By John Ozcan, MBBS(Hons)
Anaesthetic Registrar, Peter MacCallum Cancer Centre
Perioperative bridging anticoagulation for patients on warfarin therapy is used to reduce the risk of thromboembolism, however evidence supporting this practice is lacking. Douketis and colleagues conducted a large prospective, randomised, double-blinded and placebo controlled trial to investigate bridging versus no bridging of anticoagulation on rates of perioperative arterial thromboembolism and major bleeding.
1884 patients were enrolled (mean CHADS2 score 2.3), and randomly assigned to receive bridging anticoagulation or placebo, with a standardised protocol for discontinuing and resuming warfarin therapy. Rates of arterial thromboembolism at 30 days were 0.3% in the bridging group and 0.4% in the no bridging group, and no bridging was found to be noninferior to bridging for prevention of thromboembolism. Major bleed was significantly higher in the bridging group (3.2%) versus no bridging (1.3%). There was also greater minor bleeding in the bridging group, but no significant difference in other secondary endpoints (death, myocardial infarction, DVT, PE).
A limitation of this trial is that only 3% of patients had a CHADS2 score of 5 or 6, therefore generalisability to patients at highest risk of thromboembolism is limited. Also, patients undergoing major surgical procedures associated with high rates of arterial thromboembolism and bleeding (e.g. carotid endarterectomy, major cancer surgery, cardiac surgery, or neurosurgery) were not represented in the trial. Finally, extrapolation of these findings to novel oral anticoagulants or fast track warfarin reversal programmes is difficult.
Link to download the full article: www.nejm.org/doi/pdf/10.1056/NEJMoa1501035