title: Biological versus mechanical prosthesis in 3279 patients from the Swedish in-patients register.
abstract: OBJECTIVE
  To compare valve-related morbidity among patients aged < 70 and ≥ 70 years, receiving either a mechanical or a biological prosthesis in a population-based setting.
  
  
  METHODS
  In total, 3279 patients (21 644 patient-years) were followed up through the Swedish National In-Patients Register, which registers all hospital admissions. Death, thromboembolism, bleeding, endocarditis, valve thrombosis and reoperations were all captured.
  
  
  RESULTS
  Survival was lower among patients aged <70 years with a bioprosthesis compared to a mechanical prosthesis (p < 0.0001), but equal among older patients. A mechanical prosthesis indicated a lower risk (p < 0.001) of thromboembolism (1.5% per patient year, ppy), than bioprosthesis (2.6% ppy), irrespective of age. Bleeding was increased (p = 0.002) with a mechanical prosthesis (1.7% ppy) compared to a bioprosthesis (1.1% ppy); the risk of bleeding increased early (<5 years) whereas thromboembolism increased late (>5 years). Event-free survival was higher in younger patients with a mechanical prosthesis compared to bioprosthesis recipients (p < 0.001), but equal among older patients.
  
  
  CONCLUSIONS
  Survival was comparable in older patients irrespective of prosthesis type. Bleeding was increased with a mechanical prosthesis, especially in the elderly. The risk of thromboembolism was higher in patients with a bioprosthesis.
authors.affiliation: Department of Cardiothoracic Surgery, University Hospital, Uppsala, Sweden. laila.hellgren.johansson@akademiska.se
authors.forename: Laila
authors.initials: L
authors.lastname: Hellgren
authors.forename: Fredrik
authors.initials: F
authors.lastname: Granath
authors.forename: Anders
authors.initials: A
authors.lastname: Ekbom
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ståhle
mesh_terms: D000367:Age Factors; D000368:Aged; D001705:Bioprosthesis / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006470:Hemorrhage / Q000209:etiology / Q000401:mortality*; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D012042:Registries; D015996:Survival Rate; D013548:Sweden; D013923:Thromboembolism / Q000209:etiology / Q000401:mortality*