II. Indications
- Patients on Anticoagulation undergoing surgery
III. Background
- Follow Decision Tree below for whether Bridging Therapy is required- Based on surgical bleeding risk and Thromboembolism risk
 
IV. Efficacy: Perioperative Anticoagulation Bridging
- Bridging Risks outweigh benefits in patients with Venous Thromboembolism (esp. low risk of recurrence)
- Atrial Fibrillation patients who are bridged have more adverse events (e.g. bleeding) without benefit
V. Precautions: Pitfalls
- Over Anticoagulation or premature use results in significantly increased bleeding complications
- Bleeding complications result in transfusions and stopping Anticoagulation which risks clots
- 
                          Direct Oral Anticoagulants or DOACs (e.g. Dabigatran, rivoroxaban)- DOACs do not require bridging
- Delay surgery if possible for moderate-high risk of bleeding if high thrombosis risk
- Before surgery with low risk of bleeding, stop 1 day before surgery and restart the next day
- Before surgery with moderate risk of bleeding, stop 2 days before surgery and restart 2-3 days later
- Hold DOACs for 3-5 days before surgery if Creatinine Clearance <30 ml/min
- (2019) presc lett 26(10): 57
 
- Bridging protocol is recommended for only patients at high risk of thrombosis (as of 2015, BRIDGE Trial)- See high risk indications as below
- Bridging does not appear to reduce thrombosis risk
- Bridging is associated with major bleeding complication in 2% of patients
- Clark (2015) JAMA Intern Med 175(7): 1163-8 +PMID:26010033 [PubMed]
 
- INR need not be normalized before most emergent, stabilization procedures- INR should be normalized for sites sensitive to hemorrhagic pressure (e.g. CNS procedures, Lumbar Puncture)
- However elevated INR does not contradict most emergent procedures (esp. in compressible sites)
 
VI. Protocol: Simplified Warfarin Bridging Protocol
- Day -7: Stop Aspirin (if appropriate), Obtain INR
- Day -5: Stop Warfarin, Check INR
- Day -3: Start Low Molecular Weight Heparin (LMWH) at full dose given every 12-24 hours
- Day -1:
- Day 0: Surgery- No LMWH
- Consider Fresh Frozen Plasma (FFP) if INR not at goal (see normalization protocol below)
- Restart Warfarin at 12-24 hours on evening of surgery (if adequate Hemostasis and approved by surgery)
 
- Day 1:- Continue Warfarin (if started)
- Consider restarting LMWH per therapeutic or prophylactic dosing depending on bleeding risk- Surgeon decides the time to restart LMWH or Heparin based on surgery bleeding risk- Restart of Anticoagulation is modified for active bleeding, Thrombocytopenia and other complications
- LMWH (typically Enoxaparin or Lovenox) is preferred over Unfractionated Heparin for bridging
- Moderate-High thromboembolic risk (see below)- Consider low dose prophylactic dosing of Heparin or LMWH until surgery allows full Anticoagulation
 
 
- Moderate to high bleeding risk procedure- Avoid restarting therapeutic Heparin in first 48 hours, and until Hemostasis achieved
- May start Heparin or LMWH 48-72 hours after procedure (per surgeon discretion)
 
- Consult hematology for complex cases
- See below for how to choose dosing regimen
 
- Surgeon decides the time to restart LMWH or Heparin based on surgery bleeding risk
 
- Day 2-10: Obtain INR and stop LMWH when INR >2 for 2 consecutive days- Anticipate by Day 5
- Use caution in postoperative Anticoagulation (risk of bleeding events)
 
VII. Protocol: Invasive procedures with Moderate to High Bleeding Risk
- Indications: Procedures with high bleeding risk- Neurosurgery
- Cardiac Surgery or major thoracic surgery
- Abdominal or pelvic procedures
- Orthopedic joint procedures
- Major ENT or oral surgery
- Epidural Anesthesia
- Renal Biopsy
- Urologic Surgery
- Prolonged general Anesthesia with intubation (>45 minute procedure)
 
- 
                          DOAC Protocol  (e.g. Dabigatran, rivoroxaban)- DOACs are typically not bridged- Delay procedure if possible, if transiently high thrombosis risk (e.g. recent Venous Thromboembolism)
 
- Hold DOAC 2 days before surgery and restart 2-3 days after surgery- Stop DOAC 3-5 days before surgery if GFR <30 ml/min, impaired liver function or using strong CYP3A4 Inhibitor
- Hold Dabigatran (Pradaxa) for 4 days before surgery if GFR <50 ml/min
 
 
- DOACs are typically not bridged
- Low risk for Thromboembolism (<4% risk/year)- Indications- Single Venous Thromboembolism >12 months prior and no other Hypercoagulable risk factors
- Chronic Atrial Fibrillation without stroke and CHADS2 score <3 (CHADS2Vasc <5)
- New bileaflet aortic Valve Replacement (St. Jude or Medtronic)- No Atrial Fibrillation or other stroke risk
 
 
- Management- No bridging with Perioperative Anticoagulation required
- Stop Warfarin 4-5 days before surgery
- Allow INR to normalize
- Post-operative DVT Prophylaxis if indicated
- Restart Warfarin postoperatively
 
 
- Indications
- Intermediate risk for Thromboembolism (4-10% risk/year)- Indications- Atrial Fibrillation with CHADS-2 Score 3-4 (CHADS2Vasc 5-7)
- Venous Thromboembolism in the last 3-12 months
- Recurrent Venous Thromboembolism
- Active cancer (treated in the last 6 months or on palliative cancer management)
- Non-severe Thrombophilia (e.g. Heterozygous Factor V Leiden, Prothrombin gene mutation)
- Bileaflet aortic Valve Replacement and at least one risk factor- Atrial Fibrillation
- Prior Cerebrovascular Accident or TIA
- Hypertension
- Diabetes Mellitus
- Congestive Heart Failure
- Age >75 years old
 
 
- Management- Stop Warfarin 4-5 days before surgery
- Allow INR to decrease
- Start Anticoagulation 2 days before surgery- Low dose Heparin 5000 U SC or
- Low Molecular Weight Heparin at prophylactic doses
 
- Restart low dose Heparin or LMWH postoperatively (hold for 24-48 hours postoperatively)
- Restart Warfarin immediately postoperatively
 
 
- Indications
- High risk for Thromboembolism (>10% risk/year)- Indications- Venous Thromboembolism (PE, DVT) within last 3 months
- Cardiac Thromboembolism (any cause) within 1 month
- Cerebrovascular Accident or TIA in the last 6 months
- Atrial Fibrillation with one or more additional risks (only 3% of Atrial Fibrillation is high risk)- CHADS-2 Score 5 or CHADS2-VASc Score 7 or higher
- Cerebrovascular Accident (CVA) in last 3 months or
- Rheumatic Valvular Disease
 
- Strong Thrombophilia- Two or more Thrombophilia risks
- Active cancer associated with high VTE Risk
- Antiphospholipid Antibody Syndrome (uncommon)
- Antithrombin III Deficiency (rare)
- Protein C Deficiency
- Protein S Deficiency
 
- Mechanical Heart Valves- Mitral Valve Replacement (any)
- Caged-Ball, Tilting disc or other older aortic Valve Replacement
- Higher risks- Comorbidity (e.g. Congestive Heart Failure)
- Atrial Fibrillation with mechanical valve
 
- Exceptions: Lower risks (not needing bridging)- New aortic valves (see above)
 
 
 
- Management- See Bridging protocol above
- Stop Warfarin 4-5 days before surgery
- Allow INR to decrease
- Start Anticoagulation 2 days before surgery- Full dose Heparin or
- Full dose Low Molecular Weight Heparin
 
- Hold Heparin before surgery
- Restart Heparin after procedure
- Restart Warfarin postoperatively
 
 
- Indications
VIII. Protocol: Procedures with Low Risk of Bleeding
- Procedures- Abdominal Hernia repair
- Arthroscopy
- Gynecologic Surgery
- Endoscopy with biopsy (e.g. Colonoscopy)
- Bronchoscopy
- Coronary angiogram
- Hemorrhoidal Surgery
- Hysterectomy
- Laparoscopic Cholecystectomy
- Lymph Node biopsy
 
- Protocol- DOACs  (e.g. Dabigatran, rivoroxaban)- Hold DOAC one day before surgery and restart 1 day after surgery
- Hold Dabigatran (Pradaxa) for 3 days before surgery if GFR <50 ml/min
- Stop DOAC 3 days before surgery if GFR <30 ml/min, impaired liver function or using strong CYP3A4 Inhibitor
 
- Warfarin
 
- DOACs  (e.g. Dabigatran, rivoroxaban)
IX. Protocol: Very Low Risk of Bleeding
- Procedures
- Protocol- DOACs  (e.g. Dabigatran, rivoroxaban)- Hold DOAC on day of surgery and restart 4-6 hours after procedure
 
- Warfarin
- Consider local bleeding control if needed (dental)- Tranexamic Acid soaked gauze or pledgets
- Additional Sutures
- Gelatin sponges
- Epsilon aminocaproic acid (Amicar) mouthwash (discuss with hematology and surgeon)
 
 
- DOACs  (e.g. Dabigatran, rivoroxaban)
X. Protocol: Normalization of INR after stopping Warfarin
- Anticipate INR normalization after stopping for 4 days- Bleeding risk is low when INR <1.5
 
- Indications for transiently stopping Coumadin- Prolonged INR
- Surgery
 
- Factors predicting delayed INR decrease- Advanced age (80 years or older)
- Coumadin sensitive (maintenance dose <15 mg/week)
- Decompensated Congestive Heart Failure
- Active malignancy
- Liver disease
- Concurrent medications that potentiate Coumadin
 
- Options for reversal- Vitamin K (preferred if >12 hours pre-operative)
- Clotting Factor replacement (within 12 hours)- Fresh Frozen Plasma (FFP) 15 ml/kg
 
 
- Example Protocol- PM prior to surgery: Vitamin K 1-2.5 mg PO x1 dose
- AM of surgery: FFP if INR >1.5
- Post-operatively (12-24 hours): Anticoagulate- See protocols above for agents and dosing
 
 
