title: Safety of uninterrupted anticoagulation in patients requiring elective coronary angiography with or without percutaneous coronary intervention: a systematic review and metaanalysis.
abstract: BACKGROUND
  Patients who are receiving vitamin K antagonist (VKA) therapy pose challenges when they require surgery or invasive procedures because the risk for bleeding during the procedure must be balanced against the risk of an atherothrombotic event if the VKA is interrupted. However, it may be possible to safely perform some procedures, such as coronary angiography with or without percutaneous coronary intervention (PCI), without VKA interruption.
  
  
  METHODS
  We undertook a systematic review and metaanalysis to assess the safety of a periprocedural management strategy of uninterrupted VKA (U-VKA) vs interrupted VKA (I-VKA) with or without bridging with low-molecular-weight heparin in patients undergoing elective coronary angiography with or without PCI.
  
  
  RESULTS
  Eight studies were included in the review. Most were of moderate to very low quality. A strategy of U-VKA appears to confer approximately one-half the risk (odds ratio, 0.43; 95% CI, 0.26-0.73) of experiencing an access site bleeding complication within 1 week of the procedure compared with a strategy of I-VKA. The U-VKA strategy was associated with a pooled access site bleeding complication rate of 4.0% (95% CI, 3.0-7.0), and although high heterogeneity precluded pooling of such a rate in the I-VKA group, these rates ranged from 2% to 14%.
  
  
  CONCLUSIONS
  Although it appears that coronary angiography with or without PCI can be safely performed without interrupting VKA, the low methodologic quality of existing studies precludes any definitive conclusions. Randomized trials assessing different anticoagulation strategies are needed to establish evidence-based practice guidelines in this setting.
authors.affiliation: Department of Medicine, McMaster University and St Joseph's Healthcare, Hamilton, ON, Canada.
authors.forename: Erin
authors.initials: E
authors.lastname: Jamula
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Lloyd
authors.forename: Jon-David
authors.initials: JD
authors.lastname: Schwalm
authors.forename: K E Juhani
authors.initials: KE
authors.lastname: Airaksinen
authors.forename: James D
authors.initials: JD
authors.lastname: Douketis
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000008:administration & dosage*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000628:therapy*; D004334:Drug Administration Schedule; D006801:Humans; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology* / Q000517:prevention & control*; D013923:Thromboembolism / Q000209:etiology* / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants