When should anticoagulation (blood thinner therapy) be stopped?

When to Stop Anticoagulation Therapy

Anticoagulation therapy should be stopped 2-4 days before invasive procedures when bleeding risk is significant, and restarted 12-24 hours after surgery when hemostasis is adequate. 1

General Principles for Perioperative Anticoagulation Management

Risk Assessment

• The decision to stop anticoagulation must balance the risk of thromboembolism against the risk of bleeding during the procedure 1
• Thromboembolism risk factors include mechanical heart valves (especially mitral position), atrial fibrillation with additional risk factors, and recent venous thromboembolism 1
• Procedures with low bleeding risk may not require anticoagulation interruption 1

Low Bleeding Risk Procedures (Continue Anticoagulation)

• Dental procedures (extractions, cleaning, caries treatment) 1, 2
• Cataract or glaucoma surgery 1
• Minor skin procedures 1
• For these procedures, maintaining therapeutic anticoagulation is recommended as bleeding is easily controlled with local measures 1

High Bleeding Risk Procedures (Interrupt Anticoagulation)

• For vitamin K antagonists (VKAs) like warfarin:
  • Stop 5 days before surgery to allow INR to fall below 1.5 1
  • Resume 12-24 hours after surgery when hemostasis is achieved 1
• For direct oral anticoagulants (DOACs):
  • Timing depends on renal function and specific agent 1
  • Generally stopped 48-72 hours before high bleeding risk procedures 1

Bridging Anticoagulation

When Bridging Is Recommended

• Mechanical mitral valve replacement 1
• Older-generation mechanical aortic valve 1
• Mechanical aortic valve with additional risk factors (atrial fibrillation, previous thromboembolism, hypercoagulable condition, LV dysfunction) 1
• Recent venous thromboembolism (within 3 months) 1

When Bridging Is Not Recommended

• Bileaflet mechanical aortic valve without other risk factors 1
• Bioprosthetic heart valves without atrial fibrillation 1
• Low-risk atrial fibrillation patients (CHA₂DS₂-VASc score <4) 1

Bridging Protocol

• Stop warfarin 5 days before procedure 1
• Start therapeutic-dose LMWH or UFH when INR falls below therapeutic range 1
• Stop LMWH 24 hours before procedure (last dose given 24 hours pre-procedure) 1
• Resume anticoagulation 12-24 hours post-procedure when hemostasis is adequate 1

Special Situations

Emergency Surgery

• For patients on VKAs requiring emergency surgery:
  • Administer 4-factor prothrombin complex concentrate 1
  • Consider low-dose vitamin K (1-2 mg) 1
  • Avoid high-dose vitamin K to prevent rebound hypercoagulability 1

Cancer Patients

• For active cancer patients on therapeutic anticoagulation:
  • If platelet count ≥50,000/mm³: maintain full therapeutic dose 3
  • If platelet count 30,000-50,000/mm³: reduce dose by 50% 3
  • If platelet count <30,000/mm³: temporarily discontinue anticoagulation 3

Dental Procedures

• For most dental procedures, continue anticoagulation without interruption 2
• Consider using tranexamic acid mouthwash (5-10 mL of 5% solution) before and after the procedure 2
• Apply local hemostatic measures (pressure with gauze) to control bleeding 2

Duration of Anticoagulation Therapy

Venous Thromboembolism (VTE)

• VTE provoked by surgery or transient risk factor: treat for 3 months then stop 1, 4
• First unprovoked proximal DVT or PE: minimum 3 months, then reassess for extended therapy 1, 4
• Recurrent unprovoked VTE: indefinite anticoagulation recommended for patients with low bleeding risk 1
• Cancer-associated thrombosis: extended anticoagulation while cancer is active 1, 4

Atrial Fibrillation

• Anticoagulation is typically long-term/indefinite for stroke prevention 5, 6
• Reassess risk-benefit ratio annually, considering bleeding risk and stroke risk 6

Common Pitfalls to Avoid

• Stopping anticoagulation for low bleeding risk procedures unnecessarily increases thrombotic risk 1
• Using high-dose vitamin K for warfarin reversal can lead to prolonged resistance to re-anticoagulation 1
• Failing to restart anticoagulation promptly after surgery when hemostasis is adequate 1
• Not considering patient-specific factors like renal function when managing DOACs 1
• Overlooking the need for bridging in high-risk mechanical valve patients 1