title: Antithrombotic therapy after bioprosthetic aortic valve implantation: Warfarin versus aspirin, a randomized controlled trial.
abstract: BACKGROUND
  The optimal medical strategy for prevention of thromboembolic events after surgical bioprosthetic aortic valve replacement (BAVR) is still debated. The objective of this study was to compare warfarin therapy (target INR of 2.0 to 3.0) with aspirin 150mg daily as antithrombotic therapy for the first three months after BAVR with or without concomitant coronary artery bypass grafting (CABG). The aim was to evaluate thromboembolic complications, major bleeding complications and death.
  
  
  METHODS
  Prospective, single-centre, open-label, randomized controlled trial. 370 patients were enrolled, 328 were available for data analysis.
  
  
  RESULTS
  At baseline the warfarin and aspirin groups were comparable. Thromboembolic events were comparable between groups 11 (6.6%) vs. 12 (7.5%), p=0.83. Major bleeding events occurred numerically more often in warfarin patients 9 (5.4%) vs. 3 (1.9%), p=0.14. Warfarin was in multivariate analysis significantly associated with major bleeding OR 5.18 (CI 1.06-25.43), p=0.043. 90-day mortality was comparable between groups 8 (4.7%) vs. 6 (3.7%), p=0.79.
  
  
  CONCLUSIONS
  Our results suggest that aspirin might be equally effective as warfarin in preventing thromboembolic events after BAVR, but with less major bleedings. Although this is numerically the largest trial testing this hypothesis in a prospective randomized trial, further adequately powered studies are warranted.
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: sulman_raf@hotmail.com.
authors.forename: Sulman
authors.initials: S
authors.lastname: Rafiq
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: dastpr@gmail.com.
authors.forename: Daniel Andreas
authors.initials: DA
authors.lastname: Steinbrüchel
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: thomas.nikolaj.lilleoer@regionh.dk.
authors.forename: Nikolaj Bang
authors.initials: NB
authors.lastname: Lilleør
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: christian.moeller.02@regionh.dk.
authors.forename: Christian Holdflod
authors.initials: CH
authors.lastname: Møller
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: jlund@dadlnet.dk.
authors.forename: Jens Teglgaard
authors.initials: JT
authors.lastname: Lund
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: jens.juel.thiis@regionh.dk.
authors.forename: Jens Juel
authors.initials: JJ
authors.lastname: Thiis
authors.affiliation: Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: lars.koeber.01@regionh.dk.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: Department of Cardiothoracic Surgery, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: peter.skov.olsen@regionh.dk.
authors.forename: Peter Skov
authors.initials: PS
authors.lastname: Olsen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001021:Aortic Valve / Q000601:surgery; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use*; D001705:Bioprosthesis / Q000009:adverse effects; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D011446:Prospective Studies; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control*; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D001241:Aspirin
keywords: Anticoagulation; Aspirin; Bioprosthetic valve; Heart valve prosthesis; Thrombosis