What Deep Vein Thrombosis (DVT) prophylaxis do we give to patients admitted with Transient Ischemic Attack (TIA)?

DVT Prophylaxis for TIA Patients

For patients admitted with TIA, provide pharmacologic VTE prophylaxis with low-molecular-weight heparin (LMWH) or low-dose unfractionated heparin (LDUH) unless contraindications exist, in which case use intermittent pneumatic compression devices. 1

Risk Assessment

TIA patients qualify as acutely ill medical patients requiring thromboprophylaxis because they typically have:

• Acute neurologic illness requiring hospitalization 1
• Reduced mobility or bed confinement 1
• Age ≥40 years (common in TIA population) 1
• Additional VTE risk factors including cardiovascular disease 1

The American College of Chest Physicians guidelines specifically recommend prophylaxis for acutely ill hospitalized medical patients who are immobilized with one or more additional VTE risk factors, which encompasses the TIA population. 1

First-Line Pharmacologic Prophylaxis

LMWH is the preferred agent over unfractionated heparin for VTE prophylaxis in TIA patients. 1

Specific dosing options include:

• Enoxaparin 40 mg subcutaneously once daily 1
• Alternatively, LDUH 5,000 units subcutaneously twice or three times daily 1
• Fondaparinux 2.5 mg subcutaneously once daily is also acceptable 1

Duration: Continue prophylaxis for 6-21 days, until full mobility is restored, or until hospital discharge, whichever comes first. 1

Contraindications to Pharmacologic Prophylaxis

Do not use pharmacologic prophylaxis if the patient has:

• Active gastroduodenal ulcer (highest bleeding risk with OR 4.15) 1
• Bleeding within 3 months before admission (OR 3.64) 1
• Platelet count <50 × 10⁹/L (OR 3.37) 1
• Severe renal failure with GFR <30 mL/min/m² (OR 2.14) 1
• Hepatic failure with INR >1.5 (OR 2.18) 1

Additional high-risk bleeding factors include age ≥85 years, current cancer, ICU admission, and central venous catheter presence. 1

Mechanical Prophylaxis for High Bleeding Risk

For TIA patients with contraindications to anticoagulation, use intermittent pneumatic compression (IPC) devices. 1

• IPC significantly reduces proximal DVT risk (OR 0.65,95% CI 0.51-0.84) in immobile stroke patients 1
• IPC may reduce 6-month mortality (adjusted HR 0.86,95% CI 0.74-0.99) 1
• Do not use graduated compression stockings - they increase skin defects without preventing DVT in stroke patients 1

Special Consideration: Hemorrhagic Stroke vs. Ischemic TIA

This recommendation assumes the TIA is ischemic in nature. If imaging reveals hemorrhagic transformation or intracerebral hemorrhage:

• Delay pharmacologic prophylaxis until hemorrhage stabilizes 1
• Use IPC devices as primary prophylaxis during the delay period 1
• Consider starting low-dose subcutaneous heparin after day 4-10 once bleeding risk decreases 1

Monitoring Requirements

• No routine laboratory monitoring required for LMWH prophylaxis 2
• For LDUH, monitor platelets every 2-3 days from day 4 to day 14 to screen for heparin-induced thrombocytopenia if risk ≥1% 2
• Assess bleeding risk factors daily, particularly in elderly patients 1

Critical Pitfalls to Avoid

• Do not withhold prophylaxis in standard TIA patients without bleeding contraindications - the VTE risk outweighs bleeding risk 1
• Do not use aspirin alone as VTE prophylaxis - it is ineffective for this purpose 3, 4
• Do not use graduated compression stockings as monotherapy in stroke/TIA patients 1
• Do not delay mobilization - early ambulation reduces VTE risk and should be encouraged when neurologically appropriate 2