Late Fontan physiologies. We found that the tricuspid anterior leaflet experienced elevated maximum force, average force, and maximum yank compared to the posterior and septal leaflets. Between physiologies, maximum yank was greatest in the Norwood physiology relative to the Glenn, Fontan, and Late Fontan physiologies. These contrasting trends suggest that long- and short-term mechanics of AVV failure in single ventricle differ and that AVV interventions should account for asymmetries in force profiles between leaflets and physiologies.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

First described mitral clip in an adult extracardiac Fontan patient: a case report

Background

The use of transcatheter edge-to-edge repair (TEER) in patients with advanced heart failure has been shown to reduce hospitalizations and increase survival. As patients with Fontan circulations grow older, a significant proportion of them will develop severe atrioventricular (AV) valve regurgitation in the systemic ventricle. Conventional surgical repair and transplant carry high mortality risk for the adult Fontan patient with progressive heart failure.

Case summary

A 51-year-old female extracardiac Fontan patient developed severe AV valve regurgitation and progressive functional decline. Based on her operative risk for conventional surgical intervention or transplant, TEER using the Abbott MitraClip device was performed. The degree of mitral regurgitation was decreased from severe to moderate regurgitation.

Discussion

This is the first known case describing the use of a successful TEER in an adult patient with an extracardiac Fontan. Given the increasing numbers of patients surviving into adulthood with a Fontan circulation, transcatheter interventions may provide an alternative treatment option to conventional surgeries and medical therapies.

Longitudinal changes in ventricular size and function are associated with death and transplantation late after the Fontan operation

BACKGROUND

Cross-sectional studies have reported that ventricular dilation and dysfunction are associated with adverse clinical outcome in Fontan patients; however, longitudinal changes and their relationship with outcome are not known.

METHODS

This was a single-center retrospective analysis of Fontan patients with at least 2 cardiovascular magnetic resonance (CMR) scans without intervening interventions. Serial measures of end-diastolic volume index (EDVI), end-systolic volume index (ESVI), ejection fraction (EF), indexed mass (massi), mass-to-volume ratio, and end-systolic wall stress (ESWS) were used to estimate within-patient change over time. Changes were compared for those with and without a composite outcome (death, heart transplant, or transplant listing) as well as between patients with left (LV) and right ventricular (RV) dominance.

RESULTS

Data from 156 patients were analyzed with a mean age at 1st CMR of 17.8 ± 9.6 years. 490 CMRs were included with median of 3 CMRs/patient (range 2-9). On regression analysis with mixed effects models, volumes and ESWS increased, while mass, mass-to-volume ratio, and EF decreased over time. With a median follow-up of 10.2 years, 14% met the composite outcome. Those with the composite outcome had a greater increase in EDVI compared to those without (4.7 vs. 0.8 ml/BSA1.3/year). Compared with LV dominance, RV dominance was associated with a greater increase in ESVI (1.4 vs. 0.5 ml/BSA1.3/year), a greater decrease in EF (- 0.61%/year vs. - 0.24%/year), and a higher rate of the composite outcome (21% vs. 8%).

CONCLUSIONS

Ventricles in the Fontan circulation exhibit a steady decline in performance with an increase in EDVI, ESVI, and ESWS, and decrease in EF, mass index, and mass-to-volume ratio. Those with death or need for heart transplantation have a faster increase in EDVI. Patients with rapid increase in EDVI (> 5 ml/BSA1.3/year) may be at a higher risk of adverse outcomes and may benefit from closer surveillance. RV dominance is associated with worse clinical outcomes and remodeling compared to LV dominance.

Two-Dimensional Strain Echocardiographic Parameters and Clinical Outcomes Associated with Significant Atrioventricular Regurgitation in a Single-Center Adult Fontan Population

Background

Significant atrioventricular valve regurgitation (AVVR) is prevalent in Fontan adults. Two-dimensional speckle-tracking echocardiography allows for evaluation of subclinical myocardial dysfunction and offers technical benefits. We aimed to evaluate the association of AVVR with echocardiographic parameters and adverse outcomes.

Materials and Methods

Fontan adults (≥18 years) with lateral tunnel or extracardiac connection actively followed at our institution were retrospectively reviewed. Patients with AVVR on most recent transthoracic echocardiogram (≥grade 2 as per American Society of Echocardiography guidelines) were matched with Fontan controls. Echocardiographic parameters, including global longitudinal strain (GLS), were measured. The composite outcome of Fontan failure included Fontan conversion, protein losing enteropathy, plastic bronchitis, and New York Heart Association Class III/IV.

Results

Sixteen patients (14%, mean age 28.4 ± 7.0 years) with predominantly moderate AVVR (81%) were identified. The mean duration of AVVR was 8.1 ± 5.8 months. There was no significant reduction in ejection fraction (EF) (51.2% ± 11.7% vs. 54.7% ± 10.9%, P = 0.39) or GLS (-16.0% ± 5.2% vs. -16.0% ± 3.5%, P = 0.98) associated with AVVR. Larger atrial volumes and longer deceleration time (DT) were observed in the AVVR group. Patients with AVVR and a worse GLS (≥-16%) had higher E velocity, DT, and medial E/E' ratio. The incidence of Fontan failure did not differ from controls (38% vs. 25%, P = 0.45). Patients with worse GLS (≥-16%) demonstrated a marked trend toward a higher incidence of Fontan failure (67% vs. 20%, P = 0.09).

Conclusions

In Fontan adults, a short duration of AVVR did not influence EF or GLS but was associated with larger atrial volumes and those with worse GLS demonstrated some differences in diastolic parameters. Larger multicenter studies throughout its disease course are warranted.

Predictive factors contributing to prolonged recovery in patients after Fontan operation

Background

Prolonged recovery is a severe issue in patients after Fontan operation. However, predictive factors related to this issue are not adequately evaluated. The present study aimed to investigate potential predictive factors which can predict Fontan postoperative recovery.

Methods

We retrospectively reviewed the perioperative medical records of patients with Fontan surgery between January 2015 and December 2018, and divided patients with > 75%ile cardiac intensive care unit stay into prolonged recovery group. The others were assigned to standard recovery group. Patients that died or underwent a Fontan takedown were excluded. Statistical analysis was performed to compare data difference of the two groups.

Results

282/307 cases fulfilled the inclusion criteria. Seventy patients were considered in prolonged recovery and 212 patients were defined as standard recovery. Pre- and intra-operative data showed a higher incidence of heterotaxy syndrome, longer cardiopulmonary bypass and aortic cross-clamp time in the prolonged recovery group. Postoperative information analysis displayed that ventilation time, oxygen index after extubation, hemodynamic data, inotropic score (IS), drainage volume, volume resuscitation, pulmonary hypertension (PH) treatment, and surgical reintervention were significantly different between the two groups. Higher IS postoperatively, and PH treatment and higher fluid resuscitation within two days were independent predictive factors for prolonged recovery in our multivariate model. C-statistic model showed a high predictive ability in prolonged recovery by using the three factors.

Conclusions

Ventilation time, higher IS in postoperative day, and PH treatment and higher fluid resuscitation within two days were independent risk factors and have a high predictability for Fontan prolonged recovery.

Comparing Long-Term Sequelae of the Systemic Right Ventricle: An Overview of Single Versus Biventricular Arrangements

Patients with systemic right ventricles (RV) are at risk for heart failure and sudden cardiac death. Contributing factors to RV dysfunction include increased afterload from the systemic circulation, coronary insufficiency, progressive tricuspid valve regurgitation, the presence of residual lesions after palliation and arrhythmias. While all patients with a systemic right ventricle (SRV) are vulnerable to heart failure, there are distinct differences between patients with congenital dextro-transpostion of the great arteries (d-TGA) repaired by atrial switch, unrepaired congenitally corrected transposition of the great arteries (cc-TGA) and single systemic right ventricles palliated with a Fontan operation. Herein, we explore both the similarities and differences in progression of heart failure by phenotype as well as both the advancements and limitations in treatment options by each type of SRV.

Surgical Strategies in Single Ventricle Management of Neonates and Infants

No area of congenital heart disease has undergone greater change and innovation than Single Ventricle management over the past 20 years. Surgical and catheter lab interventions have transformed outcomes such that in some subgroups more than 80% of these patients can survive into adulthood. Driven by parallel development in diagnostic imaging and cardiac intensive care, surgical management is focused on the neonatal period as the key time to creating a balanced circulation and limiting pulmonary blood-flow. Different configurations of the circulation including new types of surgical shunts and the role of 'hybrid' circulations provide greater options and better physiology. This overview will focus on these changes in surgical management and timing but also look at the exciting areas of regenerative therapies to improve ventricular function, and the concept of ventricular rehabilitation to achieve biventricular circulations in certain groups of patients. The importance of early (neonatal) intervention and multidisciplinary approach to management is emphasised, as well as looking beyond simply survival but also improving neurodevelopmental outcomes.

Late Fontan Circulatory Failure. What Drives Systemic Venous Congestion and Low Cardiac Output in Adult Fontan Patients?

The Fontan circulation provides definite palliation for children born with a single anatomical or functional ventricle by diverting systemic venous blood directly to the pulmonary arteries, effectively rendering systemic venous return into portal vessels to the lung. Although this restores pulmonary blood flow and avoids the mixture of oxygenated and deoxygenated blood, it also results in elevated systemic venous pressures and low cardiac output. These are the two hallmarks of any Fontan circulation and the cause of Fontan circulatory failure later in life. We highlight the determinants of systemic venous return, its changed relationship with the pulmonary circulation, how it affects preload, and the changed role of the heart (myocardium, valves, and heart rate). By critically evaluating the components of the Fontan circulation, we hope to give some clues in how to optimize the Fontan circulation and avenues for future research.

Management of circulatory failure after Fontan surgery

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

Long-term management of Fontan patients: The importance of a multidisciplinary approach

The Fontan operation is a palliative procedure that leads to increased survival of patients with a functional single ventricle (SV). Starting from 1967 when the first operation was performed by Francis Fontan, more and more patients have reached adulthood. Furthermore, it is expected that in the next 20 years, the population with Fontan circulation will reach 150,000 subjects. The absence of right ventricular propulsion and the inability to improve cardiac output because of the low cardiac reserve are the main issues with the Fontan circulation; however, potential complications may also involve multiple organ systems, such as the liver, lungs, brain, bones, and the lymphatic system. As these patients were initially managed mainly by pediatric cardiologists, it was important to assure the appropriate transition to adult care with the involvement of a multidisciplinary team, including adult congenital cardiologists and multiple subspecialists, many of whom are neither yet familiar with the pathophysiology nor the end-organ consequences of the Fontan circulation. Therefore, the aim of our work was to collect all the best available evidence on Fontan's complications management to provide "simple and immediate" information sources for practitioners looking for state of the art evidence to guide their decision-making and work practices. Moreover, we suggest a model of follow-up of patients with Fontan based on a patient-centered multidisciplinary approach.

Systemic Semilunar Valve Repair/Replacement With Fontan Circulation: The Mayo Clinic Experience

Background: There is a paucity of literature regarding systemic semilunar valve (SSLV) dysfunction in patients with Fontan circulation. We sought to describe our center's 47-year experience with systemic semilunar valve replacement or repair (SSLVR) in patients with Fontan circulation. Methods: The Mayo Clinic Fontan Database is a comprehensive institutional database that stores clinical information of 1176 patients from 1973 to 2021. It was reviewed to identify patients who had a SSLV intervention at the time of or after Fontan. A cohort of 15 patients was identified and a retrospective review of their records was performed. Results: Fourteen patients had SSLV replacement (all mechanical) and one had a repair. SSLVR occurred up to 29 years following the Fontan (mean 11.3 ± 9 years, median 14 years). Thirteen of 14 with SSLVR were performed after Fontan and one was done at the time of initial Fontan. This was an older cohort and mean age at the time of Fontan was 8.7 ± 9.4 years (median 4 years). Indication for the operation was > moderate SSLV regurgitation in all patients. Six patients had decreased ventricular function (EF < 50%) prior to SSLVR and 8 had reduced function after SSLVR. Conclusion: Fortunately, the need for SSLV intervention after Fontan was rare, as evidenced by our small cohort extracted from a large single-institution database spanning a 47-year time period. Reduced preoperative and postoperative ejection fraction was common but did not seem to impact the outcome. Optimal timing for SSLV intervention after Fontan remains unclear.

Long-Term Outcomes After Fenestration Closure in High-Risk Fontan Candidates

The study aimed to assess the long-term outcomes after fenestration closure in patients at risk for Fontan failure. Of 119 patients who underwent Fontan operation between 1995 and 2004, fenestration was not created in 89 patients (NF group) and created in 30 patients with hypoplastic left heart syndrome, heterotaxy syndrome, high pulmonary arterial pressure, high systemic ventricular end-diastolic pressure, low ventricular ejection fraction, or atrioventricular valve regurgitation. All fenestrations were closed spontaneously or by catheter/surgical interventions, excepting two patients, and therefore, they were excluded. In fenestration group, patients with pre-Fontan mean pulmonary arterial pressure ≥ 15 mmHg or systemic atrioventricular valve regurgitation ≥ moderate were classified as high-risk Fontan candidates (F-HR group, n = 16), and the remaining patients were as standard-risk (F-SR group, n = 12). Protein-losing enteropathy-free survival rates did not differ among the three groups (p = 0.72). Serial follow-up catheter examinations after Fontan operation were completed in 69 patients in NF group and 11 patients in both F-SR and F-HR groups. Cardiac index and pulmonary vascular resistance significantly and similarly decreased over time in all groups, though the F-HR group showed lowest arterial oxygen saturation, lowest cardiac index, and highest pulmonary vascular resistance. The F-HR group also showed much veno-venous collaterals (p = 0.049), low peak oxygen consumption (p = 0.019), and low anaerobic threshold (p = 0.023) as compared to those in the F-SR group. In F-HR group, cyanosis remained after fenestration closure due to transformation from fenestration to veno-venous collaterals, which resulted in elevation of pulmonary vascular resistance, low cardiac index, and deterioration of exercise tolerance.

Cardiac Emergencies in Kids

Encountering a child with congenital heart disease after surgical palliation in the emergency department, specifically the single-ventricle or ventricular assist device, without a basic familiarity of these surgeries can be extremely anxiety provoking. Knowing what common conditions or complications may cause these children to visit the emergency department and how to stabilize will improve the chance for survival and is the premise for this article, regardless of practice setting.

The Year in Review: Anesthesia for Congenital Heart Disease 2020

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

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.