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The population of people living with a Fontan circulation are highly heterogenous, including both children and adults, who have complex health issues and comorbidities associated with their unique physiology throughout life. Research focused on nutritional considerations and interventions in the Fontan population is extremely limited beyond childhood. This review article discusses the current literature examining nutritional considerations in the setting of Fontan physiology and provides an overview of the available evidence to support nutritional management strategies and future research directions. Protein-losing enteropathy, growth deficits, bone mineral loss, and malabsorption are well-recognised nutritional concerns within this population, but increased adiposity, altered glucose metabolism, and skeletal muscle deficiency are also more recently identified issues. Emergencing evidence suggets that abnormal body composition is associated with poor circulatory function and health outcomes. Many nutrition-related issues, including the impact of congenital heart disease on nutritional status, factors contributing to altered body composition and comorbidities, as well as the role of the microbiome and metabolomics, remain poodly understood.

Background: Peak oxygen pulse (O 2 pulse=oxygen consumption/heart rate) is calculated by the product of stroke volume (SV) and oxygen extraction. It has been shown to be reduced in patients with a Fontan circulation. However, in the Fontan population, it may be a poor marker of SV. We propose that the slope of the O 2 pulse curve may be more reflective of SV during exercise., Methods: We analysed cardiopulmonary exercise test data in 22 subjects with a Fontan circulation (cohort A) and examined the association between peak SV during exercise (aortic flow measured on exercise cardiac MRI), and O 2 pulse parameters (absolute O 2 pulse and O 2 pulse slopes up to anaerobic threshold (AT) and peak exercise). In a separate Fontan cohort (cohort B, n=131), associations between clinical characteristics and O 2 pulse kinetics were examined., Results: In cohort A, peak aortic flow was moderately and significantly associated with O 2 pulseslope PEAK (r=0.47, p=0.02). However, neither absolute O 2 pulse AT nor O 2 pulse PEAK was significantly associated with peak aortic flow. In cohort B, O 2 pulseslope PEAK and O 2 pulseslope AT were not significantly associated with clinical parameters, apart from a weak association with forced vital capacity., Conclusion: The slope of the O 2 pulse curve to peak exercise may be more reflective of peak SV in the Fontan population than a single peak O 2 pulse value., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To define the baseline characteristics of long-term tube-fed (TF) single ventricle patients, investigate associations between long-term enteral tube feeding and growth, and determine associations with long-term outcomes after Fontan procedure., Study Design: We performed a retrospective cohort study of patients in the Australia and New Zealand Fontan Registry undergoing treatment at the Royal Children's Hospital, the Children's Hospital at Westmead, Royal Melbourne Hospital, and Royal Prince Alfred Hospital from 1981 to 2018. Patients were defined as TF or non-tube-fed (NTF) based on enteral tube feeding at the age of 90 days. Feeding groups were compared regarding body mass index (BMI) trajectory, BMI at last follow-up, and long-term incidence of severe Fontan failure., Results: Of 390 patients (56 [14%] TF, 334 [86%] NTF), TF was associated with right ventricular dominance, hypoplastic left heart syndrome, Norwood procedure, increased procedures prior to Fontan, extracardiac conduit Fontan, Fontan fenestration, and atrioventricular valve repair/replacement. TF patients were less likely to be in the higher compared with lowest 0-6 month BMI trajectory (P < .01; P = .03), had lower 6 month weight-for-age z-scores (P < .01) and length-for-age z-scores (P = .01). TF were less likely to be overweight/obese at pediatric follow-up (hazard ratio [HR] = 0.31, 95% CI: 0.12-0.80; P = .02) and more likely to be underweight at adult follow-up (HR = 16.51; 5% CI: 2.70-101.10; P < .01). TF compared with NTF was associated with increased risk of severe Fontan failure (HR = 4.13; 95% CI = 1.65-10.31; P < .01)., Conclusions: Prolonged infant enteral tube feeding is an independent marker of poor growth and adverse clinical outcomes extending long-term post-Fontan procedure., (Crown Copyright © 2023. Published by Elsevier Inc. All rights reserved.)

Objective: The effect of ventricular dominance and previous atrioventricular valve (AVV) surgery on patient outcomes after Fontan operation remains unclear. We sought to determine the effect of ventricular dominance and previous AVV surgery on transplantation-free survival and long-term AVV competency in patients with atrioventricular septal defect (AVSD) and Fontan circulation., Methods: We conducted a retrospective study of 1703 patients in the Australia and New Zealand Fontan Registry, who survived Fontan operation between 1987 and 2021., Results: Of 174 patients with AVSD, 60% (105/174) had right ventricular (RV) dominance and 40% (69/174) had left ventricular (LV) dominance. The cumulative incidence of moderate or greater AVV regurgitation at 25 years after Fontan operation in patients with LV dominance was 56% (95% CI, 35%-72%), compared with 54% (95% CI, 40%-67%) in patients with RV dominance (P = .6). Nonetheless, transplantation-free survival at 25 years in patients with LV dominance was 94% (95% CI, 86%-100%), compared with 67% (95% CI, 52%-87%) in patients with RV dominance (hazard ratio, 5.9; 95% CI, 1.4-25.4; P < .01). Of note, transplantation-free survival was not different in patients who underwent AVV surgery before or at Fontan completion compared with those who did not (15 years: 81% [95% CI, 62%-100%] vs 88% [95% CI, 81%-95%]; P = .3)., Conclusions: In patients with AVSD and Fontan circulation the rate of moderate or greater common AVV regurgitation is similar in those with LV and RV dominance. RV dominance, rather than previous AVV surgery, is a risk factor for death or transplantation., (Crown Copyright © 2022. Published by Elsevier Inc. All rights reserved.)

Background Patients with a single ventricle who experience early life growth failure suffer high morbidity and mortality in the perisurgical period. However, long-term implications of poor infant growth, as well as associations between body mass index (BMI) and outcome in adulthood, remain unclear. We aimed to model BMI trajectories of patients with a single ventricle undergoing a Fontan procedure to determine trajectory-based differences in baseline characteristics and long-term clinical outcomes. Methods and Results We performed a retrospective analysis of medical records from patients in the Australia and New Zealand Fontan Registry receiving treatment at the Royal Children's Hospital, The Children's Hospital at Westmead, Royal Melbourne Hospital, and Royal Prince Alfred Hospital from 1981 to 2018. BMI trajectories were modeled in 496 patients using latent class growth analysis from 0 to 6 months, 6 to 60 months, and 5 to 16 years. Trajectories were compared regarding long-term incidence of severe Fontan failure (defined as mortality, heart transplantation, Fontan takedown, or New York Heart Association class III/IV heart failure). Three trajectories were found for male and female subjects at each age group-lower, middle, higher. Subjects in the lower trajectory at 0 to 6 months were more likely to have an atriopulmonary Fontan and experienced increased mortality long term. No association was found between higher BMI trajectory, current BMI, and long-term outcome. Conclusions Poor growth in early life correlates with increased long-term severe Fontan failure. Delineation of distinct BMI trajectories can be used in larger and older cohorts to find optimal BMI targets for patient outcome.

Background The long-term impact of fenestration at the time of Fontan operation remains unclear. We aimed to review the early and long-term impact of Fontan fenestration in the Australia and New Zealand cohort. Methods and Results We reviewed 1443 patients (621 fenestrated, 822 nonfenestrated) from the Australia and New Zealand Fontan registry. Data were collected on preoperative demographics, operative details, and follow-up. Propensity-score matching was performed to account for the various preoperative and operative differences and risk factors. Primary outcomes were survival and freedom from failure. Median follow-up was 10.6 years. After propensity-score matching (407 matched pairs), there was no difference in survival (87% versus 90% at 20 years; P =0.16) or freedom from failure (73% versus 80% at 20 years; P =0.10) between patients with and without fenestration, respectively. Although patients with fenestration had longer bypass and cross-clamp times ( P <0.001), there was no difference in hospital length of stay or prolonged pleural effusions ( P =0.80 and P =0.46, respectively). Freedom from systemic and Fontan circuit thromboembolism was higher in the nonfenestrated group (89%; 95% CI, 88%-95%) than the fenestrated group (84%; 95% CI, 77%-89%; P =0.03). There was no difference in incidence of plastic bronchitis, protein-losing enteropathy, New York Heart Association Class III/IV symptoms, or Fontan takedown. Conclusions In the propensity score-matched analysis we have demonstrated no difference in long-term survival or freedom from Fontan failure in patients with and without fenestration. There was a higher incidence of long-term thromboembolic events in patients with fenestration. Overall, it appears that fenestration in Fontan circulation does not bring long-term benefits.

Background: Atrioventricular valve (AVV) regurgitation is increasingly prevalent in patients with a Fontan circulation., Objectives: We sought to determine the impact of ventricular dominance and AVV operation on outcomes in patients with a Fontan circulation and ≥moderate AVV regurgitation., Methods: We conducted a retrospective study, including propensity score matching analysis, of 1,703 patients who survived Fontan operation in Australia and New Zealand from 1987 to 2021., Results: Patients undergoing AVV operation were more likely to have right ventricular (RV) dominance or an atrioventricular septal defect. In the entire cohort, death or transplantation after Fontan operation was significantly higher in patients who underwent AVV operation before or at Fontan completion compared with those who did not (20 years: 18%; 95% CI: 8%-26% vs 13%; 95% CI: 10%-15%; P = 0.03). After propensity score matching, including for RV dominance, there was no significant difference in death or transplantation between the groups (20 years: 18%; 95% CI: 8%-26% vs 16%; 95% CI: 10%-22%; P = 0.41). Only patients with RV dominance who developed ≥moderate AVV regurgitation after Fontan operation were at increased risk of death or transplantation (HR: 2.8; 95% CI: 1.4-5.3; P < 0.01). In patients with left ventricular dominance, there was no significant difference in death or transplantation between patients with ≥moderate AVV regurgitation compared with those with 

Introduction: Adolescents and adults with a Fontan circulation are at risk of cognitive dysfunction; Attention and processing speed are notable areas of concern. Underlying mechanisms and brain alterations associated with worse long-term cognitive outcomes are not well determined. This study investigated brain white matter microstructure in adolescents and adults with a Fontan circulation and associations with resting and peak exercise oxygen saturations (SaO 2 ), predicted maximal oxygen uptake during exercise (% pred VO 2 ), and attention and processing speed., Methods: Ninety-two participants with a Fontan circulation (aged 13-49 years, ≥5 years post-Fontan completion) had diffusion MRI. Averaged tract-wise diffusion tensor imaging (DTI) metrics were generated for 34 white matter tracts of interest. Resting and peak exercise SaO 2 and % pred VO 2 were measured during cardiopulmonary exercise testing (CPET; N = 81). Attention and processing speed were assessed using Cogstate (N = 67 and 70, respectively). Linear regression analyses adjusted for age, sex, and intracranial volume were performed to investigate associations between i) tract-specific DTI metrics and CPET variables, and ii) tract-specific DTI metrics and attention and processing speed z-scores., Results: Forty-nine participants were male (53%), mean age was 23.1 years (standard deviation (SD) = 7.8 years). Mean resting and peak exercise SaO 2 were 93.1% (SD = 3.6) and 90.1% (SD = 4.7), respectively. Mean attention and processing speed z-scores were -0.63 (SD = 1.07) and -0.72 (SD = 1.44), respectively. Resting SaO 2 were positively associated with mean fractional anisotropy (FA) of the left corticospinal tract (CST) and right superior longitudinal fasciculus I (SLF-I) and negatively associated with mean diffusivity (MD) and radial diffusivity (RD) of the right SLF-I (p ≤ 0.01). Peak exercise SaO 2 were positively associated with mean FA of the left CST and were negatively associated with mean RD of the left CST, MD of the left frontopontine tract, MD, RD and axial diffusivity (AD) of the right SLF-I, RD of the left SLF-II, MD, RD and AD of the right SLF-II, and MD and RD of the right SLF-III (p ≤ 0.01). Percent predicted VO 2 was positively associated with FA of the left uncinate fasciculus (p < 0.01). Negative associations were identified between mean FA of the right arcuate fasciculus, right SLF-II and right SLF-III and processing speed (p ≤ 0.01). No significant associations were identified between DTI-based metrics and attention., Conclusion: Chronic hypoxemia may have long-term detrimental impact on white matter microstructure in people living with a Fontan circulation. Paradoxical associations between processing speed and tract-specific DTI metrics could be suggestive of compensatory white matter remodeling. Longitudinal investigations focused on the mechanisms and trajectory of altered white matter microstructure and associated cognitive dysfunction in people with a Fontan circulation are required to better understand causal associations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: To assess the association between body composition and the risk of adverse outcomes in Fontan patients., Methods: Participants from the Australian and New Zealand Fontan Registry with dual-energy X-ray absorptiometry scans were included. Appendicular lean mass (ALM), appendicular lean mass index (ALM divided by height squared; ALMI) and total body fat mass percentage (%BF) were calculated. ALMI and %BF z-scores were derived using age- and sex-matched reference ranges. The primary outcome was Fontan failure (death, transplantation, New York Heart Association functional class III/IV, protein-losing enteropathy, and plastic bronchitis) or moderate-or-severe ventricular dysfunction., Results: 144 patients were included. Mean %BF was 29% (SD 10) with 50% having increased adiposity. Mean ALMI z-score was -1.4 (SD 1.1); one third of patients had skeletal muscle deficiency (ALMI z-score < -1 and -2) and another third had Fontan-associated myopaenia (ALMI z-score < -2). Age and %BF were associated with the risk of the endpoint in univariable regression (age: HR 1.09 per year, 95% CI 1.02-1.17, p = 0.01; %BF: HR 1.08, 95% CI 1.01-1.17, p = 0.03). On multivariable regression, every 1% increase in %BF was associated with a 10% increased risk of reaching the clinical endpoint (HR 1.10, 95% CI 1.01-1.19; p = 0.03). ALM was not associated with the endpoint (HR 1.02 per kg, 95% CI 0.88-1.20, p = 0.77)., Conclusions: Increased adiposity is associated with higher risk for adverse outcomes. Prospective studies to assess lifestyle interventions to optimise body composition should be prioritised., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Neurocognitive outcomes beyond childhood in people with a Fontan circulation are not well defined. This study aimed to investigate neurocognitive functioning in adolescents and adults with a Fontan circulation and associations with structural brain injury, brain volumetry, and postnatal clinical factors., Methods: In a binational study, participants with a Fontan circulation without a preexisting major neurological disability were prospectively recruited from the Australia and New Zealand Fontan Registry. Neurocognitive function was assessed by using Cogstate software in 107 participants with a Fontan circulation and compared with control groups with transposition of the great arteries (n=50) and a normal circulation (n=41). Brain MRI with volumetric analysis was performed in the participants with a Fontan circulation and compared with healthy control data from the ABIDE I and II (Autism Brain Imaging Data Exchange) and PING (Pediatric Imaging, Neurocognition, and Genetics) data repositories. Clinical data were retrospectively collected., Results: Of the participants with a Fontan circulation who had a neurocognitive assessment, 55% were male and the mean age was 22.6 years (SD 7.8). Participants with a Fontan circulation performed worse in several areas of neurocognitive function compared with those with transposition of the great arteries and healthy controls ( P <0.05). Clinical factors associated with worse neurocognitive outcomes included more inpatient days during childhood, younger age at Fontan surgery, and longer time since Fontan procedure ( P <0.05). Adults with a Fontan circulation had more marked neurocognitive dysfunction than adolescents with a Fontan circulation in 2 domains (psychomotor function, P =0.01 and working memory, P =0.02). Structural brain injury was present in the entire Fontan cohort; the presence of white matter injury was associated with worse paired associate learning ( P <0.001), but neither the presence nor severity of infarct, subcortical gray matter injury, and microhemorrhage was associated with neurocognitive outcomes. Compared with healthy controls, people with a Fontan circulation had smaller global brain volumes ( P <0.001 in all regions) and smaller regional brain volumes in most cerebral cortical regions ( P <0.05). Smaller global brain volumes were associated with worse neurocognitive functioning in several domains ( P <0.05). A significant positive association was also identified between global brain volumes and resting oxygen saturations ( P ≤0.04)., Conclusions: Neurocognitive impairment is common in adolescents and adults with a Fontan circulation and is associated with smaller gray and white matter brain volume. Understanding modifiable factors that contribute to brain injury to optimize neurocognitive function is paramount.

Background: Heterotaxy is considered a risk factor for poor outcomes after the Fontan operation. However, long-term data to support this notion are lacking. The aims of this study were to ascertain the long-term outcomes of patients with heterotaxy after hospital discharge after Fontan completion and to compare these outcomes with those of a contemporary nonheterotaxy cohort., Methods: A binational Fontan registry (n = 1540) was analyzed to identify patients with heterotaxy and compare them with patients without heterotaxy. The primary composite end point was Fontan failure, encompassing death, heart transplantation, Fontan takedown or conversion, protein-losing enteropathy, plastic bronchitis, or New York Heart Association functional class III or IV., Results: A total of 109 patients with heterotaxy were identified and they were compared with 1431 nonheterotaxy patients after Fontan completion. There was no difference in unadjusted 15-year freedom from Fontan failure (heterotaxy, 78% vs nonheterotaxy, 85%; P = .2). Patients in the heterotaxy group had a significantly higher cumulative incidence of post-Fontan arrhythmias (P < .001). Propensity-score matching for confounders yielded 73 patients with heterotaxy matched with 439 patients without heterotaxy, in whom 15-year freedom from Fontan failure was also not different (heterotaxy, 76% vs nonheterotaxy, 81%; P = .2). There was no difference in 15-year freedom from Fontan failure in patients with right vs left isomerism (right isomerism, 80% vs left isomerism, 76%; P = .7)., Conclusions: Although heterotaxy may complicate the pre-Fontan course, once the Fontan procedure is successfully completed, heterotaxy does not appear to be an important risk factor for Fontan failure. Patients with heterotaxy are at a higher risk of post-Fontan arrhythmias compared with patients without heterotaxy., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Heterotaxy is considered a risk factor for adverse events at all stages in the pre-Fontan pathway, and Fontan outcomes are expected to be worse in patients with heterotaxy. The aim of this study was to review existing literature reporting outcomes of the Fontan operation systematically in patients with heterotaxy., Methods: A systematic review and meta-analysis was performed to identify and synthesize early mortality and medium- and long-term survival in heterotaxy patients after the Fontan procedure. Subsequent outcome analyses were stratified by study period era, cohort size, and proportion of right versus left atrial isomerism to explore predictors of outcome., Results: A total of 21 studies were included for analysis, which were composed of 848 post-Fontan heterotaxy patients. Early mortality varied between 1% and 30% with a weighted event rate of 14% (95% confidence interval [CI], 10%-19%). Survival at 1, 5, and 10 years was 86% (95% CI, 79%-91%), 80% (95% CI, 71%-87%), and 74% (95% CI, 59%-85%), respectively. Stratification by study period highlighted that studies with a median study period year of 1995 or later had similar early mortality and 1- and 5-year survival, but superior 10-year survival (P = .02) compared with earlier studies. Stratification by cohort size and right versus left atrial isomerism did not reveal subgroup differences., Conclusions: Compared with existing literature, in patients with heterotaxy, early mortality after Fontan is higher than for the overall Fontan population. Long-term survival is comparable to the overall Fontan cohort. When heterotaxy patients are successfully transitioned to Fontan, subsequent survival is acceptable and predictable. Long-term follow-up is lacking., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background We sought to characterize body composition abnormalities in young patients living with a Fontan circulation and explore potential pathophysiologic associations. Methods and Results Twenty-eight patients with a Fontan circulation were prospectively recruited in this cross-sectional study. Participants underwent cardiopulmonary exercise testing, dual-energy X-ray absorptiometry, echocardiography, and biochemical assessment. Mean age was 26±7 years. Skeletal muscle mass, estimated by appendicular lean mass index Z score, was reduced compared with reference data (-1.49±1.10, P <0.001). Percentage body fat Z score overall was within normal range (0.23±1.26, P =0.35), although 46% had elevated adiposity. Those with reduced skeletal muscle mass (appendicular lean mass index Z score of -1 or lower) had lower percent predicted oxygen pulse (55±15 versus 76±16%, P =0.002). Overall agreement between body mass index and dual-energy X-ray absorptiometry to assess adiposity was fair only (weighted [linear] κ coefficient: 0.53; 95% CI, 0.34-0.73) and slight in the setting of muscle mass deficiency (weighted κ coefficient: 0.32; 95% CI, 0.13-0.50). Appendicular lean mass was independently associated with absolute peak VO 2 (β=70.6 mL/min, P =0.001). Appendicular lean mass index Z score was inversely associated with hemoglobin ( r =-0.4, P =0.04), and the degree of muscle deficit was associated with ventricular systolic impairment. Conclusions Young patients with a Fontan circulation have a body composition characterized by reduced skeletal muscle mass, which is associated with peak exercise capacity. Increased adiposity is common despite a normal body mass index. Low skeletal muscle mass is associated with systolic dysfunction and compensatory erythrocytosis.

Objective and Patients: This study aimed to characterize bone mineral density abnormalities and pathophysiological associations in young adults living with a Fontan circulation., Design: Participants underwent bone mineral density measurement using dual-energy X-ray absorptiometry and serum biochemical analysis, cardiopulmonary exercise and strength testing and transthoracic echocardiography., Results: In our cohort (n = 28), 29% had osteopenic-range bone mineral density and one patient was osteoporotic (average hip t score: -0.6 ± 1.1; spine t score: -0.6 ± 0.9). Four patients (14%) had z scores < -2.0. Parathyroid hormone levels were increased compared with laboratory median (6.1 ± 3.5 vs 4 pmol/L, P = .01) and 27% had 25-hydroxy-vitamin D < 50 nmol/L. 25-hydroxy-vitamin D negatively correlated with parathyroid hormone (ρ = -0.53, P = .01) suggesting secondary hyperparathyroidism. Atrioventricular valve systolic to diastolic duration ratio, an echocardiographic measure of diastolic dysfunction, inversely correlated with hip t and z scores (P < .01). Hip t scores were positively associated with oxygen saturations (ρ = 0.45, P = .05) and tended to be inversely associated with parathyroid hormone levels (ρ = -0.44, P = .07) and N-Terminal pro b-type natriuretic peptide (ρ = -0.42, P = .08)., Conclusions: Many young adults with a Fontan circulation have abnormal bone mineral density. The underlying pathophysiology is likely multifactorial. Possible contributors include secondary hyperparathyroidism, hypoxemia, diastolic cardiac dysfunction and neurohormonal activation. As low bone mineral density is clinically relevant and potentially treatable, assessment of bone mineral density should be part of routine care in this cohort., (© 2019 Wiley Periodicals, Inc.)

Objectives: D-transposition of the great arteries and l-transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction are complex biventricular congenital heart diseases for which decision-making regarding surgical strategy remains challenging. We investigated the intermediate-term outcomes of Fontan versus biventricular procedures in these patients., Methods: We analyzed 129 patients with d-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction (n = 85) or l-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction (n = 44) and 2 functional ventricles from Australia who had primary surgical management (29 Fontan, 100 biventricular repair) undertaken between 1990 and 2015., Results: Median operative age of patients was 2.9 years (range, 0.2-26.8 years). During a median follow-up of 6.2 years (range, 2 days to 25.8 years), 9 patients died after biventricular repair (3 early and 6 late deaths). One patient received a transplant 1.2 years after Fontan completion. Overall transplant-free survivals at 1, 5, 10, and 15 years were 95%, 93%, 92%, and 90%, respectively. Overall reintervention-free survivals at 1, 5, 10, and 15 years were 79%, 64%, 45%, and 29% respectively. Biventricular repair tended to be associated with a higher rate of death, transplantation, or reintervention than the Fontan pathway (hazard ratio, 1.83; 95% confidence interval, 0.90-3.71; P = .10). Some 73% of transplant-free survivors had New York Heart Association class I. Functional status was similar between the Fontan and biventricular groups., Conclusions: Intermediate-term outcomes were comparable between patients with d-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction and patients with l-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction. Both Fontan and biventricular pathways are associated with excellent mortality and functional outcomes. Biventricular patients have a greater risk of reintervention. The Fontan procedure is a viable option when anatomic risk factors preclude biventricular repair., (Copyright © 2019 The American Association for Thoracic Surgery. All rights reserved.)

Background: Patients with a Fontan circulation are at risk of renal dysfunction. We analyzed cross-sectional data in pediatric and adult Fontan patients in order to assess the accuracy of commonly used serum creatinine-based methods in estimating glomerular filtration rate (GFR)., Methods: A total of 124 Fontan patients (58 children, 66 adults) were enrolled across three study centers. Measurement of GFR (mGFR) using in vivo 99m Tc-DTPA clearance was performed. Various serum creatinine-based equations were used to calculate estimated GFR (eGFR)., Results: Mean mGFR was 108 ± 28 mL/min/1.73 m 2 in children and 92 ± 20 mL/min/1.73 m 2 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90 mL/min/1.73 m 2 . There was no significant correlation between mGFR and eGFR (Schwartz) in children (r = 0.22, P = .1), which substantially overestimated mGFR (bias 50.8, 95%CI: 41.1-60.5 mL/min/1.73 m 2 , P < .0001). The Bedside Schwartz equation also performed poorly in the children (r = 0.08, P = .5; bias 5.9, 95%CI: -2.9-14.6 mL/min/1.73 m 2 , P < .0001). There was a strong correlation between mGFR and both eGFR (CKD-EPI) and eGFR (MDRD) in adults (r = 0.67, P < .0001 in both cases), however, both methods overestimated mGFR (eGFR(CKD-EPI):bias 23.8, 95%CI: 20-27.6 mL/min/1.73 m 2 , P < .0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8-20.4 mL/min/1.73 m 2 , P < .0001). None of the children with an mGFR <90 mL/min/1.73 m 2 had an eGFR (Schwartz) <90 mL/min/1.73 m 2 . Sensitivity and specificity of eGFR (CKD-EPI) and eGFR (MDRD) for mGFR <90 mL/min/1.73 m 2 in adults were 25% and 92% and 39% and 100%, respectively., Conclusions: This study identifies the unreliability of using creatinine-based equations to estimate GFR in children with a Fontan circulation. The accuracy of formulas incorporating cystatin C should be further investigated and may aid noninvasive surveillance of renal function in this population., (© 2019 Wiley Periodicals, Inc.)

Background: A subset of patients who underwent Fontan operations has two adequate-sized ventricles, but an anatomic biventricular circulation cannot be achieved because of complex morphology or for technical reasons. This study sought to determine whether these patients with two-ventricle Fontan circulation had superior outcomes compared with those with a single ventricle., Methods: A binational Fontan Registry of patients (n = 1,377) was analyzed to identify those patients with two adequate ventricles. This cohort was compared with patients with single-ventricle Fontan circulation. The primary end point was a composite end point called "Fontan failure" encompassing death, heart transplantation, Fontan takedown or conversion, protein-losing enteropathy, plastic bronchitis, or New York Heart Association functional class III or IV., Results: A total of 79 Fontan patients with two adequate ventricles (2V) were compared with 1,291 single ventricle (1V) Fontan patients. Median follow-up for the entire cohort was 11.5 years (interquartile range, 5.1 to 18.8 years). There was no difference in unadjusted 15-year freedom from Fontan failure (2V: 81% [95% confidence interval (CI), 69% to 94%] vs 1V: 86% [95% CI, 83% to 88%], p = 0.4). Propensity-score matching for potential confounding factors yielded 75 two-ventricle Fontan patients matched with 604 single-ventricle Fontan patients, in which 15-year freedom from Fontan failure was also not different (2V: 79% [95% CI, 67% to 94%] vs 1V: 87% [95% CI, 84% to 91%], p = 0.3)., Conclusions: The two-ventricle Fontan circulation does not have better outcomes compared with the single-ventricle Fontan circulation. Late outcomes may depend more on other characteristics of the Fontan circulation. This finding is relevant when the Fontan procedure is being considered as an alternative to anatomic repair in patients with complex two-ventricle morphologies., (Copyright © 2019 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Atrioventricular valve failure (moderate or greater regurgitation, or valve operation) is a risk factor for adverse outcomes in patients undergoing Fontan palliation., Objectives: This study determined the incidence of atrioventricular valve failure and its clinical impact on patients undergoing Fontan palliation., Methods: A retrospective cohort longitudinal study was conducted using patient data extracted from an existing bi-national, population-based registry., Results: A total of 1,468 patients who underwent Fontan palliation were identified; complete follow-up data were available for 1,199 patients. Six hundred eighty-six patients had 2 atrioventricular valves, 286 had a single mitral valve, 130 had a common atrioventricular valve, and 97 had a single tricuspid valve. A total of 132 repairs were performed in 110 patients, and 15 replacements were performed in 13 patients. The cumulative incidence of atrioventricular valve failure at 25 years of age for patients with a common atrioventricular, single tricuspid, single mitral, and 2 atrioventricular valves was 56% (95% confidence interval [CI]: 46% to 67%), 46% (95% CI: 31% to 61%), 8% (95% CI: 4% to 12%), and 26% (95% CI: 21% to 30%), respectively. In patients without valve failure, freedom from Fontan failure at 10 and 20 years post-Fontan palliation was 91% (95% CI: 89% to 93%) and 77% (95% CI: 73% to 81%), respectively, compared with 77% (95% CI: 69% to 85%) and 54% (95% CI: 42% to 68%), respectively, in patients with valve failure (hazard ratio: 2.43; 95% CI: 1.74 to 3.39; p < 0.001)., Conclusions: Atrioventricular valve failure occurs frequently in patients undergoing Fontan palliation. Patients with valve failure are twice as likely to have their Fontan circulation fail than those without valve failure., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Hepatic and renal dysfunction have been observed in survivors of the Fontan procedure, however their incidence and associated factors remain poorly defined., Methods: A total of 152 participants from a Registry of 1528 patients underwent abdominal ultrasound, transient elastography (FibroScan), serum fibrosis score (FibroTest), in vivo Tc-99m DTPA measurement of glomerular filtration rate (mGFR), and urine albumin-creatinine ratio (ACR)., Results: Mean age and time since Fontan were 19.8 ± 9.3 and 14.1 ± 7.6 years, respectively. Features suggestive of hepatic fibrosis were observed on ultrasound in 87/143 (61%) and no patient was diagnosed with hepatocellular carcinoma. FibroScan median kPa was ≥10 in 117/133 (88%), ≥15 in 75/133 (56%), and ≥20 in 41/133 (31%). Fifty-four patients (54/118, 46%) had a FibroTest score ≥0.49 (equivalent to ≥F2 fibrosis). FibroTest score correlated with FibroScan value (r = 0.24, p = 0.015) and ACR (r = 0.29, p = 0.002), and patients with ultrasound features of hepatic fibrosis had a higher FibroScan median kPa (19.5 vs 15.4, p = 0.002). Renal impairment was mild (mGFR 60-89 ml/min/1.73 m 2 ) in 46/131 (35%) and moderate (mGFR 30-59 ml/min/1.73 m 2 ) in 3/131 (2%). Microalbuminuria was detected in 52/139 participants (37%). By multivariable analysis, time since Fontan was associated with increased FibroScan median kPa (β = 0.89, 95% CI 0.54-1.25, p = 0.002) and decreased mGFR (β = -0.77, 95% CI -1.29-0.24, p = 0.005)., Conclusions: In the second decade after Fontan hepatic and renal structure and function are abnormal in a significant number of patients: close to 60% have ultrasonographic evidence of structural hepatic abnormalities, 46% have elevated serum hepatic fibrosis scores, and 57% have either reduced glomerular filtration rate or microalbuminuria. Hepatic and renal function should be monitored for potential impacts on outcomes after Fontan completion., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Patients with a Fontan circulation have reduced exercise capacity and respiratory muscle strength. Inspiratory muscle training (IMT) improves exercise capacity and quality of life in adults with heart failure. We assessed whether 6 weeks of a home-based program of IMT improves inspiratory muscle strength and the ventilatory efficiency of exercise in adolescent patients with a Fontan circulation., Methods and Results: Twenty-three adolescent participants (aged 16±2 years) with a Fontan circulation underwent 6 weeks of IMT for 30 minutes daily. Respiratory muscle strength (maximal inspiratory pressure and expiratory pressure), lung function, and exercise capacity (cardiopulmonary exercise testing) were assessed. Fourteen of 23 participants also underwent exercise cardiac magnetic resonance imaging to examine the effects of IMT on cardiac output and systemic and pulmonary blood flow. Six weeks of IMT improved maximal inspiratory pressure by 36±24 cm H 2 O (61±46%) with no change in maximal expiratory pressure. Ventilatory efficiency of exercise improved after 6 weeks of IMT (from 34.2±7.8 to 32.2±5.6, P =0.04). In those who underwent exercise cardiac magnetic resonance imaging, IMT increased resting cardiac output (from 4.2±1.2 to 4.5±1.0 L/min, P =0.03) and ejection fraction (from 50.1±4.3 to 52.8±6.1%, P =0.03)., Conclusions: Six weeks of IMT is associated with improved inspiratory muscle strength, ventilatory efficiency of exercise, and resting cardiac output in young Fontan patients. IMT may be a simple beneficial addition to the current management of Fontan patients, potentially reducing exercise intolerance and long-term morbidity and mortality., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background Successful anatomic repair of congenitally corrected transposition of the great arteries achieves excellent outcomes. Several centers report excellent long-term survival with the Fontan pathway as well. We have selectively applied both approaches depending on individual patient morphology, with anatomic repair preferred but utilizing the Fontan pathway when high technical complexity or operative risk is anticipated. Methods Hospital records over an 18-year period (1998-2016) were reviewed to identify patients with congenitally corrected transposition of the great arteries who underwent surgical management. Physiological repairs and hypoplastic ventricles were excluded. Patient- and procedure-related variables were reviewed. Results We identified 19 patients. Group 1 consisted of 12 anatomic repairs, of which 10 (83.3%) required prior interim staging procedures. Mean age at anatomic repair was 2.6 ± 1.3 years, mean follow-up was 8.7 ± 5.3 years. Nine (75%) patients experienced important complications and 4 (33.3%) required reintervention during follow-up. There were no deaths; one patient required heart transplantation. Group 2 (7 patients) underwent Fontan palliation. Mean age at Fontan completion was 7.2 ± 3.8 years, mean follow-up was 6.3 ± 4 years. There was no reintervention, death, or transplant. Conclusion Patients with congenitally corrected transposition of the great arteries and two adequate-sized ventricles do well with both anatomic repair and the Fontan pathway in the medium term. Excellent outcomes with reduced early complication and reintervention rates can be achieved for this cohort of patients when a strategy of avoiding complex anatomic repair in favor of the Fontan pathway is used.

Failing Fontan continues to be major problem for patients on the univentricular pathway. Failing Fontan is often complicated by chylothorax, plastic bronchitis and protein loosing enteropathy. The role of lymphatic circulation in Fontan circulation is still being researched. Newer imaging modalities give insight into the role of abnormal dilatation and retrograde flow in lymphatic channels post Fontan. Interventional strategies targeting abnormal lymphatic channels, provides an alternative management strategy for patients with failing Fontan. This review focuses on the role of lymphatic system in adaptations to Fontan circulation.

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.

Background: Despite a lack of evidence supporting the use of angiotensin-converting enzyme (ACE) inhibitors in patients with a Fontan circulation, their use is frequent. We decided to identify the rationale for ACE inhibitor therapy in patients within the Australia and New Zealand Fontan Registry., Methods: All patients in the Registry taking an ACE inhibitor at last follow up were identified, and a review of medical records was undertaken to determine the rationale for treatment initiation and reasons for treatment continuation or dose increase., Results: In 2015, 36% of the surviving patients in the Registry (462/1268) were taking an ACE inhibitor. Indications for initiation of therapy were ventricular systolic or diastolic dysfunction (29%), atrioventricular valve regurgitation (19%), preservation of normal ventricular function (7%), prolonged effusions at Fontan (6%), hypertension (6%), other (6%) and unknown (2%). No indication was stated in the remaining patients (25%). Those with hypoplastic left heart syndrome were more likely to be on an ACE inhibitor than those with an alternative primary morphology (70% vs 32%; p<0.001). Only 36% of the patients treated with an ACE inhibitor at last follow up (166/462) had an indication that would generally justify treatment in a two-ventricle circulation., Conclusion: It is likely that the use of ACE inhibitors in patients with a Fontan circulation is excessive within our region. The coordination of prospective, multicentre studies and initiatives such as the Australia and New Zealand Fontan Registry will facilitate further investigations to guide treatment decisions in the growing Fontan population., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)