title: Population-based evaluation of a suggested anatomic and clinical classification of congenital heart defects based on the International Paediatric and Congenital Cardiac Code.
abstract: BACKGROUND
  Classification of the overall spectrum of congenital heart defects (CHD) has always been challenging, in part because of the diversity of the cardiac phenotypes, but also because of the oft-complex associations. The purpose of our study was to establish a comprehensive and easy-to-use classification of CHD for clinical and epidemiological studies based on the long list of the International Paediatric and Congenital Cardiac Code (IPCCC).
  
  
  METHODS
  We coded each individual malformation using six-digit codes from the long list of IPCCC. We then regrouped all lesions into 10 categories and 23 subcategories according to a multi-dimensional approach encompassing anatomic, diagnostic and therapeutic criteria. This anatomic and clinical classification of congenital heart disease (ACC-CHD) was then applied to data acquired from a population-based cohort of patients with CHD in France, made up of 2867 cases (82% live births, 1.8% stillbirths and 16.2% pregnancy terminations).
  
  
  RESULTS
  The majority of cases (79.5%) could be identified with a single IPCCC code. The category "Heterotaxy, including isomerism and mirror-imagery" was the only one that typically required more than one code for identification of cases. The two largest categories were "ventricular septal defects" (52%) and "anomalies of the outflow tracts and arterial valves" (20% of cases).
  
  
  CONCLUSIONS
  Our proposed classification is not new, but rather a regrouping of the known spectrum of CHD into a manageable number of categories based on anatomic and clinical criteria. The classification is designed to use the code numbers of the long list of IPCCC but can accommodate ICD-10 codes. Its exhaustiveness, simplicity, and anatomic basis make it useful for clinical and epidemiologic studies, including those aimed at assessment of risk factors and outcomes.
authors.affiliation: Hôpital Marie-Lannelongue, CMR-M3C, Université Paris-Sud, 133 avenue de la Résistance, 92350 Le Plessis-Robinson, France. l.houyel@ccml.fr
authors.forename: Lucile
authors.initials: L
authors.lastname: Houyel
authors.forename: Babak
authors.initials: B
authors.lastname: Khoshnood
authors.forename: Robert H
authors.initials: RH
authors.lastname: Anderson
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lelong
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Thieulin
authors.forename: François
authors.initials: F
authors.lastname: Goffinet
authors.forename: Damien
authors.initials: D
authors.lastname: Bonnet
mesh_terms: D000328:Adult; D002675:Child, Preschool; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005602:France / Q000453:epidemiology; D006330:Heart Defects, Congenital / Q000145:classification* / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D038801:International Classification of Diseases; D038622:Internationality; D008297:Male; D010372:Pediatrics; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology; D012042:Registries; D012955:Societies, Medical; D009626:Terminology as Topic