title: Repeated thromboembolic and bleeding events after mechanical aortic valve replacement.
abstract: BACKGROUND
  The choice of a valve substitute in young adults requires a decision balancing the risks of long-term anticoagulation versus reoperation(s). This article analyzes the long-term risk and determinants of thromboembolic (TE) and bleeding (BLE) complications after mechanical aortic valve replacement (AVR).
  
  
  METHODS
  From December 1963 to January 1974, 249 patients survived a mechanical AVR at our institution. Mean age was 41.8+/-12.4 years and 81% (n = 202) were male. Ball valves were implanted in 24% (n = 61) and disc valves in 76% (n = 188). Patients were anticoagulated with vitamin K antagonists and dipyridamole. A total of 4,855 patient-years was available for analysis. Mean follow-up was 19.5+/-9.4 years and was 100% complete. Analyses were performed with Kaplan-Meier and multivariable Cox regression methods.
  
  
  RESULTS
  One hundred and two patients had one TE or BLE postoperative event and 58 patients had two postoperative events. Six patients had more than five postoperative events. Freedom from a first postoperative event was 74.8%+/-2.9%, 55.3%+/-3.5%, and 46.8%+/-4.0% at 10, 20, and 30 years, respectively. Freedom from a second postoperative event was 45.4%+/-5.4%, 29%+/-6.0%, and 23.2%+/-7.1% at 10, 20, and 30 years, respectively. Multivariate predictors for TE or BLE complications were ball valve (Odds Ratio (OR) = 2.9), postoperative endocarditis (OR = 2.2), and any surgery (OR = 2.2). The incidence of events was highest the first 5 postoperative years.
  
  
  CONCLUSIONS
  The risk of adverse events is highest the first 5 postoperative years. Once an event has occurred, the risk for a second event is increased. The incidence and frequency of events is substantial and should be considered in the choice of a valve substitute.
authors: Department of Cardiovascular Surgery, St Antonius Ziekenhuis, Nieuwegein, The Netherlands. casself@hotmail.com
authors: F P
authors: FP
authors: Casselman
authors: M L
authors: ML
authors: Bots
authors: W
authors: W
authors: Van Lommel
authors: P J
authors: PJ
authors: Knaepen
authors: R
authors: R
authors: Lensen
authors: F E
authors: FE
authors: Vermeulen
mesh_terms: D000328:Adult; D000368:Aged; D001022:Aortic Valve Insufficiency / Q000601:surgery*; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000379:methods; D006470:Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013923:Thromboembolism / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors