title: Early postoperative bridging anticoagulation after mechanical heart valve replacement: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To perform a systematic review and meta-analysis of studies evaluating anticoagulation during the early postoperative period following mechanical heart valve implantation.
  
  
  METHODS
  Five literature databases were searched to assess the rates of bleeding and thromboembolic events among patients receiving oral anticoagulation (OAC), both with and without bridging anticoagulation therapy with unfractionated heparin (UFH) or subcutaneous low molecular weight heparin (LMWH). The studies' results were pooled via a mixed effects meta-analysis. Heterogeneity (I(2) ) and publication bias were both evaluated.
  
  
  RESULTS
  Twenty-three studies including 9534 patients were included. The bleeding rates were 1.8% (95% confidence interval CI 1.0-3.3) in the group receiving OAC, 2.2% (95% CI 0.9-5.3) in the OAC + UFH group, and 5.5% (95% CI 2.9-10.4) in the OAC + LMWH group (P = 0.042). The thromboembolic event rate was 2.1% (95% CI 1.5-2.9) in the group receiving OAC, as compared with 1.1% (95% CI 0.7-1.8) when the bridging therapy groups were combined as follows: OAC + UFH and OAC + LMWH (P = 0.035). Most of the analyses showed moderate heterogeneity and negative test results for publication bias.
  
  
  CONCLUSIONS
  Bridging therapy following cardiac valve surgery was associated with a lower thromboembolic event rate, although the difference was small, with considerable overlap of the CIs. Direct comparisons are missing. Bridging therapy with UFH appears to be safe; however, this observation has a risk of bias. Early bridging therapy with LMWH appears to be associated with consistently high bleeding rates across multiple analyses. On the basis of the quality of the included studies, more trials are necessary to establish the clinical relevance of bridging therapy and the safety of LMWH.
authors.affiliation: School of Medicine, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.|Postgraduate Program in Adult Health Sciences, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: L G
authors.initials: LG
authors.lastname: Passaglia
authors.affiliation: School of Medicine, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.
authors.forename: G M
authors.initials: GM
authors.lastname: de Barros
authors.affiliation: School of Medicine, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.|Postgraduate Program in Adult Health Sciences, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: M R
authors.initials: MR
authors.lastname: de Sousa
mesh_terms: D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016022:Case-Control Studies; D015331:Cohort Studies; D004867:Equipment Design; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D017052:Hospital Mortality; D006801:Humans; D011183:Postoperative Complications / Q000188:drug therapy* / Q000517:prevention & control; D011184:Postoperative Period; D017594:Publication Bias; D013923:Thromboembolism / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D019851:Thrombophilia / Q000188:drug therapy* / Q000209:etiology; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D014859:Warfarin; D006493:Heparin
keywords: anticoagulants; cardiac surgical procedures; heart valve diseases; heart valve prosthesis implantation; meta-analysis