Anticoagulation

From Anvita Health Wiki

Contents 1 More Specific Terms 2 Indications 3 Monitor 4 Complications 5 Management 6 More General Terms 7 Additional Terms 8 References

More Specific Terms

• perioperative anticoagulation
• perioperative antiplatelet therapy

Indications

• treatment of deep vein thrombosis, pulmonary embolus, atrial fibrillation or valvular heart disease: INR 2.0-3.0; atrial fibrillation with rheumatic valve disease: INR 2.5-3.5
• antiphospholipid antibody syndrome: INR 3.0-4.0
• mechanical prosthetic heart valves:* INR 2.5-3.5
• arterial thrombosis or prevention of recurrent myocardial infarction: INR 2.5-3.5
• treatment of arterial thromboembolism, 1st generation mechanical heart valves (Star-Edwards or Bjork-Shiley): INR 2.5-3.5 + aspirin 80-100 mg QD
• recurrent systemic embolism: INR 3.0-4.5
• long-term low-intensity anticoagulation for patients with idiopathic deep vein thrombosis: INR 1.5-2.0 (after 3 months of standard therapy) [3] * except 1st generation mechanical heart valves (Star-Edwards or Bjork-Shiley); may be combined with aspirin for high- risk patients at the cost of increased risk of bleeding

Monitor

• after stabilization of dose, INR is monitored monthly for most patients (every other month for low-intensity anticoagulation)
• self management may be appropriate for subgroup [7]

Complications

• (also see warfarin
• intracranial hemorrhage

• risk associated with INR > 3.5, age > 85 [5]

• bleeding, especially GI bleeding

• 6 fold increased risk of intracerebral hemorrhage
• risk of major hemorrhage 13.1 events/100 patient years in elderly >= 80 vs 4.75 in patients < 80 [8]

Management

• anticoagulation for non- cardiac surgery

• dental extractions & minimally invasive procedures (i.e. biopsies)

• may be done without interruption of anticoagulation
• adjustment to INR of about 2.0 prior to procedure

• high-risk procedures/patients*

• stop warfarin 3-5 days prior to procedure
• start intravenous heparin when INR falls below 2.5
• adjust aPTT to 60-80 sec
• stop heparin 4-6 hours prior to surgery
• restart heparin after surgery as soon as considered safe
• restart warfarin
• stop heparin with INR is therapeutic

• contraception for women on warfarin anticoagulation

• do not use estrogen-containing contraceptives

• increased risk of thromboembolism

• progestin-only contraceptives appear save
• intrauterine device ( IUD)

• levonorgestrel-releasing intrauterine device (LNG- IUD) is effective for heavy menstrual bleeding associated with anticoagulation or bleeding disorders

• * mechanical heart valve recurrent venous thromboembolism in setting of malignancy antiphospholipid antibody syndrome atrial fibrillation with previous stroke

More General Terms

• pharmacologic therapy

Additional Terms

• coagulation cascade
• coagulation factor
• heparin
• International normalized ratio (INR)
• prophylaxis for venous thromboembolism
• warfarin (Coumadin, Panwarfin)
• ximelagatran (Exanta)

References

1. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15, American College of Physicians, Philadelphia 1998, 2006, 2009
2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 350
3. Prescriber's Letter 10(3):13 2003
4. th ACCP Consensus Conference on Antithrombic Therapy, American College of Physicians; Chest 119/1 Suppl Jan 2001
5. Journal Watch 25(2):14, 2005 Fang MC, Chang Y, Hylek EM, Rosand J, Greenberg SM, Go AS, Singer DE. Advanced age, anticoagulation intensity, and risk for intracranial hemorrhage among patients taking warfarin for atrial fibrillation. Ann Intern Med. 2004 Nov 16;141(10):745-52. Summary for patients in: Ann Intern Med. 2004 Nov 16;141 (10):I38. PMID: [1]
6. Fang MC, Singer DE. Anticoagulation for atrial fibrillation. Cardiol Clin. 2004 Feb;22(1):47-62. Review. PMID: [2]
7. Fitzmaurice DA, Self management of oral anticoagulation: Randomized trial. BMJ 2005; 331:1057 PMID: [3]
   - Heneghan C, Alonso-Coello P, Garcia-Alamino JM, Perera R, Meats E, Glasziou P. Self-monitoring of oral anticoagulation: a systematic review and meta-analysis. Lancet. 2006 Feb 4;367(9508):404-11. Review. PMID: [4]
8. Hylek EM et al, Major hemorrhage and tolerability of warfarin in the first year of therapy among elderly patients with atrial fibrillation. Circulation 2007, 115:2689 PMID: [5]
   - Wyse DG Bleeding while starting anticoagulation for thromboembolism prophylaxis in elderly patients with atrial fibrillation: From bad to worse. Circulation 2007, 115:2684 PMID: [6]
9. Garcia DA et al, Risk of thromboembolism with short-term iterruption of warfarin therapy. Arch Intern Med 2008, 168:63 PMID: [7]
10. Culwell KR & Curtis KM. Use of contraceptive methods by women with current venous thrombosis on anticoagulant therapy: A systematic review. Contraception 2009 Oct; 80:337. PMID: [8]
11. National Guideline Clearinghouse
    - Prevention of venous thromboembolism. American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). ngc-guideline: [9]
    - Venous thromboembolism, thrombophilia, antithrombotic therapy, and pregnancy. American College of Chest Physicians evidence- based clinical practice guidelines (8th edition). ngc-guideline: [10]
    - Anticoagulation therapy supplement. (Institute for Clinical Systems Improvement) ngc-guideline: [11]
    - An evidence-based review and guidelines for patient self-testing and management of oral anticoagulation. British Committee for Standards in Haematology ngc-guideline: [12]
    - Guidelines on oral anticoagulation with warfarin - fourth edition. British Committee for Standards in Haematology ngc-guideline: [13]
    - Safety indicators for inpatient and outpatient oral anticoagulant care: recommendations from the British Committee for Standards in Haematology and National Patient Safety Agency. ngc-guideline: [14]

anticoagulation