Anticoagulation in Acute Stroke

General Principles

The American College of Chest Physicians recommends early aspirin therapy (160-325 mg) within 48 hours of symptom onset for patients with acute ischemic stroke, over therapeutic parenteral anticoagulation 2, 4
For patients with restricted mobility after ischemic stroke, prophylactic-dose subcutaneous heparin (LMWH or UFH) or intermittent pneumatic compression devices are suggested to prevent venous thromboembolism 1, 2
The American College of Chest Physicians prefers LMWH over UFH for thromboprophylaxis in patients with ischemic stroke and restricted mobility 2, 3

Active intracranial hemorrhage or primary hemorrhagic stroke is an absolute contraindication to prophylactic anticoagulation 3, 5
Severe hemorrhagic transformation of ischemic stroke (HI2, PH1, PH2 in the Heidelberg classification) is an absolute contraindication to prophylactic anticoagulation 5
Evidence of significant hemorrhage on neuroimaging is an absolute contraindication to prophylactic anticoagulation 1, 6

For primary intracerebral hemorrhage, prophylactic anticoagulation should be delayed until days 2-4 after onset, and only if follow-up imaging shows no expansion of hemorrhage 3
In patients with minor hemorrhagic transformation (HI1), antiplatelet therapy may be initiated within 24-48 hours after confirming no progression of bleeding 5
For more severe hemorrhagic transformations, anticoagulation should be delayed for 7-10 days 5
In patients with large ischemic strokes, anticoagulation should be delayed until the risk of hemorrhagic transformation decreases (typically 5-7 days) 1

Intermittent pneumatic compression devices should be applied as early as possible, ideally within 24 hours of admission 5
Early mobilization (between 24-48 hours after stroke onset) should be encouraged when clinically appropriate 5
Elastic compression stockings alone are not recommended for VTE prophylaxis 3, 5

For patients with high thromboembolic risk (mechanical heart valves, intracardiac thrombi), the decision to initiate anticoagulation must carefully balance bleeding versus thrombotic risks 1
For patients with acute ischemic stroke who are "out of window" for thrombolysis, the same principles apply regarding prophylactic anticoagulation - it should be avoided in those with large infarcts or evidence of hemorrhagic transformation 1, 2