title: [Long-term studies following heart valve replacement].
abstract: Heart valve replacement has become a routine procedure in the treatment of patients suffering from valvular lesions. The results of long-term follow-up studies after valve replacement are still important and help to choose the optimal time for surgical intervention and the type of prosthesis. In order to ensure comparability of publications a consent must be found with regard to the demands these publications should fulfill concerning the selection and presentation of data. Generally, retrospective analyses are inappropriate to prove the influence of preoperative or perioperative parameters (e.g. the type of prosthesis) on the late outcome. They may be useful for raising hypotheses. Survival or event-free rates can only be determined reproducibly if adequate follow-up methods are used. By questionnaires at long time intervals important informations are often lost. The duration of the follow-up period depends on whether the event in question occurs with a constant incidence (e.g. bleeding complications due to anticoagulant therapy) or has an inconstant hazard-rate (e.g. primary failure of tissue valves). Increasing hazard-rates in the late postoperative course necessitate adequate follow-up periods. The number of patients followed up has to be determined prospectively so that differences between patient groups may be sufficiently proven after an adequate follow-up period.
mesh_terms: D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis; D006801:Humans; D011183:Postoperative Complications / Q000601:surgery*; D011475:Prosthesis Failure; D012086:Reoperation
vernacular_title: Langzeitbeobachtungen nach Herzklappenersatz.