title: Comparison of mechanical and biological prostheses when used to replace heart valves in children and adolescents with rheumatic fever.
abstract: OBJECTIVE
  To assess the outcomes in children and adolescents with rheumatic fever of the implantation of mechanical as opposed to biological heart valves.
  
  
  METHODS
  We assessed 73 patients with rheumatic heart disease under the age of 18 years, who underwent replacement of heart valves between January, 1996, and December, 2005, at the National Institute of Cardiology in Rio de Janeiro, Brazil. Of the group, 71 patients survived, and were divided into a group of 52 receiving mechanical prostheses, and 19 with biological prostheses. We compared endpoints between the groups in terms of mortality, reoperation, haemorrhage, and stroke. Survival curves were estimated using the Kaplan-Meier method and were compared by the Mantel (log-rank) test.
  
  
  RESULTS
  Overall mortality was 8.2%. In those receiving mechanical prostheses, 2 (3.8%) patients died, 5 (9.6%) underwent reoperation, 2 (3.8%) suffered severe haemorrhage, and 3 (5.8%) had strokes. In those receiving biological valves, 2 (10.5%) patients died, and 4 (21%) underwent reoperation. After 2, 4, and 8 years, overall survival was 96%, 93% and 86%, respectively, with a borderline difference between the groups (p = 0.06). The probabilities of remaining free from reoperation (p = 0.13), and from combined endpoints, showed no statistically significant difference between the groups (p = 0.28).
  
  
  CONCLUSIONS
  Patients with mechanical prostheses had lower mortality and required fewer reoperations, but when all combined endpoints were considered, the groups did not differ. The biological prosthesis proved to be a good option for cardiac surgery in children and adolescents with difficulties or risks of anticoagulation.
authors.affiliation: Serviço de Cardiologia da Criança e do Adolescente do Instituto Nacional de Cardiologia, Rio de Janeiro, RJ, Brazil. paulotravancas@gmail.com
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Travancas
authors.forename: Ana H
authors.initials: AH
authors.lastname: Dorigo
authors.forename: Luiz C
authors.initials: LC
authors.lastname: Simões
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Fonseca
authors.forename: Kátia V
authors.initials: KV
authors.lastname: Bloch
authors.forename: Gesmar V
authors.initials: GV
authors.lastname: Herdy
mesh_terms: D000293:Adolescent; D001705:Bioprosthesis; D001938:Brazil / Q000453:epidemiology; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000209:etiology / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D012189:Retrospective Studies; D012213:Rheumatic Fever / Q000150:complications / Q000401:mortality / Q000601:surgery*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome