The Australian and New Zealand Fontan Registry Quality of Life Study: Protocol for a population-based assessment of quality of life among people with a Fontan circulation, their parents, and siblings.

INTRODUCTION: Advances in the care of patients with single-ventricle congenital heart disease have led to a new generation of individuals living with a Fontan circulation. For people with Fontan physiology, physical, psychological and neurodevelopmental challenges are common. The objective of this study is to describe and develop a deeper understanding of the factors that contribute to quality of life (QOL) among children, adolescents and adults living with a Fontan circulation across Australia and New Zealand, their parents and siblings. METHODS AND ANALYSIS: This article presents the protocol for the Australian and New Zealand Fontan Registry (ANZFR) QOL Study, a cross-sectional, population-based study designed to examine QOL among people of all ages with a Fontan circulation, their parents and siblings. Study eligibility criteria includes (1) individuals with a Fontan circulation aged ≥6 years, at least 12 months post-Fontan procedure and enrolled in the ANZFR; (2) parents of individuals enrolled in the ANZFR; and (3) siblings aged ≥6 years of an individual enrolled in the ANZFR. A novel, online research platform is used to distribute personalised assessments tailored to participant age and developmental stage. A suite of validated psychometric self-report and parent-proxy report instruments capture potential correlates and predictors of QOL, including symptoms of psychological distress, personality attributes, coping and cognitive appraisals, family functioning, healthcare experiences and costs, access to emotional support and socioeconomic factors. Clinical characteristics are captured via self-report and parent-proxy report, as well as the ANZFR. Descriptive analyses and multilevel models will be used to examine QOL across groups and to investigate potential explanatory variables. ETHICS AND DISSEMINATION: Approval has been obtained from all relevant Human Research Ethics Committees (HRECs), including the Sydney Children's Hospitals Network and the Royal Children's Hospital Melbourne HRECs. Study findings will be published in peer-reviewed journals and presented at national and international meetings and seminars.

Incidence and management of the left ventricular outflow obstruction in patients with atrioventricular septal defects.

OBJECTIVES: Left ventricular outflow tract obstruction (LVOTO) is a recognized complication after complete repair of atrioventricular septal defect (AVSD). This study reviewed the incidence and management of LVOTO following AVSD repair at a single institution. METHODS: From 1975 to 2019, 24 patients (3.3%, 24/730) underwent reoperation due to LVOTO following partial AVSD (pAVSD) and complete AVSD (cAVSD) repair. The data were retrospectively reviewed. RESULTS: The incidence of LVOTO following pAVSD and cAVSD repair was 4.4% (12/275) and 2.6% (12/455). Freedom from LVOTO reoperation following pAVSD and cAVSD repair at 25 years was 94.3% [95% confidence interval (CI); 89.7-96.7] and 95% (95% CI; 91.1-97.3). The median time from complete repair of pAVSD and cAVSD to LVOTO reoperation was 4.4 years [interquartile range (IQR): 3.4-6.7] and 2.6 years (IQR: 2.2-4.7). Freedom from second LVOTO reoperation at 5, 10 and 15 years was 83.7% (95% CI; 57.2-98.2), 59.2% (95% CI; 28.7, 80.3) and 39.5% (95% CI; 13.2-65.3). The median time between the first and the second LVOTO reoperation in the groups of pAVSD and cAVSD was 6.1 years (IQR: 3.4-8.9) and 8.6 years (IQR: 5.7-9.8). There was no significant difference regarding the first (P = 0.7406) and subsequent LVOTO (P = 0.7153) following complete repair of pAVSD and cAVSD. Combined access to the left ventricular outflow tract was not protective regarding LVOTO reoccurrence. Survival for both groups after LVOTO reoperation at 15 years was 95.6% (95% CI 99.4-72.9). CONCLUSIONS: Incidence of LVOTO after AVSD repair is low but the reoccurrence rate is high. Standard subaortic resection does not always provide definitive LVOTO relief. The survival after LVOTO reoperation is excellent.

Cross-sectional assessment of haemostatic profile and hepatic dysfunction in Fontan patients.

BACKGROUND: Fontan-associated liver disease is accompanied by a hypercoagulable state. While hepatic dysfunction in Fontan patients is common, its relationship with haemostatic changes and clinical outcomes in this patient population remains unclear. OBJECTIVE: To correlate liver dysfunction and haemostatic profiles with clinical outcomes in the Fontan population. PATIENTS/METHODS: Patients were enrolled in a multicentre, cross-sectional study in Australia and New Zealand. Hepatic structure and function were assessed using serum-based calculations (Fibrotest and model for end-stage liver disease excluding international normalised ratio scores). Haemostatic profiles were assessed by Thrombin Generation. Platelet function was assessed via Platelet Factor 4 (PF4) and P-selectin (P-SEL). Clinical outcomes were obtained from the Australian and New Zealand Fontan Registry. RESULTS: Seventy-three patients participated in the study (mean age 18.9±8.5 years with a mean of 13.5±6.9 years post-Fontan). The Endogenous Thrombin Potential (ETP) for patients who suffered thrombotic events (TE) (1366.4±66.2 nM/min) was higher compared with patients with major bleeding events (1011.1±138.4 nM/min) (p=0.03). Except for a negative correlation between Fibrotest-score and PF4 (p=0.045), PF4 and P-SEL concentrations did not correlate with markers of hepatic dysfunction or structural abnormality. CONCLUSIONS: Increased ETP is associated with TE during clinical follow-up after Fontan. This study reinforces that hepatic dysfunction may contribute to the derangement of coagulation factors, impacting the individual risk of haemostatic complications for the Fontan population.

Reintervention and survival in 1428 patients in the Australian and New Zealand Fontan Registry.

OBJECTIVE: Patients undergoing single-ventricle palliation have experienced significant improvement in survival in the recent era. However, a substantial proportion of these patients undergo reoperations. We performed a review of the Australia and New Zealand (ANZ) Fontan Registry to determine the overall reintervention and reoperative burden in these patients. METHODS: A retrospective longitudinal cohort study was performed using data from patients who underwent a Fontan operation between 1975 and 2016 from the ANZ Fontan Registry. The data obtained included Fontan operation, reinterventions and most recent follow-up status. We examined the type and timing of reinterventions and survival. RESULTS: Of the 1428 patients identified, 435 (30%) underwent at least one reintervention after the Fontan operation: 110 patients underwent early reintervention and 413 underwent late reinterventions. Excluding Fontan conversion and transplantation, 220 patients underwent at least one interventional procedure and 209 patients underwent at least one reoperation. Fenestration closure and pacemaker-related procedures were the most common catheter and surgical interventions, respectively. The cumulative incidence of reintervention following Fontan was 23%, 37% and 55% at 10, 20 and 30 years, respectively. Survival and freedom from failure were worse in patients requiring later reintervention after Fontan surgery (51% vs 83% and 42% vs 69%, respectively at 30 years, p<0.001). This difference persisted after excluding pacemaker-related procedures (p<0.001). Operative mortality for non-pacemaker late reoperations after Fontan was 6%. CONCLUSIONS: A substantial proportion of Fontan patients require further intervention to maintain effective single-ventricle circulation. Patients undergoing reoperation after Fontan have higher rates of mortality and failure, despite intervention.

Development and Validation of the Warfarin-Aspirin Bleeding Assessment Tool (WA-BAT) in Children.

Bleeding assessment tools (BATs) aim to screen and estimate bleeding risk in patients with inherited bleeding disorders. However, the use of BAT as a standardized measure for comparing bleeding in patients on long-term thromboprophylaxis has not yet been validated. We developed a self-administrable BAT to assess bleeding in patients undergoing long-term thromboprophylaxis with aspirin or warfarin. Eligible participants were invited to complete the warfarin-aspirin -BAT (WA-BAT) online. The WA-BAT was readministered a number of weeks later to determine intrarater reliability. The WA-BAT showed substantial intrarater reliability and assesses major and minor bleeding associated with long-term warfarin or aspirin use.

Hospital Inpatient Costs for Single Ventricle Patients Surviving the Fontan Procedure.

We estimated the inpatient resource use for a Fontan patient from birth to adulthood and explored factors that might induce cost differences (2014 US dollar). Inpatient costing records from 4 hospitals with greatest numbers of Fontan patients in Australia and New Zealand were linked with the Fontan registry database. Inpatient records between July 1995 and September 2014 for 420 Fontan patients were linked, and the most frequent primary diagnoses were hypoplastic left heart syndrome (20.7%), tricuspid atresia (19.7%), and double inlet left ventricle (17.1%). The mean hospital cost for a Fontan patient from birth to 18 years of age was estimated to be $390,601 (95% confidence interval [CI] $264,703 to $516,499), corresponding to 164 (95% CI 98 to 231) inpatient days. The cost incurred from birth through to Fontan completion (the staged procedures period) was $219,482 (95% CI $202,410 to $236,553) and the cost thereafter over 15 years was $146,820 (95% CI $44,409 to $249,231), corresponding to 82 (95% CI 72 to 92) and 65 (95% CI 18 to 112) inpatient days, respectively. Costs were higher in male and hypoplastic left heart syndrome patients in the staged procedures period (p <0.001). Having fenestration was associated with higher costs in the staged procedures period (p <0.001) and lower cost after Fontan over 15 years (p = 0.66). In conclusion, patients with single ventricle congenital heart disease continue to demand considerable inpatient resources after the staged procedures period. Over 40% of the pediatric hospital costs for Fontan patients were estimated to occur after the last planned surgery.

Hospital costs and cost implications of co-morbid conditions for patients with single ventricle in the period through to Fontan completion.

BACKGROUND: Patients undergoing palliative surgeries for single-ventricle conditions are affected by multiple comorbidities or non-cardiac conditions. The prevalence, costs and the cost implications of these conditions have not been assessed. METHODS: Administrative costing records from four hospitals in Australia and New Zealand were linked with the Fontan registry database to analyze the inpatient resource use for co-morbid or non-cardiac conditions. Inpatient costing records from the birth year through to Fontan completion were available for 156 patients. The most frequent primary diagnoses were hypoplastic left heart syndrome (33%), double inlet left ventricle (13%), and tricuspid atresia (12%). RESULTS: During the staged surgical treatment period, children had a mean of 10±6 inpatient admissions and spent 85±64days in hospital. Among these admissions, 3±5 were for non-cardiac conditions, totaling 21±41 inpatient days. Whilst cardiac surgeries were the major reason for resource use (77% of the total cost), other cardiac care that is not surgical contributed 5% and non-cardiac admissions 18% of the total cost. The three most prevalent non-cardiac diagnostic admission categories were 'Respiratory system', 'Digestive system', and 'Ear, nose, mouth and throat', affecting 28%, 21% and 34% of the patients respectively. Multivariate regression estimated that admissions for each of these categories resulted in an increased cost of $34,563 (P=0.08), $52,438 (P=0.05) and $10,525 (P=0.53) per patient respectively for the staged surgical treatment period. CONCLUSIONS: Non-cardiac admissions for single-ventricle patients are common and have substantial resource implications. Further research assessing the causes of admission and extent to which admissions are preventable is warranted.

The Cost Differential Between Warfarin Versus Aspirin Treatment After a Fontan Procedure.

BACKGROUND: The use of aspirin versus warfarin for treatment of patients after a Fontan procedure remains contentious. Current preference-based models of treatment across Australia and New Zealand show variation in care that is unlikely to reflect patient differences and/or clinical risk. METHODS: We combine data from the Australian and New Zealand Fontan Registry and a home INR (International Normalised Ratio) monitoring program (HINRMP) from the Royal Children's Hospital (RCH) Melbourne, to estimate the cost difference for Fontan recipients receiving aspirin versus warfarin for 2015. We adopt a societal perspective to costing which includes cost to the health system (e.g. medical consults, pathology tests) and costs to patients and carers (e.g. travel and time), but excludes costs of adverse events. Costs are presented in Australian 2015 dollars; any costs from previous years have been inflated using appropriate rates from the Australian Bureau of Statistics. RESULTS: We find that warfarin patients face additional costs of $825 per annum, with the majority ($584 or 71%) of those borne by the patient or family. If aspirin is as clinically as effective as warfarin, Fontan recipients could be enjoying far less costly, invasive and time-consuming treatment. While achieving such clinical consensus can be difficult, economics shows us that there are large costs associated with a failure to achieve it.