Rodney C. G. Franklin

An internationally approved and globally used classification scheme for the diagnosis of CHD has long been sought. The International Paediatric and Congenital Cardiac Code (IPCCC), which was produced and has been maintained by the International Society for Nomenclature of Paediatric and Congenital Heart Disease (the International Nomenclature Society), is used widely, but has spawned many “short list” versions that differ in content depending on the user. Thus, efforts to have a uniform identification of patients with CHD using a single up-to-date and coordinated nomenclature system continue to be thwarted, even if a common nomenclature has been used as a basis for composing various “short lists”. In an attempt to solve this problem, the International Nomenclature Society has linked its efforts with those of the World Health Organization to obtain a globally accepted nomenclature tree for CHD within the 11th iteration of the International Classification of Diseases (ICD-11). The International Nomenclature Society has submitted a hierarchical nomenclature tree for CHD to the World Health Organization that is expected to serve increasingly as the “short list” for all communities interested in coding for congenital cardiology. This article reviews the history of the International Classification of Diseases and of the IPCCC, and outlines the process used in developing the ICD-11 congenital cardiac disease diagnostic list and the definitions for each term on the list. An overview of the content of the congenital heart anomaly section of the Foundation Component of ICD-11, published herein in its entirety, is also included. Future plans for the International Nomenclature Society include linking again with the World Health Organization to tackle procedural nomenclature as it relates to cardiac malformations. By doing so, the Society will continue its role in standardising nomenclature for CHD across the globe, thereby promoting research and better outcomes for fetuses, children, and adults with congenital heart anomalies.

There has been a progressive evolution in systems of classification for cardiomyopathy, driven by advances in imaging modalities, disease recognition, and genetics, following initial clinical descriptions in the 1960s. A pathophysiological classification emerged and was endorsed by World Health Organisation Task Forces in 1980 and 1995: dilated, hypertrophic, restrictive, and arrhythmogenic right ventricular cardiomyopathies; subdivided into idiopathic and disease-specific cardiomyopathies. Genetic advances have increasingly linked “idiopathic” phenotypes to specific mutations, although most linkages exhibit highly variable or little genotype–phenotype correlation, confounded by age-dependent changes and varying penetrance. The following two dominant classification systems are currently in use, with advocates in both continents. First, American Heart Association (2006): “A heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that usually exhibit inappropriate ventricular hypertrophy or dilatation due to a variety of causes that frequently are genetic”. These are subdivided to those predominantly involving the heart – primary – due to genetic mutation, including ion channelopathies, acquired disease, or mixed; and those with systemic involvement in other organ systems – secondary. Second, European Society of Cardiology (2008): “A myocardial disorder in which heart muscle is structurally and functionally abnormal… sufficient to cause the observed myocardial abnormality”, with subdivision to familial and non-familial, excluding ion channelopathies, and split to specific disease subtypes and idiopathic. Further differences exist in the definitions for hypertrophic cardiomyopathy; however, whichever high-level classification is used, the clinical reality remains phenotype driven. Clinical evaluation and diagnostic imaging dominate initial patient contact, revealing diagnostic red flags that determine further specific tests. Genetic testing is undertaken early. A recent attempt to harmonise these competing systems named the MOGE(S) system, based on descriptive logical nosology, currently remains unproven as a fully practical solution.

Mortality has traditionally been perceived as a straightforward measure of outcome and has been used to evaluate surgical performance. In the rapidly developing arena of paediatric cardiac surgery, the insightful analysis of mortality figures is challenging. This report discusses the issues involved when mortality is used as a marker for surgical outcome, referring to national and international audit and research data. Mortality is an important variable and should be transparently defined, reported and monitored. Definitions of mortality, assessments of risk and interpretations of reported statistics all have limitations that must be recognized. Traditional use of raw early mortality as a simplistic indicator of outcome and performance is evolving to include risk-adjusted mortality, longer-term survival, reinterventions and complications. As the vast majority of children undergoing cardiac surgery now survive beyond 30 days, the focus for measures of quality is shifting towards morbidity.

Clinicians working in the field of congenital and paediatric cardiology have long felt the need for a common diagnostic and therapeutic nomenclature and coding system with which to classify patients of all ages with congenital and acquired cardiac disease. A cohesive and comprehensive system of nomenclature, suitable for setting a global standard for multicentric analysis of outcomes and stratification of risk, has only recently emerged, namely, The International Paediatric and Congenital Cardiac Code. This review, will give an historical perspective on the development of systems of nomenclature in general, and specifically with respect to the diagnosis and treatment of patients with paediatric and congenital cardiac disease. Finally, current and future efforts to merge such systems into the paperless environment of the electronic health or patient record on a global scale are briefly explored.On October 6, 2000, The International Nomenclature Committee for Pediatric and Congenital Heart Disease was established. In January, 2005, the International Nomenclature Committee was constituted in Canada as The International Society for Nomenclature of Paediatric and Congenital Heart Disease. This International Society now has three working groups. The Nomenclature Working Group developed The International Paediatric and Congenital Cardiac Code and will continue to maintain, expand, update, and preserve this International Code. It will also provide ready access to the International Code for the global paediatric and congenital cardiology and cardiac surgery communities, related disciplines, the healthcare industry, and governmental agencies, both electronically and in published form. The Definitions Working Group will write definitions for the terms in the International Paediatric and Congenital Cardiac Code, building on the previously published definitions from the Nomenclature Working Group. The Archiving Working Group, also known as The Congenital Heart Archiving Research Team, will link images and videos to the International Paediatric and Congenital Cardiac Code. The images and videos will be acquired from cardiac morphologic specimens and imaging modalities such as echocardiography, angiography, computerized axial tomography and magnetic resonance imaging, as well as intraoperative images and videos.Efforts are ongoing to expand the usage of The International Paediatric and Congenital Cardiac Code to other areas of global healthcare. Collaborative efforts are underway involving the leadership of The International Nomenclature Committee for Pediatric and Congenital Heart Disease and the representatives of the steering group responsible for the creation of the 11th revision of the International Classification of Diseases, administered by the World Health Organisation. Similar collaborative efforts are underway involving the leadership of The International Nomenclature Committee for Pediatric and Congenital Heart Disease and the International Health Terminology Standards Development Organisation, who are the owners of the Systematized Nomenclature of Medicine or “SNOMED”.The International Paediatric and Congenital Cardiac Code was created by specialists in the field to name and classify paediatric and congenital cardiac disease and its treatment. It is a comprehensive code that can be freely downloaded from the internet (http://www.IPCCC.net) and is already in use worldwide, particularly for international comparisons of outcomes. The goal of this effort is to create strategies for stratification of risk and to improve healthcare for the individual patient. The collaboration with the World Heath Organization, the International Health Terminology Standards Development Organisation, and the healthcare industry, will lead to further enhancement of the International Code, and to its more universal use.