title: Antithrombotic strategy after bioprosthetic aortic valve replacement in patients in sinus rhythm: evaluation of guideline implementation.
abstract: OBJECTIVE
  After elective aortic valve replacement, patients are at risk of developing valve thrombosis and systemic arterial thromboembolism. Current guidelines recommend antithrombotic therapy with aspirin or vitamin K antagonists (VKAs) during the first 3 months after the procedure, but have level 2 or 3 evidence. As a consequence, the most appropriate antithrombotic therapy is still a matter of debate. This retrospective study analysed all thromboembolic and bleeding complications in patients with either antiplatelet or anticoagulation therapy 1 year after bioprosthetic aortic valve replacement.
  
  
  METHODS
  A total of 402 patients undergoing bioprosthetic aortic valve implantation at the VU University Medical Centre and subsequently treated at three regional hospitals were included. The individual duration of either VKAs (acenocoumarol) or aspirin was determined and related to thrombotic and bleeding events. Patients were followed and censored at 1 year postoperatively for survival, cerebral ischaemia, myocardial infarction, peripheral arterial embolism, and minor and major haemorrhages.
  
  
  RESULTS
  A total of 24 thromboembolic complications and 31 bleeding episodes occurred. Multivariable analyses revealed that acenocoumarol caused more bleeding episodes (risk ratio [RR]: 8.41, 95% CI: 3.58-19.79) and a similar amount of thromboembolic events (RR: 1.2, 95% CI: 0.47-3.02) compared with aspirin. Prior use of acenocoumarol was found to be a risk factor for thromboembolic events (RR: 3.1, 95% CI: 1.31-7.19). Gender, dyslipidaemia, prior percutaneous coronary intervention, prior use of acenocoumarol and concomitant coronary artery bypass grafting were found to be predictors for bleeding events.
  
  
  CONCLUSIONS
  In patients 1 year following bioprosthetic aortic valve replacement, acenocoumarol therapy was associated with a significant increased risk of bleeding events and no reduction in thromboembolic events compared with antiplatelet therapy. These findings support the recommendations of aspirin over VKAs as postoperative thromboprophylaxis.
authors.affiliation: Department of Thrombosis and Hemostasis, Leiden University Medical Centre Leiden, Leiden, Netherlands s.j.van_der_wall@lumc.nl.
authors.forename: Sake Johannes
authors.initials: SJ
authors.lastname: van der Wall
authors.affiliation: Department of Cardiology, Medical Centre Alkmaar, Alkmaar, Netherlands.
authors.forename: Victor A W M
authors.initials: VA
authors.lastname: Umans
authors.affiliation: Department of Cardiology, Zaandam Medical Centre, Zaandam, Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Schotten
authors.affiliation: Department of Cardiology, Kennemer Gasthuis Hospital, Haarlem, Netherlands.
authors.forename: Mitran
authors.initials: M
authors.lastname: Keijzers
authors.affiliation: Department of Medical Statistics and Bio-informatics, Leiden University Medical Centre, Leiden, Netherlands.
authors.forename: Ron
authors.initials: R
authors.lastname: Wolterbeek
authors.affiliation: Department of Cardiothoracic Surgery, VU University Medical Centre, Amsterdam, Netherlands.
authors.forename: Evert K
authors.initials: EK
authors.lastname: Jansen
authors.affiliation: Department of Thrombosis and Hemostasis, Leiden University Medical Centre Leiden, Leiden, Netherlands.
authors.forename: Menno V
authors.initials: MV
authors.lastname: Huisman
authors.affiliation: Department of Cardiothoracic Surgery, VU University Medical Centre, Amsterdam, Netherlands.
authors.forename: Alexander B A
authors.initials: AB
authors.lastname: Vonk
mesh_terms: D000074:Acenocoumarol / Q000009:adverse effects / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use; D001705:Bioprosthesis; D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006470:Hemorrhage / Q000453:epidemiology / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011183:Postoperative Complications / Q000188:drug therapy / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D013923:Thromboembolism / Q000188:drug therapy / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control
chemical_list: D005343:Fibrinolytic Agents; D000074:Acenocoumarol; D001241:Aspirin
keywords: Anticoagulation; Antithrombotic therapy; Aortic valve; Heart valve bioprosthesis