Retrospective Cohort Study of Additional Procedures and Transplant-Free Survival for Patients With Functionally Single Ventricle Disease Undergoing Staged Palliation in England and Wales.

BACKGROUND: Reinterventions may influence the outcomes of children with functionally single-ventricle (f-SV) congenital heart disease. METHODS AND RESULTS: We undertook a retrospective cohort study of children starting treatment for f-SV between 2000 and 2018 in England, using the national procedure registry. Patients were categorized based on whether they survived free of transplant beyond 1 year of age. Among patients who had transplant-free survival beyond 1 year of age, we explored the relationship between reinterventions in infancy and the outcomes of survival and Fontan completion, adjusting for complexity. Of 3307 patients with f-SV, 909 (27.5%), had no follow-up beyond 1 year of age, among whom 323 (35.3%) had ≥1 reinterventions in infancy. A total of 2398 (72.5%) patients with f-SV had transplant-free survival beyond 1 year of age, among whom 756 (31.5%) had ≥1 reinterventions in infancy. The 5-year transplant-free survival and cumulative incidence of Fontan, among those who survived infancy, were 93.4% (95% CI, 92.4%-94.4%) and 79.3% (95% CI, 77.4%-81.2%), respectively. Both survival and Fontan completion were similar for those with a single reintervention and those who had no reinterventions. Patients who had >1 additional surgery (adjusted hazard ratio, 3.93 [95% CI, 1.87-8.27] P<0.001) had higher adjusted risk of mortality. Patients who had >1 additional interventional catheter (adjusted subdistribution hazard ratio, 0.71 [95% CI, 0.52-0.96] P=0.03) had a lower likelihood of achieving Fontan. CONCLUSIONS: Among children with f-SV, the occurrence of >1 reintervention in the first year of life, especially surgical reinterventions, was associated with poorer prognosis later in childhood.

Secundum atrial septal defect closure in adults in the UK.

AIMS: To examine determinants of access to treatment, outcomes and hospital utilization in patients undergoing secundum atrial septal defect (ASD) closure in adulthood in England and Wales. METHODS AND RESULTS: Large retrospective cohort study of all adult patients undergoing secundum ASD closures in England and Wales between 2000/01 and 2016/17. Data were from population-based official data sets covering congenital heart disease procedures, hospital episodes and death registries.Out of 6 541 index closures, 79.4% were transcatheter (median age 47 years, IQR 34-61) and 20.6% were surgical (40 years, 28-52). The study cohort was predominantly female (66%), with socio-ethnic profile similar to the general population.Mortality in hospital was 0.2% and at one year 1.0% (95%CI 0.8%-1.2%). Risk of death was lower for transcatheter repairs, adjusting for age, sex, year of procedure, comorbidities and cardiac risk factors (in-hospital adjusted-OR 0.09, 95%CI 0.02-0.46, one-year adjusted-HR 0.5, 0.3-0.9). There was excess mortality one year after ASD closure compared to matched population data.Median (IQR) peri-procedural length of stay was 1.8 (1.4-2.5) and 7.3 (6.2-9.2) days for transcatheter and surgical closures, respectively. Hospital resource use for cardiac reasons started the year before repair (median 2 inpatient and 2 outpatient-only days) and decreased post-repair (zero inpatient and one outpatient days during the first two years). CONCLUSION: This national study confirms that ASD closure in adults, by surgical or transcatheter methods, is provided independently of ethnic or socioeconomic differences, it is low (but not no) risk and appears to reduce future cardiac hospitalisation even in older ages.

Defining the Spectrum of Hypoplastic Left Heart Syndrome (HLHS).

The 2021 International Paediatric and Congenital Cardiac Code and the Eleventh Revision of the International Classification of Diseases provide the following definition for hypoplastic left heart syndrome (HLHS): "Hypoplastic left heart syndrome (HLHS) is defined as a spectrum of congenital cardiovascular malformations with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral valve, or both valves, and hypoplasia of the ascending aorta and aortic arch." Although HLHS with intact ventricular septum (HLHS + IVS) and HLHS with ventricular septal defect (HLHS + VSD) are different cardiac phenotypes, both of these lesions are part of the spectrum of HLHS.

Differences in Quality of Life in Children Across the Spectrum of Congenital Heart Disease.

OBJECTIVE: To create complexity groups based upon a patient's cardiac medical history and to test for group differences in health-related quality of life (HRQOL). METHODS: Patients 8-18 years with congenital heart disease (CHD) and parent-proxies from the Pediatric Cardiac Quality of Life Inventory (PCQLI) Testing Study were included. Outcome variables included PCQLI Total, Disease Impact, and Psychosocial Impact scores. Using a patient's medical history (cardiac, neurologic, psychological, and cognitive diagnosis), latent class analysis (LCA) was used to create CHD complexity groups. Covariates included demographics and burden of illness (number of: school weeks missed, physician visits in the past year, and daily medications). Generalized estimation equations tested for differences in burden of illness and patient and parent-proxy PCQLI scores. RESULTS: Using 1482 CHD patients (60% male; 84% white; age 12.3 ± 3.0 years), latent class analysis (LCA) estimates showed 4 distinct CHD complexity groups (Mild, Moderate 1, Moderate 2, and Severe). Increasing CHD complexity was associated with increased risk of learning disorders, seizures, mental health problems, and history of stroke. Greater CHD complexity was associated with greater burden of illness (P < .01) and lower patient- and parent-reported PCQLI scores (P < .001). CONCLUSIONS: LCA identified 4 congenital heart disease (CHD) complexity groupings. Increasing CHD complexity was associated with higher burden of illness and worse patient- and parent-reported HRQOL.

Hospital resource utilization in a national cohort of functionally single ventricle patients undergoing surgical treatment.

Objective: The study objective was to provide a detailed overview of health resource use from birth to 18 years old for patients with functionally single ventricles and identify associated risk factors. Methods: All patients with functionally single ventricles treated between 2000 and 2017 in England and Wales were linked to hospital and outpatient records using data from the Linking AUdit and National datasets in Congenital HEart Services project. Hospital stay was described in yearly age intervals, and associated risk factors were explored using quantile regression. Results: A total of 3037 patients with functionally single ventricles were included, 1409 (46.3%) undergoing a Fontan procedure. During the first year of life, the median days spent in hospital was 60 (interquartile range, 37-102), mostly inpatient days, mirroring a mortality of 22.8%. This decreases to between 2 and 9 in-hospital days/year afterward. Between 2 and 18 years, most hospital days were outpatient, with a median of 1 to 5 days/year. Lower age at the first procedure, hypoplastic left heart syndrome/mitral atresia, unbalanced atrioventricular septal defect, preterm birth, congenital/acquired comorbidities, additional cardiac risk factors, and severity of illness markers were associated with fewer days at home and more intensive care unit days in the first year of life. Only markers of early severe illness were associated with fewer days at home in the first 6 months after the Fontan procedure. Conclusions: Hospital resource use in functionally single ventricle cases is not uniform, decreasing 10-fold during adolescence compared with the first year of life. There are subsets of patients with worse outcomes during their first year of life or with persistently high hospital use throughout their childhood, which could be the target of future research.

Expert Consensus Statement: Anatomy, Imaging, and Nomenclature of Congenital Aortic Root Malformations.

Over the past 2 decades, several categorizations have been proposed for the abnormalities of the aortic root. These schemes have mostly been devoid of input from specialists of congenital cardiac disease. The aim of this review is to provide a classification, from the perspective of these specialists, based on an understanding of normal and abnormal morphogenesis and anatomy, with emphasis placed on the features of clinical and surgical relevance. We contend that the description of the congenitally malformed aortic root is simplified when approached in a fashion that recognizes the normal root to be made up of 3 leaflets, supported by their own sinuses, with the sinuses themselves separated by the interleaflet triangles. The malformed root, usually found in the setting of 3 sinuses, can also be found with 2 sinuses, and very rarely with 4 sinuses. This permits description of trisinuate, bisinuate, and quadrisinuate variants, respectively. This feature then provides the basis for classification of the anatomical and functional number of leaflets present. By offering standardized terms and definitions, we submit that our classification will be suitable for those working in all cardiac specialties, whether pediatric or adult. It is of equal value in the settings of acquired or congenital cardiac disease. Our recommendations will serve to amend and/or add to the existing International Paediatric and Congenital Cardiac Code, along with the Eleventh iteration of the International Classification of Diseases provided by the World Health Organization.

Expert Consensus Statement: Anatomy, Imaging, and Nomenclature of Congenital Aortic Root Malformations.

Over the past 2 decades, several categorizations have been proposed for the abnormalities of the aortic root. These schemes have mostly been devoid of input from specialists of congenital cardiac disease. The aim of this review is to provide a classification, from the perspective of these specialists, based on an understanding of normal and abnormal morphogenesis and anatomy, with emphasis placed on the features of clinical and surgical relevance. We contend that the description of the congenitally malformed aortic root is simplified when approached in a fashion that recognizes the normal root to be made up of 3 leaflets, supported by their own sinuses, with the sinuses themselves separated by the interleaflet triangles. The malformed root, usually found in the setting of 3 sinuses, can also be found with 2 sinuses, and very rarely with 4 sinuses. This permits description of trisinuate, bisinuate, and quadrisinuate variants, respectively. This feature then provides the basis for classification of the anatomical and functional number of leaflets present. By offering standardized terms and definitions, we submit that our classification will be suitable for those working in all cardiac specialties, whether pediatric or adult. It is of equal value in the settings of acquired or congenital cardiac disease. Our recommendations will serve to amend and/or add to the existing International Paediatric and Congenital Cardiac Code, along with the Eleventh iteration of the International Classification of Diseases provided by the World Health Organization.

Behavioral and Emotional Outcomes in Children with Congenital Heart Disease: Effects of Disease Severity, Family Life Stress, Disease-Related Chronic Stress, and Psychosocial Adaptation.

OBJECTIVE: To evaluate whether effects of congenital heart disease (CHD) severity and family life stress on behavioral and emotional functioning are mediated by disease-related chronic stress and psychosocial adaptation. STUDY DESIGN: A cross-sectional analysis of the Pediatric Cardiac Quality of Life Inventory Testing Study was performed. Relationships between CHD severity (comprising 3 groups: mild heart disease, moderate biventricular disease, and single ventricle) and family life stress, on patient- and parent disease-related chronic stress, psychosocial adaptation, and behavioral-emotional outcomes were assessed using structural equation modeling. Patient and parent models were reported separately. RESULTS: There were 981 patient-parent dyads: 22% had mild heart disease, 63% biventricular, and 15% single ventricle; 19% of families reported moderate to major family life stress. Path models revealed that CHD severity and family life stress were mediated by disease-related chronic stress and psychosocial adaptation factors (R2 = 0.18-0.24 for patient outcomes and R2 = 0.33-0.34 for parent outcomes, P < .001, respectively). CONCLUSIONS: The effects of greater CHD severity and family life stress on behavioral-emotional outcomes were mediated by worse disease-related chronic stress and psychosocial adaptation factors. Both disease-related chronic stress and psychosocial adaptation factors may be targets for interventions to improve behavioral and emotional outcomes.

Long-Term Quality of Life in Congenital Heart Disease Surgical Survivors: Multicenter Retrospective Study of Surgical and ICU Explanatory Factors.

OBJECTIVES: Greater congenital heart disease (CHD) complexity is associated with lower health-related quality of life (HRQOL). There are no data on the association between surgical and ICU factors and HRQOL in CHD survivors. This study assess the association between surgical and ICU factors and HRQOL in child and adolescent CHD survivors. DESIGN: This was a corollary study of the Pediatric Cardiac Quality of Life Inventory (PCQLI) Testing Study. SETTING: Eight pediatric hospitals participating in the PCQLI Study. PATIENTS: Patients in the study had the Fontan procedure, surgery for tetralogy of Fallot (TOF), and transposition of the great arteries (TGAs). MEASUREMENTS AND MAIN RESULTS: Surgical/ICU explanatory variables were collected by reviewing the medical records. Primary outcome variables (PCQLI Total patient and parent scores) and covariates were obtained from the Data Registry. General linear modeling was used to create the multivariable models. There were 572 patients included: mean ± sd of age 11.7 ± 2.9 years; CHD Fontan 45%, TOF/TGA 55%; number of cardiac surgeries 2 (1-9); and number of ICU admissions 3 (1-9). In multivariable models, lowest body temperature on cardiopulmonary bypass (CPB) was negatively associated with patient total score (p < 0.05). The total number of CPB runs was negatively associated with parent-reported PCQLI Total score (p < 0.02). Cumulative days on an inotropic/vasoactive drug in the ICU was negatively associated with all patient-/parent-reported PCQLI scores (p < 0.04). Neurological deficit at discharge was negatively associated with parent-reported PCQLI total score (p < 0.02). The variance explained by these factors ranged from 24% to 29%. CONCLUSIONS: Surgical/ICU factors, demographic, and medical care utilization variables explain a low-to-moderate amount of variation in HRQOL. Research is needed to determine whether modification of these surgical and ICU factors improves HRQOL, and to identify other factors that contribute to unexplained variability.

Long-term survival and center volume for functionally single-ventricle congenital heart disease in England and Wales.

OBJECTIVES: Long-term survival is an important metric for health care evaluation, especially in functionally single-ventricle (f-SV) congenital heart disease (CHD). This study's aim was to evaluate the relationship between center volume and long-term survival in f-SV CHD within the centralized health care service of England and Wales. METHODS: This was a retrospective cohort study of children born with f-SV CHD between 2000 and 2018, using the national CHD procedure registry, with survival ascertained in 2020. RESULTS: Of 56,039 patients, 3293 (5.9%) had f-SV CHD. Median age at first intervention was 7 days (interquartile range [IQR], 4, 27), and median follow-up time was 7.6 years (IQR, 1.0, 13.3). The largest diagnostic subcategories were hypoplastic left heart syndrome, 1276 (38.8%); tricuspid atresia, 440 (13.4%); and double-inlet left ventricle, 322 (9.8%). The survival rate at 1 year and 5 years was 76.8% (95% confidence interval [CI], 75.3%-78.2%) and 72.1% (95% CI, 70.6%-73.7%), respectively. The unadjusted hazard ratio for each 5 additional patients with f-SV starting treatment per center per year was 1.04 (95% CI, 1.02-1.06), P < .001. However, after adjustment for significant risk factors (diagnostic subcategory; antenatal diagnosis; younger age, low weight, acquired comorbidity, increased severity of illness at first procedure), the hazard ratio for f-SV center volume was 1.01 (95% CI, 0.99-1.04) P = .28. There was strong evidence that patients with more complex f-SV (hypoplastic left heart syndrome, Norwood pathway) were treated at centers with greater f-SV case volume (P < .001). CONCLUSIONS: After adjustment for case mix, there was no evidence that f-SV center volume was linked to longer-term survival in the centralized health service provided by the 10 children's cardiac centers in England and Wales.

Arterial Switch for Transposition of the Great Arteries: Treatment Timing, Late Outcomes, and Risk Factors.

Background: Reports of long-term mortality and reintervention after transposition of the great arteries with intact ventricular septum treatment, although favorable, are mostly limited to single-center studies. Even less is known about hospital resource utilization (days at hospital) and the impact of treatment choices and timing on outcomes. Objectives: The purpose of this study was to describe survival, reintervention and hospital resource utilization after arterial switch operation (ASO) in a national dataset. Methods: Follow-up and life status data for all patients undergoing ASO between 2000 and 2017 in England and Wales were collected and explored using multivariable regressions and matching. Results: A total of 1,772 patients were identified, with median ASO age of 9.5 days (IQR: 6.5-14.5 days). Mortality and cardiac reintervention at 10 years after ASO were 3.2% (95% CI: 2.5%-4.2%) and 10.7% (95% CI: 9.1%-12.2%), respectively. The median time spent in hospital during the ASO spell was 19 days (IQR: 14, 24). Over the first year after the ASO patients spent 7 days (IQR: 4-10 days) in hospital in total, decreasing to 1 outpatient day/year beyond the fifth year. In a subgroup with complete risk factor data (n = 652), ASO age, and balloon atrial septostomy (BAS) use were not associated with late mortality and reintervention, but cardiac or congenital comorbidities, low weight, and circulatory/renal support at ASO were. After matching for patient characteristics, BAS followed by ASO and ASO as first procedure, performed within the first 3 weeks of life, had comparable early and late outcomes, including hospital resource utilization. Conclusions: Mortality and hospital resource utilization are low, while reintervention remains relatively frequent. Early ASO and individualized use of BAS allows for flexibility in treatment choices and a focus on at-risk patients.

Transfer of congenital heart patients from paediatric to adult services in England.

OBJECTIVE: This study assessed the transfer of patients from paediatric cardiac to adult congenital heart disease (ACHD) services in England and the factors impacting on this process. METHODS: This retrospective cohort study used a population-based linked data set (LAUNCHES QI data set: 'Linking Audit and National datasets in Congenital Heart Services for Quality Improvement') including all patients born between 1987 and 2000, recorded as having a congenital heart disease (CHD) procedure in childhood. Hospital Episode Statistics data identified transfer from paediatric to ACHD services between the ages of 16 and 22 years. RESULTS: Overall, 63.8% of a cohort of 10 298 patients transferred by their 22nd birthday. The estimated probability of transfer by age 22 was 96.5% (95% CI 95.3 to 97.7), 86.7% (95% CI 85.6 to 87.9) and 41.0% (95% CI 39.4 to 42.6) for severe, moderate and mild CHD, respectively. 166 patients (1.6%) died between 16 and 22 years; 42 of these (0.4%) died after age 16 but prior to transfer. Multivariable ORs in the moderate and severe CHD groups up to age 20 showed significantly lower likelihood of transfer among female patients (0.87, 95% CI 0.78 to 0.97), those with missing ethnicity data (0.31, 95% CI 0.18 to 0.52), those from deprived areas (0.84, 95% CI 0.72 to 0.98) and those with moderate (compared with severe) CHD (0.30, 95% CI 0.26 to 0.35). The odds of transfer were lower for the horizontal compared with the vertical care model (0.44, 95% CI 0.27 to 0.72). Patients who did not transfer had a lower probability of a further National Congenital Heart Disease Audit procedure between ages 20 and 30 compared with those who did transfer: 12.3% (95% CI 5.1 to 19.6) vs 32.5% (95% CI 28.7 to 36.3). CONCLUSIONS: Majority of patients with moderate or severe CHD in England transfer to adult services. Patients who do not transfer undergo fewer elective CHD procedures over the following decade.

Linkage of National Congenital Heart Disease Audit data to hospital, critical care and mortality national data sets to enable research focused on quality improvement.

OBJECTIVES: To link five national data sets (three registries, two administrative) and create longitudinal healthcare trajectories for patients with congenital heart disease (CHD), describing the quality and the summary statistics of the linked data set. DESIGN: Bespoke linkage of record-level patient identifiers across five national data sets. Generation of spells of care defined as periods of time-overlapping events across the data sets. SETTING: National Congenital Heart Disease Audit (NCHDA) procedures in public (National Health Service; NHS) hospitals in England and Wales, paediatric and adult intensive care data sets (Paediatric Intensive Care Audit Network; PICANet and the Case Mix Programme from the Intensive Care National Audit & Research Centre; ICNARC-CMP), administrative hospital episodes (hospital episode statistics; HES inpatient, outpatient, accident and emergency; A&E) and mortality registry data. PARTICIPANTS: Patients with any CHD procedure recorded in NCHDA between April 2000 and March 2017 from public hospitals. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary: number of linked records, number of unique patients and number of generated spells of care. Secondary: quality and completeness of linkage. RESULTS: There were 143 862 records in NCHDA relating to 96 041 unique patients. We identified 65 797 linked PICANet patient admissions, 4664 linked ICNARC-CMP admissions and over 6 million linked HES episodes of care (1.1M inpatient, 4.7M outpatient). The linked data set had 4 908 153 spells of care after quality checks, with a median (IQR) of 3.4 (1.8-6.3) spells per patient-year. Where linkage was feasible (in terms of year and centre), 95.6% surgical procedure records were linked to a corresponding HES record, 93.9% paediatric (cardiac) surgery procedure records to a corresponding PICANet admission and 76.8% adult surgery procedure records to a corresponding ICNARC-CMP record. CONCLUSIONS: We successfully linked four national data sets to the core data set of all CHD procedures performed between 2000 and 2017. This will enable a much richer analysis of longitudinal patient journeys and outcomes. We hope that our detailed description of the linkage process will be useful to others looking to link national data sets to address important research priorities.

Divided left atrium with totally anomalous drainage of normally connected pulmonary veins.

In the December 2021 issue of Cardiology in the Young, Hubrechts and colleagues, from Brussels and Leuven in Belgium, describe their experience in which the pulmonary veins were normally connected to the morphologically left atrium. By virtue of the presence of a shelf dividing the morphologically left atrium, however, the venous return was to the morphologically right atrium, with no evidence of formation of the superior interatrial fold, meaning that there was no obstruction of flow into the systemic venous circulation. The question posed by the Belgian authors is whether the shelf dividing the morphologically left atrium is a deviated primary atrial septum, as the arrangement has previously been interpreted. As they discuss, it is currently impossible to arbitrate this conundrum. In our commentary, we discuss the background to the dilemma. We point out that, as yet, it is not possible to code accurately this congenital cardiac malformation within The International Paediatric and Congenital Cardiac Code (IPCCC), nor within the newly produced 11th Revision of the International Classification of Diseases (ICD-11).

Cohort study of intervened functionally univentricular heart in England and Wales (2000-2018).

OBJECTIVE: Given the paucity of long-term outcome data for complex congenital heart disease (CHD), we aimed to describe the treatment pathways and survival for patients who started interventions for functionally univentricular heart (FUH) conditions, excluding hypoplastic left heart syndrome. METHODS: We performed a retrospective cohort study using all procedure records from the National Congenital Heart Diseases Audit for children born in 2000-2018. The primary outcome was mortality, ascertained from the Office for National Statistics in 2020. RESULTS: Of 53 615 patients, 1557 had FUH: 55.9% were boys and 67.4% were of White ethnic groups. The largest diagnostic categories were tricuspid atresia (28.9%), double inlet left ventricle (21.0%) and unbalanced atrioventricular septal defect (AVSD) (15.2%). The ages at staged surgery were: initial palliation 11.5 (IQR 5.5-43.5) days, cavopulmonary shunt 9.2 (IQR 6.0-17.1) months and Fontan 56.2 (IQR 45.5-70.3) months. The median follow-up time was 10.8 (IQR 7.0-14.9) years and the 1, 5 and 10-year survival rates after initial palliation were 83.6% (95% CI 81.7% to 85.4%), 79.4% (95% CI 77.3% to 81.4%) and 77.2% (95% CI 75.0% to 79.2%), respectively. Higher hazards were present for unbalanced AVSD HR 2.75 (95% CI 1.82 to 4.17), atrial isomerism HR 1.75 (95% CI 1.14 to 2.70) and low weight HR 1.65 (95% CI 1.13 to 2.41), critical illness HR 2.30 (95% CI 1.67 to 3.18) or acquired comorbidities HR 2.71 (95% CI 1.82 to 4.04) at initial palliation. CONCLUSION: Although treatment pathways for FUH are complex and variable, nearly 8 out of 10 children survived to 10 years. Longer-term analyses of outcome based on diagnosis (rather than procedure) can inform parents, patients and clinicians, driving practice improvements for complex CHD.

The road to hell is paved with good intentions: the experience of applying for national data for linkage and suggestions for improvement.

BACKGROUND: We can improve healthcare services by better understanding current provision. One way to understand this is by linking data sets from clinical and national audits, national registries and other National Health Service (NHS) encounter data. However, getting to the point of having linked national data sets is challenging. OBJECTIVE: We describe our experience of the data application and linkage process for our study 'LAUNCHES QI', and the time, processes and resource requirements involved. To help others planning similar projects, we highlight challenges encountered and advice for applications in the current system as well as suggestions for system improvements. FINDINGS: The study set up for LAUNCHES QI began in March 2018, and the process through to data acquisition took 2.5 years. Several challenges were encountered, including the amount of information required (often duplicate information in different formats across applications), lack of clarity on processes, resource constraints that limit an audit's capacity to fulfil requests and the unexpected amount of time required from the study team. It is incredibly difficult to estimate the resources needed ahead of time, and yet necessary to do so as early on as funding applications. Early decisions can have a significant impact during latter stages and be hard to change, yet it is difficult to get specific information at the beginning of the process. CONCLUSIONS: The current system is incredibly complex, arduous and slow, stifling innovation and delaying scientific progress. NHS data can inform and improve health services and we believe there is an ethical responsibility to use it to do so. Streamlining the number of applications required for accessing data for health services research and providing clarity to data controllers could facilitate the maintenance of stringent governance, while accelerating scientific studies and progress, leading to swifter application of findings and improvements in healthcare.

Nomenclature for Pediatric and Congenital Cardiac Care: Unification of Clinical and Administrative Nomenclature - The 2021 International Paediatric and Congenital Cardiac Code (IPCCC) and the Eleventh Revision of the International Classification of Diseases (ICD-11).

Substantial progress has been made in the standardization of nomenclature for paediatric and congenital cardiac care. In 1936, Maude Abbott published her Atlas of Congenital Cardiac Disease, which was the first formal attempt to classify congenital heart disease. The International Paediatric and Congenital Cardiac Code (IPCCC) is now utilized worldwide and has most recently become the paediatric and congenital cardiac component of the Eleventh Revision of the International Classification of Diseases (ICD-11). The most recent publication of the IPCCC was in 2017. This manuscript provides an updated 2021 version of the IPCCC.The International Society for Nomenclature of Paediatric and Congenital Heart Disease (ISNPCHD), in collaboration with the World Health Organization (WHO), developed the paediatric and congenital cardiac nomenclature that is now within the eleventh version of the International Classification of Diseases (ICD-11). This unification of IPCCC and ICD-11 is the IPCCC ICD-11 Nomenclature and is the first time that the clinical nomenclature for paediatric and congenital cardiac care and the administrative nomenclature for paediatric and congenital cardiac care are harmonized. The resultant congenital cardiac component of ICD-11 was increased from 29 congenital cardiac codes in ICD-9 and 73 congenital cardiac codes in ICD-10 to 318 codes submitted by ISNPCHD through 2018 for incorporation into ICD-11. After these 318 terms were incorporated into ICD-11 in 2018, the WHO ICD-11 team added an additional 49 terms, some of which are acceptable legacy terms from ICD-10, while others provide greater granularity than the ISNPCHD thought was originally acceptable. Thus, the total number of paediatric and congenital cardiac terms in ICD-11 is 367. In this manuscript, we describe and review the terminology, hierarchy, and definitions of the IPCCC ICD-11 Nomenclature. This article, therefore, presents a global system of nomenclature for paediatric and congenital cardiac care that unifies clinical and administrative nomenclature.The members of ISNPCHD realize that the nomenclature published in this manuscript will continue to evolve. The version of the IPCCC that was published in 2017 has evolved and changed, and it is now replaced by this 2021 version. In the future, ISNPCHD will again publish updated versions of IPCCC, as IPCCC continues to evolve.