Table of Contents

    INR RANGES AND DURATION OF WARFARIN THERAPY

 

Indication

 

Target INR

 

Duration of Therapy

Moderate Intensity Therapy

Prophylaxis of THR, TKR, HFS1

Treatment of DVT or PE                   

     : Due to reversible risk factors

     : Idiopathic

     : 2 unprovoked episodes

     : cancer
 

2.0-3.0

 

10 to 35 days

 

3 months

3 months or longer2

Indefinite

Indefinite3

Chronic atrial fibrillation

Cardioversion for atrial fibrillation
48h or of unknown duration

 

 

Indefinite

3 weeks pre and 4 weeks
post cardioversion


Chronic thromboembolic pulmonary HTN

Antiphospholipid syndrome

 

 

 
Indefinite

Indefinitie


Tissue mitral valve

Tissue aortic or mitral valve and history of or risk factors for thromboembolism4

Mechanical aortic valve5 (normal left atrial size and normal sinus rhythm)

 

 


3 months

3 months or longer (+/- ASA 81mg daily)

 
Indefinite

 
Acute anterior myocardial infarction
(STEMI high risk6)

 

 

 
at least 3 months post STEMI
(with ASA 81mg daily)

High Intensity Therapy
 

2.5-3.5

 

Mechanical mitral valve5

Mechanical aortic or mitral valve with additional risk factors for thromboembolism4

Antiphospholipid syndrome with recurrent thromboembolism

Very High Intensity Therapy

Mechanical aortic or mitral valve and systemic embolism despite therapeutic INR 2.5-3.5

 

 

 

 

3.0-4.0

 

Indefinite

Indefinite (with ASA 81mg daily)


Indefinite

 


Indefinite (+/- ASA 81mg daily)

    1 THR = total hip replacement; TKR = total knee replacement; HFS = hip fracture surgery

    2 Long-term recommended for first unprovoked episode that is a proximal DVT or PE,and if no risk factors for

      bleeding and good anticoagulant monitoring is achievable (if less frequent INR monitoring desired, can decrease

      goal INR to 1.5-1.9 after 3 months)

    3 After initial treatment with LMWH for 3-6 months

    4 Risk factors for thromboembolism include atrial fibrillation, hypercoagulable state, left atrial enlargement, low ejection
      fraction; add ASA if low risk of bleeding and age
80

    5 St Jude Medical bileaflet valve, Carbomedics bileaflet valve, Medtronic-Hall tilting disc valve

    6 Large anterior MI or those with intracardiac thrombus, atrial fibrillation, significant heart failure or history of thromboembolic event