When to discontinue warfarin (anticoagulant) before surgery?

From the Guidelines

Warfarin should typically be discontinued 5 days before surgery to allow adequate time for its anticoagulant effect to diminish. This recommendation is based on the most recent and highest quality study available, which suggests that for high-risk endoscopic procedures in patients at low thrombotic risk, warfarin should be discontinued 5 days before the procedure 1. The study, published in 2021, provides strong evidence for this approach, with a strong recommendation and high-quality evidence.

Key Considerations

• For patients at high risk of thromboembolism, bridging therapy with low molecular weight heparin (LMWH) may be necessary, starting 2 days after stopping warfarin, with the last dose of LMWH administered at least 24 hours prior to the procedure 1.
• Patients should have their INR checked prior to the procedure to ensure it has decreased to an acceptable level, typically below 1.5 1.
• After surgery, warfarin can usually be resumed within 12-24 hours if there is adequate hemostasis, with bridging therapy continued until the INR returns to the therapeutic range.

Patient-Specific Factors

• The specific timing of warfarin discontinuation and bridging therapy may need to be adjusted based on individual patient factors, such as renal function, bleeding risk, and the type of surgical procedure planned.
• Patients with a high risk of thromboembolism, such as those with mechanical heart valves or atrial fibrillation, may require more aggressive bridging therapy 1.

Monitoring and Follow-Up

• Patients should be closely monitored for signs of bleeding or thromboembolism after surgery, with regular INR checks to ensure that the anticoagulant effect is within the therapeutic range.
• The decision to discontinue warfarin and initiate bridging therapy should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history.

From the Research

Discontinuation of Warfarin Before Surgery

• The decision to discontinue warfarin before surgery is based on the patient's individual risk of thromboembolism and bleeding 2.
• One study suggests that most patients should stop taking warfarin 5 days before elective surgery 2.
• The use of heparin as a bridge to surgery is not always necessary, and most patients do not require it in the perioperative period 2.

Comparison of Anticoagulants

• Low molecular weight heparin (LMWH) and unfractionated heparin (UFH) have been compared in terms of efficacy and safety in preventing thromboembolism in general surgery 3.
• LMWH has been shown to have a significantly better safety profile than UFH, with a lower risk of minor bleeding 3.
• The choice of anticoagulant depends on the individual patient's risk factors and the type of surgery being performed [(4,5)].

Alternative Anticoagulants

• Newer anticoagulants, such as dabigatran, have been developed and are being studied as potential alternatives to warfarin and heparin 6.
• Dabigatran has been shown to be effective in preventing thrombus formation on mechanical heart valves in vitro 6.