Treatment of Ischemic Stroke Outside the 4-Hour Window

Time-Based Treatment Algorithm

The American College of Chest Physicians recommends that for patients presenting between 4.5 and 6 hours after stroke onset, IV tPA should NOT be administered, and treatment should focus on aspirin therapy and supportive care, including VTE prophylaxis 1, 2
The American Heart Association recommends IV tPA administration to eligible patients who can be treated between 3 and 4.5 hours after stroke onset, with a Class I recommendation and Level B evidence 3, 4

The American College of Chest Physicians recommends initiating aspirin 160-325 mg within 48 hours of stroke onset for all patients not receiving thrombolysis 1, 2
The American College of Radiology suggests that for patients with proximal cerebral artery occlusions who do not meet IV tPA eligibility criteria, intraarterial thrombolysis may be considered within 6 hours of symptom onset, with a Grade 2C recommendation 1

The American College of Chest Physicians recommends initiating prophylactic-dose subcutaneous heparin or intermittent pneumatic compression devices for patients with restricted mobility, with a Grade 2B recommendation 2
The American College of Chest Physicians suggests that LMWH is preferred over UFH for VTE prophylaxis 2

The American College of Chest Physicians strongly advises against administering IV tPA beyond 4.5 hours based on the strong evidence of harm without benefit 1, 2
The American College of Chest Physicians recommends not delaying aspirin therapy in patients outside the thrombolytic window, unless there are specific contraindications like hemorrhagic transformation 1, 2