1. Anticoagulation Bridging Decision Support
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Click here for references

2. Oral Anticoagulants
What oral anticoagulant does the patient take? Warfarin (Coumadin®, others) Dabigatran (Pradaxa®) Rivaroxaban (Xarelto®)

3. Is surgery or procedure elective or emergent?

4. Thromboembolism Risk
This risk classification is an initial guide for decision-making that should be adapted to individual patient circumstances. If you are unsure of your patient’s risk of thromboembolism, continue with decision support here.
If you already know your patient’s risk of thromboembolism, choose management plan below:
High Thromboembolic Risk Perioperative Bridging
Moderate Thromboembolic Risk Perioperative Bridging
Low Thromboembolic Risk – no bridging therapy

5. Is patient having any of the following (very low bleeding risk procedures): 1) Dental extraction? 2) Cataract extraction/IOL? 3) Upper GI endoscopy? 4) Carpal Tunnel Release? 5) Needle Breast Biopsy? 6) Cutaneous procedure (Mohs, excisions)?
Yes No

6. HIGH RISK: Does patient have any of the following
HIGH RISK: Does patient have any of the following? 1) Any mitral valve prosthesis? 2) Caged-ball or tilting disc valve prosthesis? (Types of Mechanical Valves) 3) Stroke, TIA, or VTE in last 3 months? 4) Stroke or TIA with mechanical valve in last 6 months? 5) Severe thrombophilia? (examples) 6) CHADS2 score of 5 or 6 with atrial fibrillation? (CHADS2 Scoring Tool) 7) Rheumatic valvular heart disease with atrial fibrillation?
Yes No

7. MODERATE RISK: Does patient have any of the following
MODERATE RISK: Does patient have any of the following? 1) Bileaflet aortic valve prosthesis with at least one risk factor? (risk factors) 2) CHADS2 score of 3 or 4 with atrial fibrillation? 3) Prior thromboembolism with atrial fibrillation during interruption of warfarin? 4) VTE within past 3-12 months? 5) Recurrent VTE? 6) Active cancer (treated within 6 months or palliative)? 7) Non-severe thrombophilia? (examples)
Yes No

8. Patient does not meet criteria for moderate or high risk of thromboembolism. Consider no bridging therapy during interruption of warfarin unless patient’s history indicates otherwise. Exit

9. No need to stop warfarin before surgery or procedure. Exit

10. Types of Mechanical Valves
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Valve Type
Valve Name(s)
Bileaflet
St. Jude; CarboMedics; ATS Open Pivot; On-X; Conform-X
Tilting Disc (single leaflet)
Bjork-Shiley (now discontinued); Medtronic Hall; Omnicarbon; Monostrut
Caged-Ball
Starr-Edwards (only one FDA approved)
Bioprosthetic (does not require anticoagulation)
Carpentier-Edwards (porcine); Hancock II and Mosaic (both by Medtronic, porcine); Edwards Prima Plus, Medtronic Freestyle, and Toronto SPV (by St. Jude) are pericardial porcine valves.
Prosthetic Heart Valves. Author: Eric M Kardon, MD, FACEP, Attending Emergency Physician, Georgia Emergency Medicine Specialists; Physician, Division of Emergency Medicine, Athens Regional Medical Center.

11. Return to previous slide
CHADS2 Scoring Tool
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Characteristic
Points
Recent CHF exacerbation 1
Hypertension (treated or untreated)
Age > 75 years
Diabetes
Prior Stroke or TIA 2

12. Examples of Severe Thrombophilia
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Protein C Deficiency
Protein S Deficiency
Antithrombin Deficiency
Antiphospholipid Syndrome
Multiple abnormalities

13. Return to previous slide
Risk Factors
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Atrial fibrillation
Prior stroke or TIA
Hypertension
Diabetes
Congestive heart failure
Age > 75

14. Examples of Non-severe Thrombophilia
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Heterozygous factor V Leiden mutation
Factor II (prothrombin) mutation

15. Patient is at HIGH risk for thromboembolism Consider bridging patient with therapeutic enoxaparin if bleeding risk acceptable. Consider use of heparin infusion for patients with mechanical valve. Click here for suggested bridging plan.

16. Patient is at MODERATE risk of thromboembolism If patient is undergoing a major cardiac surgery or carotid endarterectomy surgery, consider no bridging therapy. If patient is undergoing a surgery or procedure with low risk for bleeding, consider bridging with heparin infusion, therapeutic enoxaparin, or low-dose enoxaparin based on patient's history. For all other patients with moderate risk, bridging therapy should be chosen based on patient’s history. Click here for suggested bridging plans.

17. Patient is at LOW risk of thromboembolism Consider no bridging therapy during interruption of warfarin based on patient’s history. Exit

18. High Thromboembolism Risk Perioperative Bridging
Day
Anticoagulation Plan
Pre-op Day 5
Stop warfarin (last dose on Pre-op Day 6).
Pre-op Day 3
Start therapeutic enoxaparin bridging (1 mg/kg SC q12h) or heparin infusion when INR < goal range.
Pre-op Day 1
Check INR, give vitamin K mg orally if INR > 1.5. Last dose of therapeutic enoxaparin (if using) must be > 24 hours prior to surgery.
Day of Surgery
Check INR, consider additional vitamin K if INR > Stop heparin infusion (if using) 4-6 hours prior to surgery. Assess hemostasis postoperatively. May resume warfarin evening of surgery if patient taking fluids.
Post-op Day 1
Standard bleeding risk: Resume therapeutic enoxaparin or heparin infusion 24 hours after surgery if hemostasis achieved.
High bleeding risk: Consider no bridging or low-dose enoxaparin (40 mg SC daily) 24 hours after surgery if hemostasis achieved.
Post-op Day 2
High bleeding risk: Resume therapeutic enoxaparin or heparin infusion hours after surgery if hemostasis achieved.
Post-op Day 4+
Discontinue bridging when INR in goal range.
Exit

19. Moderate Thromboembolism Risk Perioperative Bridging
Day
Anticoagulation Plan
Pre-op Day 5
Stop warfarin (last dose on Pre-op Day 6).
Pre-op Day 3
Start low-dose enoxaparin (40mg SC daily), therapeutic enoxaparin (1 mg/kg SC q12h), or heparin infusion based on patient’s bleeding risk when INR < goal range.
Pre-op Day 1
Check INR, give vitamin K mg orally if INR > 1.5. Last dose of any enoxaparin (if using) must be > 24 hours prior to surgery.
Day of Surgery
Check INR, consider additional vitamin K if INR > Stop heparin infusion (if using) 4-6 hours prior to surgery. Assess hemostasis postoperatively. May resume warfarin evening of surgery if patient taking fluids.
Post-op Day 1
Standard bleeding risk: Resume low-dose enoxaparin, therapeutic enoxaparin, or heparin infusion 24 hours after surgery if hemostasis achieved.
High bleeding risk: Consider no bridging or low-dose enoxaparin 24 hours after surgery if hemostasis achieved.
Post-op Day 2
High bleeding risk: Continue low-dose enoxaparin (if started post-op day 1) or resume therapeutic enoxaparin or heparin infusion hours after surgery if hemostasis achieved.
Post-op Day 4+
Discontinue bridging when INR in goal range.
Exit

20. Emergency Surgery When rapid reversal is required for any INR:
Discontinue warfarin temporarily
Administer vitamin K1 2-5mg by slow IV infusion**
Supplement with fresh frozen plasma (at least 15ml/kg)
Recheck INR and administer additional vitamin K1 in 4-8 hrs, if necessary
** Intravenous vitamin K should be diluted in 50mg Dextrose 5% and administered over 60 minutes to decrease risk of anaphylaxis.
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Exit

21. High Bleeding Risk Examples
Urologic surgery and procedures consisting of TURP, bladder resection, or tumor ablation; nephrectomy; or kidney biopsy
Pacemaker or implantable cardioverter-defibrillator device implantation
Colonic polyp resction, typically of large (1-2 cm long) sessile polyps
Surgery and procedures in highly vascular organs (kidney, liver, spleen)
Bowel resection
Major surgery with extensive tissue injury (cancer surgery, joint arthroplasty, reconstructive plastic surgery)
Cardiac, intracranial, or spinal surgery
Return to High Thromboembolism Risk Perioperative Bridging
Return to Moderate Thromboembolism Risk Perioperative Bridging

22. Dabigatran “Bridging”
Emergent Surgery:
Stop dabigatran. If appropriate, consider delaying surgery until aPTT is normal or appropriate amount of time has passed for drug to have cleared (see table below). INR is not a reliable indicator.
There is no reversal agent for dabigatran. Transfuse FFP, PRBC and platelets as indicated. Consider use of recombinant factor VIIa or hemodialysis. PCC is not available at St. Mary’s Hospital.
Consider Hematology Consult.
Elective Surgery:
*dabigatran is contraindicated when CrCl ≤ 30 mL/min
Restart dabigatran post-operatively when hemostasis achieved and wound is stable. Bridging anticoagulation is not necessary due to rapid onset of dabigatran, but use of an alternate route anticoagulant (e.g. LMWH) may be appropriate if the patient cannot take medications by mouth.
Creatinine
Clearance
(mL/min)
Dabigatran Half-life (hours)
Last dose of dabigatran prior to surgery
Standard Bleeding Risk
High Bleeding Risk
> 80
13 (11-22)
24 hours
2-4 days
> 50 to ≤ 80
15 (12-34)
> 30 to ≤ 50
18 (13-23)
At least 2 days (48 hours)
4 days
≤ 30*
27 (22-35)
2-5 days
> 5 days
Exit

23. Rivaroxaban “Bridging”
Emergent Surgery:
Stop rivaroxaban. If appropriate, consider delaying surgery until PT (not INR) is normal or appropriate amount of time has passed for drug to have cleared (see below).
There is no reversal agent for rivaroxaban. Transfuse FFP, PRBC and platelets as indicated. Consider use of recombinant factor VIIa. Rivaroxaban is not dialyzable. PCC is not available at St. Mary’s Hospital.
Consider Hematology consult.
Elective Surgery: Hold rivaroxaban for 1-2 days prior to surgery based on elimination half-life (5-9 hours in healthy adults, hours in elderly adults).
Restart rivaroxaban post-operatively when hemostasis achieved, at least 6-10 hours. Bridging anticoagulation is not necessary due to rapid onset or rivaroxaban, but use of an alternate route anticoagulant (e.g. LMWH) may be appropriate if the patient cannot take medications by mouth.
Exit

24. References Return to Anticoagulation Bridging Decision Support
Douketis JD, Spyropoulos AC, Spencer FA, Mayr M, Jaffer AK, Eckman MH, et al. Perioperative management of antithrombotic therapy: antithrombotic therapy and prevention of thrombosis, 9th ed: American college of chest physicians evidence-based clinical practice guidelines. Chest. 2012;141:e326S-e350S.
Douketis JD. Perioperative management of patients who are receiving warfarin therapy: an evidence-based and practical approach. Blood. 2011;117(19):
Garcia DA. Update in bridging anticoagulation. J Thromb Thrombolysis. 2011;31(3):
Lexi-comp OnlineTM , Lexi-Drugs OnlineTM , Hudson, Ohio: Lexi-Comp, Inc.; September 20, 2011.
Guidelines for testing and perioperative management of dabigatran. New Zealand Government PHARMAC.
DeLoughery TG. Practical aspects of the oral new anticoagulants. Am J Hematol. 2011;86:
Updated May 14, 2012
Katherine Rotzenberg, PharmD; Dr. Roy Kim; Dave Pauly, RPh