title: Safety of Uninterrupted Warfarin Therapy in Patients Undergoing Cardiovascular Endovascular Procedures: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  To conduct a systematic review and meta-analysis of complication rates and outcomes in patients undergoing endovascular procedures who receive uninterrupted versus interrupted warfarin therapy.
  
  
  METHODS
  Literature published between 1990 and 2014 was searched for reports of comparative studies of vascular procedures. Information on periprocedural complications and patient deaths less than 30 days after the procedure was extracted. A random effects model was used and odds ratios (ORs) were reported. An OR of less than 1 was considered to indicate lower risk of the outcome with uninterrupted warfarin therapy. Meta-analysis was conducted by using meta-analysis software.
  
  
  RESULTS
  A total of 27 studies of 20,376 patients were included. For arterial procedures, there were no significant differences between the uninterrupted and interrupted warfarin therapy groups in access site hematoma (OR, 0.59; 95% confidence interval [CI]: 0.33, 1.03; P = .06), any bleeding complications (OR, 0.56; 95% CI: 0.30, 1.06; P = .07), mortality (OR, 1.40; 95% CI: 0.37, 5.25; P = .62), intracranial hemorrhage (OR, 0.55; 95% CI: 0.03, 8.91; P = .68), ischemic stroke (OR, 0.85; 95% CI: 0.12, 5.84; P = .87), and major bleeding (OR, 0.56; 95% CI: 0.21, 1.51; P = .25). For venous procedures, uninterrupted warfarin was associated with lower odds of access site hematoma (OR, 0.70; 95% CI: 0.50, 0.99; P = .04), any bleeding complications (OR, 0.61; 95% CI: 0.48, 0.77; P < .01), ischemic stroke (OR, 0.21; 95% CI: 0.10, 0.45; P < .01), and major bleeding (OR, 0.64; 95% CI: 0.51, 0.80; P < .01). For arterial and venous procedures combined, uninterrupted warfarin was associated with lower odds of access site hematoma (OR, 0.68; 95% CI: 0.51, 0.91; P = .01), bleeding complications (OR, 0.59; 95% CI: 0.48, 0.74; P < .01), ischemic stroke (OR, 0.25; 95% CI: 0.12, 0.50; P < .01), and major bleeding (OR, 0.61; 95% CI: 0.49, 0.77; P < .01). Heterogeneity in most analyses was low, and confidence in the estimates was moderate.
  
  
  CONCLUSIONS
  Uninterrupted perioperative warfarin therapy is safe for patients undergoing arterial procedures, but interrupted warfarin may be preferred for those undergoing venous procedures; no differences in outcome rates were found in the randomized controlled trials. Future studies should be performed to validate these results.
authors.affiliation: From the Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, Minn (V.S.); and Department of Radiology (W.B., D.F.K.), Center for Science of Healthcare Delivery (M.H.M.), and Department of Cardiology (S.J.A.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
authors.forename: Varun
authors.initials: V
authors.lastname: Shahi
authors.affiliation: From the Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, Minn (V.S.); and Department of Radiology (W.B., D.F.K.), Center for Science of Healthcare Delivery (M.H.M.), and Department of Cardiology (S.J.A.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
authors.forename: Waleed
authors.initials: W
authors.lastname: Brinjikji
authors.affiliation: From the Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, Minn (V.S.); and Department of Radiology (W.B., D.F.K.), Center for Science of Healthcare Delivery (M.H.M.), and Department of Cardiology (S.J.A.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Murad
authors.affiliation: From the Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, Minn (V.S.); and Department of Radiology (W.B., D.F.K.), Center for Science of Healthcare Delivery (M.H.M.), and Department of Cardiology (S.J.A.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
authors.affiliation: From the Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, Minn (V.S.); and Department of Radiology (W.B., D.F.K.), Center for Science of Healthcare Delivery (M.H.M.), and Department of Cardiology (S.J.A.), Mayo Clinic, 200 First St SW, Rochester, MN 55905.
authors.forename: David F
authors.initials: DF
authors.lastname: Kallmes
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D002318:Cardiovascular Diseases / Q000628:therapy*; D057510:Endovascular Procedures; D006801:Humans; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin