Perioperative Bridging Anticoagulation in Patients with Atrial Fibrillation

Mychal Outlaw, Mercer University College of Pharmacy

According to the American Heart Association, bridging anticoagulation aims to reduce patients’ risk of developing blood clots during a procedure when their oral anticoagulant administration is interrupted, but bridging anticoagulation could potentially increase patients’ risk for developing potentially serious complications after surgery. (1)

Design Randomized, double-blind, placebo-controlled trial; N= 1884
Objective To address whether heparin bridging is needed during interruption of warfarin therapy before and after an operation or other invasive procedures
Study Groups Patients receiving dalteparin (Bridging); n= 934

Patients receiving placebo (No Bridging); n= 950

Methods Patients were randomly assigned to receive bridging anticoagulation therapy with dalteparin sodium 100 IU/kg twice daily or to receive an identical administration of a placebo medication from 3 days before the procedure until 24 hours before the procedure and then for 5 to 10 days after the procedure. Warfarin treatment was stopped 5 days before the procedure, and administration of the study drug was started 3 days before the procedure. The last pre-procedure dose of dalteparin or placebo was given in the morning, 24 hours before the procedure. Warfarin treatment was restarted on the evening of or the day after the procedure, at the patient’s usual dose. Administration of dalteparin or placebo was resumed 12 to 24 hours after a minor (or low-bleeding-risk) procedure and 48 to 72 hours after a major (or high-bleeding-risk) procedure.
Duration July 2009 to December 2014
Primary Outcome Measure Arterial thromboembolism (including stroke, transient ischemic attack, and systemic embolism) at 30 days
Baseline Characteristics
Characteristic No Bridging

(N= 950)

Bridging

(N= 934)

Mean age (years) 71.8 71.6
Male, n (%) 696 (73.3) 686 (73.4)
Race: White, n (%) 860 (90.5) 849 (90.9)
Mean INR 2.4 2.4
Results At 30 days after the procedure, the incidence of arterial thromboembolism was 0.4% (four events among 918 patients) in the no-bridging group and 0.3% (three events among 895 patients) in the bridging group.
Adverse Events Common Adverse Events: N/A
Serious Adverse Events: N/A
Percentage that Discontinued due to Adverse Events: N/A
Study Author Conclusions In the BRIDGE trial, it was found that for patients with atrial fibrillation who require temporary interruption of warfarin treatment for an elective operation or other elective invasive procedures, a strategy of no bridging anticoagulation was noninferior to perioperative bridging with low-molecular-weight heparin for the prevention of arterial thromboembolism. The strategy of forgoing bridging treatment also decreased the risk of major bleeding.

There are potential limitations of this trial. Patients undergoing major surgical procedures associated with high rates of arterial thromboembolism and bleeding were not represented in this trial. Most of the procedures performed in this study were low-risk procedures, such as colonoscopy and ambulatory surgery; high-risk procedures were not properly represented.

Major bleeding was a secondary endpoint for this study. This study showed that major bleeding occurred in 1.3% of the patients (12 of 918) in the no-bridging group and in 3.2% (29 of 895) in the bridging group. These results show that no bridging was superior to bridging with regard to major bleeding. Overall, this study demonstrates that temporary interruption of warfarin treatment does not indicate that bridging anticoagulation is necessary. (2)

References

  1. Bridging anticoagulation: is it needed when warfarin is interrupted around the time of a surgery or procedure?. Circulation. 2012;125(12):e496-8.
  2. Douketis JD, Spyropoulos AC, Kaatz S, et al. Perioperative Bridging Anticoagulation in Patients with Atrial Fibrillation. N Engl J Med. 2015;
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