title: Anticoagulation versus antiplatelet or no therapy in patients undergoing bioprosthetic valve implantation: a systematic review and meta-analysis.
abstract: Use of vitamin K antagonist (VKA) versus antiplatelet (AP)/no therapy following bioprosthetic valve implantation remains controversial. The aims of the current study were to (a) systematically review the published literature comparing the use of VKA versus AP/no treatment in such patients and (b) perform a meta-analysis of the risks and benefits of using a VKA compared with AP/no therapy.
  
  
  
  Five databases were searched including PubMed, Medline, Embase, Ovid and Cochrane for randomised clinical trials and observational studies comparing VKA (group I) versus AP/no therapy (group II). Outcome was after surgical intervention. Mantel-Haenszel odds ratio (OR) was calculated using random-effects meta-analysis for the outcome. Heterogeneity was assessed by I2statistics. A total of 14 studies were included (two randomised trials, 12 observational studies and one conference abstract, 31 740 patients).
  
  
  
  Between groups I (VKA) and II (AP/no therapy), there were no differences in thromboembolic events (145 (1%) vs 262 (1.5%), OR 0.96 (95% CI 0.60 to 1.52)), all-cause mortality (351 (3.5%) vs 415 (2.9%), OR 1.48 (95% CI 0.87 to 2.50)) or need for redo surgery (47 (3.3%) vs 55 (3.2%); OR 0.81 (95% CI 0.42 to 1.58)). However, there were more bleeding events in group I versus group II (292 (2.6%) vs 189 (1.1%); OR 2.26 (95% CI 1.67 to 3.05)).
  
  
  
  In a meta-analysis of randomised and observational studies of VKA versus AP/no treatment in patients undergoing bioprosthetic valve implantation, there was no benefit of adding a VKA regarding thromboembolism or mortality. However, use of a VKA was associated with increased risk of major bleeding.
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Masri
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: A Marc
authors.initials: AM
authors.lastname: Gillinov
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Johnston
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Sabik
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Lars G
authors.initials: LG
authors.lastname: Svensson
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: L Leonardo
authors.initials: LL
authors.lastname: Rodriguez
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Samir R
authors.initials: SR
authors.lastname: Kapadia
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Stewart
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Grimm
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Griffin
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Heart and Vascular Institute, Cleveland, Ohio, USA.
authors.forename: Milind Y
authors.initials: MY
authors.lastname: Desai
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001705:Bioprosthesis; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000379:methods; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D011182:Postoperative Care / Q000379:methods; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control; D014812:Vitamin K / Q000037:antagonists & inhibitors
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014812:Vitamin K