|
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
:
³
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
|