When is it appropriate to restart anticoagulation after a hypertensive basal ganglia intracerebral hemorrhage, given controlled blood pressure and indications such as atrial fibrillation (CHA2DS2‑VASc ≥5), recent venous thromboembolism, or a mechanical heart valve?

When to Restart Anticoagulation After Hypertensive Basal Ganglia Hemorrhage

For patients with hypertensive basal ganglia intracerebral hemorrhage (ICH) and strong indications for anticoagulation, restart timing depends on thrombotic risk: 7-10 days for mechanical heart valves or CHADS₂ ≥4, and 4-6 weeks for moderate thrombotic risk (CHADS₂ 2-3 or remote VTE). 1

Risk Stratification Determines Timing

High Thrombotic Risk (Restart at 7-10 Days)

• Mechanical heart valves carry thromboembolism rates of at least 4% per year off anticoagulation, justifying earlier restart at 7-10 days after confirming hemorrhage stability 1
• Atrial fibrillation with CHADS₂ ≥4 or prior ischemic stroke warrants restart at 7-10 days 1
• Recent VTE (within 3 months) requires restart at 7-10 days 1
• Limited retrospective data showed only 0.8% rebleeding rate when anticoagulation was restarted at 7-10 days, versus 5% thromboembolism rate when held 1
• In a study of mechanical heart valve patients, there was no increased hazard of hemorrhagic or thrombotic complications when anticoagulation was resumed within 7 days versus 7-30 days after ICH 2

Moderate Thrombotic Risk (Restart at 4-6 Weeks)

• Atrial fibrillation with CHADS₂ 2-3 should have anticoagulation restarted at 4-6 weeks 1
• Remote VTE (>3 months) can wait 4-6 weeks for restart 1
• The European Society of Cardiology recommends anticoagulation may be reinitiated after 4-8 weeks provided the cause of bleeding or relevant risk factor has been treated or controlled 3

Mandatory Pre-Restart Requirements

Imaging Confirmation

• Obtain repeat brain imaging (CT or MRI) to confirm hemorrhage stability and absence of expansion before restarting anticoagulation 1
• Brain imaging should be performed to confirm resolution or stability of the hemorrhage 4

Blood Pressure Control

• Ensure adequate blood pressure control (target <130/80 mmHg long-term) before restarting anticoagulation 1
• Uncontrolled hypertension increases the risk of bleeding on oral anticoagulation 3
• Acute lowering of systolic blood pressure to a target of 140 mmHg is recommended within 6 hours of ICH onset 3

Document Absence of High-Risk Features

• Document absence of new microbleeds if MRI available before restarting 1
• Microbleeds on gradient echo MRI predict 9.3% ICH risk on anticoagulation versus 1.3% without, indicating extreme caution 1

Critical Location-Specific Considerations

Deep (Basal Ganglia) vs. Lobar Hemorrhage

Basal ganglia hemorrhages are generally safer for anticoagulation resumption than lobar hemorrhages because:

• Lobar hemorrhages carry the highest risk of recurrence and likely indicate underlying cerebral amyloid angiopathy, particularly in elderly patients 1
• The American Heart Association/American Stroke Association guidelines recommend avoiding long-term anticoagulation after lobar ICH in patients with nonvalvular atrial fibrillation due to relatively high rebleeding risk 1
• Data suggest that resumption may be safer in non-lobar ICH compared to lobar ICH 5
• For your patient with hypertensive basal ganglia hemorrhage, this is favorable for eventual anticoagulation resumption 5

Anticoagulant Selection

Direct Oral Anticoagulants (DOACs) Preferred

• DOACs are recommended in preference to warfarin or aspirin in atrial fibrillation patients with a previous stroke 3
• DOACs have practical advantages over warfarin, including lower ICH risk in primary prevention trials and no need for INR monitoring 1
• The usefulness of apixaban in patients with atrial fibrillation and past ICH to decrease risk of recurrence is uncertain (Class IIb, Level of Evidence C) 1

Avoid Bridging Therapy

• Do not use "bridging" with heparin when initiating DOACs, as this increases bleeding risk without additional benefit 4

Alternative Strategies for High-Risk Patients

When Anticoagulation Should Not Be Restarted

• For lobar ICH patients, strongly consider antiplatelet monotherapy or left atrial appendage closure as safer alternatives to any anticoagulant 1
• Percutaneous left atrial appendage closure is a viable alternative for atrial fibrillation patients who cannot restart anticoagulation 1

Antiplatelet Therapy

• Aspirin monotherapy appears generally safe after ICH, including in cerebral amyloid angiopathy patients, and can be restarted beyond 24 hours after ICH symptom onset 1
• In patients who suffer a stroke while on anticoagulation, aspirin should be considered for prevention of secondary stroke until the initiation or resumption of oral anticoagulation 3
• After TIA or stroke, combination therapy of oral anticoagulation and an antiplatelet is not recommended 3

Common Pitfalls to Avoid

Reversal of Anticoagulation

• Failure to reverse warfarin and achieve normal INR has been associated with increased rebleeding risk 1
• Anticoagulation should be discontinued immediately and reversed as soon as possible in patients with anticoagulant-associated ICH 3

Premature Restart

• Patients restarted on anticoagulation before 72 hours were more likely to hemorrhage 6
• Anticoagulation with heparin or low molecular weight heparin immediately after an ischemic stroke is not recommended in atrial fibrillation patients 3

Delayed Restart in High-Risk Patients

• Withholding anticoagulation >30 days was associated with elevated acute ischemic stroke risk (HR 15.9) in mechanical heart valve patients 2
• Patients restarted on anticoagulation after 72 hours were significantly more likely to have a thromboembolic complication 6

Subtherapeutic Anticoagulation

• Re-initiation of anticoagulation at a lower intensity significantly increased the risk of thromboembolic complications 6
• Use full therapeutic dosing when restarting 6

Evidence Quality and Consensus

The guidelines are consistent across multiple societies 3, 1, though all acknowledge the evidence is based primarily on observational studies rather than randomized trials 3. Large observational studies and meta-analyses suggest that patients after ICH with indication for long-term oral anticoagulation benefit from resumption given significant reductions of thromboembolic events without significantly increasing bleeding complications 5. The Canadian Stroke Best Practice Recommendations note that consultation with a stroke expert, cardiologist, or hematologist/thrombosis expert may be considered to optimize individual patient care 3.