What is anticoagulant bridging?

Anticoagulant Bridging Explained Simply

Bridging anticoagulation is when doctors give you a short-acting blood thinner (like heparin shots) during the time when your regular long-term blood thinner (like warfarin) is temporarily stopped for a surgery or procedure. 1

What Is Bridging?

• Bridging is like using a temporary bridge to cross a river when the main bridge is closed for repairs. When your regular blood thinner needs to be paused, doctors may use a shorter-acting medication to keep you protected from blood clots during that gap 1
• The temporary blood thinner (usually low-molecular-weight heparin [LMWH] like enoxaparin or unfractionated heparin [UFH]) works quickly and leaves your system quickly, unlike warfarin which takes days 1
• Bridging typically happens for about 10-12 days when your regular blood thinner is stopped and your blood isn't thin enough 1

Why Do We Need Bridging?

• When you stop taking your regular blood thinner (like warfarin), it takes several days for its effects to wear off 1
• Similarly, when you restart your regular blood thinner, it takes several days to become fully effective again 1
• During this time without protection, you could develop dangerous blood clots if you're at high risk 1
• The short-acting blood thinner fills this protection gap 1

Who Needs Bridging?

Not everyone needs bridging! It depends on:

• High risk patients who definitely need bridging:

  • People with mechanical heart valves (especially mitral valves) 1
  • People who had a blood clot very recently (within 3 months) 1, 2
  • People with certain severe clotting disorders 2

• Medium-to-low risk patients who might not need bridging:

  • People with atrial fibrillation and lower CHA₂DS₂-VASc scores (≤5) 2
  • People with bileaflet mechanical aortic valves without other risk factors 1
  • People with stable coronary artery disease 2

How Bridging Works

1. Before procedure:

   • Stop warfarin 5-6 days before surgery 2
   • Start LMWH injections about 3 days before surgery 2
   • Give the last dose 24 hours before surgery (at half the daily dose) 2

2. After procedure:

   • For low bleeding risk procedures: restart warfarin the evening of surgery and restart LMWH 24 hours after surgery 2
   • For high bleeding risk procedures: restart warfarin the evening of surgery but wait 48-72 hours before restarting LMWH 2
   • Continue LMWH until your INR (blood test) shows your warfarin is working well again (INR ≥ 2.0) 2, 3

Special Cases

• Minor procedures (dental work, cataract surgery): You might not need to stop your regular blood thinner at all 1, 2
• Newer blood thinners (dabigatran, rivaroxaban, apixaban): These usually don't need bridging because they work and clear from your body quickly 4, 5
• Kidney problems: Your doctor might adjust the bridging medication or use a different type 2

Common Mistakes to Avoid

• Using bridging when it's not needed (increases bleeding risk without benefit) 4, 6
• Not using bridging when it is needed (increases clot risk) 6
• Restarting blood thinners too soon after surgery (can cause bleeding) 4, 2
• Waiting too long to restart blood thinners (can allow clots to form) 2

Remember that bridging decisions should be based on your personal risk of blood clots versus your risk of bleeding with the specific procedure you're having 1, 2.