Adult Congenital Heart Disease in Australia and New Zealand: A Call for Optimal Care.

BACKGROUND: Adult congenital heart disease (ACHD) is a relatively new subspecialty in the cardiology field. The prevalence of ACHD is estimated at ∼ 3,000 per million adult population. The ACHD patient group is estimated to grow at ∼ 5% per year and in the next decade it is forecast that 1 in 150 young adults will carry some form of ACHD diagnosis. These estimates translate to ∼ 72,000 ACHD patients in Australia and ∼ 14,000 in New Zealand, although no current numbers are available. The Cardiac Society of Australia and New Zealand (CSANZ) has recently published Recommendations for Standards of Care for Adult Congenital Heart Disease (ACHD) in 2016. There is currently no long-term plan or proposal to address this huge health care burden within the federal government. This document details the size of the problem insofar as it is known and recommends solutions to be implemented. METHODS: This document was developed by the Adult Congenital Heart Disease Working Group of the Paediatric and Congenital Council (the Congenital Heart Alliance of Australia and New Zealand) as a response to the chronic under resourcing in this area, the risk this poses to patients and clinicians, and the clear need for long-term planning to develop safe care pathways. RESULTS: These issues were raised with the CSANZ Board in December 2015 and the document was developed in response to the Board's request for more information. The current iteration was finalised on 14 November 2017. CONCLUSIONS: The authorship group comprised participants in the CSANZ adult CHD standards of care recommendations from 2013 with the inclusion of some newly trained ACHD cardiologists, who represented most states and territories across ANZ. None of the authors has any academic or professional conflict of interest.

The Long-Term Management of Children and Adults with a Fontan Circulation: A Systematic Review and Survey of Current Practice in Australia and New Zealand.

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.

Optimising echocardiographic screening for rheumatic heart disease in New Zealand: not all valve disease is rheumatic.

AIMS: Echocardiography detects a greater prevalence of rheumatic heart disease than heart auscultation. Echocardiographic screening for rheumatic heart disease combined with secondary prophylaxis may potentially prevent severe rheumatic heart disease in high-risk populations. We aimed to determine the prevalence of rheumatic heart disease in children from an urban New Zealand population at high risk for acute rheumatic fever. METHODS AND RESULTS: To optimise accurate diagnosis of rheumatic heart disease, we utilised a two-step model. Portable echocardiography was conducted on 1142 predominantly Maori and Pacific children aged 10-13 years. Children with an abnormal screening echocardiogram underwent clinical assessment by a paediatric cardiologist together with hospital-based echocardiography. Rheumatic heart disease was then classified as definite, probable, or possible. Portable echocardiography identified changes suggestive of rheumatic heart disease in 95 (8.3%) of 1142 children, which reduced to 59 (5.2%) after cardiology assessment. The prevalence of definite and probable rheumatic heart disease was 26.0 of 1000, with 95% confidence intervals ranging from 12.6 to 39.4. Portable echocardiography overdiagnosed rheumatic heart disease with physiological valve regurgitation diagnosed in 28 children. A total of 30 children (2.6%) had non-rheumatic cardiac abnormalities, 11 of whom had minor congenital mitral valve anomalies. CONCLUSIONS: We found high rates of undetected rheumatic heart disease in this high-risk population. Rheumatic heart disease screening has resource implications with cardiology evaluation required for accurate diagnosis. Echocardiographic screening for rheumatic heart disease may overdiagnose rheumatic heart disease unless congenital mitral valve anomalies and physiological regurgitation are excluded.

Health professionals' views of newborn pulse oximetry screening in a midwifery-led maternity setting. "It's a good thing to do, but fund it!"

OBJECTIVE: To understand from health professionals who care for newborns their views on the introduction of pulse oximetry screening for the detection of hypoxaemia in a midwifery-led maternity setting. Although oximetry screening for newborns is internationally accepted, national screening is not yet introduced in New Zealand. In this context, we drew on maternity carers' reflections during a feasibility study of oximetry screening to provide perspectives on barriers and enablers to universal screening. METHODS: Data were generated from nine focus groups during five months of 2018 in two north island regions of New Zealand. Participants' (n = 45) opinions about the use of oximetry screening in newborns were analysed thematically using an inductive approach. FINDINGS: Overall, participants stated pulse oximetry screening was easy to do, non-invasive, and worthwhile. Midwives were reassured by screening that provided evidence of either a healthy baby or a need for urgent review. From participants' reports, we identified three themes: (1) oximetry screening for newborns is reassuring, practical and worthwhile; (2) midwifery services workload expectations and under-resourcing will hinder universal screening, and (3) location of the baby at the time of screening could impede universal access. CONCLUSION AND IMPLICATIONS FOR PRACTICE: Midwives viewed implementing a national pulse oximetry screening programme as sensible but problematic unless resourced and funded appropriately. Policymakers should view the concerns of midwives about human and physical resources as significant and account for the need to resource this screening programme appropriately as a priority before implementation.

RACHS - ANZ : A Modified Risk Adjustment in Congenital Heart Surgery Model for Outcome Surveillance in Australia and New Zealand.

Background Outcomes for pediatric cardiac surgery are commonly reported from international databases compiled from voluntary data submissions. Surgical outcomes for all children in a country or region are less commonly reported. We aimed to describe the bi-national population-based outcome for children undergoing cardiac surgery in Australia and New Zealand and determine whether the Risk Adjustment for Congenital Heart Surgery ( RACHS ) classification could be used to create a model that accurately predicts in-hospital mortality in this population. Methods and Results The study was conducted in all children's hospitals performing cardiac surgery in Australia and New Zealand between January 2007 and December 2015. The performance of the original RACHS -1 model was assessed and compared with an alternative RACHS - ANZ (Australia and New Zealand) model, developed balancing discrimination with parsimonious variable selection. A total of 14 324 hospital admissions were analyzed. The overall hospital mortality was 2.3%, ranging from 0.5% for RACHS category 1 procedures, to 17.0% for RACHS category 5 or 6 procedures. The original RACHS -1 model was poorly calibrated with death overpredicted (1161 deaths predicted, 289 deaths observed). The RACHS - ANZ model had better performance in this population with excellent discrimination (Az- ROC of 0.830) and acceptable Hosmer and Lemeshow goodness-of-fit ( P=0.216). Conclusions The original RACHS -1 model overpredicts mortality in children undergoing heart surgery in the current era. The RACHS - ANZ model requires only 3 risk variables in addition to the RACHS procedure category, can be applied to a wider range of patients than RACHS -1, and is suitable to use to monitor regional pediatric cardiac surgery outcomes.

Transcatheter closure of secundum atrial septal defects with the Amplatzer septal occluder in adults and children-follow-up closure rates, degree of mitral regurgitation and evolution of arrhythmias.

AIM: To report the results of transcatheter atrial septal defect (ASD) closure with the Amplatzer septal occluder (ASO) from the single centre providing interventions for congenital heart disease in New Zealand. METHODS: A single centre retrospective review of all patients 1997-2004 inclusive, undergoing planned transcatheter ASD closure was undertaken. Implantation success, complications and latest patient follow-up are described. RESULTS: Percutaneous ASD closure was planned in 227 adults and children. (55% had additional medical co-morbidities.) The mean ASD size was 22+/-6 mm, and device size ranged from 5 to 40 mm. Closure was successful in 93%, unsuccessful in 5% and not attempted in 2%. There were two device embolisations, one immediately post-release and one within 24h. Minor procedural complications occurred in 5% of patients. There were no cases of suspected or proven device erosion. Ninety-two percent had documented follow-up beyond 6 months. At latest follow-up the closure rate was 98.5%. There was no significant change in the degree of mitral regurgitation. Sixteen of 24 with pre-closure arrhythmias resolved while 10 remained in atrial fibrillation. Six patients developed new arrhythmias but these were well controlled medically. CONCLUSION: There is a high implantation and closure rate using transcatheter ASD closure with the Amplatzer septal occluder in children and adults avoiding the need for cardiac surgery. Follow-up at one year shows there is no progression of mitral regurgitation, and supraventricular arrhythmias have usually resolved.

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.

Ten-year outcomes of Fontan conversion in Australia and New Zealand demonstrate the superiority of a strategy of early conversion.

OBJECTIVE: To investigate the benefits of a strategy of early Fontan conversion. METHODS: Using the Australia and New Zealand Fontan Registry, retrospective analysis of their long-term follow-up data was performed. RESULTS: Between 1990 and 2014, a total of 39 patients underwent surgical conversion in 6 centres at a median age of 23.8 years (IQR: 19.3-28.2), 18.7 ± 5.0 years post-Fontan. One centre tended to perform conversion earlier: interval since first documented arrhythmia 2.9 ± 4.0 vs 4.0 ± 4.2 years, average NYHA Class 2 ± 0.4 vs 3 ± 0.9 (P = 0.008), mean number of preop anti-arrhythmics 1 ± 0.4 vs 2 ± 0.6 (P = 0.05). Two patients underwent conversion to an extracardiac conduit only, while 36 had concomitant right atrial cryoablation, of which 16 also had pacemaker implantation. Nine patients suffered major cardiac-related complications (7 low output syndrome, 3 ECMO, 3 acute renal failure, one stroke) (2/17 from the early conversion centre and 7/22 of the others; P = 0.14). Four patients died in hospital (10.3%) and 4 late after a median of 0.9 years [95% confidence interval (CI): 0.5-1] after conversion. An additional 2 patients needed transplantation at 1 and 8.8 years after conversion, respectively. The 10-year freedom from heart transplantation was 86% (95% CI: 51-97%). Outcomes from the centre with an early conversion strategy were significantly better: 8-year freedom from death or heart transplantation was 86% (95% CI: 53-96) vs 51% (95% CI: 22-74; log-rank P = 0.007). Eight additional patients required pacemaker implantation and 5 had arrhythmia recurrence. CONCLUSIONS: Fontan conversion is associated with lasting survival outcomes up to 10 years after conversion. A strategy of surgical conversion at earlier stage of failure may be associated with better survival free from transplantation.

Valvular Regurgitation Using Portable Echocardiography in a Healthy Student Population: Implications for Rheumatic Heart Disease Screening.

BACKGROUND: There is increasing use of portable echocardiography as a screening test for rheumatic heart disease (RHD). The prevalence of valvular regurgitation in healthy populations as determined using portable echocardiography has not been well defined. Minimal echocardiographic criteria for RHD have recently been clarified, but the overlap of normal and abnormal valvular regurgitation warrants further study. The aim of this study was to determine the spectrum of echocardiographic findings using portable echocardiography in children from a population with low prevalence of RHD. METHODS: Screening echocardiography was conducted in 396 healthy students aged 10 to 12 years using portable echocardiographic equipment. Echocardiograms were assessed according to 2012 World Heart Federation criteria for RHD. The prevalence of physiologic valvular regurgitation was compared with that found in previous studies of children using large-platform machines. RESULTS: Physiologic mitral regurgitation (MR) was present in 14.9% of subjects (95% CI, 11.7%-18.7%) and pathologic MR in 1.3% (95% CI, 0.6%-2.9%). Two percent (95% CI, 1.0%-3.9%) had physiologic aortic regurgitation, and none had pathologic aortic valve regurgitation. Physiologic tricuspid regurgitation was present in 72.7% of subjects (95% CI, 68.1%-76.9%) and physiologic pulmonary regurgitation in 89.6% (95% CI, 85.7%-91.8%). After cardiology review, no cases of definite RHD were found, but 0.5% of patients (95% CI, 0.1%-1.8%) had pathologic MR meeting World Heart Federation criteria for borderline RHD. Two percent (95% CI, 1.4%-4.6%) of the cohort had minor forms of congenital heart disease. CONCLUSIONS: The spectrum of physiologic cardiac valvular regurgitation in healthy children as determined using portable echocardiography is described and is within the range of previous studies using large-platform echocardiographic equipment. The finding of two children with pathologic-grade MR, likely representing the upper limit of physiologic regurgitation, has implications for echocardiographic screening for RHD in high-prevalence regions.

Heart transplantation in pediatric and congenital heart disease: a single-center experience.

PURPOSE: To describe the indications and outcomes for pediatric patients and patients with congenital heart disease (CHD) undergoing heart transplantation (HT) in New Zealand. METHODS: A retrospective audit of 253 patients who underwent HT from 1987 to end 2012 was undertaken. Thirty-seven patients were subdivided into two groups, those aged <18 years--pediatric heart disease (PHD) and those with CHD. Six patients aged <18 years were included in both the analyses. Demographic and clinical information were collected and outcomes established. RESULTS: Overall actuarial survival of 37 patients with PHD or CHD was 92% at one year, 85% at five years, and 52% at ten years. The PHD group comprised 22 (8.7%) patients, median age 14 years (range 6-17), 14 (64%) male, with cardiomyopathy in 13, CHD in 6, and rheumatic heart disease in 3. At follow-up, 11 patients had died. Actuarial survival was 91% at one year and 79% at five years. Of the four patients with a mechanical assist device to bridge, three were transplanted and alive at follow-up. The CHD group comprised 21 (8.3%) patients, median age 25 years (range 6-48) and 19 (90%) were male. At follow-up, three patients had died. Actuarial survival was 95% at one year, 94% at five years, and 85% at ten years. All five patients with pre-HT Fontan circulation were alive a median of eight years following HT. CONCLUSION: Heart transplantation for carefully selected pediatric patients and patients with CHD can be successfully performed with favorable outcomes in a geographically isolated unit.

Improved long-term survival for rheumatic mitral valve repair compared to replacement in the young.

BACKGROUND: Mitral valve (MV) repair offers potential advantages over replacement in patients with rheumatic heart disease (RHD). We present the first long-term study that compares MV repair with replacement in children with RHD. METHODS AND RESULTS: Single institute retrospective review of patients with RHD under 20 years of age, who underwent their first isolated MV surgery between 1990 and 2006. Of the 81 patients, 98% were Maori or Pacific Islander. The median age was 12.7 (3-19) years. The MV was repaired in 59%, a mechanical valve replacement (MVR) took place in 35% and bioprosthetic valve replacement in 6% of the patients. Follow-up data were available for 91.4% of the patients with mean follow-up of 7.6 years (range 0-19.4 years), a total of 620 patient years. Actuarial survival at 10 and 14 years for patients with MVR was 79% and 44%, compared to 90% and 90% for patients who underwent repair (P = .06). Actuarial freedom from late reoperation at 10 and 14 years for patients with MVR was 88% and 73%, compared to 76% and 76% for patients with repair (P = .52). Actuarial freedom from thrombotic, embolic, and hemorrhagic events at 10 and 14 years for patients with MVR was 63% and 45%, compared to 100% and 100% for patients with repair P < .01). CONCLUSION: This study shows that MV repair is superior to replacement for RHD in the young with follow-up to 19 years. Repair offers a survival advantage, greater freedom from valve-related morbidity, and long-term durability that equals that of MVR.

Congenital mitral valve lesions : Correlation between morphology and imaging.

Congenital malformations of the mitral valve are often complex and affect multiple segments of the valve apparatus. They may occur in isolation or in association with other congenital heart defects. The majority of mitral valve malformations are not simply classified, and descriptive terms with historical significance (parachute, mitral, or arcade) often lack the specificity that cardiac surgeons demand as part of preoperative echocardiographic morphological assessment. This paper examines the strengths and limitations of commonly used descriptions and classification systems of congenitally malformed mitral valves. It correlates pathological, surgical, and echocardiographic findings. Finally, it makes recommendations for the systematic evaluation of the congenitally malformed mitral valve using segmental echocardiographic analysis to assist precise communication and optimal surgical management.

Midterm results of repair of perimembranous or conal ventricular septal defects using the transaortic direct suture technique.

BACKGROUND: A midterm retrospective analysis of the transaortic primary suture repair of perimembranous or conal ventricular septal defects with aortic valve prolapse was conducted. METHODS: From January 1998 to January 2006, 56 patients underwent transaortic repair of perimembranous or conal ventricular septal defects using the direct suture technique. The mean age at operation was 7.7+/-5.0 years (37 males). Twenty-eight patients had none or trivial aortic regurgitation (AR), 19 had mild AR, and 9 had moderate or severe AR. The mean defect size was 7.0+/-2.6 mm at operation. RESULTS: There was no early mortality. In the immediate postoperative period, AR remained unchanged in 32 patients, improved in 17, and worsened in 9, including 2 patients who required early reoperation. Median follow-up was 3 years (range, 2 months to 8 years). There was 1 late death. Aortic regurgitation had deteriorated in 21 patients, 3 of whom required late reoperation, and improved in 5 compared with the preoperative state. Freedom from deterioration in AR was 97% at 2 years and 71% at 4 years. Deterioration in aortic valve function was independent of demographic and morphologic features. CONCLUSIONS: This surgical technique does not prevent progressive aortic valve dysfunction, which may be related to structural deficiency of the valve leaflet or distortion of the annulus by direct suture closure of the ventricular septal defect. Early closure may prevent structural leaflet damage, whereas adaptation of the transaortic technique to include a shallow ventricular septal defect patch may be beneficial in older patients.

The influence of measured versus assumed uptake of oxygen in assessing pulmonary vascular resistance in patients with a bidirectional Glenn anastomosis.

AIMS: To determine the accuracy of data relating to pulmonary vascular resistance data in patients with a bidirectional Glenn anastomosis as calculated using predicted versus measured uptake of oxygen. METHODS: We studied retrospectively the data from 33 patients with a bidirectional Glenn anastomosis who underwent cardiac catheterisation prior to surgery to complete the Fontan circulation. Their weight ranged from 5.4 to 51.7 kg, and they were aged up to 12 years. Uptake of oxygen was measured using the Deltatrac II metabolic monitor. From the calculated indexed pulmonary vascular resistance, cases were stratified according to the risk of failure of the subsequent Fontan circulation. The six patients with a resistance of greater than 4 Um2 were deemed at high risk, the six with a resistance from 3 to 4 Um2 at moderate risk, and the 21 patients with a resistance less than 3 Um2 at low risk. Uptake of oxygen was also estimated from the predictive formulas of Lindahl, Lundell et al. and LaFarge and Miettinen. The indexed resistance was similarly calculated using these formulas and a comparable stratification of risk made from this data. RESULTS: The predicted values for uptake of oxygen were consistently higher than those measured, leading to an underestimation of indexed resistance, with mean difference between -0.62 and -1.57 Um2. This difference resulted in misclassification of between five and nine of the 12 patients considered at moderate or high risk as being at low-risk. No other haemodynamic data could reliably separate the subjects deemed at low-risk from those considered to be at high-risk. A transpulmonary gradient of greater than 7 mm of mercury was found to be 100 percent specific for elevated indexed resistance, but only 60 percent sensitive. CONCLUSIONS: In patients with bidirectional Glenn anastomoses, all formulas based on predictive uptake of oxygen lead to underestimation of the true indexed pulmonary vascular resistance, to an extent that could significantly influence clinical decision-making. The transpulmonary gradient is not a reliable surrogate for indexed pulmonary vascular resistance.