What anticoagulation therapy is recommended for atrial fibrillation pending surgery?

Perioperative Anticoagulation Management for Atrial Fibrillation

For most patients with atrial fibrillation requiring surgery, a no-bridging approach is recommended as it provides similar protection against thromboembolism while significantly reducing bleeding risk compared to bridging with heparin or LMWH. 1

Risk Stratification Approach

Step 1: Assess Thromboembolic Risk

• High Risk (consider bridging):

  • Recent stroke/TIA (<3 months)
  • CHA₂DS₂-VASc score ≥7
  • CHADS₂ score of 5-6
  • Prior perioperative stroke

• Low to Moderate Risk (no bridging needed):

  • Most patients with atrial fibrillation without high-risk features

Step 2: Assess Procedural Bleeding Risk

• High Bleeding Risk Procedures:

  • Major surgery
  • Neurosurgery
  • Complex cardiac procedures
  • Major urological procedures

• Low Bleeding Risk Procedures:

  • Dental extractions
  • Cataract surgery
  • Minor dermatologic procedures
  • Diagnostic endoscopy without biopsy

Management Algorithm

For Patients on Warfarin:

1. Low-Moderate Thromboembolic Risk:

   • Stop warfarin 5 days before procedure
   • Check INR day before surgery (target <1.5)
   • Resume warfarin evening of or day after procedure
   • No bridging therapy needed 1

2. High Thromboembolic Risk:

   • Stop warfarin 5 days before procedure
   • Start bridging with LMWH (e.g., dalteparin 200 IU/kg daily or enoxaparin 1mg/kg twice daily) 3 days before procedure
   • Last dose of LMWH 24 hours before procedure
   • Resume warfarin postoperatively
   • Resume LMWH 24-72 hours after procedure (depending on bleeding risk) until INR ≥2.0 1

For Patients on DOACs:

1. Low-Moderate Thromboembolic Risk:

   • Stop DOAC 24-48 hours before low bleeding risk procedures
   • Stop DOAC 48-72 hours before high bleeding risk procedures
   • Longer interruption for impaired renal function
   • Resume DOAC 24 hours after low bleeding risk procedures
   • Resume DOAC 48-72 hours after high bleeding risk procedures
   • No bridging therapy needed 1

2. High Thromboembolic Risk:

   • Same interruption schedule as above
   • Generally no bridging needed, but consider individual risk factors 1

Important Considerations

Evidence Against Routine Bridging

The BRIDGE trial demonstrated that no bridging was non-inferior to LMWH bridging for arterial thromboembolism prevention (0.3% vs 0.4%), but bridging conferred a threefold increased risk of major bleeding (3.2% vs 1.3%) 1. Multiple studies consistently show increased bleeding risk with bridging without significant reduction in thromboembolic events.

Special Populations Requiring Bridging

While most AF patients don't need bridging, certain high-risk patients should receive it:

• Recent stroke/TIA (<3 months)
• CHA₂DS₂-VASc score ≥7
• Prior perioperative stroke
• Mechanical heart valves (especially older-generation or mitral position)

Common Pitfalls to Avoid

1. Unnecessary bridging in low-risk patients, which increases bleeding without reducing thromboembolism
2. Resuming full-dose anticoagulation too early after high bleeding risk procedures
3. Delaying anticoagulation resumption too long after surgery in high thromboembolic risk patients
4. Failing to adjust DOAC interruption timing based on renal function
5. Using bridging for DOACs, which is generally unnecessary due to their predictable offset and onset

Practical Tips

• For minor procedures with low bleeding risk (dental work, skin biopsies), consider continuing anticoagulation without interruption 1
• Use a perioperative anticoagulation calendar (paper or electronic) to guide patients through the complex timing of medication adjustments 1
• Ensure clear communication between surgical team, primary care, and cardiology regarding the perioperative plan

By following this evidence-based approach to perioperative anticoagulation management in atrial fibrillation, you can minimize both thromboembolic and bleeding complications while optimizing patient outcomes.