title: Effect of standardized perioperative dabigatran interruption on the residual anticoagulation effect at the time of surgery or procedure.
abstract: ESSENTIALS: Anticoagulants need to be stopped preprocedure so there is little or no remaining anticoagulant effect. We assessed the residual anticoagulant effect with standardized interruption for patients on dabigatran. With this protocol, 80-86% of patients had no residual anticoagulant effect at the time of a procedure. A standardized perioperative dabigatran protocol appears to be safe, but requires further study.
  
  
  BACKGROUND
  In patients taking dabigatran who require treatment interruption for a surgery/procedure, a sufficient interruption interval is needed so that there is little or no residual anticoagulant effect at the time of the surgery/procedure.
  
  
  METHODS
  A prospective cohort study of patients receiving dabigatran (110 mg or 150 mg twice daily) who required an elective surgery/procedure and received a standardized dabigatran interruption protocol based on surgery/procedure bleeding risk and renal function was performed. Before the surgery/procedure, a blood sample was taken for measurement of the prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and dilute thrombin time (dTT). We determined the proportion of all patients and those having a high bleeding risk surgery/procedure with normal coagulation test results at the time of the surgery/procedure. The APTT and dTT were considered to be most likely to reflect a dabigatran anticoagulant effect. Patients were followed up for 30 days postprocedure to assess for bleeding and thromboembolism.
  
  
  RESULTS
  One hundred and eighty-one patients were studied: 118 with low bleeding risk, and 63 with high bleeding risk. For all patients, the proportions with normal PT, APTT, TT dTT levels were 92.8%, 79.6%, 33.1%, and 80.7%, respectively. In patients with high bleeding risk, the proportions with normal PT, APTT, TT dTT levels were 93.7%, 85.7%, 57.1%, and 87.3%, respectively. During follow-up, there was one (0.6%) major bleed, there were nine (5.0%) minor bleeds, and there was one (0.6%) transient ischemic attack.
  
  
  CONCLUSIONS
  In patients receiving dabigatran who require an elective surgery/procedure, a standardized interruption protocol yielded 80-86% of patients with no residual anticoagulant effect at the time of surgery/procedure, and with a low incidence of bleeding.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.|Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Douketis
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.|Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Chan
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.|Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: J W
authors.initials: JW
authors.lastname: Eikelboom
authors.affiliation: Department of Anesthesia, McMaster University, Hamilton, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Syed
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Barty
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.|Hamilton Regional Laboratory Medicine Program, McMaster University, Hamilton, Ontario, Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Moffat
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.|Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: F A
authors.initials: FA
authors.lastname: Spencer
authors.affiliation: Department of Medicine, McGill University, Montréal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Blostein
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.|Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Schulman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D001777:Blood Coagulation / Q000187:drug effects; D001780:Blood Coagulation Tests; D000069604:Dabigatran / Q000008:administration & dosage*; D017558:Elective Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D059035:Perioperative Period; D011446:Prospective Studies; D011517:Prothrombin Time; D012306:Risk; D013918:Thrombin Time; D013923:Thromboembolism / Q000175:diagnosis; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D000069604:Dabigatran
keywords: bleeding; blood coagulation tests; dabigatran; direct thrombin inhibitors; surgery