Successful Implementation of Enhanced Recovery After Surgery (ERAS) in Paediatric Cardiac Surgery in Australia.

BACKGROUND & AIM: Fast-track or enhanced recovery after surgery (ERAS) is a care pathway for surgical patients based on a multidisciplinary team approach aimed at optimising recovery without increasing risk with protocols based on scientific evidence, which is monitored continuously to ensure compliance and improvement. These protocols have been shown to reduce the duration of postoperative mechanical ventilation and intensive care unit (ICU) length of stay (LOS) following paediatric cardiac surgery. We present the first structured implementation of ERAS in paediatric cardiac surgery in Australia. METHODS: All patients enrolled in the ERAS pathway between October 2019 and July 2023 were identified. Demographic and perioperative data were collected retrospectively from hospital records for patients operated before June 2021 and prospectively from June 2021. A control group (non-ERAS) was identified using propensity matching from patients who underwent similar procedures and were not enrolled in the ERAS pathway (prior to October 2019). Patients were matched for age, weight, and comprehensive Aristotle score. Outcomes of interest were duration of postoperative mechanical ventilation, ICU LOS, readmission to the ICU, hospital LOS, cardiac reintervention rate, postoperative complication rate, and number of 30-day readmissions. RESULTS: Of 1,084 patients who underwent cardiac surgery during the study period (October 2019-July 2023), 121 patients (11.2%) followed the ERAS pathway. The median age at the time of surgery was 4.8 years (interquartile range [IQR] 2.8-8.8 years). The most common procedure was the closure of atrial septal defect (n=58, 47.9%). The median cardiopulmonary bypass and cross-clamp times were 40 min (IQR 28-53.5 minutes) and 24.5 min (IQR 13-34 minutes) respectively. The majority were extubated in the operating theatre (n=108, 89.3%). The median ICU and hospital LOS were 4.5 hrs (IQR 4.1-5.6 hours) and 4 days (IQR 4-5 days) respectively. None of the patients required readmission to the ICU within 24 hrs of discharge from the ICU. Three (3) patients (2.5%) required reintervention. When compared with the non-ERAS group, the duration of postoperative mechanical ventilation, ICU and hospital LOS were significantly lower in the ERAS group. There was no significant difference in the ICU readmission rate, reintervention rate, complication rate, and number of 30-day readmissions between both groups. CONCLUSIONS: ERAS after paediatric cardiac surgery is feasible and safe in select patients with low preoperative risk. This pathway reduces the duration of postoperative mechanical ventilation, ICU and hospital LOS without increasing risks, enabling the optimisation of resources.

Clinical stakeholder preferences for paediatric cardiac surgery outcome reporting in Australia and New Zealand.

BACKGROUND: Outcome reporting is an essential element of quality assurance. Evaluation of the information needs of stakeholders of outcome reporting is limited. This study aimed to examine stakeholder preferences for the content, format, and dissemination of paediatric cardiac surgery performance data in Australia and New Zealand. METHODS: Semi-structured interviews were completed with a purposive sample of Queensland stakeholders to evaluate their attitudes and expectations regarding reporting of paediatric cardiac surgery outcomes. The interviews were audio-recorded and transcribed. Two researchers used an interpretive description approach to analyse the transcripts qualitatively. RESULTS: Nineteen stakeholders were interviewed including fifteen clinicians, four parents, one hospital administrator, and one consumer advocate were interviewed. Mortality was highlighted as the area of greatest interest in reports by clinical and consumer groups. The majority preferred hospital rather than individual/clinician-level reporting. Annual reports were preferred by clinicians who requested reports be distributed electronically. CONCLUSIONS: The evidence generated from outcome reporting in paediatric cardiac surgery is highly desired by clinicians, administrators, parents, families, and advocacy groups. Clinical users prefer information to assist in clinical decision-making, while families seek personalised information at crucial time points in their clinical journey.

Implementation of a novel vocal cord dysfunction management pathway using the consolidated framework for implementation research.

Every year in Australia over a thousand children who are born with congenital heart disease require surgical intervention. Vocal cord dysfunction (VCD) can be an unavoidable and potentially devastating complication of surgery for congenital heart disease. Structured, multidisciplinary care pathways help to guide clinical care and reduce mortality and morbidity. An implementation study was conducted to embed a novel, multidisciplinary management pathway into practice using the consolidated framework for implementation research (CFIR). The goal of the pathway was to prepare children with postoperative vocal cord dysfunction to safely commence and transition to oral feeding. Education sessions to support pathway rollout were completed with clinical stakeholders. Other implementation strategies used included adaptation of the pre-procedural pathway to obtain consent, improving the process of identifying patients on the VCD pathway, and nominating a small team who were responsible for the ongoing monitoring of patients following recruitment. Implementation success was evaluated according to compliance with pathway defined management. Our study found that while there were several barriers to pathway adoption, implementation of the pathway was feasible despite pathway adaptations that were required in response to COVID-19.

Cardiopulmonary bypass in a child with severe Factor XII deficiency.

Factor XII (FXII) deficiency presents as a prolonged activated partial thromboplastin time (aPTT) but is not associated with clinically significant bleeding. Activated clotting time (ACT) is used routinely to monitor anticoagulation with unfractionated heparin in patients undergoing cardiopulmonary bypass (CPB). The coagulation activator reagents in most ACT tests are dependent on adequate FXII concentrations to initiate contact factor coagulation pathways. We report the case of a 14.7 kg girl undergoing CPB with a pre-admission FXII concentration of <1% and aPTT >200 seconds. The child was transfused with fresh-frozen plasma to replenish FXII, allowing safe ACT monitoring of heparin anticoagulation throughout CPB.

Effect of Nitric Oxide via Cardiopulmonary Bypass on Ventilator-Free Days in Young Children Undergoing Congenital Heart Disease Surgery: The NITRIC Randomized Clinical Trial.

Importance: In children undergoing heart surgery, nitric oxide administered into the gas flow of the cardiopulmonary bypass oxygenator may reduce postoperative low cardiac output syndrome, leading to improved recovery and shorter duration of respiratory support. It remains uncertain whether nitric oxide administered into the cardiopulmonary bypass oxygenator improves ventilator-free days (days alive and free from mechanical ventilation). Objective: To determine the effect of nitric oxide applied into the cardiopulmonary bypass oxygenator vs standard care on ventilator-free days in children undergoing surgery for congenital heart disease. Design, Setting, and Participants: Double-blind, multicenter, randomized clinical trial in 6 pediatric cardiac surgical centers in Australia, New Zealand, and the Netherlands. A total of 1371 children younger than 2 years undergoing congenital heart surgery were randomized between July 2017 and April 2021, with 28-day follow-up of the last participant completed on May 24, 2021. Interventions: Patients were assigned to receive nitric oxide at 20 ppm delivered into the cardiopulmonary bypass oxygenator (n = 679) or standard care cardiopulmonary bypass without nitric oxide (n = 685). Main Outcomes and Measures: The primary end point was the number of ventilator-free days from commencement of bypass until day 28. There were 4 secondary end points including a composite of low cardiac output syndrome, extracorporeal life support, or death; length of stay in the intensive care unit; length of stay in the hospital; and postoperative troponin levels. Results: Among 1371 patients who were randomized (mean [SD] age, 21.2 [23.5] weeks; 587 girls [42.8%]), 1364 (99.5%) completed the trial. The number of ventilator-free days did not differ significantly between the nitric oxide and standard care groups, with a median of 26.6 days (IQR, 24.4 to 27.4) vs 26.4 days (IQR, 24.0 to 27.2), respectively, for an absolute difference of -0.01 days (95% CI, -0.25 to 0.22; P = .92). A total of 22.5% of the nitric oxide group and 20.9% of the standard care group developed low cardiac output syndrome within 48 hours, needed extracorporeal support within 48 hours, or died by day 28, for an adjusted odds ratio of 1.12 (95% CI, 0.85 to 1.47). Other secondary outcomes were not significantly different between the groups. Conclusions and Relevance: In children younger than 2 years undergoing cardiopulmonary bypass surgery for congenital heart disease, the use of nitric oxide via cardiopulmonary bypass did not significantly affect the number of ventilator-free days. These findings do not support the use of nitric oxide delivered into the cardiopulmonary bypass oxygenator during heart surgery. Trial Registration: anzctr.org.au Identifier: ACTRN12617000821392.

Outcomes After Stage I Norwood Palliation in a Recently Established Program Can Achieve Results Similar to Longer Established Services.

BACKGROUND: Infants with hypoplastic left heart syndrome (HLHS) or similar single ventricle cardiac lesions require a three-stage surgical approach, the first step being the Stage I Norwood procedure. The Queensland Children's Hospital (QCH) in Australia is a tertiary hospital providing the only cardiac surgical service to children in Queensland and northern New South Wales. OBJECTIVE: To review the centre's outcomes of Norwood procedures performed in the last 6 years. MATERIALS AND METHODS: We retrospectively evaluated all infants undergoing the stage I Norwood procedure between January 2015 and August 2021. Mortality, intensive care length of stay, events of cardiac arrest following surgery and duration of mechanical ventilation were calculated and analysed for subgroups depending on type of pulmonary shunt type (right-ventricle-to-pulmonary-artery shunt [RVPAS] vs the modified Blalock-Taussig shunt [MBTS]). RESULTS: Forty-nine (49) patients were included. Overall survival to stage two operation (Glenn) was 90%. Both shunts were used evenly with the RVPA conduit preferred for HLHS and the MBTS largely chosen for hypoplastic left heart variants. In univariable analysis there was no difference in cardiac arrest or mortality rate for the patient with a RVPAS compared to the patient with a MBTS. CONCLUSION: We show that a recently established Norwood program can achieve results that are comparable to those reported by longer established centres, and the international literature.

Balloon dilatation versus surgical valvotomy for congenital aortic stenosis: a propensity score matched study.

BACKGROUND: Balloon valvuloplasty and surgical aortic valvotomy have been the treatment mainstays for congenital aortic stenosis in children. Choice of intervention often differs depending upon centre bias with limited relevant, comparative literature. OBJECTIVES: This study aims to provide an unbiased, contemporary matched comparison of these balloon and surgical approaches. METHODS: Retrospective analysis of patients with congenital aortic valve stenosis who underwent balloon valvuloplasty (Queensland Children's Hospital, Brisbane) or surgical valvotomy (Royal Children's Hospital, Melbourne) between 2005 and 2016. Patients were excluded if pre-intervention assessment indicated ineligibility to either group. Propensity score matching was performed based on age, weight, and valve morphology. RESULTS: Sixty-five balloon patients and seventy-seven surgical patients were included. Overall, the groups were well matched with 18 neonates/25 infants in the balloon group and 17 neonates/28 infants in the surgical group. Median age at balloon was 92 days (range 2 days - 18.8 years) compared to 167 days (range 0 days - 18.1 years) for surgery (rank-sum p = 0.08). Mean follow-up was 5.3 years. There was one late balloon death and two early surgical deaths due to left ventricular failure. There was no significant difference in freedom from reintervention at latest follow-up (69% in the balloon group and 70% in the surgical group, p = 1.0). CONCLUSIONS: Contemporary analysis of balloon aortic valvuloplasty and surgical aortic valvotomy shows no difference in overall reintervention rates in the medium term. Balloon valvuloplasty performs well across all age groups, achieving delay or avoidance of surgical intervention.

Prevalence and Cost of Managing Paediatric Cardiac Disease in Queensland.

BACKGROUND: There is a paucity of contemporary information regarding the prevalence and related health care expenditure of the most common cardiac conditions in Australian children, including congenital heart disease (CHD). METHODS: The 10 most common cardiac conditions managed by Queensland Paediatric Cardiac Service during 2014-2015 were identified from an electronic database: ventricular septal defect (VSD), pulmonary stenosis, aortic stenosis, tetralogy of Fallot, atrioventricular septal defect, transposition, Ebstein's anomaly, long QT syndrome, dilated cardiomyopathy, and rheumatic carditis. Demographic data, clinic attendance, investigational procedures, and therapeutic interventions were extracted from the electronic health records to derive indicative population estimates and direct health care expenditure relating to CHD. RESULTS: A total of 2,519 patients diagnosed with the 10 target conditions were being actively managed, including 456 (18.1%) new-born and 787 prevalent cases (2.5/1,000 population) aged <5 years. A total of 12,180 (4.8/case) investigations were performed (6,169 echocardiographic and 279 cardiac catheterisation procedures) costing $2.25 million/annum. A further 5,326 clinic visits (2.1/case, 22% regional) were conducted at a cost of $550,000/annum. A combined total of 804 catheter-based interventions and surgical procedures were performed in 300 cases (11.9%) at a cost of $13.6 million/annum. VSD (38.6% of cases) was the single greatest contributor ($5.1 million/annum) to total combined direct health care costs of $13.6 million/annum for the 2,519 patients. CONCLUSIONS: These pilot data indicate a significant patient population and health care burden imposed by CHD in Queensland. Future initiatives to better quantify this burden, from an individual to health system perspective, are urgently needed.

Queensland Paediatric Cardiac Service: Lessons from evolution to a unified service in a tertiary children's hospital.

We describe a complex change process for the paediatric cardiac service in Queensland that involved transitioning the service out of an essentially adult hospital into one of two children's hospitals in Brisbane. This initial step was complex as the governance was changed from Queensland Health to Mater Health, an independent faith-based organisation who became the new employer. Six years later, the service was again transitioned; this time to the newly constructed Queensland Children's Hospital, with a Hospital and Health Services Board as the employer under the aegis of Queensland Health. This was a complex journey. As with all change processes there was resistance to change on the part of some individuals. Five years on from the second major change, the service is settled, has an excellent workplace culture, has excellent clinical outcomes and has become research intensive.

Congenital Heart Disease Long-term Improvement in Functional hEalth (CHD LIFE): A partnership programme to improve the long-term functional health of children with congenital heart disease in Queensland.

Children who undergo open-heart surgery in the first year of life for congenital heart disease (CHD) are at high-risk for impaired development across multiple domains. International recommendations include systematic periodic developmental surveillance into adolescence and the establishment of long-term follow-up programmes. This article describes the establishment and evolution of the Queensland Paediatric Cardiac Service neurodevelopmental follow-up programme - CHD LIFE (Long-term Improvement in Functional hEalth). Contextualising best practice recommendations to ensure a family-centred and sustainable approach to understand and support the long-term functional health needs of high-risk children with CHD as standard care was needed. We describe the transition from a centralised pilot Programme to the implementation of an integrated statewide approach aimed at delivering consistent high-level standards of care and a platform to evaluate therapeutic interventions.

Balloon Aortic Valvuloplasty for Congenital Aortic Stenosis: A 14-Year Single Centre Review.

BACKGROUND: The approach to intervention for congenital aortic valve stenosis (AS) differs depending upon centre bias toward a primary catheter or surgical approach. We therefore investigated associations with freedom from re-intervention (FFI) in the cohort of children who underwent primary balloon aortic valvuloplasty (BAV) for congenital AS in our centre. METHODS: All patients who underwent BAV as a primary procedure in the period between 2001 and 2015 in a single service were included. Echocardiographic parameters before and after catheterisation and procedural data was collected on all patients. RESULTS: Sixty-four (64) patients underwent BAV as the primary intervention during the study period. Follow-up data was available for 60 of these. Balloon aortic valvuloplasty was performed at a median age of 143 days (range 2 days-18.8 years). Freedom from re-intervention was observed in 75% of patients with a median follow-up of 6.8 years and a mean follow-up of 3 years. Catheter-based peak-to-peak aortic valve gradients decreased from 58±15.9mmHg to 22.9±13.1mmHg. There was no short- or long-term mortality. FFI was predicted by aortic valve morphology (p<0.01), post-BAV mean echo gradient (p=0.03) and post-BAV regurgitation (p<0.01). No patient had re-intervention for restenosis with post-BAV mean echo gradient <30mmHg. Catheter gradients before and after BAV approached significance for predicting FFI (p=0.06 and p=0.09 respectively). Fifteen (15) patients were neonates with significantly lower aortic valve (AoV) Z-scores (mean 0.63 vs 1.76, p=0.002) and no difference in FFI (p=0.19). Annulus size, balloon/annulus ratio (within the range utilised) and pre-BAV echo findings were not predictive for re-intervention. CONCLUSIONS: Balloon aortic valvuloplasty is an effective primary approach to congenital valvular AS with the potential of avoiding surgical intervention in the majority of patients at all ages. Freedom from re-intervention in our cohort was associated with valve morphology and the degree of stenosis and regurgitation immediately post BAV.

Impact of Viral Respiratory Pathogens on Outcomes After Pediatric Cardiac Surgery.

OBJECTIVES: Viral respiratory infection is commonly considered a relative contraindication to elective cardiac surgery. We aimed to determine the frequency and outcomes of symptomatic viral respiratory infection in pediatric cardiac surgical patients. DESIGN: Retrospective cohort study of children undergoing cardiac surgery. Symptomatic children were tested using a multiplex Polymerase Chain Reaction (respiratory virus polymerase chain reaction) panel capturing nine respiratory viruses. Tests performed between 72 prior to and 48 hours after PICU admission were included. Mortality, length of stay in PICU, and intubation duration were investigated as outcomes. SETTING: Tertiary PICU providing state-wide pediatric cardiac services. PATIENTS: Children less than 18 years admitted January 1, 2008 to November 29, 2014 for cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Respiratory virus polymerase chain reaction was positive in 73 (4.2%) of 1,737 pediatric cardiac surgical admissions, including 13 children with multiple viruses detected. Commonly detected viruses included rhino/enterovirus (48%), adenovirus (32%), parainfluenza virus 3 (10%), and respiratory syncytial virus (3%). Pediatric Index of Mortality 2, Aristotle scores, and cardiopulmonary bypass times were similar between virus positive and negative/untested cohorts. Respiratory virus polymerase chain reaction positive patients had a median 2.0 days greater PICU length of stay (p < 0.001) and longer intubation duration (p < 0.001). Multivariate analysis adjusting for age, Aristotle score, cardiopulmonary bypass duration, and need for preoperative PICU admission confirmed that virus positive patients had significantly greater intubation duration and PICU length of stay (p < 0.001). Virus positive patients were more likely to require PICU admission greater than 4 days (odds ratio, 3.5; 95% CI, 1.9-6.2) and more likely to require intubation greater than 48 hours (odds ratio, 2.5; 95% CI, 1.4-4.7). There was no difference in mortality. No association was found between coinfection and outcomes. CONCLUSIONS: Pediatric cardiac surgical patients with a respiratory virus detected at PICU admission had prolonged postoperative recovery with increased length of stay and duration of intubation. Our results suggest that postponing cardiac surgery in children with symptomatic viral respiratory infection is appropriate, unless the benefits of early surgery outweigh the risk of prolonged ventilation and PICU stay.

Comparison of outcomes in Australian indigenous and non-indigenous children and adolescents undergoing cardiac surgery.

BACKGROUND: Population-based registries report 95% 5-year survival for children undergoing surgery for CHD. This study investigated paediatric cardiac surgical outcomes in the Australian indigenous population. METHODS: All children who underwent cardiac surgery between May, 2008 and August, 2014 were studied. Demographic information including socio-economic status, diagnoses and co-morbidities, and treatment and outcome data were collected at time of surgery and at last follow-up. RESULTS: A total of 1528 children with a mean age 3.4±4.6 years were studied. Among them, 123 (8.1%) children were identified as indigenous, and 52.7% (62) of indigenous patients were in the lowest third of the socio-economic index compared with 28.2% (456) of non-indigenous patients (p⩽0.001). The indigenous sample had a significantly higher Comprehensive Aristotle Complexity score (indigenous 9.4±4.2 versus non-indigenous 8.7±3.9, p=0.04). The probability of having long-term follow-up did not differ between groups (indigenous 93.8% versus non-indigenous 95.6%, p=0.17). No difference was noted in 30-day mortality (indigenous 3.2% versus non-indigenous 1.4%, p=0.13). The 6-year survival for the entire cohort was 95.9%. The Cox survival analysis demonstrated higher 6-year mortality in the indigenous group - indigenous 8.1% versus non-indigenous 5.0%; hazard ratio (HR)=2.1; 95% confidence intervals (CI): 1.1, 4.2; p=0.03. Freedom from surgical re-intervention was 79%, and was not significantly associated with the indigenous status (HR=1.4; 95% CI: 0.9, 1.9; p=0.11). When long-term survival was adjusted for the Comprehensive Aristotle Complexity score, no difference in outcomes between the populations was demonstrated (HR=1.6; 95% CI: 0.8, 3.2; p=0.19). CONCLUSION: The indigenous population experienced higher late mortality. This apparent relationship is explained by increased patient complexity, which may reflect negative social and environmental factors.

Upper partial sternal split for pediatric cardiac surgery.

OBJECTIVES: We introduced the use of an upper partial sternal split for pediatric cardiac surgical procedures in our unit in 2016. We report the outcomes of our experience in 51 patients using this approach. METHODS: From February 2016 to September 2022, 51 patients underwent congenital cardiac surgical procedures using an upper partial sternal split including vascular ring repair (n = 20), subaortic membrane (n = 12), ventricular septal defect closure with aortic valve resuspension (n = 9), aortic arch repair (n = 4), pulmonary artery band (n = 2), pulmonary artery sling (n = 1), supravalvular aortic stenosis (n = 1), aortic valve replacement (n = 1), and pulmonary artery plasty (n = 1). The surgical approach involved a midline skin incision, based on the manubrium, followed by an upper manubriotomy. No special surgical instrumentation was required. Median patient age was 2.9 years (IQR 1.3, 6.0); median body weight was 15 kg (IQR 9.8, 20). RESULTS: There was no mortality and no patient required intraoperative conversion to full sternotomy. One patient required re-exploration for bleeding when the incision was converted to a full sternotomy. There were no wound complications in any patient. Twenty-one patients (41%) were extubated on the table and of the remaining 30 patients, 23 patients (76%) were extubated within 24 h of surgery. Eleven patients did not require intensive care unit (ICU) admission. Median ICU and hospital stay was 1 day (IQR 1, 1.25) and 5 days (IQR 4, 8) ,respectively. CONCLUSION: An upper partial sternal split approach is straightforward and can be performed safely with a preferable cosmetic result in selected pediatric cardiac operations.

Early outcomes after post-cardiotomy extracorporeal membrane oxygenation in paediatric patients: a contemporary, binational cohort study.

OBJECTIVES: The aim of this study was to assess the early outcomes and risk factors of paediatric patients requiring extracorporeal membrane oxygenation after cardiac surgery (post-cardiotomy). METHODS: Retrospective binational cohort study from the Australia and New Zealand Congenital Outcomes Registry for Surgery database. All patients younger than 18 years of age who underwent a paediatric cardiac surgical procedure from 1 January 2013 to 31 December 2021 and required post-cardiotomy extracorporeal membrane oxygenation (PC-ECMO) in the same hospital admission were included in the study. RESULTS: Of the 12 290 patients included in the study, 376 patients required post-cardiotomy ECMO (3%). Amongst these patients, hospital mortality was 35.6% and two-thirds of patients experienced a major complication. Hypoplastic left heart syndrome was the most common diagnosis (17%). The Norwood procedure and modified Blalock-Taussig shunts had the highest incidence of requiring PC-ECMO (odds ratio of 10 and 6.8 respectively). Predictors of hospital mortality after PC-ECMO included single-ventricle physiology, intracranial haemorrhage and chylothorax. CONCLUSIONS: In the current era, one-third of patients who required PC-ECMO after paediatric cardiac surgery in Australia and New Zealand did not survive to hospital discharge. The Norwood procedure and isolated modified Blalock-Taussig shunt had the highest incidence of requiring PC-ECMO. Patients undergoing the Norwood procedure had the highest mortality (48%). Two-thirds of patients on PC-ECMO developed a major complication.

Performance of CardioCel in Cardiac Surgery: A Systematic Review.

A systematic review was performed for evaluation of the performance of CardioCel® in cardiac surgery. The review included all studies published from January 2013 to December 2020. We conclude that CardioCel is a strong, flexible tissue substitute with good handling characteristics and a low incidence of thrombosis, aneurysm formation, infection, or structural degeneration. It can be used for a variety of intracardiac and extracardiac repairs of congenital heart defects in all age groups with good durability at mid-term follow-up. However, the use of CardioCel in certain positions requires caution. Information on the long-term performance of CardioCel is lacking.

Impact of Aortic Atresia After Fontan Operation in Patients With Hypoplastic Left Heart Syndrome.

BACKGROUND: Patients with aortic atresia have the worst prognosis in the spectrum of hypoplastic left heart syndrome. It remains unknown whether patients with aortic atresia continue to do poorly after Fontan operation. This study aimed to determine the association between aortic atresia and atrioventricular valve (AVV) function and clinical outcomes after Fontan operation in patients with hypoplastic left heart syndrome. METHODS: We performed a retrospective study of 1731 patients who survived the Fontan operation from the Australia and New Zealand Fontan Registry between 1975 and 2020. RESULTS: We identified 188 patients with hypoplastic left heart syndrome, including 99 (53%) with aortic atresia. Overall transplant-free survival and freedom from failure of Fontan circulation at 15 years was 91% (95% CI, 86%-96%) and 79% (95% CI, 71%-88%), respectively. The cumulative incidence of AVV operation at 15 years of age for patients with aortic atresia and aortic stenosis was 28% (95% CI, 19%-38%) and 14% (95% CI, 7%-22%; P = .03), respectively. The cumulative incidence of AVV failure (moderate or greater regurgitation or AVV operation) at 15 years of age for patients with aortic atresia and aortic stenosis was 50% (95% CI, 37%-61%) and 30% (95% CI, 19%-42%; P = .01). Patients with AVV failure were at increased risk of having moderately, or worse, decreased systolic ventricular function (odds ratio 6.7; 95% CI, 1.7-33; P = .01) and failure of Fontan circulation (hazard ratio 3.7; 95% CI, 1.5-9.1; P < .01). CONCLUSIONS: In patients with hypoplastic left heart syndrome, there is no significant difference in transplant-free survival after Fontan operation between patients with aortic atresia and patients with aortic stenosis. However, patients with aortic atresia have a much higher burden of AVV failure than patients with aortic stenosis. Atrioventricular valve failure is associated with failure of Fontan circulation.

Atrioventricular septal defect in Fontan circulation: Right ventricular dominance, not valve surgery, adversely affects survival.

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.

A machine learning approach to predicting 30-day mortality following paediatric cardiac surgery: findings from the Australia New Zealand Congenital Outcomes Registry for Surgery (ANZCORS).

OBJECTIVES: We aim to develop the first risk prediction model for 30-day mortality for the Australian and New Zealand patient populations and examine whether machine learning (ML) algorithms outperform traditional statistical approaches. METHODS: Data from the Australia New Zealand Congenital Outcomes Registry for Surgery, which contains information on every paediatric cardiac surgical encounter in Australian and New Zealand for patients aged <18 years between January 2013 and December 2021, were analysed (n = 14 343). The outcome was mortality within the 30-day period following a surgical encounter, with ∼30% of the observations randomly selected to be used for validation of the final model. Three different ML methods were used, all of which employed five-fold cross-validation to prevent overfitting, with model performance judged primarily by the area under the receiver operating curve (AUC). RESULTS: Among the 14 343 30-day periods, there were 188 deaths (1.3%). In the validation data, the gradient-boosted tree obtained the best performance [AUC = 0.87, 95% confidence interval = (0.82, 0.92); calibration = 0.97, 95% confidence interval = (0.72, 1.27)], outperforming penalized logistic regression and artificial neural networks (AUC of 0.82 and 0.81, respectively). The strongest predictors of mortality in the gradient boosting trees were patient weight, STAT score, age and gender. CONCLUSIONS: Our risk prediction model outperformed logistic regression and achieved a level of discrimination comparable to the PRAiS2 and Society of Thoracic Surgery Congenital Heart Surgery Database mortality risk models (both which obtained AUC = 0.86). Non-linear ML methods can be used to construct accurate clinical risk prediction tools.