ASK DIS: Warfarin: Bridging Anticoagulation

suggest the use of bridging in individuals taking warfarin for one of the following conditions

Embolic stroke or systemic embolic event within the previous three months
Mechanical mitral valve
Mechanical aortic valve and additional stroke risk factors
Atrial fibrillation and very high risk of stroke (eg, CHADS₂ score of 5 or 6, stroke or systemic embolism within the previous 12 weeks)
Venous thromboembolism (VTE) within the previous three months (preoperative and postoperative bridging)
Recent coronary stenting (eg, within the previous 12 weeks)
Previous thromboembolism during interruption of chronic anticoagulation

Other Conditions

For most other patients on warfarin with atrial fibrillation (ie, for most individuals not included in the list of examples above), we suggest not using bridging anticoagulation.
avoiding bridging the lower the patient’s baseline thromboembolic risk (eg, lower CHADS₂ or CHA₂DS₂-VASc score and the higher the risk of bleeding.
This practice is supported by the BRIDGE trial (Bridging Anticoagulation in Patients who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery)
A potential role for bridging in reducing the risk of "rebound hypercoagulability" has also been proposed; however, this premise is not supported by data from the BRIDGE trial discussed above

Heparin Products

LMW heparins have similar efficacy compared with unfractionated heparin, are more convenient to use, and generally do not require monitoring
Heparins can be dosed at prophylactic doses, therapeutic doses, or doses intermediate between the two.
There are no clinical trial data or practice standards to guide dosing, and clinical judgment is required to determine the appropriate dose for each patient

Therapeutic dosing (also called "full dose") is appropriate for bridging anticoagulation for individuals with a potential arterial thromboembolic source (eg, atrial fibrillation, mechanical heart valve) or VTE within the preceding month.
enoxaparin, 1 mg/kg subcutaneously twice daily

Intermediate dose anticoagulation may be appropriate for individuals with atrial fibrillation or VTE within the preceding month when bridging is needed but concerns about bleeding are greater.
enoxaparin, 40 mg twice daily

Prophylactic dose anticoagulation (also called "low dose") generally is not used for bridging in patients with atrial fibrillation, because there is no evidence that prophylactic dose heparin prevents stroke in this setting.
This dose level may be reasonable in patients who have had a VTE event between within the preceding 3 to 12 months.
enoxaparin, 40 mg once daily

Timing of bridging: Preoperative

initiate heparin bridging three days before a planned procedure (ie, two days after stopping warfarin), when the PT/INR has started to drop below the therapeutic range.
discontinue LMW heparin 24 hours before the planned surgery or procedure, based on a biologic half-life of most subcutaneous LMW heparins of approximately three to five hours

Timing of bridging: Postoperative

For those undergoing major surgery or those with a high bleeding risk procedure, therapeutic-dose unfractionated heparin or LMW heparin should be delayed for 48 to 72 hours after hemostasis has been secured
For most minor procedures associated with a low bleeding risk in which bridging is used (eg, laparoscopic hernia repair), therapeutic-dose unfractionated heparin or LMW heparin can usually be resumed 24 hours after the procedure

Reference

ASK DIS