perioperative anticoagulation

Introduction

Risk of hemorrhage from procedure vs. risk of thrombosis

perioperative prophylaxis for venous thromboembolism

• see prophylaxis for venous thromboembolism
• see perioperative antiplatelet therapy

Management

• low risk procedures
  • direct oral anticoagulants should be stopped 24-36 hours prior to procedure in low to intermediate-risk patients (2-3 days)
  • low risk procedures may be done without interruption of warfarin
    • adjustment to INR of about 2.0 prior to procedure
      • INR of 2.4 is acceptable
    • ref suggests perioperative target INR is 1.3-1.5
  • includes
    • dental extractions
    • cataract surgery
    • dermatologic procedures
    • diagnostic coronary arteriography
    • gastrointestinal endoscopy with or without mucosal biopsy or polypectomy
    • arthrocentesis
    • bronchoscopy
    • cystoscopy
    • pacemaker placement
• high risk procedures/low risk patients
  • stop direct oral anticoagulant (DOAC) 24-36 hours prior to procedure in low to intermediate-risk patients (2-3 days) (presumably sooner in patients with renal insufficiency)
  • restart DOAC 1-3 days after procedure (depending on bleeding risk)
  • stop DOAC 24 hours prior to GI endoscopy & resume 24 hours after for low risk procedures & 48 hours later for high risk procedures in patients with atrial fibrillation
  • stop warfarin 5 days prior to procedure
  • recheck INR to ensure that it is < 1.5 on the day of surgery
  • restart warfarin within 12-24 hours if hemostasis is secure (allow about 5 days for therapeutic anticoagulation)
  • newer aortic valve prosthesis have < 5% annual risk of thromboembolism, thus bridging anticoagulation unnecessary for otherwise low-risk patients
• high-risk procedures/patients*
  • stop direct oral anticoagulant 2-3 days before surgery in patients with normal kidney function (GFR = > 50 mL/min)
    • 3 days before surgery
    • if GFR = 31-50 mL/min: 2-3 days apixaban, 1-2 days rivaroxaban, 2-4 days dabigatran
    • if GFR = < 30 mL/min: > 3 days apixaban, 2-3 days rivaroxaban, > 4 days dabigatran
  • stop warfarin 5 days prior to procedure
  • start intravenous heparin when INR falls below 2.5,
    • ~ 2 days after stopping warfarin
  • adjust aPTT to 60-80 sec
  • stop heparin 4-6 hours prior to surgery
  • if LMW heparin is used, administer last full dose of LMW heparin 24 hours before surgery;
    • stop LMW heparin 12 hours before surgery
  • restart heparin after surgery as soon as considered safe (24 hours)
  • restart LMW heparin at 24 hours; at full dose 48-72 hours after procedure with high-risk of hemorrhage if hemostasis is secure
  • restart warfarin within 12-24 hours if hemostasis is secure (allow about 5 days for therapeutic anticoagulation)
  • stop heparin when INR is therapeutic
  • restart dabigatran, rivaroxaban, apixaban 24 hours after surgery
• therapeutic doses of LMW heparin may be used as alternative to heparin as bridging therapy
  • no benefit for post-operative bridging with LMW heparin regardless if anticoagulation is for atrial fibrillation or mechanical heart valve
• consider vit K 1-2 mg PO if INR remains elevated

* risk factors for perioperative thrombosis

• use HAS-BLED score to assess perioperative bleeding risk
• DVT within 1 year or history of recurrent DVT
  • intermediate risk = DVT with 3-12 months
  • high risk = DVT within < 3 months
• atrial fibrillation with
  • CHA2DS2-VASC score >= 7
    • CHADS score not a factor
  • prior thromboembolism or stroke
  • mechanical valve; aortic mechanical valve
  • moderate-severe mitral stenosis
• maybe not atrial fibrillation
  • bridging for patients with atrial fibrillation increases 30-day combined risk for myocardial infarction, major bleeding, thromboembolism, hospitalization & death
  • bridging for patients with atrial fibrillation does not prevent thromboembolism, but does increase the risk of bleeding
• bridging indicated for patients with recent TIA or stroke, & for patients with rheumatic valvular heart disease
• prior stroke
  • high risk = ischemic stroke within 6 months
• active malignancy (treated within 6 months or palliatively)
• example of preoperative evaluation of patient with atrial fibrillation scheduled for resection of colon cancer with history of stroke 3 months prior - assessed at moderate risk of thrombosis & high risk of bleeding
  • stop DOAC 2 days prior to surgery, no bridging necessary
  • high risk of bleeding in general precludes perioperative bridging
• hypercoagulable state = intermediate risk
• mechanical heart valve
  • high risk = older mechanical valve or mitral valve replacement
• any mitral valve prosthesis
• moderate-severe mitral stenosis

More general terms

• perioperative management
• anticoagulation

Additional terms

• perioperative antiplatelet therapy
• prophylaxis for venous thromboembolism (VTE)