Multi-Center Single Arm Trial to Determine The Effectiveness of Warfarin Therapy Duration For Heparin-Induced Thrombocytopenia (HIT)

Inclusion criteria:

• Patient must be able to provide an informed consent
• Patient older than 18 years' old
• Patient with suspected diagnosis of HIT, need 2 of the following:

have a fall in platelet count of > 30% from a baseline prior to heparin/LMWH Platelet factor 4 (PF4) ELISA positive Develop skin lesions secondary to subcutaneous heparin With T score more than 4 For those less than 4 we will use serotonin release assay-SRA

• Patient received the bridging therapy of non-heparin anticoagulant
• Patient is receiving the standard of care treatment for HIT
• Patient is willing to be followed up for by one of the physicians listed in the delegation log
• The Primary physician responsible for the patient is agreeing for the patient to participate
• Patients are not involved in a clinical trial for HIT management

Exclusion Criteria:

• Patient is unable to sign an informed consent
• Patient doesn't have a confirmed diagnosis of HIT
• Patient Does not have Pulmonary embolus
• Patient does is not on Warfarin for other indications
• Patient is a known case of hypercoagulable disorder
• Patient is not willing to come back for follow up
• Patient is critically ill or has a life expectancy of less than 3 months
• Pregnancy that is in First trimester.
• Multi-system organ failure or estimated survival of less than 30 days
• Uncontrolled hypertension defined as a blood pressure >180/110 mm Hg